PATENT DOCUMENT

Publication Number: US-12126393-B2
Application Number: US-202017440725-A
Country: US
Kind Code: B2

Title: Calculation of a reference signal received power of a resynchronisation signal in LTE

Abstract:
This disclosure describes methods, systems, and devices for measuring a reference signal received power (RSRP) in a user equipment (UE) that operates in machine type communication (MTC). In one example, a method involves receiving, from a radio access network (RAN) serving the UE, a resynchronization signal (RSS). The method also involves calculating a reference signal received power (RSRP) of the RSS.

Claims:
What is claimed is: 
     
       1. A method comprising:
 receiving, from a radio access network (RAN), a resynchronization signal (RSS); and 
 calculating a reference signal received power (RSRP) of the RSS using an equation comprising: 
 
       
         
           
             
               
                 
                   RSRP 
                   
                     ResourceBlock 
                     ⁡ 
                     ( 
                     RB 
                     ) 
                   
                 
                 = 
                 
                   
                     1 
                     
                       2 
                       ⁢ 
                       
                         ( 
                         
                           M 
                           - 
                           1 
                         
                         ) 
                       
                     
                   
                   ⁢ 
                   absolute 
                   ⁢ 
                       
                   value 
                   ⁢ 
                   
                     { 
                     
                       
                         
                           ∑ 
                             
                         
                         
                           i 
                           = 
                           1 
                         
                         2 
                       
                       ⁢ 
                       
                         
                           ∑ 
                             
                         
                         
                           k 
                           = 
                           1 
                         
                         
                           M 
                           - 
                           1 
                         
                       
                       ⁢ 
                       
                         
                           y 
                           ⁡ 
                           ( 
                           
                             i 
                             , 
                             k 
                           
                           ) 
                         
                         · 
                         complex 
                       
                       ⁢ 
                           
                       
                         conjugate 
                         ( 
                         
                           y 
                           ⁡ 
                           ( 
                           
                             i 
                             , 
                             
                               k 
                               + 
                               1 
                             
                           
                           ) 
                         
                         ) 
                       
                     
                     } 
                   
                 
               
               , 
             
           
         
          wherein y(i,k) is a respective portion of the RSS at an i-th subcarrier and k-th symbol, M is a symbol number in an RSS duration, and M has a value greater than 1. 
       
     
     
       2. The method of  claim 1 , wherein the RSS is a first RSS, the RSRP is a first RSRP, and the equation is a first equation, and wherein the method further comprises:
 receiving a second RSS from the RAN; and 
 calculating a second RSRP of the second RSS based on a second equation comprising a frequency domain scalar product. 
 
     
     
       3. The method of  claim 2 , wherein the second equation comprises: 
       
         
           
             
               
                 RSRP 
                 RB 
               
               = 
               
                 
                   1 
                   
                     2 
                     ⁢ 
                     
                       ( 
                       
                         M 
                         - 
                         1 
                       
                       ) 
                     
                   
                 
                 ⁢ 
                 absolute 
                 ⁢ 
                     
                 value 
                 ⁢ 
                 
                   
                     { 
                     
                       
                         
                           ∑ 
                             
                         
                         
                           k 
                           = 
                           1 
                         
                         M 
                       
                       ⁢ 
                       
                         
                           y 
                           ⁡ 
                           ( 
                           
                             1 
                             , 
                             k 
                           
                           ) 
                         
                         · 
                         complex 
                       
                       ⁢ 
                           
                       
                         conjugate 
                         ( 
                         
                           y 
                           ⁡ 
                           ( 
                           
                             2 
                             , 
                             k 
                           
                           ) 
                         
                         ) 
                       
                     
                     } 
                   
                   . 
                 
               
             
           
         
       
     
     
       4. The method of  claim 1 , wherein the RSS is a first RSS, the RSRP is a first RSRP, and the equation is a first equation, and wherein the method further comprises:
 receiving a second RSS from the RAN; and 
 calculating a second RSRP of the second RSS based on a second equation comprising a frequency domain and time domain scalar product. 
 
     
     
       5. The method of  claim 4 , wherein the second equation comprises: 
       
         
           
             
               
                 RSRP 
                 RB 
               
               = 
               
                 
                   
                     1 
                     
                       4 
                       ⁢ 
                       
                         ( 
                         
                           M 
                           - 
                           1 
                         
                         ) 
                       
                     
                   
                   ⁢ 
                   absolute 
                   ⁢ 
                       
                   value 
                   ⁢ 
                   
                     { 
                     
                       
                         
                           ∑ 
                             
                         
                         
                           k 
                           = 
                           1 
                         
                         M 
                       
                       ⁢ 
                       
                         
                           y 
                           ⁡ 
                           ( 
                           
                             1 
                             , 
                             k 
                           
                           ) 
                         
                         · 
                         complex 
                       
                       ⁢ 
                           
                       
                         conjugate 
                         ( 
                         
                           y 
                           ⁡ 
                           ( 
                           
                             2 
                             , 
                             k 
                           
                           ) 
                         
                         ) 
                       
                     
                     } 
                   
                 
                 + 
                 
                   
                     1 
                     
                       4 
                       ⁢ 
                       
                         ( 
                         
                           M 
                           - 
                           1 
                         
                         ) 
                       
                     
                   
                   ⁢ 
                   absolute 
                   ⁢ 
                       
                   value 
                   ⁢ 
                   
                     
                       { 
                       
                         
                           
                             ∑ 
                               
                           
                           
                             i 
                             = 
                             1 
                           
                           2 
                         
                         ⁢ 
                         
                           
                             ∑ 
                               
                           
                           
                             k 
                             = 
                             1 
                           
                           
                             M 
                             - 
                             1 
                           
                         
                         ⁢ 
                         
                           
                             y 
                             ⁡ 
                             ( 
                             
                               i 
                               , 
                               k 
                             
                             ) 
                           
                           · 
                             
                           complex 
                         
                         ⁢ 
                             
                         
                           conjugate 
                           ( 
                           
                             y 
                             ⁡ 
                             ( 
                             
                               i 
                               , 
                               
                                 k 
                                 + 
                                 1 
                               
                             
                             ) 
                           
                           ) 
                         
                       
                       } 
                     
                     . 
                   
                 
               
             
           
         
       
     
     
       6. The method of  claim 1 , further comprising:
 receiving, from the RAN, a cell specific reference signal (CRS); and 
 combining the CRS with the RSS, wherein calculating the RSRP of the RSS comprises calculating the RSRP of the combined signal. 
 
     
     
       7. The method of  claim 1 , wherein a duration of the RSS is based on a coverage enhancement (CE) level. 
     
     
       8. The method of  claim 1 , wherein the RSS spans a plurality of subframes, and wherein calculating the RSRP of the RSS comprises:
 calculating respective RSRPs of the plurality of subframes; and 
 calculating an average of the respective RSRPs. 
 
     
     
       9. A machine type communication (MTC) User Equipment (UE) comprising:
 a radio front end module configured to receive, from a radio access network (RAN), a resynchronization signal (RSS); and 
 one or more processors configured to perform operations comprising calculating a reference signal received power (RSRP) of the RSS using an equation comprising: 
 
       
         
           
             
               
                 
                   RSRP 
                   
                     ResourceBlock 
                     ⁡ 
                     ( 
                     RB 
                     ) 
                   
                 
                 = 
                 
                   
                     1 
                     
                       2 
                       ⁢ 
                       
                         ( 
                         
                           M 
                           - 
                           1 
                         
                         ) 
                       
                     
                   
                   ⁢ 
                   absolute 
                   ⁢ 
                       
                   value 
                   ⁢ 
                   
                     { 
                     
                       
                         
                           ∑ 
                             
                         
                         
                           k 
                           = 
                           1 
                         
                         M 
                       
                       ⁢ 
                       
                         
                           y 
                           ⁡ 
                           ( 
                           
                             1 
                             , 
                             k 
                           
                           ) 
                         
                         · 
                         complex 
                       
                       ⁢ 
                           
                       
                         conjugate 
                         ( 
                         
                           y 
                           ⁡ 
                           ( 
                           
                             2 
                             , 
                             k 
                           
                           ) 
                         
                         ) 
                       
                     
                     } 
                   
                 
               
               , 
             
           
         
          where y(i,k) is a respective portion of the RSS at an i-th subcarrier and k-th symbol, where i=1, 2, M is a symbol number in an RSS duration, and M has a value greater than 1. 
       
     
     
       10. The MTC UE of  claim 9 , wherein the RSS is a first RSS, the RSRP is a first RSRP, and the equation is a first equation, and wherein the operations further comprise:
 calculating a second RSRP of a second RSS based on a second equation comprising a time domain scalar product. 
 
     
     
       11. The MTC UE of  claim 10 , wherein the second equation comprises: 
       
         
           
             
               
                 RSRP 
                 RB 
               
               = 
               
                 
                   1 
                   
                     2 
                     ⁢ 
                     
                       ( 
                       
                         M 
                         - 
                         1 
                       
                       ) 
                     
                   
                 
                 ⁢ 
                 absolute 
                 ⁢ 
                     
                 value 
                 ⁢ 
                 
                   
                     { 
                     
                       
                         
                           ∑ 
                             
                         
                         
                           i 
                           = 
                           1 
                         
                         2 
                       
                       ⁢ 
                       
                         
                           ∑ 
                             
                         
                         
                           k 
                           = 
                           1 
                         
                         
                           M 
                           - 
                           1 
                         
                       
                       ⁢ 
                       
                         
                           y 
                           ⁡ 
                           ( 
                           
                             i 
                             , 
                             k 
                           
                           ) 
                         
                         · 
                         complex 
                       
                       ⁢ 
                           
                       
                         conjugate 
                         ( 
                         
                           y 
                           ⁡ 
                           ( 
                           
                             i 
                             , 
                             
                               k 
                               + 
                               1 
                             
                           
                           ) 
                         
                         ) 
                       
                     
                     } 
                   
                   . 
                 
               
             
           
         
       
     
     
       12. The MTC UE of  claim 9 , wherein the RSS is a first RSS, the RSRP is a first RSRP, and the equation is a first equation, and wherein the operations further comprise:
 calculating a second RSRP of a second RSS based on a second equation comprising a frequency domain and time domain scalar product. 
 
     
     
       13. The MTC UE of  claim 12 , wherein the second equation comprises: 
       
         
           
             
               
                 RSRP 
                 RB 
               
               = 
               
                 
                   
                     1 
                     
                       4 
                       ⁢ 
                       
                         ( 
                         
                           M 
                           - 
                           1 
                         
                         ) 
                       
                     
                   
                   ⁢ 
                   absolute 
                   ⁢ 
                       
                   value 
                   ⁢ 
                   
                     { 
                     
                       
                         
                           ∑ 
                             
                         
                         
                           k 
                           = 
                           1 
                         
                         M 
                       
                       ⁢ 
                       
                         
                           y 
                           ⁡ 
                           ( 
                           
                             1 
                             , 
                             k 
                           
                           ) 
                         
                         · 
                           
                         complex 
                       
                       ⁢ 
                           
                       
                         conjugate 
                         ( 
                         
                           y 
                           ⁡ 
                           ( 
                           
                             2 
                             , 
                             k 
                           
                           ) 
                         
                         ) 
                       
                     
                     } 
                   
                 
                 + 
                 
                   
                     1 
                     
                       4 
                       ⁢ 
                       
                         ( 
                         
                           M 
                           - 
                           1 
                         
                         ) 
                       
                     
                   
                   ⁢ 
                   absolute 
                   ⁢ 
                       
                   value 
                   ⁢ 
                   
                     
                       { 
                       
                         
                           
                             ∑ 
                               
                           
                           
                             i 
                             = 
                             1 
                           
                           2 
                         
                         ⁢ 
                         
                           
                             ∑ 
                               
                           
                           
                             k 
                             = 
                             1 
                           
                           
                             M 
                             - 
                             1 
                           
                         
                         ⁢ 
                         
                           
                             y 
                             ⁡ 
                             ( 
                             
                               i 
                               , 
                               k 
                             
                             ) 
                           
                           · 
                           complex 
                         
                         ⁢ 
                             
                         
                           conjugate 
                           ( 
                           
                             y 
                             ⁡ 
                             ( 
                             
                               i 
                               , 
                               
                                 k 
                                 + 
                                 1 
                               
                             
                             ) 
                           
                           ) 
                         
                       
                       } 
                     
                     . 
                   
                 
               
             
           
         
       
     
     
       14. The MTC UE of  claim 9 ,
 wherein the front end module is further configured to receive, from the RAN, a cell specific reference signal (CRS), and wherein the operations further comprise: 
 combining the CRS with the RSS, wherein calculating the RSRP of the RSS comprises calculating the RSRP of the combined signal. 
 
     
     
       15. The MTC UE of  claim 9 , wherein a duration of the RSS is based on a coverage enhancement (CE) level of the MTC UE. 
     
     
       16. One or more processors comprising: circuitry configured to perform operations comprising:
 controlling a radio front end module to receive, from a radio access network (RAN), a resynchronization signal (RSS); and 
 calculating a reference signal received power (RSRP) of the RSS using an equation comprising: 
 
       
         
           
             
               
                 
                   RSRP 
                   RB 
                 
                 = 
                 
                   
                     
                       1 
                       
                         4 
                         ⁢ 
                         
                           ( 
                           
                             M 
                             - 
                             1 
                           
                           ) 
                         
                       
                     
                     ⁢ 
                     absolute 
                     ⁢ 
                         
                     value 
                     ⁢ 
                     
                       { 
                       
                         
                           
                             ∑ 
                               
                           
                           
                             k 
                             = 
                             1 
                           
                           M 
                         
                         ⁢ 
                         
                           
                             y 
                             ⁡ 
                             ( 
                             
                               1 
                               , 
                               k 
                             
                             ) 
                           
                           · 
                           complex 
                         
                         ⁢ 
                             
                         
                           conjugate 
                           ( 
                           
                             y 
                             ⁡ 
                             ( 
                             
                               2 
                               , 
                               k 
                             
                             ) 
                           
                           ) 
                         
                       
                       } 
                     
                   
                   + 
                   
                     
                       1 
                       
                         4 
                         ⁢ 
                         
                           ( 
                           
                             M 
                             - 
                             1 
                           
                           ) 
                         
                       
                     
                     ⁢ 
                     absolute 
                     ⁢ 
                       
                     value 
                     ⁢ 
                     
                       { 
                       
                         
                           
                             ∑ 
                               
                           
                           
                             i 
                             = 
                             1 
                           
                           2 
                         
                         ⁢ 
                         
                           
                             ∑ 
                               
                           
                           
                             k 
                             = 
                             1 
                           
                           
                             M 
                             - 
                             1 
                           
                         
                         ⁢ 
                         
                           
                             y 
                             ⁡ 
                             ( 
                             
                               i 
                               , 
                               k 
                             
                             ) 
                           
                           · 
                             
                           complex 
                         
                         ⁢ 
                             
                         
                           conjugate 
                           ( 
                           
                             y 
                             ⁡ 
                             ( 
                             
                               i 
                               , 
                               
                                 k 
                                 + 
                                 1 
                               
                             
                             ) 
                           
                           ) 
                         
                       
                       } 
                     
                   
                 
               
               , 
             
           
         
          where y(i,k) is a respective portion of the RSS at an i-th subcarrier and k-th symbol, and M is a symbol number in an RSS duration and has a value greater than 1. 
       
     
     
       17. The one or more processors of  claim 16 , wherein the RSS is a first RSS, the RSRP is a first RSRP, and the equation is a first equation, and wherein the operations further comprise:
 controlling the radio front end module to receive a second RSS from the RAN; and 
 calculating a second RSRP of the second RSS based on a second equation comprising a time domain scalar product. 
 
     
     
       18. The one or more processors of  claim 17 , wherein the second equation comprises: 
       
         
           
             
               
                 RSRP 
                 RB 
               
               = 
               
                 
                   1 
                   
                     2 
                     ⁢ 
                     
                       ( 
                       
                         M 
                         - 
                         1 
                       
                       ) 
                     
                   
                 
                 ⁢ 
                 absolute 
                 ⁢ 
                     
                 value 
                 ⁢ 
                 
                   
                     { 
                     
                       
                         
                           ∑ 
                             
                         
                         
                           i 
                           = 
                           1 
                         
                         2 
                       
                       ⁢ 
                       
                         
                           ∑ 
                             
                         
                         
                           k 
                           = 
                           1 
                         
                         
                           M 
                           - 
                           1 
                         
                       
                       ⁢ 
                       
                         
                           y 
                           ⁡ 
                           ( 
                           
                             i 
                             , 
                             k 
                           
                           ) 
                         
                         · 
                           
                         complex 
                       
                       ⁢ 
                           
                       
                         conjugate 
                         ( 
                         
                           y 
                           ⁡ 
                           ( 
                           
                             i 
                             , 
                             
                               k 
                               + 
                               1 
                             
                           
                           ) 
                         
                         ) 
                       
                     
                     } 
                   
                   . 
                 
