Patent Publication Number: US-10313955-B2

Title: Carrier aggregation (CA) for user equipment (UE) and wireless relays

Description:
RELATED CASES 
     This patent application is a continuation of U.S. patent application Ser. No. 15/154,947 that was filed on May 14, 2016 and is entitled “CARRIER AGGREGATION (CA) FOR USER EQUIPMENT (UE) AND WIRELESS RELAYS.” U.S. patent application Ser. No. 15/154,947 is hereby incorporated by reference into this patent application. 
    
    
     TECHNICAL BACKGROUND 
     Data communication systems exchange user data to provide various services like media streaming, audio/video conferencing, data messaging, and internet access. The data communication systems use several communication networks to transfer the user data. In particular, the data communication systems use wireless networks to provide mobile and convenient access to their data services. Exemplary wireless communication protocols include Long Term Evolution (LTE) and Wireless Fidelity (WIFI). In wireless networks, the LTE and WIFI protocols typically carry the user data in Internet Protocol (IP) packets. 
     To implement wireless access, User Equipment (UE) and network base stations exchange wireless signals that transport user data and network signaling. The network base stations communicate with each other and core networks. Carrier Aggregation (CA) is often used on the wireless link between the UEs and the network base stations. 
     CA allocates additional bandwidth to UEs and relays in the form of Orthogonal Frequency Division Multiplex (OFDM) resource blocks. These simultaneous OFDM resource blocks may be contiguous and non-contiguous, and they may be intra-band or inter-band. Thus, the base stations and UEs exchange user data over parallel streams by using multiple CA resource blocks per OFDM time period. 
     To extend wireless access beyond the network base stations, wireless relays are deployed between the UEs and the base stations. The wireless relays exchange the user data between the UEs and the network base stations to extend data services like internet access, voice calling, and video conferencing to these UEs. CA is also used between the UEs and wireless relays, and between the wireless relays and the network base stations. 
     CA requires the various receiving devices to return acknowledgement signals (ACKs). The ACK load may become oppressive, especially for Downlink (DL) CA that transmits the ACKs on a thin Uplink (UL). Network base stations may turn CA off in times of radio interference, buffer overload, and the like. Unfortunately, network base stations do not effectively and efficiently control CA in wireless networks that use wireless relays. 
     TECHNICAL OVERVIEW 
     A wireless relay receives a user network Identifier (ID) and a relay network ID. The wireless relay attaches to the relay network responsive to the relay network ID. The wireless relay broadcasts the user network ID and User Equipment (UEs) attach to the wireless relay responsive to the user network ID. The wireless relay exchanges user data with the UEs over user network carrier aggregation links. The wireless relay exchanges the user data with the relay network over relay network carrier aggregation links. Responsive to carrier aggregation loading, the wireless relay receives an instruction to terminate the user network carrier aggregation links, and the wireless relay terminates the user network carrier aggregation links. The wireless relay now exchanges the user data with the UEs over non-carrier aggregation links. The wireless relay continues to exchange the user data with the relay network over the relay network carrier aggregation links. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a wireless communication network to control Carrier Aggregation (CA) used by wireless relays and User Equipment (UE). 
         FIG. 2  illustrates the operation of the wireless communication network to control CA used by wireless relays and UEs. 
         FIG. 3  illustrates a Long Term Evolution (LTE) communication network to control CA used by wireless relays and UEs. 
         FIG. 4  illustrates the operation of the LTE communication network to control CA used by wireless relays and UEs. 
         FIG. 5  illustrates the operation of the LTE communication network to control CA used by wireless relays and UEs. 
         FIG. 6  illustrates the operation of the LTE communication network to control CA used by wireless relays and UEs. 
         FIG. 7  illustrates a wireless relay to control CA used by UEs. 
         FIG. 8  illustrates a macrocell base station to control CA used by wireless relays and UEs. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates wireless communication network  100  to control Carrier Aggregation (CA) used by wireless relay  120  and User Equipment (UEs)  111 - 113  and  121 - 123 . Wireless communication network  100  comprises macrocell base station  110  and wireless relay  120 . Macrocell base station  110  serves a first set of UEs  111 - 113  by delivering user data services like media conferencing, Internet access, user messaging, and data transfers. Wireless relay  120  serves a second set of UEs  121 - 123  by delivering these user data services. Macrocell base station  110  serves wireless relay  120  by delivering relay data services like network signaling and relay data tunneling. Wireless relay  120  may also serve other wireless relays with these relay data services. 
     Macrocell base station  110  comprises antennas, radio heads, baseband units, controllers, and network interfaces. One exemplary base station is a Long Term Evolution (LTE) evolved Node B (eNodeB). Wireless relay  120  comprises antennas, radio heads, baseband units, and controllers. Wireless relay  120  may be an LTE femtocell, picocell, or some other LTE data hub. UEs  111 - 113  and  121 - 123  comprise phones, computers, servers, or some other machines with intelligent communication transceivers. 