               
             
           
         
       
     
     
       19. The one or more processors of  claim 16 , wherein the RSS is a first RSS, the RSRP is a first RSRP, and the equation is a first equation, and wherein the operations further comprise:
 controlling the radio front end module to receive a second RSS from the RAN; and 
 calculating a second RSRP of the second RSS based on a second equation comprising a frequency domain scalar product. 
 
     
     
       20. The one or more processors of  claim 19 , wherein the second equation comprises: 
       
         
           
             
               
                 RSRP 
                 RB 
               
               = 
               
                 
                   1 
                   
                     2 
                     ⁢ 
                     
                       ( 
                       
                         M 
                         - 
                         1 
                       
                       ) 
                     
                   
                 
                 ⁢ 
                 absolute 
                 ⁢ 
                     
                 value 
                 ⁢ 
                 
                   
                     { 
                     
                       
                         
                           ∑ 
                             
                         
                         
                           k 
                           = 
                           1 
                         
                         M 
                       
                       ⁢ 
                       
                         
                           y 
                           ⁡ 
                           ( 
                           
                             1 
                             , 
                             k 
                           
                           ) 
                         
                         · 
                         complex 
                       
                       ⁢ 
                           
                       
                         conjugate 
                         ( 
                         
                           y 
                           ⁡ 
                           ( 
                           
                             2 
                             , 
                             k 
                           
                           ) 
                         
                         ) 
                       
                     
                     } 
                   
                   .

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This disclosure is a national phase entry under 35 U.S.C. § 371 of International Application No. PCT/US2020/025393, filed on Mar. 27, 2020, entitled “RSS BASED RSRP CALCULATION,” which claims the benefit of the priority of U.S. Provisional Patent Application No. 62/826,706, entitled “RSS BASED RSRP CALCULATION AND ACCURACY” and filed on Mar. 29, 2019. The above-identified applications are incorporated herein by reference in its entirety their entireties. 
    
    
     TECHNICAL FIELD 
     This disclosure relates generally to signaling in wireless communication systems. 
     BACKGROUND 
     User equipment (UE) can wirelessly communicate data using wireless communication networks. To wirelessly communicate data, the UE connects to a node of a radio access network (RAN) and synchronizes with the network. 
     SUMMARY 
     This disclosure describes methods, systems, and devices for measuring a reference signal received power (RSRP) in a user equipment (UE) that operates in machine type communication (MTC). 
     In accordance with one aspect of the present disclosure, a method involves receiving, from a radio access network (RAN) serving the UE, a resynchronization signal (RSS). The method also involves calculating a reference signal received power (RSRP) of the RSS. 
     Other versions include corresponding systems, apparatus, and computer programs to perform the actions of methods defined by instructions encoded on computer readable storage devices. These and other versions may optionally include one or more of the following features. 
     In some implementations, calculating the RSRP of the RSS includes calculating the RSRP of the RSS based on a time domain by scalar product. 
     In some implementations, calculating the RSRP of the RSS based on a time domain by scalar product uses an equation: 
                 RSRP   RB     =       1     2   ⁢     (     M   -   1     )         ⁢   abs   ⁢     {         ∑           i   =   1     2     ⁢       ∑           k   =   1       M   -   1       ⁢       y   ⁡   (     i   ,   k     )     ·     conj   ⁡   (     y   ⁡   (     i   ,     k   +   1       )     )         }         ,         
where M is a symbol number in an RSS duration.
 
     In some implementations, calculating the RSRP of the RSS includes calculating the RSRP of the RSS based on a frequency domain by scalar product. 
     In some implementations, calculating the RSRP of the RSS based on a frequency domain by scalar product uses an equation: 
                 RSRP   RB     =       1     2   ⁢     (     M   -   1     )         ⁢   abs   ⁢     {         ∑           k   =   1     M     ⁢       y   ⁡   (     1   ,   k     )     ·     conj   ⁡   (     y   ⁡   (     2   ,   k     )     )         }         ,         
where M is a symbol number in an RSS duration.
 
     In some implementations, calculating the RSRP of the RSS includes calculating the RSRP of the RSS based on a frequency domain and time domain by scalar product. 
     In some implementations, calculating the RSRP of the RSS based on a frequency domain by scalar product uses an equation: 
                 RSRP   RB     =         1     4   ⁢     (     M   -   1     )         ⁢   abs   ⁢     {         ∑           k   =   1     M     ⁢       y   ⁡   (     1   ,   k     )     ·     conj   ⁡   (     y   ⁡   (     2   ,   k     )     )         }       +       1     4   ⁢     (     M   -   1     )         ⁢   abs   ⁢     {         ∑           i   =   1     2     ⁢       ∑           k   =   1       M   -   1       ⁢       y   ⁡   (     i   ,   k     )     ·     conj   ⁡   (     y   ⁡   (     i   ,     k   +   1       )     )         }           ,         
where M is a symbol number in an RSS duration.
 
     In some implementations, the method further includes: receiving, from the RAN, a cell specific reference signal (CRS); combining the CRS with the RSS; and calculating a reference signal received power (RSRP) of the combined signal. 
     In some implementations, a duration of the RSS may be based on a coverage enhancement (CE) level of the MTC UE. 
     In some implementations, the RSS spans a plurality of subframes, and where calculating a reference signal received power (RSRP) of the RSS includes: calculating respective RSRPs of the plurality of subframes; and calculating an average of the respective RSRPs. 
     The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features and advantages will be apparent from the description and drawings, and from the claims. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    illustrates an example of a wireless communication system, according to some implementations of the present disclosure. 
         FIGS.  2 A,  2 B, and  2 C  illustrate reference signal received power (RSRP) calculation methods, according to some implementations of the present disclosure. 
         FIGS.  3 A,  3 B, and  3 C  illustrate RSRP simulation results, according to some implementations of the present disclosure. 
         FIGS.  4 A and  4 B  illustrate additional RSRP simulation results, according to some implementations of the present disclosure. 
         FIG.  5    illustrates a flowchart of an example method, according to some implementations of the present disclosure. 
         FIG.  6    illustrates an example architecture of a system including a core network, according to some implementations of the present disclosure. 
         FIG.  7    illustrates another example architecture of a system including a core network, according to some implementations of the present disclosure. 
         FIG.  8    illustrates an example of infrastructure equipment, according to some implementations of the present disclosure. 
         FIG.  9    illustrates an example of a platform or device, according to some implementations of the present disclosure. 
         FIG.  10    illustrates example components of baseband circuitry and radio front end circuitry, according to some implementations of the present disclosure. 
         FIG.  11    illustrates example protocol functions that may be implemented in wireless communication systems, according to some implementations of the present disclosure. 
         FIG.  12    illustrates an example of a computer system, according to some implementations of the present disclosure. 
     
    
    
     Like reference symbols in the various drawings indicate like elements. 
     DETAILED DESCRIPTION 
     In order to support mobility in cellular networks, a user equipment (UE) may measure the power of signals received from a serving cell and/or nearby cells. In 3GPP LTE systems, a UE may use a Cell Specific Reference Signal (CRS) for calculating a reference signal received power (RSRP). 
     This disclosure describes a technique for measuring a reference signal received power (RSRP) in UEs that operate in machine type communication (MTC) and/or enhanced-MTC (e-MTC). Additionally, this disclosure describes techniques for determining an RSRP accuracy and measurement period. Accurately measuring the reference signal facilitates important network functionality, such as supporting UE mobility and/or cell selection/reselection. 
       FIG.  1    illustrates an example of a wireless communication system  100 . For purposes of convenience and without limitation, the example system  100  is described in the context of the LTE and 5G NR communication standards as defined by the Third Generation Partnership Project (3GPP) technical specifications. However, other types of wireless standards are possible. 
     The system  100  includes UE  101   a  and UE  101   b  (collectively referred to as the “UEs  101 ”). In this example, the UEs  101  are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices connectable to one or more cellular networks). In other examples, any of the UEs  101  can include other mobile or non-mobile computing devices, such as consumer electronics devices, cellular phones, smartphones, feature phones, tablet computers, wearable computer devices, personal digital assistants (PDAs), pagers, wireless handsets, desktop computers, laptop computers, in-vehicle infotainment (IVI), in-car entertainment (ICE) devices, an Instrument Cluster (IC), head-up display (HUD) devices, onboard diagnostic (OBD) devices, dashtop mobile equipment (DME), mobile data terminals (MDTs), Electronic Engine Management System (EEMS), electronic/engine control units (ECUs), electronic/engine control modules (ECMs), embedded systems, microcontrollers, control modules, engine management systems (EMS), networked or “smart” appliances, machine-type communications (MTC) devices, machine-to-machine (M2M) devices, Internet of Things (IoT) devices, or combinations of them, among others. 
     In some implementations, any of the UEs  101  may be IoT UEs, which can include a network access layer designed for low-power IoT applications utilizing short-lived UE connections. An IoT UE can utilize technologies such as M2M or MTC for exchanging data with an MTC server or device using, for example, a public land mobile network (PLMN), proximity services (ProSe), device-to-device (D2D) communication, sensor networks, IoT networks, or combinations of them, among others. The M2M or MTC exchange of data may be a machine-initiated exchange of data. An IoT network describes interconnecting IoT UEs, which can include uniquely identifiable embedded computing devices (within the Internet infrastructure), with short-lived connections. The IoT UEs may execute background applications (e.g., keep-alive messages or status updates) to facilitate the connections of the IoT network. 
     The UEs  101  are configured to connect (e.g., communicatively couple) with a radio access network (RAN)  110 . In some implementations, the RAN  110  may be a next generation RAN (NG RAN), an evolved UMTS terrestrial radio access network (E-UTRAN), or a legacy RAN, such as a UMTS terrestrial radio access network (UTRAN) or a GSM EDGE radio access network (GERAN). As used herein, the term “NG RAN” may refer to a RAN  110  that operates in a 5G NR system  100 , and the term “E-UTRAN” may refer to a RAN  110  that operates in an LTE or 4G system  100 . 
     To connect to the RAN  110 , the UEs  101  utilize connections (or channels)  103  and  104 , respectively, each of which can include a physical communications interface or layer, as described below. In this example, the connections  103  and  104  are illustrated as an air interface to enable communicative coupling, and can be consistent with cellular communications protocols, such as a global system for mobile communications (GSM) protocol, a code-division multiple access (CDMA) network protocol, a push-to-talk (PTT) protocol, a PTT over cellular (POC) protocol, a universal mobile telecommunications system (UMTS) protocol, a 3GPP LTE protocol, a 5G NR protocol, or combinations of them, among other communication protocols. 
     The UE  101   b  is shown to be configured to access an access point (AP)  106  (also referred to as “WLAN node  106 ,” “WLAN 106,” “WLAN Termination  106 ,” “WT  106 ” or the like) using a connection  107 . The connection  107  can include a local wireless connection, such as a connection consistent with any IEEE 802.11 protocol, in which the AP  106  would include a wireless fidelity (Wi-Fi) router. In this example, the AP  106  is shown to be connected to the Internet without connecting to the core network of the wireless system, as described in further detail below. 
     The RAN  110  can include one or more nodes such as RAN nodes  111   a  and  111   b  (collectively referred to as “RAN nodes  111 ” or “RAN node  111 ”) that enable the connections  103  and  104 . As used herein, the terms “access node,” “access point,” or the like may describe equipment that provides the radio baseband functions for data or voice connectivity, or both, between a network and one or more users. These access nodes can be referred to as base stations (BS), gNodeBs, gNBs, eNodeBs, eNBs, NodeBs, RAN nodes, rode side units (RSUs), transmission reception points (TRxPs or TRPs), and the link, and can include ground stations (e.g., terrestrial access points) or satellite stations providing coverage within a geographic area (e.g., a cell), among others. As used herein, the term “NG RAN node” may refer to a RAN node  111  that operates in an 5G NR system  100  (for example, a gNB), and the term “E-UTRAN node” may refer to a RAN node  111  that operates in an LTE or 4G system  100  (e.g., an eNB). In some implementations, the RAN nodes  111  may be implemented as one or more of a dedicated physical device such as a macrocell base station, or a low power (LP) base station for providing femtocells, picocells or other like cells having smaller coverage areas, smaller user capacity, or higher bandwidth compared to macrocells. 
     In some implementations, some or all of the RAN nodes  111  may be implemented as one or more software entities running on server computers as part of a virtual network, which may be referred to as a cloud RAN (CRAN) or a virtual baseband unit pool (vBBUP). The CRAN or vBBUP may implement a RAN function split, such as a packet data convergence protocol (PDCP) split in which radio resource control (RRC) and PDCP layers are operated by the CRAN/vBBUP and other layer two (e.g., data link layer) protocol entities are operated by individual RAN nodes  111 ; a medium access control (MAC)/physical layer (PHY) split in which RRC, PDCP, MAC, and radio link control (RLC) layers are operated by the CRAN/vBBUP and the PHY layer is operated by individual RAN nodes  111 ; or a “lower PHY” split in which RRC, PDCP, RLC, and MAC layers and upper portions of the PHY layer are operated by the CRAN/vBBUP and lower portions of the PHY layer are operated by individual RAN nodes  111 . 
     This virtualized framework allows the freed-up processor cores of the RAN nodes  111  to perform, for example, other virtualized applications. In some implementations, an individual RAN node  111  may represent individual gNB distributed units (DUs) that are connected to a gNB central unit (CU) using individual F1 interfaces (not shown in  FIG.  1   ). In some implementations, the gNB-DUs can include one or more remote radio heads or RFEMs (see, e.g.,  FIG.  8   ), and the gNB-CU may be operated by a server that is located in the RAN  110  (not shown) or by a server pool in a similar manner as the CRAN/vBBUP. Additionally or alternatively, one or more of the RAN nodes  111  may be next generation eNBs (ng-eNBs), including RAN nodes that provide E-UTRA user plane and control plane protocol terminations toward the UEs  101 , and are connected to a 5G core network (e.g., core network  120 ) using a next generation interface. 
     In vehicle-to-everything (V2X) scenarios, one or more of the RAN nodes  111  may be or act as RSUs. The term “Road Side Unit” or “RSU” refers to any transportation infrastructure entity used for V2X communications. A RSU may be implemented in or by a suitable RAN node or a stationary (or relatively stationary) UE, where a RSU implemented in or by a UE may be referred to as a “UE-type RSU,” a RSU implemented in or by an eNB may be referred to as an “eNB-type RSU,” a RSU implemented in or by a gNB may be referred to as a “gNB-type RSU,” and the like. In some implementations, an RSU is a computing device coupled with radio frequency circuitry located on a roadside that provides connectivity support to passing vehicle UEs  101  (vUEs  101 ). The RSU may also include internal data storage circuitry to store intersection map geometry, traffic statistics, media, as well as applications or other software to sense and control ongoing vehicular and pedestrian traffic. The RSU may operate on the 5.9 GHz Direct Short Range Communications (DSRC) band to provide very low latency communications required for high speed events, such as crash avoidance, traffic warnings, and the like. 
     Additionally or alternatively, the RSU may operate on the cellular V2X band to provide the aforementioned low latency communications, as well as other cellular communications services. Additionally or alternatively, the RSU may operate as a Wi-Fi hotspot (2.4 GHz band) or provide connectivity to one or more cellular networks to provide uplink and downlink communications, or both. The computing device(s) and some or all of the radiofrequency circuitry of the RSU may be packaged in a weatherproof enclosure suitable for outdoor installation, and can include a network interface controller to provide a wired connection (e.g., Ethernet) to a traffic signal controller or a backhaul network, or both. 
     Any of the RAN nodes  111  can terminate the air interface protocol and can be the first point of contact for the UEs  101 . In some implementations, any of the RAN nodes  111  can fulfill various logical functions for the RAN  110  including, but not limited to, radio network controller (RNC) functions such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management. 
     In some implementations, the UEs  101  can be configured to communicate using orthogonal frequency division multiplexing (OFDM) communication signals with each other or with any of the RAN nodes  111  over a multicarrier communication channel in accordance with various communication techniques, such as, but not limited to, OFDMA communication techniques (e.g., for downlink communications) or SC-FDMA communication techniques (e.g., for uplink communications), although the scope of the techniques described here not limited in this respect. The OFDM signals can comprise a plurality of orthogonal subcarriers. 
     The RAN nodes  111  can transmit to the UEs  101  over various channels. Various examples of downlink communication channels include Physical Broadcast Channel (PBCH), Physical Downlink Control Channel (PDCCH), and Physical Downlink Shared Channel (PDSCH). Other types of downlink channels are possible. The UEs  101  can transmit to the RAN nodes  111  over various channels. Various examples of uplink communication channels include Physical Uplink Shared Channel (PUSCH), Physical Uplink Control Channel (PUCCH), and Physical Random Access Channel (PRACH). Other types of uplink channels are possible. 
     In some implementations, a downlink resource grid can be used for downlink transmissions from any of the RAN nodes  111  to the UEs  101 , while uplink transmissions can utilize similar techniques. The grid can be a time-frequency grid, called a resource grid or time-frequency resource grid, which is the physical resource in the downlink in each slot. Such a time-frequency plane representation is a common practice for OFDM systems, which makes it intuitive for radio resource allocation. Each column and each row of the resource grid corresponds to one OFDM symbol and one OFDM subcarrier, respectively. The duration of the resource grid in the time domain corresponds to one slot in a radio frame. The smallest time-frequency unit in a resource grid is denoted as a resource element. Each resource grid comprises a number of resource blocks, which describe the mapping of certain physical channels to resource elements. Each resource block comprises a collection of resource elements; in the frequency domain, this may represent the smallest quantity of resources that currently can be allocated. There are several different physical downlink channels that are conveyed using such resource blocks. 
     The PDSCH carries user data and higher-layer signaling to the UEs  101 . The PDCCH carries information about the transport format and resource allocations related to the PDSCH channel, among other things. It may also inform the UEs  101  about the transport format, resource allocation, and hybrid automatic repeat request (HARD) information related to the uplink shared channel. Downlink scheduling (e.g., assigning control and shared channel resource blocks to the UE  101   b  within a cell) may be performed at any of the RAN nodes  111  based on channel quality information fed back from any of the UEs  101 . The downlink resource assignment information may be sent on the PDCCH used for (e.g., assigned to) each of the UEs  101 . 
     The PDCCH uses control channel elements (CCEs) to convey the control information. Before being mapped to resource elements, the PDCCH complex-valued symbols may first be organized into quadruplets, which may then be permuted using a sub-block interleaver for rate matching. In some implementations, each PDCCH may be transmitted using one or more of these CCEs, in which each CCE may correspond to nine sets of four physical resource elements collectively referred to as resource element groups (REGs). Four Quadrature Phase Shift Keying (QPSK) symbols may be mapped to each REG. The PDCCH can be transmitted using one or more CCEs, depending on the size of the downlink control information (DCI) and the channel condition. In LTE, there can be four or more different PDCCH formats defined with different numbers of CCEs (e.g., aggregation level, L=1, 2, 4, or 8). 
     Some implementations may use concepts for resource allocation for control channel information that are an extension of the above-described concepts. For example, some implementations may utilize an enhanced PDCCH (EPDCCH) that uses PDSCH resources for control information transmission. The EPDCCH may be transmitted using one or more enhanced CCEs (ECCEs). Similar to above, each ECCE may correspond to nine sets of four physical resource elements collectively referred to as an enhanced REG (EREG). An ECCE may have other numbers of EREGs. 
     The RAN nodes  111  are configured to communicate with one another using an interface  112 . In examples, such as where the system  100  is an LTE system (e.g., when the core network  120  is an evolved packet core (EPC) network as shown in  FIG.  6   ), the interface  112  may be an X2 interface  112 . The X2 interface may be defined between two or more RAN nodes  111  (e.g., two or more eNBs and the like) that connect to the EPC  120 , or between two eNBs connecting to EPC  120 , or both. In some implementations, the X2 interface can include an X2 user plane interface (X2-U) and an X2 control plane interface (X2-C). The X2-U may provide flow control mechanisms for user data packets transferred over the X2 interface, and may be used to communicate information about the delivery of user data between eNBs. For example, the X2-U may provide specific sequence number information for user data transferred from a master eNB to a secondary eNB; information about successful in sequence delivery of PDCP protocol data units (PDUs) to a UE  101  from a secondary eNB for user data; information of PDCP PDUs that were not delivered to a UE  101 ; information about a current minimum desired buffer size at the secondary eNB for transmitting to the UE user data, among other information. The X2-C may provide intra-LTE access mobility functionality, including context transfers from source to target eNBs or user plane transport control; load management functionality; inter-cell interference coordination functionality, among other functionality. 
     In some implementations, such as where the system  100  is a 5G NR system (e.g., when the core network  120  is a 5G core network as shown in  FIG.  7   ), the interface  112  may be an Xn interface  112 . The Xn interface may be defined between two or more RAN nodes  111  (e.g., two or more gNBs and the like) that connect to the 5G core network  120 , between a RAN node  111  (e.g., a gNB) connecting to the 5G core network  120  and an eNB, or between two eNBs connecting to the 5G core network  120 , or combinations of them. In some implementations, the Xn interface can include an Xn user plane (Xn-U) interface and an Xn control plane (Xn-C) interface. The Xn-U may provide non-guaranteed delivery of user plane PDUs and support/provide data forwarding and flow control functionality. The Xn-C may provide management and error handling functionality, functionality to manage the Xn-C interface; mobility support for UE  101  in a connected mode (e.g., CM-CONNECTED) including functionality to manage the UE mobility for connected mode between one or more RAN nodes  111 , among other functionality. 
     The mobility support can include context transfer from an old (source) serving RAN node  111  to new (target) serving RAN node  111 , and control of user plane tunnels between old (source) serving RAN node  111  to new (target) serving RAN node  111 . A protocol stack of the Xn-U can include a transport network layer built on Internet Protocol (IP) transport layer, and a GPRS tunneling protocol for user plane (GTP-U) layer on top of a user datagram protocol (UDP) or IP layer(s), or both, to carry user plane PDUs. The Xn-C protocol stack can include an application layer signaling protocol (referred to as Xn Application Protocol (Xn-AP or XnAP)) and a transport network layer (TNL) that is built on a stream control transmission protocol (SCTP). The SCTP may be on top of an IP layer, and may provide the guaranteed delivery of application layer messages. In the transport IP layer, point-to-point transmission is used to deliver the signaling PDUs. In other implementations, the Xn-U protocol stack or the Xn-C protocol stack, or both, may be same or similar to the user plane and/or control plane protocol stack(s) shown and described herein. 
     The RAN  110  is shown to be communicatively coupled to a core network  120  (referred to as a “CN  120 ”). The CN  120  includes one or more network elements  122 , which are configured to offer various data and telecommunications services to customers/subscribers (e.g., users of UEs  101 ) who are connected to the CN  120  using the RAN  110 . The components of the CN  120  may be implemented in one physical node or separate physical nodes and can include components to read and execute instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium). In some implementations, network functions virtualization (NFV) may be used to virtualize some or all of the network node functions described here using executable instructions stored in one or more computer-readable storage mediums, as described in further detail below. A logical instantiation of the CN  120  may be referred to as a network slice, and a logical instantiation of a portion of the CN  120  may be referred to as a network sub-slice. NFV architectures and infrastructures may be used to virtualize one or more network functions, alternatively performed by proprietary hardware, onto physical resources comprising a combination of industry-standard server hardware, storage hardware, or switches. In other words, NFV systems can be used to execute virtual or reconfigurable implementations of one or more network components or functions, or both. 
     An application server  130  may be an element offering applications that use IP bearer resources with the core network (e.g., UMTS packet services (PS) domain, LTE PS data services, among others). The application server  130  can also be configured to support one or more communication services (e.g., VoIP sessions, PTT sessions, group communication sessions, social networking services, among others) for the UEs  101  using the CN  120 . The application server  130  can use an IP communications interface  125  to communicate with one or more network elements  112 . 
     In some implementations, the CN  120  may be a 5G core network (referred to as “5GC  120 ” or “5G core network  120 ”), and the RAN  110  may be connected with the CN  120  using a next generation interface  113 . In some implementations, the next generation interface  113  may be split into two parts, an next generation user plane (NG-U) interface  114 , which carries traffic data between the RAN nodes  111  and a user plane function (UPF), and the S1 control plane (NG-C) interface  115 , which is a signaling interface between the RAN nodes  111  and access and mobility management functions (AMFs). Examples where the CN  120  is a 5G core network are discussed in more detail with regard to  FIG.  7   . 
     In some implementations, the CN  120  may be an EPC (referred to as “EPC  120 ” or the like), and the RAN  110  may be connected with the CN  120  using an S1 interface  113 . In some implementations, the S1 interface  113  may be split into two parts, an S1 user plane (S1-U) interface  114 , which carries traffic data between the RAN nodes  111  and the serving gateway (S-GW), and the S1-MME interface  115 , which is a signaling interface between the RAN nodes  111  and mobility management entities (MMEs). 
     In an embodiment, the UE  101  may be a machine type communication (MTC) UE that may be configured to operate in a new radio (NR) network. In some examples, the MTC UE  101  may receive and decode synchronization signals from the node. In particular, the MTC UE  101  may receive and decode a primary synchronization signal (PSS) and a secondary synchronization signal (SSS). The MTC UE  101  may use these signals to determine a system timing. Additionally and/or alternatively, the MTC UE  101  may receive, from the node, parameters of a resynchronization signal (RSS). The MTC UE  101  may use the resynchronization to resynchronize with the network after the MTC UE  102  awakens from a power saving mode. The MTC UE  101  may determine an updated system timing based the RSS. In some examples, the RSS can be used as a cell-specific signal for re-synchronization. 
     In an example, the RSS may be periodically received by the MTC UE  101 . In this example, the periodicity of a first subframe of the RSS may be configurable to 160, 320, 640, and 1280 milliseconds (ms). In another example, the time offset of each RSS burst may also be configurable. In yet another example, the RSS may occupy two resource blocks (RBs) in the frequency domain and may last for several consecutive subframes in the time domain. As previously described, a time-frequency resource grid used as the downlink grid includes a number of RBs, which describe the mapping of certain physical channels to resource elements. The duration of the resource grid in the time domain corresponds to one slot in a radio frame, where two consecutive slots make a subframe. The smallest time-frequency unit in a resource grid is denoted as a resource element. The resource element consists of one subcarrier in the frequency domain and one symbol interval in the time domain. Each resource grid comprises a number of resource blocks, which describe the mapping of certain physical channels to resource elements. In an example, a number of subframes that the RSS lasts is configurable. 
     In an embodiment, the UE may use the RSS signal to measure a received power level of a signal. In an implementation, the UE may calculate the reference signal receive power (RSRP) of the RSS. Generally, RSRP is defined as the average power of the Resource Elements (REs) that carry cell-specific Reference Signals (RSs) within the considered bandwidth. 
     In an embodiment, the UE may calculate the RSS RSRP in the frequency domain and/or the time domain. In particular, the UE may first decode the received RSS, perhaps using fast Fourier transform (FFT). The descrambled received signal in each resource element may be represented as y i,k , where i is a frequency index of the RE and k is the time index of the RE in the time-frequency resource grid. The UE may then calculate the RSS RSRP using the descrambled REs. 
     In one implementation, the RSS RSRP may be calculated based on a time-domain by scalar product. In one example, the RSS RSRP may be calculated as: 
                     RSRP   RB     =       1     2   ⁢     (     M   -   1     )         ⁢   abs   ⁢       {         ∑           i   =   1     2     ⁢       ∑           k   =   1       M   -   1       ⁢       y   ⁡   (     i   ,   k     )     ·     conj   ⁡   (     y   ⁡   (     i   ,     k   +   1       )     )         }     .               Equation   ⁢           (   1   )                 
In Equation (1), M is a symbol number in the RSS duration. As shown, Equation (1) involves calculating the scalar product of values of two resource elements that are sequential in time.
 
       FIG.  2 A  illustrates a representation  200  of a time-domain by scalar product calculation, according to some implementations. In particular,  FIG.  2 A  illustrates resource elements of the descrambled RSS signal. As shown in  FIG.  2 A , the resource elements of the descrambled RSS signal span two resource blocks  202 ,  204  in the frequency domain and span n slots in the time domain. In  FIG.  2 A , each resource element may be represented as y i,k . Furthermore,  FIG.  2 A  illustrates arrows  206  that represent the time domain by scalar product calculation. In particular, Equation (1) involves taking the scalar product of two resource blocks that are sequential in the time-domain. For example, as shown by arrow  206 , Equation (1) may involve taking the scalar product of a value of the resource element y 1,1  and a value based on the resource element y 1,2 . 
     In another implementation, the RSS RSRP may be calculated based on a frequency domain by scalar product. In one example, the RSS RSRP may be calculated as: 
                     RSRP   RB     =       1     2   ⁢     (     M   -   1     )         ⁢   abs   ⁢       {         ∑           k   =   1     M     ⁢       y   ⁡   (     1   ,   k     )     ·     conj   ⁡   (     y   ⁡   (     2   ,   k     )     )         }     .               Equation   ⁢           (   2   )                 
In Equation (2), M is the symbol number in the RSS duration. As shown, Equation (2) involves calculating the scalar product of values of two resource elements that are sequential in frequency.
 
       FIG.  2 B  illustrates a representation  210  of frequency-domain by scalar product calculation, according to some implementations. In particular,  FIG.  2 B  illustrates resource elements of the descrambled RSS signal (similar to those illustrated in  FIG.  2 A ). In  FIG.  2 B , arrows  208  represent the calculation in the frequency-domain. In particular, Equation (2) involves taking the scalar product of two resource blocks that are sequential in the frequency-domain. For example, as shown by arrow  208 , Equation (2) may involve taking the scalar product of a value of the resource element y 1,1  and a value based on the resource element y 2,1 . 
     In yet another implementation, the RSS RSRP is calculated based on both a frequency-domain and time-domain by scalar product. In one example, the RSS RSRP may be calculated as: 
                     RSRP   RB     =         1     4   ⁢     (     M   -   1     )         ⁢   abs   ⁢     {         ∑           k   =   1     M     ⁢       y   ⁡   (     1   ,   k     )     ·     conj   ⁡   (     y   ⁡   (     2   ,   k     )     )         }       +       1     4   ⁢     (     M   -   1     )         ⁢   abs   ⁢       {         ∑           i   =   1     2     ⁢       ∑           k   =   1       M   -   1       ⁢       y   ⁡   (     i   ,   k     )     ·     conj   ⁡   (     y   ⁡   (     i   ,     k   +   1       )     )         }     .                 Equation   ⁢           (   3   )                 
In Equation (3), M is the symbol number in the RSS duration. As shown, Equation (3) involves calculating the scalar product of values of two resource elements that are sequential in frequency and calculating the scalar product of values of two resource elements that are sequential in time.
 
       FIG.  2 C  illustrates a representation  214  of a frequency-domain and time-domain by scalar product calculation, according to some implementations. In particular,  FIG.  2 C  illustrates resource elements of the descrambled RSS signal (similar to those illustrated in  FIGS.  2 A,  2 B ). In  FIG.  2 C , arrows  208  represent the calculation in the frequency-domain and arrows  206  represent the calculation in the time-domain. In particular, Equation (3) involves taking the scalar product of two resource blocks that are sequential in the frequency domain. For example, as shown by arrow  208 , Equation (2) may involve taking the scalar product of a value of the resource element y 1,1  and a value based on the resource element y 2,1 . Additionally, Equation (3) involves taking the scalar product of two resource blocks that are sequential in the time domain. For example, as shown by arrow  206 , Equation (3) may involve taking the scalar product of a value of the resource element y 1,1  and a value based on the resource element y 1,2 . 
     Within examples, Equations (1), (2), and (3) calculate the RSS RSRP per subframe. Because the RSS can last for more than one subframe, the calculations can be performed for each subframe that the RSS spans. In some examples, after calculating the RSRP per subframe, the calculation can be further improved by averaging across the subframes. In other examples, prior to performing the RSRP calculations, the RSS may be added to a received CRS. The RSRP calculation is then performed based on the combined signal. Doing so may improve RSRP accuracy. 
       FIGS.  3 A,  3 B, and  3 C  illustrate RSRP simulation results, according to some implementations. In these simulations, EPA1 (Extended Pedestrian A model) channel models are used.  FIG.  3 A  compares the RSRP simulation results using the three equations for one sample,  FIG.  3 B  compares the RSRP simulation results using the three equations for three samples, and  FIG.  3 C  compares the RSRP simulation results using the three equations for five samples. In graph  300  of  FIG.  3 A , results  302  correspond to a simulation performed using Equation (1), results  304  correspond to a simulation performed using Equation (2), and results  306  correspond to a simulation performed using Equation (3). 
     In graph  310  of  FIG.  3 B , results  312  correspond to a simulation performed using Equation (1), results  314  correspond to a simulation performed using Equation (2), and results  316  correspond to a simulation performed using Equation (3). In graph  320  of  FIG.  3 C , results  322  correspond to a simulation performed using Equation (1), results  324  correspond to a simulation performed using Equation (2), and results  326  correspond to a simulation performed using Equation (3). These three simulations show that combing time-frequency domain averaging (e.g., using Equation (3)) may result in a greater RSRP accuracy than using only time-domain or frequency-domain averaging. 
       FIGS.  4 A and  4 B  also illustrate RSRP simulation results, according to some implementations. These simulations compare RSS RSRP performance with different configurations and different evaluation times. In these simulations, N is the averaging sample number, which corresponds to evaluation time. In some examples, each sample may correspond to one subframe.  FIG.  4 A  illustrates results  400  of a simulation performed using an 8 millisecond (ms) signal. More specifically,  FIG.  4 A  compares the results for N values of 1, 3, and 5. In  FIG.  4 A , results  402  correspond to a simulation performed using N=1, results  404  correspond to a simulation performed using N=3, and results  406  correspond to a simulation performed using N=5.  FIG.  4 B  illustrates results  410  of a simulation performed using a 40 millisecond (ms) signal. More specifically,  FIG.  4 B  compares the results for N values of 1, 3, and 5. In  FIG.  4 B , results  412  correspond to a simulation performed using N=1, results  414  correspond to a simulation performed using N=3, and results  416  correspond to a simulation performed using N=5. 
     In some embodiments, for UEs operating in e-MTC, the signal-to-noise ratio (SNR) conditions may be very low (e.g., SNR&lt;−12 dB). In order to provide good RSRP measurement performance, for example, during short RSS (e.g., 8 ms), more than 1 sample for evaluation may be used. Thus, the number of samples used may be based on the RSS duration. In some embodiments, to satisfy RAN4 measurement accuracy requirements, for a particular measurement period, the sample number may be greater than 1. 
     Furthermore, the configuration of the RSS measurements may depend on the coverage enhancement (CE) level in which the UE may be operating. In some examples, multiple CE Levels may be defined. For instance, enhanced coverage may have 4 levels, defined by RSRP thresholds provided by CE SIB2, also called PRACH CE level 1, 2, 3, and 4. If a UE is in CE level 1/2, it may operate in CE Mode A, and if the UE is in CE level 3/4, it may operate in CE mode B. In an embodiment, in CE mode B where the SNR may be less than −12 dB, a longer RSS duration (e.g., 40 ms or greater than 8 ms) may be used. Thus, the RSS duration may be based on the CE mode. These configurations are supported by the simulation results of  FIGS.  4 A and  4 B . Furthermore, a network (e.g., a radio access network) may configure the described RSS parameters. 
       FIG.  5    illustrates a flowchart of an example process, according to some implementations. For clarity of presentation, the description that follows generally describes the processes in the context of the other figures in this description. For example, process  500  can be performed by a UE (e.g., UE  101 ) shown in  FIG.  1   . However, it will be understood that the processes may be performed, for example, by any suitable system, environment, software, and hardware, or a combination of systems, environments, software, and hardware, as appropriate. In some implementations, various steps of the processes can be run in parallel, in combination, in loops, or in any order. 
       FIG.  5    is a flowchart of an example method  500  for measuring a reference signal received power (RSRP) in a user equipment (UE) that operates in machine type communication (MTC). At step  502 , the method involves receiving, from a radio access network (RAN) serving a machine type communication (MTC) User Equipment (UE), a resynchronization signal (RSS). At step  504 , the method involves calculating a reference signal received power (RSRP) of the RSS. 
     In some implementations, calculating the RSRP of the RSS includes calculating the RSRP of the RSS based on a time domain by scalar product. In some implementations, calculating the RSRP of the RSS based on a time domain by scalar product uses an equation: 
                 RSRP   RB     =       1     2   ⁢     (     M   -   1     )         ⁢   abs   ⁢     {         ∑           i   =   1     2     ⁢       ∑           k   =   1       M   -   1       ⁢       y   ⁡   (     i   ,   k     )     ·     conj   ⁡   (     y   ⁡   (     i   ,     k   +   1       )     )         }         ,         
where M is a symbol number in an RSS duration.
 