     Macrocell base station  110  wirelessly broadcasts a relay network identifier (ID) and a macro network ID. The network IDs are typically Public Land Mobile Network (PLMN) IDs, but other identifying codes could be used like Access Point Names (APNs), Quality-of-Service (QoS) Class IDs (QCIs), Service Set IDs (SSIDs), and Uniform Resource Indicators (URIs)—including combinations thereof. 
     Likewise, wireless relay  120  wirelessly broadcasts a relay network ID and a macro network ID. UEs  111 - 113  attach to macrocell base station  110  and UEs  121 - 123  attach to wireless relay  120  in response to the macro network ID broadcasts. Wireless relay  120  attaches to macrocell base station  110  in response to the relay network ID broadcast. Other wireless relays may attach to macrocell base station  110  or wireless relay  120  in response to the relay network ID broadcasts. 
     Macrocell base station  110  uses CA to serve UEs  111 - 113  on the Downlink (DL) and/or the Uplink (UL). Macrocell base station  110  turns this macro network CA on and off based on base station loading. Macrocell base station  110  also uses CA to serve wireless relay  120  on the DL and/or the UL. Macrocell base station  110  typically leaves this relay network CA on—although it could be turned off if necessary. 
     Wireless relay  120  uses CA to serve UEs  121 - 123  on the DL and/or the UL. Macrocell base station  110  turns this macro network CA on and off at relay  120  based on its own base station  110  loading. Wireless relay  120  may use CA to serve other wireless relays on the DL and/or the UL. Macrocell base station  110  typically leaves this relay network CA on—although it could be turned off if necessary. 
     Macrocell base station  110  determines its loading by radio conditions, UE numbers, relay numbers, bandwidth, memory usage, processing capacity, and the like. Macrocell base station  110  compares the loading to one or more thresholds to determine if macro network CA should be turned off and where. For example, macrocell base station  110  may compare its total UE number (all downstream UEs) to a maximum number and begin to selectively turn CA off until UE numbers subside. 
     To turn off the macro network CA at wireless relay  120 , macrocell base station  110  transfers an instruction to wireless relay  120  indicating that CA should be terminated for the macro network ID. In response to the instruction, wireless relay  120  terminates CA for UEs  121 - 123 . The instruction may traverse a link like Radio Resource Control (RRC), System Information Block (SIB), X2, and the like. Wireless relay  120  and macrocell base station  120  continue to use CA for the relay network ID. 
     Macrocell base station  110  may use various approaches to terminating the CA. For example, base station  110  may initially stop CA for the first set of UEs  111 - 113  but leave CA on for the second set of UEs  121 - 123 . Macrocell base station  110  then determines if the CA threshold is still exceeded. If the CA threshold is no longer exceeded, then the process may await further changes. If the CA threshold is no longer exceeded, then base station  110  transfers the instruction to wireless relay  120  to terminate CA for the second set of UEs  121 - 123 . In a reciprocal manner, macrocell base station  111  may first stop CA at UEs  121 - 123 , check the CA threshold, and then stop CA at relay  120  if needed. In a relay cascade, the base station may stop CA in a forward or reverse progression through the cascade. 
       FIG. 2  illustrates the operation of wireless communication network  100  to control DL CA used by wireless relay  120  and UEs  111 - 113  and  121 - 123 . Macrocell base station  110  wirelessly broadcasts a relay network ID. Wireless relay  120  attaches to macrocell base station  110  in response to the relay network ID broadcast, and other wireless relays may attach to macrocell base station  110  in response to the relay network ID broadcast. Wireless relay  120  wirelessly broadcasts a macro network ID. UEs  111 - 121  attach to macrocell base station  110  in response to the macro network ID broadcast. Other UEs may attach to wireless relay  120  in response to the macro network ID broadcast. Macrocell base station  110  exchanges user data with various systems. Macrocell base station  110  exchanges some of the user data with UEs  111 - 113  using DL CA. Macrocell base station  110  exchanges some of the user data wireless relay  120  using DL CA. Wireless relay  120  exchanges this user data with UEs  121 - 123  using DL CA. 
     Macrocell base station  110  compares its load metrics to one or more thresholds to determine if macro DL CA should be turned off. In this example, a base station CA ACK threshold is exceeded, so macrocell base station  110  transfers an instruction to wireless relay  120  to turn off DL CA for the macro network ID. Macrocell base station  110  then exchanges additional user data with the external systems. Macrocell base station  110  and UEs  111 - 113  now exchange user data without using DL CA. Macrocell base station  110  still exchanges some of the user data with wireless relay  120  using DL CA. Wireless relay  120  and UEs  121 - 123  now exchange user data without using DL CA. Macrocell base station  110  will continue to compare its metrics to the thresholds to determine if macro DL CA should be turned on. If DL CA should be turned on, then macrocell base station  110  transfers an instruction to wireless relay  120  to turn DL CA back on for the macro network ID. 