     In some implementations, calculating the RSRP of the RSS includes calculating the RSRP of the RSS based on a frequency domain by scalar product. In some implementations, calculating the RSRP of the RSS based on a frequency domain by scalar product uses an equation: 
                 RSRP   RB     =       1     2   ⁢     (     M   -   1     )         ⁢   abs   ⁢     {         ∑           k   =   1     M     ⁢       y   ⁡   (     1   ,   k     )     ·     conj   ⁡   (     y   ⁡   (     2   ,   k     )     )         }         ,         
where M is a symbol number in an RSS duration.
 
     In some implementations, calculating the RSRP of the RSS includes calculating the RSRP of the RSS based on a frequency domain and time domain by scalar product. In some implementations, calculating the RSRP of the RSS based on a frequency domain by scalar product uses an equation: 
                 RSRP   RB     =         1     4   ⁢     (     M   -   1     )         ⁢   abs   ⁢     {         ∑           k   =   1     M     ⁢       y   ⁡   (     1   ,   k     )     ·     conj   ⁡   (     y   ⁡   (     2   ,   k     )     )         }       +       1     4   ⁢     (     M   -   1     )         ⁢   abs   ⁢     {         ∑           i   =   1     2     ⁢       ∑           k   =   1       M   -   1       ⁢       y   ⁡   (     i   ,   k     )     ·     conj   ⁡   (     y   ⁡   (     i   ,     k   +   1       )     )         }           ,         
where M is a symbol number in an RSS duration.
 
     In some implementations, the method further includes: receiving, from the RAN, a cell specific reference signal (CRS); combining the CRS with the RSS; and calculating a reference signal received power (RSRP) of the combined signal. In some implementations, a duration of the RSS may be based on a coverage enhancement (CE) level of the MTC UE. In some implementations, the RSS spans a plurality of subframes, and where calculating a reference signal received power (RSRP) of the RSS includes: calculating respective RSRPs of the plurality of subframes; and calculating an average of the respective RSRPs. 
     The example process shown in  FIG.  5    can be modified or reconfigured to include additional, fewer, or different steps (not shown in  FIG.  5   ), which can be performed in the order shown or in a different order. In an example, the process  500  may further include using the calculated RSRP to support UE mobility. In another example, the process  500  may further include using the calculated RSRP for cell (node) selection/reselection. 
       FIG.  6    illustrates an example architecture of a system  600  including a first CN  620 , in accordance with various embodiments. In this example, system  600  may implement the LTE standard wherein the CN  620  is an EPC  620  that corresponds with CN XQ20 of Figure XQ. Additionally, the UE  601  may be the same or similar as the UEs XQ01 of Figure XQ, and the E-UTRAN  610  may be a RAN that is the same or similar to the RAN XQ10 of Figure XQ, and which may include RAN nodes XQ11 discussed previously. The CN  620  may comprise MMEs  621 , an S-GW  622 , a P-GW  623 , a HSS  624 , and a SGSN  625 . 
     The MMEs  621  may be similar in function to the control plane of legacy SGSN, and may implement MM functions to keep track of the current location of a UE  601 . The MMEs  621  may perform various MM procedures to manage mobility aspects in access such as gateway selection and tracking area list management. MM (also referred to as “EPS MM” or “EMM” in E-UTRAN systems) may refer to all applicable procedures, methods, data storage, etc. that are used to maintain knowledge about a present location of the UE  601 , provide user identity confidentiality, and/or perform other like services to users/subscribers. Each UE  601  and the MME  621  may include an MM or EMM sublayer, and an MM context may be established in the UE  601  and the MME  621  when an attach procedure is successfully completed. The MM context may be a data structure or database object that stores MM-related information of the UE  601 . The MMEs  621  may be coupled with the HSS  624  via an S6a reference point, coupled with the SGSN  625  via an S3 reference point, and coupled with the S-GW  622  via an S11 reference point. 
     The SGSN  625  may be a node that serves the UE  601  by tracking the location of an individual UE  601  and performing security functions. In addition, the SGSN  625  may perform Inter-EPC node signaling for mobility between 2G/3G and E-UTRAN 3GPP access networks; PDN and S-GW selection as specified by the MMEs  621 ; handling of UE  601  time zone functions as specified by the MMEs  621 ; and MME selection for handovers to E-UTRAN 3GPP access network. The S3 reference point between the MMEs  621  and the SGSN  625  may enable user and bearer information exchange for inter-3GPP access network mobility in idle and/or active states. 
     The HSS  624  may comprise a database for network users, including subscription-related information to support the network entities&#39; handling of communication sessions. The EPC  620  may comprise one or several HSSs  624 , depending on the number of mobile subscribers, on the capacity of the equipment, on the organization of the network, etc. For example, the HSS  624  can provide support for routing/roaming, authentication, authorization, naming/addressing resolution, location dependencies, etc. An S6a reference point between the HSS  624  and the MMES  621  may enable transfer of subscription and authentication data for authenticating/authorizing user access to the EPC  620  between HSS  624  and the MMES  621 . 
     The S-GW  622  may terminate the S1 interface XQ13 (“S1-U” in  FIG.  6   ) toward the RAN  610 , and routes data packets between the RAN  610  and the EPC  620 . In addition, the S-GW  622  may be a local mobility anchor point for inter-RAN node handovers and also may provide an anchor for inter-3GPP mobility. Other responsibilities may include lawful intercept, charging, and some policy enforcement. The S11 reference point between the S-GW  622  and the MMES  621  may provide a control plane between the MMES  621  and the S-GW  622 . The S-GW  622  may be coupled with the P-GW  623  via an S5 reference point. 
     The P-GW  623  may terminate an SGi interface toward a PDN  630 . The P-GW  623  may route data packets between the EPC  620  and external networks such as a network including the application server XQ30 (alternatively referred to as an “AF”) via an IP interface XQ25 (see e.g., Figure XQ). In embodiments, the P-GW  623  may be communicatively coupled to an application server (application server XQ30 of Figure XQ or PDN  630  in  FIG.  6   ) via an IP communications interface XQ25 (see, e.g., Figure XQ). The S5 reference point between the P-GW  623  and the S-GW  622  may provide user plane tunneling and tunnel management between the P-GW  623  and the S-GW  622 . The S5 reference point may also be used for S-GW  622  relocation due to UE  601  mobility and if the S-GW  622  needs to connect to a non-collocated P-GW  623  for the required PDN connectivity. The P-GW  623  may further include a node for policy enforcement and charging data collection (e.g., PCEF (not shown)). Additionally, the SGi reference point between the P-GW  623  and the packet data network (PDN)  630  may be an operator external public, a private PDN, or an intra operator packet data network, for example, for provision of IMS services. The P-GW  623  may be coupled with a PCRF  626  via a Gx reference point. 
     PCRF  626  is the policy and charging control element of the EPC  620 . In a non-roaming scenario, there may be a single PCRF  626  in the Home Public Land Mobile Network (HPLMN) associated with a UE  601 &#39;s Internet Protocol Connectivity Access Network (IP-CAN) session. In a roaming scenario with local breakout of traffic, there may be two PCRFs associated with a UE  601 &#39;s IP-CAN session, a Home PCRF (H-PCRF) within an HPLMN and a Visited PCRF (V-PCRF) within a Visited Public Land Mobile Network (VPLMN). The PCRF  626  may be communicatively coupled to the application server  630  via the P-GW  623 . The application server  630  may signal the PCRF  626  to indicate a new service flow and select the appropriate QoS and charging parameters. The PCRF  626  may provision this rule into a PCEF (not shown) with the appropriate TFT and QCI, which commences the QoS and charging as specified by the application server  630 . The Gx reference point between the PCRF  626  and the P-GW  623  may allow for the transfer of QoS policy and charging rules from the PCRF  626  to PCEF in the P-GW  623 . An Rx reference point may reside between the PDN  630  (or “AF  630 ”) and the PCRF  626 . 
       FIG.  7    illustrates an architecture of a system  700  including a second CN  720  in accordance with various embodiments. The system  700  is shown to include a UE  701 , which may be the same or similar to the UEs XQ01 and UE  601  discussed previously; a (R)AN  710 , which may be the same or similar to the RAN XQ10 and RAN  610  discussed previously, and which may include RAN nodes XQ11 discussed previously; and a DN  703 , which may be, for example, operator services, Internet access or 3rd party services; and a 5GC  720 . The 5GC  720  may include an AUSF  722 ; an AMF  721 ; a SMF  724 ; a NEF  723 ; a PCF  726 ; a NRF  725 ; a UDM  727 ; an AF  728 ; a UPF  702 ; and a NSSF  729 . 
     The UPF  702  may act as an anchor point for intra-RAT and inter-RAT mobility, an external PDU session point of interconnect to DN  703 , and a branching point to support multi-homed PDU session. The UPF  702  may also perform packet routing and forwarding, perform packet inspection, enforce the user plane part of policy rules, lawfully intercept packets (UP collection), perform traffic usage reporting, perform QoS handling for a user plane (e.g., packet filtering, gating, UL/DL rate enforcement), perform Uplink Traffic verification (e.g., SDF to QoS flow mapping), transport level packet marking in the uplink and downlink, and perform downlink packet buffering and downlink data notification triggering. UPF  702  may include an uplink classifier to support routing traffic flows to a data network. The DN  703  may represent various network operator services, Internet access, or third party services. DN  703  may include, or be similar to, application server XQ30 discussed previously. The UPF  702  may interact with the SMF  724  via an N4 reference point between the SMF  724  and the UPF  702 . 
     The AUSF  722  may store data for authentication of UE  701  and handle authentication-related functionality. The AUSF  722  may facilitate a common authentication framework for various access types. The AUSF  722  may communicate with the AMF  721  via an N12 reference point between the AMF  721  and the AUSF  722 ; and may communicate with the UDM  727  via an N13 reference point between the UDM  727  and the AUSF  722 . Additionally, the AUSF  722  may exhibit an Nausf service-based interface. 
     The AMF  721  may be responsible for registration management (e.g., for registering UE  701 , etc.), connection management, reachability management, mobility management, and lawful interception of AMF-related events, and access authentication and authorization. The AMF  721  may be a termination point for the an N11 reference point between the AMF  721  and the SMF  724 . The AMF  721  may provide transport for SM messages between the UE  701  and the SMF  724 , and act as a transparent proxy for routing SM messages. AMF  721  may also provide transport for SMS messages between UE  701  and an SMSF (not shown by  FIG.  7   ). AMF  721  may act as SEAF, which may include interaction with the AUSF  722  and the UE  701 , receipt of an intermediate key that was established as a result of the UE  701  authentication process. Where USIM based authentication is used, the AMF  721  may retrieve the security material from the AUSF  722 . AMF  721  may also include a SCM function, which receives a key from the SEA that it uses to derive access-network specific keys. Furthermore, AMF  721  may be a termination point of a RAN CP interface, which may include or be an N2 reference point between the (R)AN  710  and the AMF  721 ; and the AMF  721  may be a termination point of NAS (N1) signalling, and perform NAS ciphering and integrity protection. 
     AMF  721  may also support NAS signalling with a UE  701  over an N3 IWF interface. The N3IWF may be used to provide access to untrusted entities. N3IWF may be a termination point for the N2 interface between the (R)AN  710  and the AMF  721  for the control plane, and may be a termination point for the N3 reference point between the (R)AN  710  and the UPF  702  for the user plane. As such, the AMF  721  may handle N2 signalling from the SMF  724  and the AMF  721  for PDU sessions and QoS, encapsulate/de-encapsulate packets for IPSec and N3 tunnelling, mark N3 user-plane packets in the uplink, and enforce QoS corresponding to N3 packet marking taking into account QoS requirements associated with such marking received over N2. N3IWF may also relay uplink and downlink control-plane NAS signalling between the UE  701  and AMF  721  via an N1 reference point between the UE  701  and the AMF  721 , and relay uplink and downlink user-plane packets between the UE  701  and UPF  702 . The N3IWF also provides mechanisms for IPsec tunnel establishment with the UE  701 . The AMF  721  may exhibit an Namf service-based interface, and may be a termination point for an N14 reference point between two AMFs  721  and an N17 reference point between the AMF  721  and a 5G-EIR (not shown by  FIG.  7   ). 
     The UE  701  may need to register with the AMF  721  in order to receive network services. RM is used to register or deregister the UE  701  with the network (e.g., AMF  721 ), and establish a UE context in the network (e.g., AMF  721 ). The UE  701  may operate in an RM-REGISTERED state or an RM-DEREGISTERED state. In the RM DEREGISTERED state, the UE  701  is not registered with the network, and the UE context in AMF  721  holds no valid location or routing information for the UE  701  so the UE  701  is not reachable by the AMF  721 . In the RM REGISTERED state, the UE  701  is registered with the network, and the UE context in AMF  721  may hold a valid location or routing information for the UE  701  so the UE  701  is reachable by the AMF  721 . In the RM-REGISTERED state, the UE  701  may perform mobility Registration Update procedures, perform periodic Registration Update procedures triggered by expiration of the periodic update timer (e.g., to notify the network that the UE  701  is still active), and perform a Registration Update procedure to update UE capability information or to re-negotiate protocol parameters with the network, among others. 
     The AMF  721  may store one or more RM contexts for the UE  701 , where each RM context is associated with a specific access to the network. The RM context may be a data structure, database object, etc. that indicates or stores, inter alia, a registration state per access type and the periodic update timer. The AMF  721  may also store a 5GC MM context that may be the same or similar to the (E)MM context discussed previously. In various embodiments, the AMF  721  may store a CE mode B Restriction parameter of the UE  701  in an associated MM context or RM context. The AMF  721  may also derive the value, when needed, from the UE&#39;s usage setting parameter already stored in the UE context (and/or MM/RM context). 
     CM may be used to establish and release a signaling connection between the UE  701  and the AMF  721  over the N1 interface. The signaling connection is used to enable NAS signaling exchange between the UE  701  and the CN  720 , and comprises both the signaling connection between the UE and the AN (e.g., RRC connection or UE-N3IWF connection for non-3GPP access) and the N2 connection for the UE  701  between the AN (e.g., RAN  710 ) and the AMF  721 . The UE  701  may operate in one of two CM states, CM-IDLE mode or CM-CONNECTED mode. When the UE  701  is operating in the CM-IDLE state/mode, the UE  701  may have no NAS signaling connection established with the AMF  721  over the N1 interface, and there may be (R)AN  710  signaling connection (e.g., N2 and/or N3 connections) for the UE  701 . When the UE  701  is operating in the CM-CONNECTED state/mode, the UE  701  may have an established NAS signaling connection with the AMF  721  over the N1 interface, and there may be a (R)AN  710  signaling connection (e.g., N2 and/or N3 connections) for the UE  701 . Establishment of an N2 connection between the (R)AN  710  and the AMF  721  may cause the UE  701  to transition from CM-IDLE mode to CM-CONNECTED mode, and the UE  701  may transition from the CM-CONNECTED mode to the CM-IDLE mode when N2 signaling between the (R)AN  710  and the AMF  721  is released. 
     The SMF  724  may be responsible for SM (e.g., session establishment, modify and release, including tunnel maintain between UPF and AN node); UE IP address allocation and management (including optional authorization); selection and control of UP function; configuring traffic steering at UPF to route traffic to proper destination; termination of interfaces toward policy control functions; controlling part of policy enforcement and QoS; lawful intercept (for SM events and interface to LI system); termination of SM parts of NAS messages; downlink data notification; initiating AN specific SM information, sent via AMF over N2 to AN; and determining SSC mode of a session. SM may refer to management of a PDU session, and a PDU session or “session” may refer to a PDU connectivity service that provides or enables the exchange of PDUs between a UE  701  and a data network (DN)  703  identified by a Data Network Name (DNN). PDU sessions may be established upon UE  701  request, modified upon UE  701  and 5GC  720  request, and released upon UE  701  and 5GC  720  request using NAS SM signaling exchanged over the N1 reference point between the UE  701  and the SMF  724 . Upon request from an application server, the 5GC  720  may trigger a specific application in the UE  701 . In response to receipt of the trigger message, the UE  701  may pass the trigger message (or relevant parts/information of the trigger message) to one or more identified applications in the UE  701 . The identified application(s) in the UE  701  may establish a PDU session to a specific DNN. The SMF  724  may check whether the UE  701  requests are compliant with user subscription information associated with the UE  701 . In this regard, the SMF  724  may retrieve and/or request to receive update notifications on SMF  724  level subscription data from the UDM  727 . 
     The SMF  724  may include the following roaming functionality: handling local enforcement to apply QoS SLAB (VPLMN); charging data collection and charging interface (VPLMN); lawful intercept (in VPLMN for SM events and interface to LI system); and support for interaction with external DN for transport of signalling for PDU session authorization/authentication by external DN. An N16 reference point between two SMFs  724  may be included in the system  700 , which may be between another SMF  724  in a visited network and the SMF  724  in the home network in roaming scenarios. Additionally, the SMF  724  may exhibit the Nsmf service-based interface. 
     The NEF  723  may provide means for securely exposing the services and capabilities provided by 3GPP network functions for third party, internal exposure/re-exposure, Application Functions (e.g., AF  728 ), edge computing or fog computing systems, etc. In such embodiments, the NEF  723  may authenticate, authorize, and/or throttle the AFs. NEF  723  may also translate information exchanged with the AF  728  and information exchanged with internal network functions. For example, the NEF  723  may translate between an AF-Service-Identifier and an internal 5GC information. NEF  723  may also receive information from other network functions (NFs) based on exposed capabilities of other network functions. This information may be stored at the NEF  723  as structured data, or at a data storage NF using standardized interfaces. The stored information can then be re-exposed by the NEF  723  to other NFs and AFs, and/or used for other purposes such as analytics. Additionally, the NEF  723  may exhibit an Nnef service-based interface. 
     The NRF  725  may support service discovery functions, receive NF discovery requests from NF instances, and provide the information of the discovered NF instances to the NF instances. NRF  725  also maintains information of available NF instances and their supported services. As used herein, the terms “instantiate,” “instantiation,” and the like may refer to the creation of an instance, and an “instance” may refer to a concrete occurrence of an object, which may occur, for example, during execution of program code. Additionally, the NRF  725  may exhibit the Nnrf service-based interface. 
     The PCF  726  may provide policy rules to control plane function(s) to enforce them, and may also support unified policy framework to govern network behaviour. The PCF  726  may also implement an FE to access subscription information relevant for policy decisions in a UDR of the UDM  727 . The PCF  726  may communicate with the AMF  721  via an N15 reference point between the PCF  726  and the AMF  721 , which may include a PCF  726  in a visited network and the AMF  721  in case of roaming scenarios. The PCF  726  may communicate with the AF  728  via an N5 reference point between the PCF  726  and the AF  728 ; and with the SMF  724  via an N7 reference point between the PCF  726  and the SMF  724 . The system  700  and/or CN  720  may also include an N24 reference point between the PCF  726  (in the home network) and a PCF  726  in a visited network. Additionally, the PCF  726  may exhibit an Npcf service-based interface. 
     The UDM  727  may handle subscription-related information to support the network entities&#39; handling of communication sessions, and may store subscription data of UE  701 . For example, subscription data may be communicated between the UDM  727  and the AMF  721  via an N8 reference point between the UDM  727  and the AMF. The UDM  727  may include two parts, an application FE and a UDR (the FE and UDR are not shown by  FIG.  7   ). The UDR may store subscription data and policy data for the UDM  727  and the PCF  726 , and/or structured data for exposure and application data (including PFDs for application detection, application request information for multiple UEs  701 ) for the NEF  723 . The Nudr service-based interface may be exhibited by the UDR  221  to allow the UDM  727 , PCF  726 , and NEF  723  to access a particular set of the stored data, as well as to read, update (e.g., add, modify), delete, and subscribe to notification of relevant data changes in the UDR. The UDM may include a UDM-FE, which is in charge of processing credentials, location management, subscription management and so on. Several different front ends may serve the same user in different transactions. The UDM-FE accesses subscription information stored in the UDR and performs authentication credential processing, user identification handling, access authorization, registration/mobility management, and subscription management. The UDR may interact with the SMF  724  via an N10 reference point between the UDM  727  and the SMF  724 . UDM  727  may also support SMS management, wherein an SMS-FE implements the similar application logic as discussed previously. Additionally, the UDM  727  may exhibit the Nudm service-based interface. 
     The AF  728  may provide application influence on traffic routing, provide access to the NCE, and interact with the policy framework for policy control. The NCE may be a mechanism that allows the 5GC  720  and AF  728  to provide information to each other via NEF  723 , which may be used for edge computing implementations. In such implementations, the network operator and third party services may be hosted close to the UE  701  access point of attachment to achieve an efficient service delivery through the reduced end-to-end latency and load on the transport network. For edge computing implementations, the 5GC may select a UPF  702  close to the UE  701  and execute traffic steering from the UPF  702  to DN  703  via the N6 interface. This may be based on the UE subscription data, UE location, and information provided by the AF  728 . In this way, the AF  728  may influence UPF (re)selection and traffic routing. Based on operator deployment, when AF  728  is considered to be a trusted entity, the network operator may permit AF  728  to interact directly with relevant NFs. Additionally, the AF  728  may exhibit an Naf service-based interface. 
     The NSSF  729  may select a set of network slice instances serving the UE  701 . The NSSF  729  may also determine allowed NSSAI and the mapping to the subscribed S-NSSAIs, if needed. The NSSF  729  may also determine the AMF set to be used to serve the UE  701 , or a list of candidate AMF(s)  721  based on a suitable configuration and possibly by querying the NRF  725 . The selection of a set of network slice instances for the UE  701  may be triggered by the AMF  721  with which the UE  701  is registered by interacting with the NSSF  729 , which may lead to a change of AMF  721 . The NSSF  729  may interact with the AMF  721  via an N22 reference point between AMF  721  and NSSF  729 ; and may communicate with another NSSF  729  in a visited network via an N31 reference point (not shown by  FIG.  7   ). Additionally, the NSSF  729  may exhibit an Nnssf service-based interface. 
     As discussed previously, the CN  720  may include an SMSF, which may be responsible for SMS subscription checking and verification, and relaying SM messages to/from the UE  701  to/from other entities, such as an SMS-GMSC/IWMSC/SMS-router. The SMS may also interact with AMF  721  and UDM  727  for a notification procedure that the UE  701  is available for SMS transfer (e.g., set a UE not reachable flag, and notifying UDM  727  when UE  701  is available for SMS). 
     The CN  120  may also include other elements that are not shown by  FIG.  7   , such as a Data Storage system/architecture, a 5G-EIR, a SEPP, and the like. The Data Storage system may include a SDSF, an UDSF, and/or the like. Any NF may store and retrieve unstructured data into/from the UDSF (e.g., UE contexts), via N18 reference point between any NF and the UDSF (not shown by  FIG.  7   ). Individual NFs may share a UDSF for storing their respective unstructured data or individual NFs may each have their own UDSF located at or near the individual NFs. Additionally, the UDSF may exhibit an Nudsf service-based interface (not shown by  FIG.  7   ). The 5G-EIR may be an NF that checks the status of PEI for determining whether particular equipment/entities are blacklisted from the network; and the SEPP may be a non-transparent proxy that performs topology hiding, message filtering, and policing on inter-PLMN control plane interfaces. 
     Additionally, there may be many more reference points and/or service-based interfaces between the NF services in the NFs; however, these interfaces and reference points have been omitted from  FIG.  7    for clarity. In one example, the CN  720  may include an Nx interface, which is an inter-CN interface between the MME (e.g., MME  621 ) and the AMF  721  in order to enable interworking between CN  720  and CN  620 . Other example interfaces/reference points may include an N5g-EIR service-based interface exhibited by a 5G-EIR, an N27 reference point between the NRF in the visited network and the NRF in the home network; and an N31 reference point between the NSSF in the visited network and the NSSF in the home network. 
       FIG.  8    illustrates an example of infrastructure equipment  800  in accordance with various embodiments. The infrastructure equipment  800  (or “system  800 ”) may be implemented as a base station, radio head, RAN node such as the RAN nodes XQ11 and/or AP XQ06 shown and described previously, application server(s) XQ30, and/or any other element/device discussed herein. In other examples, the system  800  could be implemented in or by a UE. 
     The system  800  includes application circuitry  805 , baseband circuitry  810 , one or more radio front end modules (RFEMs)  815 , memory circuitry  820 , power management integrated circuitry (PMIC)  825 , power tee circuitry  830 , network controller circuitry  835 , network interface connector  840 , satellite positioning circuitry  845 , and user interface  850 . In some embodiments, the device  800  may include additional elements such as, for example, memory/storage, display, camera, sensor, or input/output (I/O) interface. In other embodiments, the components described below may be included in more than one device. For example, said circuitries may be separately included in more than one device for CRAN, vBBU, or other like implementations. 
     Application circuitry  805  includes circuitry such as, but not limited to one or more processors (or processor cores), cache memory, and one or more of low drop-out voltage regulators (LDOs), interrupt controllers, serial interfaces such as SPI, I2C or universal programmable serial interface module, real time clock (RTC), timer-counters including interval and watchdog timers, general purpose input/output (I/O or IO), memory card controllers such as Secure Digital (SD) MultiMediaCard (MMC) or similar, Universal Serial Bus (USB) interfaces, Mobile Industry Processor Interface (MIPI) interfaces and Joint Test Access Group (JTAG) test access ports. The processors (or cores) of the application circuitry  805  may be coupled with or may include memory/storage elements and may be configured to execute instructions stored in the memory/storage to enable various applications or operating systems to run on the system  800 . In some implementations, the memory/storage elements may be on-chip memory circuitry, which may include any suitable volatile and/or non-volatile memory, such as DRAM, SRAM, EPROM, EEPROM, Flash memory, solid-state memory, and/or any other type of memory device technology, such as those discussed herein. 
     The processor(s) of application circuitry  805  may include, for example, one or more processor cores (CPUs), one or more application processors, one or more graphics processing units (GPUs), one or more reduced instruction set computing (RISC) processors, one or more Acorn RISC Machine (ARM) processors, one or more complex instruction set computing (CISC) processors, one or more digital signal processors (DSP), one or more FPGAs, one or more PLDs, one or more ASICs, one or more microprocessors or controllers, or any suitable combination thereof. In some embodiments, the application circuitry  805  may comprise, or may be, a special-purpose processor/controller to operate according to the various embodiments herein. As examples, the processor(s) of application circuitry  805  may include one or more may include one or more Apple A-series processors, Intel Pentium®, Core®, or Xeon® processor(s); Advanced Micro Devices (AMD) Ryzen® processor(s), Accelerated Processing Units (APUs), or Epyc® processors; ARM-based processor(s) licensed from ARM Holdings, Ltd. such as the ARM Cortex-A family of processors and the ThunderX2® provided by Cavium™, Inc.; a MIPS-based design from MIPS Technologies, Inc. such as MIPS Warrior P-class processors; and/or the like. In some embodiments, the system  800  may not utilize application circuitry  805 , and instead may include a special-purpose processor/controller to process IP data received from an EPC or 5GC, for example. 
     In some implementations, the application circuitry  805  may include one or more hardware accelerators, which may be microprocessors, programmable processing devices, or the like. The one or more hardware accelerators may include, for example, computer vision (CV) and/or deep learning (DL) accelerators. As examples, the programmable processing devices may be one or more a field-programmable devices (FPDs) such as field-programmable gate arrays (FPGAs) and the like; programmable logic devices (PLDs) such as complex PLDs (CPLDs), high-capacity PLDs (HCPLDs), and the like; ASICs such as structured ASICs and the like; programmable SoCs (PSoCs); and the like. In such implementations, the circuitry of application circuitry  805  may comprise logic blocks or logic fabric, and other interconnected resources that may be programmed to perform various functions, such as the procedures, methods, functions, etc. of the various embodiments discussed herein. In such embodiments, the circuitry of application circuitry  805  may include memory cells (e.g., erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, static memory (e.g., static random access memory (SRAM), anti-fuses, etc.)) used to store logic blocks, logic fabric, data, etc. in look-up-tables (LUTs) and the like. 
     The baseband circuitry  810  may be implemented, for example, as a solder-down substrate including one or more integrated circuits, a single packaged integrated circuit soldered to a main circuit board or a multi-chip module containing two or more integrated circuits. The various hardware electronic elements of baseband circuitry  810  are discussed infra with regard to  FIG.  10   . 
     User interface circuitry  850  may include one or more user interfaces designed to enable user interaction with the system  800  or peripheral component interfaces designed to enable peripheral component interaction with the system  800 . User interfaces may include, but are not limited to, one or more physical or virtual buttons (e.g., a reset button), one or more indicators (e.g., light emitting diodes (LEDs)), a physical keyboard or keypad, a mouse, a touchpad, a touchscreen, speakers or other audio emitting devices, microphones, a printer, a scanner, a headset, a display screen or display device, etc. Peripheral component interfaces may include, but are not limited to, a nonvolatile memory port, a universal serial bus (USB) port, an audio jack, a power supply interface, etc. 
     The radio front end modules (RFEMs)  815  may comprise a millimeter wave (mmWave) RFEM and one or more sub-mmWave radio frequency integrated circuits (RFICs). In some implementations, the one or more sub-mmWave RFICs may be physically separated from the mmWave RFEM. The RFICs may include connections to one or more antennas or antenna arrays (see e.g., antenna array  1011  of  FIG.  10    infra), and the RFEM may be connected to multiple antennas. In alternative implementations, both mmWave and sub-mmWave radio functions may be implemented in the same physical RFEM  815 , which incorporates both mmWave antennas and sub-mmWave. 
     The memory circuitry  820  may include one or more of volatile memory including dynamic random access memory (DRAM) and/or synchronous dynamic random access memory (SDRAM), and nonvolatile memory (NVM) including high-speed electrically erasable memory (commonly referred to as Flash memory), phase change random access memory (PRAM), magnetoresistive random access memory (MRAM), etc., and may incorporate the three-dimensional (3D) cross-point (XPOINT) memories from Intel® and Micron®. Memory circuitry  820  may be implemented as one or more of solder down packaged integrated circuits, socketed memory modules and plug-in memory cards. 
     The PMIC  825  may include voltage regulators, surge protectors, power alarm detection circuitry, and one or more backup power sources such as a battery or capacitor. The power alarm detection circuitry may detect one or more of brown out (under-voltage) and surge (over-voltage) conditions. The power tee circuitry  830  may provide for electrical power drawn from a network cable to provide both power supply and data connectivity to the infrastructure equipment  800  using a single cable. 
     The network controller circuitry  835  may provide connectivity to a network using a standard network interface protocol such as Ethernet, Ethernet over GRE Tunnels, Ethernet over Multiprotocol Label Switching (MPLS), or some other suitable protocol. Network connectivity may be provided to/from the infrastructure equipment  800  via network interface connector  840  using a physical connection, which may be electrical (commonly referred to as a “copper interconnect”), optical, or wireless. The network controller circuitry  835  may include one or more dedicated processors and/or FPGAs to communicate using one or more of the aforementioned protocols. In some implementations, the network controller circuitry  835  may include multiple controllers to provide connectivity to other networks using the same or different protocols. 
     The positioning circuitry  845  includes circuitry to receive and decode signals transmitted/broadcasted by a positioning network of a global navigation satellite system (GNSS). Examples of navigation satellite constellations (or GNSS) include United States&#39; Global Positioning System (GPS), Russia&#39;s Global Navigation System (GLONASS), the European Union&#39;s Galileo system, China&#39;s BeiDou Navigation Satellite System, a regional navigation system or GNSS augmentation system (e.g., Navigation with Indian Constellation (NAVIC), Japan&#39;s Quasi-Zenith Satellite System (QZSS), France&#39;s Doppler Orbitography and Radio-positioning Integrated by Satellite (DORIS), etc.), or the like. The positioning circuitry  845  comprises various hardware elements (e.g., including hardware devices such as switches, filters, amplifiers, antenna elements, and the like to facilitate OTA communications) to communicate with components of a positioning network, such as navigation satellite constellation nodes. In some embodiments, the positioning circuitry  845  may include a Micro-Technology for Positioning, Navigation, and Timing (Micro-PNT) IC that uses a master timing clock to perform position tracking/estimation without GNSS assistance. The positioning circuitry  845  may also be part of, or interact with, the baseband circuitry  810  and/or RFEMs  815  to communicate with the nodes and components of the positioning network. The positioning circuitry  845  may also provide position data and/or time data to the application circuitry  805 , which may use the data to synchronize operations with various infrastructure (e.g., RAN nodes XQ11, etc.), or the like. 
     The components shown by  FIG.  8    may communicate with one another using interface circuitry, which may include any number of bus and/or interconnect (IX) technologies such as industry standard architecture (ISA), extended ISA (EISA), peripheral component interconnect (PCI), peripheral component interconnect extended (PCIx), PCI express (PCIe), or any number of other technologies. The bus/IX may be a proprietary bus, for example, used in a SoC based system. Other bus/IX systems may be included, such as an I2C interface, an SPI interface, point to point interfaces, and a power bus, among others. 
       FIG.  9    illustrates an example of a platform  900  (or “device  900 ”) in accordance with various embodiments. In embodiments, the computer platform  900  may be suitable for use as UEs XQ01,  601 ,  701 , application servers XQ30, and/or any other element/device discussed herein. The platform  900  may include any combinations of the components shown in the example. The components of platform  900  may be implemented as integrated circuits (ICs), portions thereof, discrete electronic devices, or other modules, logic, hardware, software, firmware, or a combination thereof adapted in the computer platform  900 , or as components otherwise incorporated within a chassis of a larger system. The block diagram of  FIG.  9    is intended to show a high level view of components of the computer platform  900 . However, some of the components shown may be omitted, additional components may be present, and different arrangement of the components shown may occur in other implementations. 
     Application circuitry  905  includes circuitry such as, but not limited to one or more processors (or processor cores), cache memory, and one or more of LDOs, interrupt controllers, serial interfaces such as SPI, I2C or universal programmable serial interface module, RTC, timer-counters including interval and watchdog timers, general purpose I/O, memory card controllers such as SD MMC or similar, USB interfaces, MIPI interfaces, and JTAG test access ports. The processors (or cores) of the application circuitry  905  may be coupled with or may include memory/storage elements and may be configured to execute instructions stored in the memory/storage to enable various applications or operating systems to run on the system  900 . In some implementations, the memory/storage elements may be on-chip memory circuitry, which may include any suitable volatile and/or non-volatile memory, such as DRAM, SRAM, EPROM, EEPROM, Flash memory, solid-state memory, and/or any other type of memory device technology, such as those discussed herein. 
     The processor(s) of application circuitry  805  may include, for example, one or more processor cores, one or more application processors, one or more GPUs, one or more RISC processors, one or more ARM processors, one or more CISC processors, one or more DSP, one or more FPGAs, one or more PLDs, one or more ASICs, one or more microprocessors or controllers, a multithreaded processor, an ultra-low voltage processor, an embedded processor, some other known processing element, or any suitable combination thereof. In some embodiments, the application circuitry  805  may comprise, or may be, a special-purpose processor/controller to operate according to the various embodiments herein. 
     As examples, the processor(s) of application circuitry  905  may include an Apple A-series processor. The processors of the application circuitry  905  may also be one or more of Intel® Architecture Core™ based processor, such as a Quark™, an Atom™, an i3, an i5, an i7, or an MCU-class processor, or another such processor available from Intel® Corporation, Santa Clara, CA; Advanced Micro Devices (AMD) Ryzen® processor(s) or Accelerated Processing Units (APUs); Snapdragon™ processor(s) from Qualcomm® Technologies, Inc., Texas Instruments, Inc.® Open Multimedia Applications Platform (OMAP)™ processor(s); a MIPS-based design from MIPS Technologies, Inc. such as MIPS Warrior M-class, Warrior I-class, and Warrior P-class processors; an ARM-based design licensed from ARM Holdings, Ltd., such as the ARM Cortex-A, Cortex-R, and Cortex-M family of processors; or the like. In some implementations, the application circuitry  905  may be a part of a system on a chip (SoC) in which the application circuitry  905  and other components are formed into a single integrated circuit. 
     Additionally or alternatively, application circuitry  905  may include circuitry such as, but not limited to, one or more a field-programmable devices (FPDs) such as FPGAs and the like; programmable logic devices (PLDs) such as complex PLDs (CPLDs), high-capacity PLDs (HCPLDs), and the like; ASICs such as structured ASICs and the like; programmable SoCs (PSoCs); and the like. In such embodiments, the circuitry of application circuitry  905  may comprise logic blocks or logic fabric, and other interconnected resources that may be programmed to perform various functions, such as the procedures, methods, functions, etc. of the various embodiments discussed herein. In such embodiments, the circuitry of application circuitry  905  may include memory cells (e.g., erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, static memory (e.g., static random access memory (SRAM), anti-fuses, etc.)) used to store logic blocks, logic fabric, data, etc. in look-up tables (LUTs) and the like. 
     The baseband circuitry  910  may be implemented, for example, as a solder-down substrate including one or more integrated circuits, a single packaged integrated circuit soldered to a main circuit board or a multi-chip module containing two or more integrated circuits. The various hardware electronic elements of baseband circuitry  910  are discussed infra with regard to  FIG.  10   . 
     The RFEMs  915  may comprise a millimeter wave (mmWave) RFEM and one or more sub-mmWave radio frequency integrated circuits (RFICs). In some implementations, the one or more sub-mmWave RFICs may be physically separated from the mmWave RFEM. The RFICs may include connections to one or more antennas or antenna arrays (see e.g., antenna array  1011  of  FIG.  10    infra), and the RFEM may be connected to multiple antennas. In alternative implementations, both mmWave and sub-mmWave radio functions may be implemented in the same physical RFEM  915 , which incorporates both mmWave antennas and sub-mmWave. 
     The memory circuitry  920  may include any number and type of memory devices used to provide for a given amount of system memory. As examples, the memory circuitry  920  may include one or more of volatile memory including random access memory (RAM), dynamic RAM (DRAM) and/or synchronous dynamic RAM (SDRAM), and nonvolatile memory (NVM) including high-speed electrically erasable memory (commonly referred to as Flash memory), phase change random access memory (PRAM), magnetoresistive random access memory (MRAM), etc. The memory circuitry  920  may be developed in accordance with a Joint Electron Devices Engineering Council (JEDEC) low power double data rate (LPDDR)-based design, such as LPDDR2, LPDDR3, LPDDR4, or the like. Memory circuitry  920  may be implemented as one or more of solder down packaged integrated circuits, single die package (SDP), dual die package (DDP) or quad die package (Q17P), socketed memory modules, dual inline memory modules (DIMMs) including microDIMMs or MiniDIMMs, and/or soldered onto a motherboard via a ball grid array (BGA). In low power implementations, the memory circuitry  920  may be on-die memory or registers associated with the application circuitry  905 . To provide for persistent storage of information such as data, applications, operating systems and so forth, memory circuitry  920  may include one or more mass storage devices, which may include, inter alia, a solid state disk drive (SSDD), hard disk drive (HDD), a micro HDD, resistance change memories, phase change memories, holographic memories, or chemical memories, among others. For example, the computer platform  900  may incorporate the three-dimensional (3D) cross-point (XPOINT) memories from Intel® and Micron®. 
     Removable memory circuitry  923  may include devices, circuitry, enclosures/housings, ports or receptacles, etc. used to couple portable data storage devices with the platform  900 . These portable data storage devices may be used for mass storage purposes, and may include, for example, flash memory cards (e.g., Secure Digital (SD) cards, microSD cards, xD picture cards, and the like), and USB flash drives, optical discs, external HDDs, and the like. 
     The platform  900  may also include interface circuitry (not shown) that is used to connect external devices with the platform  900 . The external devices connected to the platform  900  via the interface circuitry include sensor circuitry  921  and electro-mechanical components (EMCs)  922 , as well as removable memory devices coupled to removable memory circuitry  923 . 
     The sensor circuitry  921  include devices, modules, or subsystems whose purpose is to detect events or changes in its environment and send the information (sensor data) about the detected events to some other a device, module, subsystem, etc. Examples of such sensors include, inter alia, inertia measurement units (IMUs) comprising accelerometers, gyroscopes, and/or magnetometers; microelectromechanical systems (MEMS) or nanoelectromechanical systems (NEMS) comprising 3-axis accelerometers, 3-axis gyroscopes, and/or magnetometers; level sensors; flow sensors; temperature sensors (e.g., thermistors); pressure sensors; barometric pressure sensors; gravimeters; altimeters; image capture devices (e.g., cameras or lensless apertures); light detection and ranging (LiDAR) sensors; proximity sensors (e.g., infrared radiation detector and the like), depth sensors, ambient light sensors, ultrasonic transceivers; microphones or other like audio capture devices; etc. 
     EMCs  922  include devices, modules, or subsystems whose purpose is to enable platform  900  to change its state, position, and/or orientation, or move or control a mechanism or (sub)system. Additionally, EMCs  922  may be configured to generate and send messages/signalling to other components of the platform  900  to indicate a current state of the EMCs  922 . Examples of the EMCs  922  include one or more power switches, relays including electromechanical relays (EMRs) and/or solid state relays (SSRs), actuators (e.g., valve actuators, etc.), an audible sound generator, a visual warning device, motors (e.g., DC motors, stepper motors, etc.), wheels, thrusters, propellers, claws, clamps, hooks, and/or other like electro-mechanical components. In embodiments, platform  900  is configured to operate one or more EMCs  922  based on one or more captured events and/or instructions or control signals received from a service provider and/or various clients. 
     In some implementations, the interface circuitry may connect the platform  900  with positioning circuitry  945 . The positioning circuitry  945  includes circuitry to receive and decode signals transmitted/broadcasted by a positioning network of a GNSS. Examples of navigation satellite constellations (or GNSS) include United States&#39; GPS, Russia&#39;s GLONASS, the European Union&#39;s Galileo system, China&#39;s BeiDou Navigation Satellite System, a regional navigation system or GNSS augmentation system (e.g., NAVIC), Japan&#39;s QZSS, France&#39;s DORIS, etc.), or the like. The positioning circuitry  945  comprises various hardware elements (e.g., including hardware devices such as switches, filters, amplifiers, antenna elements, and the like to facilitate OTA communications) to communicate with components of a positioning network, such as navigation satellite constellation nodes. In some embodiments, the positioning circuitry  945  may include a Micro-PNT IC that uses a master timing clock to perform position tracking/estimation without GNSS assistance. The positioning circuitry  945  may also be part of, or interact with, the baseband circuitry  810  and/or RFEMs  915  to communicate with the nodes and components of the positioning network. The positioning circuitry  945  may also provide position data and/or time data to the application circuitry  905 , which may use the data to synchronize operations with various infrastructure (e.g., radio base stations), for turn-by-turn navigation applications, or the like 
     In some implementations, the interface circuitry may connect the platform  900  with Near-Field Communication (NFC) circuitry  940 . NFC circuitry  940  is configured to provide contactless, short-range communications based on radio frequency identification (RFID) standards, wherein magnetic field induction is used to enable communication between NFC circuitry  940  and NFC-enabled devices external to the platform  900  (e.g., an “NFC touchpoint”). NFC circuitry  940  comprises an NFC controller coupled with an antenna element and a processor coupled with the NFC controller. The NFC controller may be a chip/IC providing NFC functionalities to the NFC circuitry  940  by executing NFC controller firmware and an NFC stack. The NFC stack may be executed by the processor to control the NFC controller, and the NFC controller firmware may be executed by the NFC controller to control the antenna element to emit short-range RF signals. The RF signals may power a passive NFC tag (e.g., a microchip embedded in a sticker or wristband) to transmit stored data to the NFC circuitry  940 , or initiate data transfer between the NFC circuitry  940  and another active NFC device (e.g., a smartphone or an NFC-enabled POS terminal) that is proximate to the platform  900 . 
     The driver circuitry  946  may include software and hardware elements that operate to control particular devices that are embedded in the platform  900 , attached to the platform  900 , or otherwise communicatively coupled with the platform  900 . The driver circuitry  946  may include individual drivers allowing other components of the platform  900  to interact with or control various input/output (I/O) devices that may be present within, or connected to, the platform  900 . For example, driver circuitry  946  may include a display driver to control and allow access to a display device, a touchscreen driver to control and allow access to a touchscreen interface of the platform  900 , sensor drivers to obtain sensor readings of sensor circuitry  921  and control and allow access to sensor circuitry  921 , EMC drivers to obtain actuator positions of the EMCs  922  and/or control and allow access to the EMCs  922 , a camera driver to control and allow access to an embedded image capture device, audio drivers to control and allow access to one or more audio devices. 
     The power management integrated circuitry (PMIC)  925  (also referred to as “power management circuitry  925 ”) may manage power provided to various components of the platform  900 . In particular, with respect to the baseband circuitry  910 , the PMIC  925  may control power-source selection, voltage scaling, battery charging, or DC-to-DC conversion. The PMIC  925  may often be included when the platform  900  is capable of being powered by a battery  930 , for example, when the device is included in a UE XQ01,  601 ,  701 . 
     In some embodiments, the PMIC  925  may control, or otherwise be part of, various power saving mechanisms of the platform  900 . For example, if the platform  900  is in an RRC_Connected state, where it is still connected to the RAN node as it expects to receive traffic shortly, then it may enter a state known as Discontinuous Reception Mode (DRX) after a period of inactivity. During this state, the platform  900  may power down for brief intervals of time and thus save power. If there is no data traffic activity for an extended period of time, then the platform  900  may transition off to an RRC Idle state, where it disconnects from the network and does not perform operations such as channel quality feedback, handover, etc. The platform  900  goes into a very low power state and it performs paging where again it periodically wakes up to listen to the network and then powers down again. The platform  900  may not receive data in this state; in order to receive data, it must transition back to RRC_Connected state. An additional power saving mode may allow a device to be unavailable to the network for periods longer than a paging interval (ranging from seconds to a few hours). During this time, the device is totally unreachable to the network and may power down completely. Any data sent during this time incurs a large delay and it is assumed the delay is acceptable. 
     A battery  930  may power the platform  900 , although in some examples the platform  900  may be mounted deployed in a fixed location, and may have a power supply coupled to an electrical grid. The battery  930  may be a lithium ion battery, a metal-air battery, such as a zinc-air battery, an aluminum-air battery, a lithium-air battery, and the like. In some implementations, such as in V2X applications, the battery  930  may be a typical lead-acid automotive battery. 
     In some implementations, the battery  930  may be a “smart battery,” which includes or is coupled with a Battery Management System (BMS) or battery monitoring integrated circuitry. The BMS may be included in the platform  900  to track the state of charge (SoCh) of the battery  930 . The BMS may be used to monitor other parameters of the battery  930  to provide failure predictions, such as the state of health (SoH) and the state of function (SoF) of the battery  930 . The BMS may communicate the information of the battery  930  to the application circuitry  905  or other components of the platform  900 . The BMS may also include an analog-to-digital (ADC) convertor that allows the application circuitry  905  to directly monitor the voltage of the battery  930  or the current flow from the battery  930 . The battery parameters may be used to determine actions that the platform  900  may perform, such as transmission frequency, network operation, sensing frequency, and the like. 
     A power block, or other power supply coupled to an electrical grid may be coupled with the BMS to charge the battery  930 . In some examples, the power block XS30 may be replaced with a wireless power receiver to obtain the power wirelessly, for example, through a loop antenna in the computer platform  900 . In these examples, a wireless battery charging circuit may be included in the BMS. The specific charging circuits chosen may depend on the size of the battery  930 , and thus, the current required. The charging may be performed using the Airfuel standard promulgated by the Airfuel Alliance, the Qi wireless charging standard promulgated by the Wireless Power Consortium, or the Rezence charging standard promulgated by the Alliance for Wireless Power, among others. 
     User interface circuitry  950  includes various input/output (I/O) devices present within, or connected to, the platform  900 , and includes one or more user interfaces designed to enable user interaction with the platform  900  and/or peripheral component interfaces designed to enable peripheral component interaction with the platform  900 . The user interface circuitry  950  includes input device circuitry and output device circuitry. Input device circuitry includes any physical or virtual means for accepting an input including, inter alia, one or more physical or virtual buttons (e.g., a reset button), a physical keyboard, keypad, mouse, touchpad, touchscreen, microphones, scanner, headset, and/or the like. The output device circuitry includes any physical or virtual means for showing information or otherwise conveying information, such as sensor readings, actuator position(s), or other like information. Output device circuitry may include any number and/or combinations of audio or visual display, including, inter alia, one or more simple visual outputs/indicators (e.g., binary status indicators (e.g., light emitting diodes (LEDs)) and multi-character visual outputs, or more complex outputs such as display devices or touchscreens (e.g., Liquid Chrystal Displays (LCD), LED displays, quantum dot displays, projectors, etc.), with the output of characters, graphics, multimedia objects, and the like being generated or produced from the operation of the platform  900 . The output device circuitry may also include speakers or other audio emitting devices, printer(s), and/or the like. In some embodiments, the sensor circuitry  921  may be used as the input device circuitry (e.g., an image capture device, motion capture device, or the like) and one or more EMCs may be used as the output device circuitry (e.g., an actuator to provide haptic feedback or the like). In another example, NFC circuitry comprising an NFC controller coupled with an antenna element and a processing device may be included to read electronic tags and/or connect with another NFC-enabled device. Peripheral component interfaces may include, but are not limited to, a non-volatile memory port, a USB port, an audio jack, a power supply interface, etc. 
     Although not shown, the components of platform  900  may communicate with one another using a suitable bus or interconnect (IX) technology, which may include any number of technologies, including ISA, EISA, PCI, PCIx, PCIe, a Time-Trigger Protocol (TTP) system, a FlexRay system, or any number of other technologies. The bus/IX may be a proprietary bus/IX, for example, used in a SoC based system. Other bus/IX systems may be included, such as an I2C interface, an SPI interface, point-to-point interfaces, and a power bus, among others. 
       FIG.  10    illustrates example components of baseband circuitry  1010  and radio front end modules (RFEM)  1015  in accordance with various embodiments. The baseband circuitry  1010  corresponds to the baseband circuitry  810  and  910  of  FIGS.  8  and  9   , respectively. The RFEM  1015  corresponds to the RFEM  815  and  915  of  FIGS.  8  and  9   , respectively. As shown, the RFEMs  1015  may include Radio Frequency (RF) circuitry  1006 , front-end module (FEM) circuitry  1008 , antenna array  1011  coupled together at least as shown. 
     The baseband circuitry  1010  includes circuitry and/or control logic configured to carry out various radio/network protocol and radio control functions that enable communication with one or more radio networks via the RF circuitry  1006 . The radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, etc. In some embodiments, modulation/demodulation circuitry of the baseband circuitry  1010  may include Fast-Fourier Transform (FFT), precoding, or constellation mapping/demapping functionality. In some embodiments, encoding/decoding circuitry of the baseband circuitry  1010  may include convolution, tail-biting convolution, turbo, Viterbi, or Low Density Parity Check (LDPC) encoder/decoder functionality. Embodiments of modulation/demodulation and encoder/decoder functionality are not limited to these examples and may include other suitable functionality in other embodiments. The baseband circuitry  1010  is configured to process baseband signals received from a receive signal path of the RF circuitry  1006  and to generate baseband signals for a transmit signal path of the RF circuitry  1006 . The baseband circuitry  1010  is configured to interface with application circuitry  805 / 905  (see  FIGS.  8  and  9   ) for generation and processing of the baseband signals and for controlling operations of the RF circuitry  1006 . The baseband circuitry  1010  may handle various radio control functions. 
     The aforementioned circuitry and/or control logic of the baseband circuitry  1010  may include one or more single or multi-core processors. For example, the one or more processors may include a 3G baseband processor  1004 A, a 4G/LTE baseband processor  1004 B, a 5G/NR baseband processor  1004 C, or some other baseband processor(s)  1004 D for other existing generations, generations in development or to be developed in the future (e.g., sixth generation (6G), etc.). In other embodiments, some or all of the functionality of baseband processors  1004 A-D may be included in modules stored in the memory  1004 G and executed via a Central Processing Unit (CPU)  1004 E. In other embodiments, some or all of the functionality of baseband processors  1004 A-D may be provided as hardware accelerators (e.g., FPGAs, ASICs, etc.) loaded with the appropriate bit streams or logic blocks stored in respective memory cells. In various embodiments, the memory  1004 G may store program code of a real-time OS (RTOS), which when executed by the CPU  1004 E (or other baseband processor), is to cause the CPU  1004 E (or other baseband processor) to manage resources of the baseband circuitry  1010 , schedule tasks, etc. Examples of the RTOS may include Operating System Embedded (OSE)™ provided by Enea®, Nucleus RTOS™ provided by Mentor Graphics®, Versatile Real-Time Executive (VRTX) provided by Mentor Graphics®, ThreadX™ provided by Express Logic®, FreeRTOS, REX OS provided by Qualcomm®, OKL4 provided by Open Kernel (OK) Labs®, or any other suitable RTOS, such as those discussed herein. In addition, the baseband circuitry  1010  includes one or more audio digital signal processor(s) (DSP)  1004 F. The audio DSP(s)  1004 F include elements for compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments. 
     In some embodiments, each of the processors  1004 A- 1004 E include respective memory interfaces to send/receive data to/from the memory  1004 G. The baseband circuitry  1010  may further include one or more interfaces to communicatively couple to other circuitries/devices, such as an interface to send/receive data to/from memory external to the baseband circuitry  1010 ; an application circuitry interface to send/receive data to/from the application circuitry  805 / 905  of  FIGS.  8   -XT); an RF circuitry interface to send/receive data to/from RF circuitry  1006  of  FIG.  10   ; a wireless hardware connectivity interface to send/receive data to/from one or more wireless hardware elements (e.g., Near Field Communication (NFC) components, Bluetooth®/Bluetooth® Low Energy components, Wi-Fi® components, and/or the like); and a power management interface to send/receive power or control signals to/from the PMIC  925 . 
     In alternate embodiments (which may be combined with the above described embodiments), baseband circuitry  1010  comprises one or more digital baseband systems, which are coupled with one another via an interconnect subsystem and to a CPU subsystem, an audio subsystem, and an interface subsystem. The digital baseband subsystems may also be coupled to a digital baseband interface and a mixed-signal baseband subsystem via another interconnect subsystem. Each of the interconnect subsystems may include a bus system, point-to-point connections, network-on-chip (NOC) structures, and/or some other suitable bus or interconnect technology, such as those discussed herein. The audio subsystem may include DSP circuitry, buffer memory, program memory, speech processing accelerator circuitry, data converter circuitry such as analog-to-digital and digital-to-analog converter circuitry, analog circuitry including one or more of amplifiers and filters, and/or other like components. In an aspect of the present disclosure, baseband circuitry  1010  may include protocol processing circuitry with one or more instances of control circuitry (not shown) to provide control functions for the digital baseband circuitry and/or radio frequency circuitry (e.g., the radio front end modules  1015 ). 
     Although not shown by  FIG.  10   , in some embodiments, the baseband circuitry  1010  includes individual processing device(s) to operate one or more wireless communication protocols (e.g., a “multi-protocol baseband processor” or “protocol processing circuitry”) and individual processing device(s) to implement PHY layer functions. In these embodiments, the PHY layer functions include the aforementioned radio control functions. In these embodiments, the protocol processing circuitry operates or implements various protocol layers/entities of one or more wireless communication protocols. In a first example, the protocol processing circuitry may operate LTE protocol entities and/or 5G/NR protocol entities when the baseband circuitry  1010  and/or RF circuitry  1006  are part of mmWave communication circuitry or some other suitable cellular communication circuitry. In the first example, the protocol processing circuitry would operate MAC, RLC, PDCP, SDAP, RRC, and NAS functions. In a second example, the protocol processing circuitry may operate one or more IEEE-based protocols when the baseband circuitry  1010  and/or RF circuitry  1006  are part of a Wi-Fi communication system. In the second example, the protocol processing circuitry would operate Wi-Fi MAC and logical link control (LLC) functions. The protocol processing circuitry may include one or more memory structures (e.g.,  1004 G) to store program code and data for operating the protocol functions, as well as one or more processing cores to execute the program code and perform various operations using the data. The baseband circuitry  1010  may also support radio communications for more than one wireless protocol. 
     The various hardware elements of the baseband circuitry  1010  discussed herein may be implemented, for example, as a solder-down substrate including one or more integrated circuits (ICs), a single packaged IC soldered to a main circuit board or a multi-chip module containing two or more ICs. In one example, the components of the baseband circuitry  1010  may be suitably combined in a single chip or chipset, or disposed on a same circuit board. In another example, some or all of the constituent components of the baseband circuitry  1010  and RF circuitry  1006  may be implemented together such as, for example, a system on a chip (SoC) or System-in-Package (SiP). In another example, some or all of the constituent components of the baseband circuitry  1010  may be implemented as a separate SoC that is communicatively coupled with and RF circuitry  1006  (or multiple instances of RF circuitry  1006 ). In yet another example, some or all of the constituent components of the baseband circuitry  1010  and the application circuitry  805 / 905  may be implemented together as individual SoCs mounted to a same circuit board (e.g., a “multi-chip package”). 
     In some embodiments, the baseband circuitry  1010  may provide for communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry  1010  may support communication with an E-UTRAN or other WMAN, a WLAN, a WPAN. Embodiments in which the baseband circuitry  1010  is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry. 
     RF circuitry  1006  may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry  1006  may include switches, filters, amplifiers, etc. to facilitate the communication with the wireless network. RF circuitry  1006  may include a receive signal path, which may include circuitry to down-convert RF signals received from the FEM circuitry  1008  and provide baseband signals to the baseband circuitry  1010 . RF circuitry  1006  may also include a transmit signal path, which may include circuitry to up-convert baseband signals provided by the baseband circuitry  1010  and provide RF output signals to the FEM circuitry  1008  for transmission. 
     In some embodiments, the receive signal path of the RF circuitry  1006  may include mixer circuitry  1006   a , amplifier circuitry  1006   b  and filter circuitry  1006   c . In some embodiments, the transmit signal path of the RF circuitry  1006  may include filter circuitry  1006   c  and mixer circuitry  1006   a . RF circuitry  1006  may also include synthesizer circuitry  1006   d  for synthesizing a frequency for use by the mixer circuitry  1006   a  of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry  1006   a  of the receive signal path may be configured to down-convert RF signals received from the FEM circuitry  1008  based on the synthesized frequency provided by synthesizer circuitry  1006   d . The amplifier circuitry  1006   b  may be configured to amplify the down-converted signals and the filter circuitry  1006   c  may be a low-pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry  1010  for further processing. In some embodiments, the output baseband signals may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, mixer circuitry  1006   a  of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect. 
     In some embodiments, the mixer circuitry  1006   a  of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry  1006   d  to generate RF output signals for the FEM circuitry  1008 . The baseband signals may be provided by the baseband circuitry  1010  and may be filtered by filter circuitry  1006   c.    
     In some embodiments, the mixer circuitry  1006   a  of the receive signal path and the mixer circuitry  1006   a  of the transmit signal path may include two or more mixers and may be arranged for quadrature downconversion and upconversion, respectively. In some embodiments, the mixer circuitry  1006   a  of the receive signal path and the mixer circuitry  1006   a  of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry  1006   a  of the receive signal path and the mixer circuitry  1006   a  of the transmit signal path may be arranged for direct downconversion and direct upconversion, respectively. In some embodiments, the mixer circuitry  1006   a  of the receive signal path and the mixer circuitry  1006   a  of the transmit signal path may be configured for super-heterodyne operation. 
     In some embodiments, the output baseband signals and the input baseband signals may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternate embodiments, the output baseband signals and the input baseband signals may be digital baseband signals. In these alternate embodiments, the RF circuitry  1006  may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry and the baseband circuitry  1010  may include a digital baseband interface to communicate with the RF circuitry  1006 . 
     In some dual-mode embodiments, a separate radio IC circuitry may be provided for processing signals for each spectrum, although the scope of the embodiments is not limited in this respect. 
     In some embodiments, the synthesizer circuitry  1006   d  may be a fractional-N synthesizer or a fractional N/N+1 synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry  1006   d  may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider. 
     The synthesizer circuitry  1006   d  may be configured to synthesize an output frequency for use by the mixer circuitry  1006   a  of the RF circuitry  1006  based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry  1006   d  may be a fractional N/N+1 synthesizer. 
     In some embodiments, frequency input may be provided by a voltage controlled oscillator (VCO), although that is not a requirement. Divider control input may be provided by either the baseband circuitry  1010  or the application circuitry  805 / 905  depending on the desired output frequency. In some embodiments, a divider control input (e.g., N) may be determined from a look-up table based on a channel indicated by the application circuitry  805 / 905 . 
     Synthesizer circuitry  1006   d  of the RF circuitry  1006  may include a divider, a delay-locked loop (DLL), a multiplexer and a phase accumulator. In some embodiments, the divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by either N or N+1 (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable, delay elements, a phase detector, a charge pump and a D-type flip-flop. In these embodiments, the delay elements may be configured to break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle. 
     In some embodiments, synthesizer circuitry  1006   d  may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be a LO frequency (fLO). In some embodiments, the RF circuitry  1006  may include an IQ/polar converter. 
     FEM circuitry  1008  may include a receive signal path, which may include circuitry configured to operate on RF signals received from antenna array  1011 , amplify the received signals and provide the amplified versions of the received signals to the RF circuitry  1006  for further processing. FEM circuitry  1008  may also include a transmit signal path, which may include circuitry configured to amplify signals for transmission provided by the RF circuitry  1006  for transmission by one or more of antenna elements of antenna array  1011 . In various embodiments, the amplification through the transmit or receive signal paths may be done solely in the RF circuitry  1006 , solely in the FEM circuitry  1008 , or in both the RF circuitry  1006  and the FEM circuitry  1008 . 
     In some embodiments, the FEM circuitry  1008  may include a TX/RX switch to switch between transmit mode and receive mode operation. The FEM circuitry  1008  may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry  1008  may include an LNA to amplify received RF signals and provide the amplified received RF signals as an output (e.g., to the RF circuitry  1006 ). The transmit signal path of the FEM circuitry  1008  may include a power amplifier (PA) to amplify input RF signals (e.g., provided by RF circuitry  1006 ), and one or more filters to generate RF signals for subsequent transmission by one or more antenna elements of the antenna array  1011 . 
     The antenna array  1011  comprises one or more antenna elements, each of which is configured convert electrical signals into radio waves to travel through the air and to convert received radio waves into electrical signals. For example, digital baseband signals provided by the baseband circuitry  1010  is converted into analog RF signals (e.g., modulated waveform) that will be amplified and transmitted via the antenna elements of the antenna array  1011  including one or more antenna elements (not shown). The antenna elements may be omnidirectional, direction, or a combination thereof. The antenna elements may be formed in a multitude of arranges as are known and/or discussed herein. The antenna array  1011  may comprise microstrip antennas or printed antennas that are fabricated on the surface of one or more printed circuit boards. The antenna array  1011  may be formed in as a patch of metal foil (e.g., a patch antenna) in a variety of shapes, and may be coupled with the RF circuitry  1006  and/or FEM circuitry  1008  using metal transmission lines or the like. 
     Processors of the application circuitry  805 / 905  and processors of the baseband circuitry  1010  may be used to execute elements of one or more instances of a protocol stack. For example, processors of the baseband circuitry  1010 , alone or in combination, may be used execute Layer 3, Layer 2, or Layer 1 functionality, while processors of the application circuitry  805 / 905  may utilize data (e.g., packet data) received from these layers and further execute Layer 4 functionality (e.g., TCP and UDP layers). As referred to herein, Layer 3 may comprise a RRC layer, described in further detail below. As referred to herein, Layer 2 may comprise a MAC layer, an RLC layer, and a PDCP layer, described in further detail below. As referred to herein, Layer 1 may comprise a PHY layer of a UE/RAN node, described in further detail below. 
       FIG.  11    illustrates various protocol functions that may be implemented in a wireless communication device according to various embodiments. In particular,  FIG.  11    includes an arrangement  1100  showing interconnections between various protocol layers/entities. The following description of  FIG.  11    is provided for various protocol layers/entities that operate in conjunction with the 5G/NR system standards and LTE system standards, but some or all of the aspects of  FIG.  11    may be applicable to other wireless communication network systems as well. 
     The protocol layers of arrangement  1100  may include one or more of PHY  1110 , MAC  1120 , RLC  1130 , PDCP  1140 , SDAP  1147 , RRC  1155 , and NAS layer  1157 , in addition to other higher layer functions not illustrated. The protocol layers may include one or more service access points (e.g., items  1159 ,  1156 ,  1150 ,  1149 ,  1145 ,  1135 ,  1125 , and  1115  in  FIG.  11   ) that may provide communication between two or more protocol layers. 
     The PHY  1110  may transmit and receive physical layer signals  1105  that may be received from or transmitted to one or more other communication devices. The physical layer signals  1105  may comprise one or more physical channels, such as those discussed herein. The PHY  1110  may further perform link adaptation or adaptive modulation and coding (AMC), power control, cell search (e.g., for initial synchronization and handover purposes), and other measurements used by higher layers, such as the RRC  1155 . The PHY  1110  may still further perform error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, modulation/demodulation of physical channels, interleaving, rate matching, mapping onto physical channels, and MIMO antenna processing. In embodiments, an instance of PHY  1110  may process requests from and provide indications to an instance of MAC  1120  via one or more PHY-SAP  1115 . According to some embodiments, requests and indications communicated via PHY-SAP  1115  may comprise one or more transport channels. 
     Instance(s) of MAC  1120  may process requests from, and provide indications to, an instance of RLC  1130  via one or more MAC-SAPs  1125 . These requests and indications communicated via the MAC-SAP  1125  may comprise one or more logical channels. The MAC  1120  may perform mapping between the logical channels and transport channels, multiplexing of MAC SDUs from one or more logical channels onto TBs to be delivered to PHY  1110  via the transport channels, de-multiplexing MAC SDUs to one or more logical channels from TBs delivered from the PHY  1110  via transport channels, multiplexing MAC SDUs onto TBs, scheduling information reporting, error correction through HARQ, and logical channel prioritization. 
     Instance(s) of RLC  1130  may process requests from and provide indications to an instance of PDCP  1140  via one or more radio link control service access points (RLC-SAP)  1135 . These requests and indications communicated via RLC-SAP  1135  may comprise one or more RLC channels. The RLC  1130  may operate in a plurality of modes of operation, including: Transparent Mode™, Unacknowledged Mode (UM), and Acknowledged Mode (AM). The RLC  1130  may execute transfer of upper layer protocol data units (PDUs), error correction through automatic repeat request (ARQ) for AM data transfers, and concatenation, segmentation and reassembly of RLC SDUs for UM and AM data transfers. The RLC  1130  may also execute re-segmentation of RLC data PDUs for AM data transfers, reorder RLC data PDUs for UM and AM data transfers, detect duplicate data for UM and AM data transfers, discard RLC SDUs for UM and AM data transfers, detect protocol errors for AM data transfers, and perform RLC re-establishment. 
     Instance(s) of PDCP  1140  may process requests from and provide indications to instance(s) of RRC  1155  and/or instance(s) of SDAP  1147  via one or more packet data convergence protocol service access points (PDCP-SAP)  1145 . These requests and indications communicated via PDCP-SAP  1145  may comprise one or more radio bearers. The PDCP  1140  may execute header compression and decompression of IP data, maintain PDCP Sequence Numbers (SNs), perform in-sequence delivery of upper layer PDUs at re-establishment of lower layers, eliminate duplicates of lower layer SDUs at re-establishment of lower layers for radio bearers mapped on RLC AM, cipher and decipher control plane data, perform integrity protection and integrity verification of control plane data, control timer-based discard of data, and perform security operations (e.g., ciphering, deciphering, integrity protection, integrity verification, etc.). 
     Instance(s) of SDAP  1147  may process requests from and provide indications to one or more higher layer protocol entities via one or more SDAP-SAP  1149 . These requests and indications communicated via SDAP-SAP  1149  may comprise one or more QoS flows. The SDAP  1147  may map QoS flows to DRBs, and vice versa, and may also mark QFIs in DL and UL packets. A single SDAP entity  1147  may be configured for an individual PDU session. In the UL direction, the NG-RAN XQ10 may control the mapping of QoS Flows to DRB(s) in two different ways, reflective mapping or explicit mapping. For reflective mapping, the SDAP  1147  of a UE XQ01 may monitor the QFIs of the DL packets for each DRB, and may apply the same mapping for packets flowing in the UL direction. For a DRB, the SDAP  1147  of the UE XQ01 may map the UL packets belonging to the QoS flows(s) corresponding to the QoS flow ID(s) and PDU session observed in the DL packets for that DRB. To enable reflective mapping, the NG-RAN  710  may mark DL packets over the Uu interface with a QoS flow ID. The explicit mapping may involve the RRC  1155  configuring the SDAP  1147  with an explicit QoS flow to DRB mapping rule, which may be stored and followed by the SDAP  1147 . In embodiments, the SDAP  1147  may only be used in NR implementations and may not be used in LTE implementations. 
     The RRC  1155  may configure, via one or more management service access points (M-SAP), aspects of one or more protocol layers, which may include one or more instances of PHY  1110 , MAC  1120 , RLC  1130 , PDCP  1140  and SDAP  1147 . In embodiments, an instance of RRC  1155  may process requests from and provide indications to one or more NAS entities  1157  via one or more RRC-SAPs  1156 . The main services and functions of the RRC  1155  may include broadcast of system information (e.g., included in MIBs or SIBs related to the NAS), broadcast of system information related to the access stratum (AS), paging, establishment, maintenance and release of an RRC connection between the UE XQ01 and RAN XQ10 (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), establishment, configuration, maintenance and release of point to point Radio Bearers, security functions including key management, inter-RAT mobility, and measurement configuration for UE measurement reporting. The MIBs and SIBs may comprise one or more IEs, which may each comprise individual data fields or data structures. 
     The NAS  1157  may form the highest stratum of the control plane between the UE XQ01 and the AMF  721 . The NAS  1157  may support the mobility of the UEs XQ01 and the session management procedures to establish and maintain IP connectivity between the UE XQ01 and a P-GW in LTE systems. 
     According to various embodiments, one or more protocol entities of arrangement  1100  may be implemented in UEs XQ01, RAN nodes XQ11, AMF  721  in NR implementations or MME  621  in LTE implementations, UPF  702  in NR implementations or S-GW  622  and P-GW  623  in LTE implementations, or the like to be used for control plane or user plane communications protocol stack between the aforementioned devices. In such embodiments, one or more protocol entities that may be implemented in one or more of UE XQ01, gNB XQ11, AMF  721 , etc. may communicate with a respective peer protocol entity that may be implemented in or on another device using the services of respective lower layer protocol entities to perform such communication. In some embodiments, a gNB-CU of the gNB XQ11 may host the RRC  1155 , SDAP  1147 , and PDCP  1140  of the gNB that controls the operation of one or more gNB-DUs, and the gNB-DUs of the gNB XQ11 may each host the RLC  1130 , MAC  1120 , and PHY  1110  of the gNB XQ11. 
     In a first example, a control plane protocol stack may comprise, in order from highest layer to lowest layer, NAS  1157 , RRC  1155 , PDCP  1140 , RLC  1130 , MAC  1120 , and PHY  1110 . In this example, upper layers  1160  may be built on top of the NAS  1157 , which includes an IP layer  1161 , an SCTP  1162 , and an application layer signaling protocol (AP)  1163 . 
     In NR implementations, the AP  1163  may be an NG application protocol layer (NGAP or NG-AP)  1163  for the NG interface XQ13 defined between the NG-RAN node XQ11 and the AMF  721 , or the AP  1163  may be an Xn application protocol layer (XnAP or Xn-AP)  1163  for the Xn interface XQ12 that is defined between two or more RAN nodes XQ11. 
     The NG-AP  1163  may support the functions of the NG interface XQ13 and may comprise Elementary Procedures (EPs). An NG-AP EP may be a unit of interaction between the NG-RAN node XQ11 and the AMF  721 . The NG-AP  1163  services may comprise two groups: UE-associated services (e.g., services related to a UE XQ01) and non-UE-associated services (e.g., services related to the whole NG interface instance between the NG-RAN node XQ11 and AMF  721 ). These services may include functions including, but not limited to: a paging function for the sending of paging requests to NG-RAN nodes XQ11 involved in a particular paging area; a UE context management function for allowing the AMF  721  to establish, modify, and/or release a UE context in the AMF  721  and the NG-RAN node XQ11; a mobility function for UEs XQ01 in ECM-CONNECTED mode for intra-system HOs to support mobility within NG-RAN and inter-system HOs to support mobility from/to EPS systems; a NAS Signaling Transport function for transporting or rerouting NAS messages between UE XQ01 and AMF  721 ; a NAS node selection function for determining an association between the AMF  721  and the UE XQ01; NG interface management function(s) for setting up the NG interface and monitoring for errors over the NG interface; a warning message transmission function for providing means to transfer warning messages via NG interface or cancel ongoing broadcast of warning messages; a Configuration Transfer function for requesting and transferring of RAN configuration information (e.g., SON information, performance measurement (PM) data, etc.) between two RAN nodes XQ11 via CN XQ20; and/or other like functions. 
     The XnAP  1163  may support the functions of the Xn interface XQ12 and may comprise XnAP basic mobility procedures and XnAP global procedures. The XnAP basic mobility procedures may comprise procedures used to handle UE mobility within the NG RAN XQ11 (or E-UTRAN  610 ), such as handover preparation and cancellation procedures, SN Status Transfer procedures, UE context retrieval and UE context release procedures, RAN paging procedures, dual connectivity related procedures, and the like. The XnAP global procedures may comprise procedures that are not related to a specific UE XQ01, such as Xn interface setup and reset procedures, NG-RAN update procedures, cell activation procedures, and the like. 
     In LTE implementations, the AP  1163  may be an S1 Application Protocol layer (S1-AP)  1163  for the S1 interface XQ13 defined between an E-UTRAN node XQ11 and an MME, or the AP  1163  may be an X2 application protocol layer (X2AP or X2-AP)  1163  for the X2 interface XQ12 that is defined between two or more E-UTRAN nodes XQ11. 
     The S1 Application Protocol layer (S1-AP)  1163  may support the functions of the S1 interface, and similar to the NG-AP discussed previously, the S1-AP may comprise S1-AP EPs. An S1-AP EP may be a unit of interaction between the E-UTRAN node XQ11 and an MME  621  within an LTE CN XQ20. The S1-AP  1163  services may comprise two groups: UE-associated services and non UE-associated services. These services perform functions including, but not limited to: E-UTRAN Radio Access Bearer (E-RAB) management, UE capability indication, mobility, NAS signaling transport, RAN Information Management (RIM), and configuration transfer. 
     The X2AP  1163  may support the functions of the X2 interface XQ12 and may comprise X2AP basic mobility procedures and X2AP global procedures. The X2AP basic mobility procedures may comprise procedures used to handle UE mobility within the E-UTRAN XQ20, such as handover preparation and cancellation procedures, SN Status Transfer procedures, UE context retrieval and UE context release procedures, RAN paging procedures, dual connectivity related procedures, and the like. The X2AP global procedures may comprise procedures that are not related to a specific UE XQ01, such as X2 interface setup and reset procedures, load indication procedures, error indication procedures, cell activation procedures, and the like. 
     The SCTP layer (alternatively referred to as the SCTP/IP layer)  1162  may provide guaranteed delivery of application layer messages (e.g., NGAP or XnAP messages in NR implementations, or S1-AP or X2AP messages in LTE implementations). The SCTP  1162  may ensure reliable delivery of signaling messages between the RAN node XQ11 and the AMF  721 /MME  621  based, in part, on the IP protocol, supported by the IP  1161 . The Internet Protocol layer (IP)  1161  may be used to perform packet addressing and routing functionality. In some implementations the IP layer  1161  may use point-to-point transmission to deliver and convey PDUs. In this regard, the RAN node XQ11 may comprise L2 and L1 layer communication links (e.g., wired or wireless) with the MME/AMF to exchange information. 
     In a second example, a user plane protocol stack may comprise, in order from highest layer to lowest layer, SDAP  1147 , PDCP  1140 , RLC  1130 , MAC  1120 , and PHY  1110 . The user plane protocol stack may be used for communication between the UE XQ01, the RAN node XQ11, and UPF  702  in NR implementations or an S-GW  622  and P-GW  623  in LTE implementations. In this example, upper layers  1151  may be built on top of the SDAP  1147 , and may include a user datagram protocol (UDP) and IP security layer (UDP/IP)  1152 , a General Packet Radio Service (GPRS) Tunneling Protocol for the user plane layer (GTP-U)  1153 , and a User Plane PDU layer (UP PDU)  1163 . 
     The transport network layer  1154  (also referred to as a “transport layer”) may be built on IP transport, and the GTP-U  1153  may be used on top of the UDP/IP layer  1152  (comprising a UDP layer and IP layer) to carry user plane PDUs (UP-PDUs). The IP layer (also referred to as the “Internet layer”) may be used to perform packet addressing and routing functionality. The IP layer may assign IP addresses to user data packets in any of IPv4, IPv6, or PPP formats, for example. 
     The GTP-U  1153  may be used for carrying user data within the GPRS core network and between the radio access network and the core network. The user data transported can be packets in any of IPv4, IPv6, or PPP formats, for example. The UDP/IP  1152  may provide checksums for data integrity, port numbers for addressing different functions at the source and destination, and encryption and authentication on the selected data flows. The RAN node XQ11 and the S-GW  622  may utilize an S1-U interface to exchange user plane data via a protocol stack comprising an L1 layer (e.g., PHY  1110 ), an L2 layer (e.g., MAC  1120 , RLC  1130 , PDCP  1140 , and/or SDAP  1147 ), the UDP/IP layer  1152 , and the GTP-U  1153 . The S-GW  622  and the P-GW  623  may utilize an S5/S8a interface to exchange user plane data via a protocol stack comprising an L1 layer, an L2 layer, the UDP/IP layer  1152 , and the GTP-U  1153 . As discussed previously, NAS protocols may support the mobility of the UE XQ01 and the session management procedures to establish and maintain IP connectivity between the UE XQ01 and the P-GW  623 . 
     Moreover, although not shown by  FIG.  11   , an application layer may be present above the AP  1163  and/or the transport network layer  1154 . The application layer may be a layer in which a user of the UE XQ01, RAN node XQ11, or other network element interacts with software applications being executed, for example, by application circuitry  805  or application circuitry  905 , respectively. The application layer may also provide one or more interfaces for software applications to interact with communications systems of the UE XQ01 or RAN node XQ11, such as the baseband circuitry  1010 . In some implementations the IP layer and/or the application layer may provide the same or similar functionality as layers 5-7, or portions thereof, of the Open Systems Interconnection (OSI) model (e.g., OSI Layer 7—the application layer, OSI Layer 6—the presentation layer, and OSI Layer 5—the session layer). 
       FIG.  12    is a block diagram illustrating components, according to some example embodiments, able to read instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium) and perform any one or more of the methodologies discussed herein. Specifically,  FIG.  12    shows a diagrammatic representation of hardware resources  1200  including one or more processors (or processor cores)  1210 , one or more memory/storage devices  1220 , and one or more communication resources  1230 , each of which may be communicatively coupled via a bus  1240 . For embodiments where node virtualization (e.g., NFV) is utilized, a hypervisor  1202  may be executed to provide an execution environment for one or more network slices/sub-slices to utilize the hardware resources  1200 . 
     The processors  1210  may include, for example, a processor  1212  and a processor  1214 . The processor(s)  1210  may be, for example, a central processing unit (CPU), a reduced instruction set computing (RISC) processor, a complex instruction set computing (CISC) processor, a graphics processing unit (GPU), a DSP such as a baseband processor, an ASIC, an FPGA, a radio-frequency integrated circuit (RFIC), another processor (including those discussed herein), or any suitable combination thereof. 
     The memory/storage devices  1220  may include main memory, disk storage, or any suitable combination thereof. The memory/storage devices  1220  may include, but are not limited to, any type of volatile or nonvolatile memory such as dynamic random access memory (DRAM), static random access memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), Flash memory, solid-state storage, etc. 
     The communication resources  1230  may include interconnection or network interface components or other suitable devices to communicate with one or more peripheral devices  1204  or one or more databases  1206  via a network  1208 . For example, the communication resources  1230  may include wired communication components (e.g., for coupling via USB), cellular communication components, NFC components, Bluetooth® (or Bluetooth® Low Energy) components, Wi-Fi® components, and other communication components. 
     Instructions  1250  may comprise software, a program, an application, an applet, an app, or other executable code for causing at least any of the processors  1210  to perform any one or more of the methodologies discussed herein. The instructions  1250  may reside, completely or partially, within at least one of the processors  1210  (e.g., within the processor&#39;s cache memory), the memory/storage devices  1220 , or any suitable combination thereof. Furthermore, any portion of the instructions  1250  may be transferred to the hardware resources  1200  from any combination of the peripheral devices  1204  or the databases  1206 . Accordingly, the memory of processors  1210 , the memory/storage devices  1220 , the peripheral devices  1204 , and the databases  1206  are examples of computer-readable and machine-readable media.

Metadata:
Filing Date: 20200327
Publication Date: 20241022
Grant Date: 20241022
Priority Date: 20190329
Inventors: LI, HUA
TANG, YANG
CUI, JIE
LI, QIMING
HUANG, RUI
Assignee: APPLE INC
CPC Classifications: [{"code": "H04W36/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W36/302", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W48/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W4/70", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W36/302", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W4/70", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B17/318", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W36/302", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B17/318", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W48/16", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W48/16", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W4/70", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W48/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W36/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B17/318", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 70465291