       FIG. 3  illustrates Long Term Evolution (LTE) Network  300  to control CA at various eNodeBs—including the eNodeBs that are resident in wireless relays. LTE Network  300  is an example of data communication network  100 , although network  100  may use alternative configurations and operations. LTE network  300  comprises: UEs  1 - 4 , Relay Equipment (REs)  1 - 3 , macro eNodeB, Serving Gateway (S-GW), Mobility Management Entity (MME), Home Subscriber System (HSS), Packet Data Network Gateway (P-GW), and Policy Charging and Rules Function (PCRF). RE  2  comprises an eNodeB and a UE that are coupled over a communication system like Ethernet. REs  1  and  3  would be similar. 
     The macro eNodeB broadcasts a macro PLMN ID, and in response, UEs  1 - 2  attach to the macro eNodeB. The eNodeBs in REs  1 - 3  also broadcast a macro PLMN ID, and in response, UEs  3 - 4  attach to the eNodeB in RE  2 . Additional UEs (not shown) attach to REs  1  and  3 . The macro eNodeB broadcasts a relay PLMN ID, and in response, REs  1 - 2  attach to the macro eNodeB. The eNodeBs in REs  1 - 3  also broadcast a relay PLMN ID, and in response, RE  3  attaches to RE  2 . Additional REs (not shown) attach to REs  1  and  3 . 
     UEs  1 - 2  and the macro eNodeB communicate using LTE RRC and DL CA. REs  1 - 2  and the macro eNodeB communicate using LTE RRC and DL CA. UEs  3 - 4  and RE  2  communicate using LTE RRC and DL CA. RE  3  and RE  2  communicate using LTE RRC and DL CA. The macro eNodeB and the MME communicate over an S1-MME link. The macro eNodeB and the S-GW communicate over 51-U links. The S-GW and the P-GW communicate over S5 links. The S-GW and the MME communicate over an S11 link. The MME and the HSS communicate over an S6 link. The P-GW and the PCRF communicate over a Gx link. 
     The macro eNodeB determines its loading by radio conditions, UE numbers, RE numbers, bandwidth, memory usage, processing capacity, and the like. The macro eNodeB compares the loading to multiple thresholds to determine if macro network DL CA should be turned off and where. For example, the macro eNodeB may compare its total RE numbers (all downstream relays) to a maximum number and begin to selectively turn DL CA off at various relays until the RE numbers subside. 
     To turn off macro network DL CA, the macro eNodeB transfers an instruction to RE  3  indicating that DL CA should be terminated for the macro PLMN ID. In response to the instruction, RE  3  terminates DL CA for its UEs (not shown). The instruction may traverse an X2 link between the macro eNodeB and the eNodeB in RE  3 . If the macro eNodeB threshold is still exceeded, then the macro eNodeB transfers an instruction to REs  1 - 2  indicating that DL CA should be terminated for the macro PLMN ID. In response to the instruction, RE  1  terminates DL CA for its UEs (not shown), and RE  2  terminates CA for UEs  3 - 4 . The instructions traverse X2 or RRC links between the macro eNodeB and REs  1 - 2 . If the macro eNodeB threshold is still exceeded, then the eNodeB transfers instructions to other REs indicating that CA should be terminated for the macro PLMN ID. If the eNodeB threshold is still exceeded, then the macro eNodeB terminates DL CA for UEs  1 - 2 . 
     In this example, the macro eNodeB shuts down DL CA at distant relays first and then shuts down CA at relays closer to the macro eNodeB. Finally, the macro eNodeB shuts down its own DL CA. Other progressions could be used. If the eNodeB threshold is still exceeded, then the eNodeB may even transfer instructions to REs  1 - 3  indicating that DL CA should be terminated for the relay PLMN ID. 
     To restart macro network CA, the macro eNodeB restarts DL CA with UEs  1 - 2 . The macro eNodeB transfers instructions to REs  1 - 3  indicating that DL CA should be re-started for the macro PLMN ID. In response to the instruction, REs  1 - 3  resume CA for their UEs. Various restart progressions could be used. 
       FIGS. 4-6  illustrate the operation of LTE Network  300  to control CA at various eNodeBs. The macro eNodeB broadcasts a macro PLMN ID and a relay PLMN ID. RE  2  broadcasts a macro PLMN ID and a relay PLMN ID. RE  3  also broadcasts a macro PLMN ID and a relay PLMN ID. In response to the macro PLMN ID, UE  1  attaches to the macro eNodeB. In response to the relay PLMN ID, RE  2  attaches to the macro eNodeB. In response to the relay PLMN ID, RE  3  attaches to RE  2 . In response to the macro PLMN ID, UE  4  attaches to RE  2 . In response to the relay PLMN ID, another RE attaches to the RE  3 . In response to the macro PLMN ID, another UE attaches to the RE  3 . 
     Referring to  FIG. 5 , the macro eNodeB exchanges user data using DL CA with UE  1 . The macro eNodeB exchanges user data using DL CA with RE  2 . RE  2  exchanges user data using DL CA with RE  3  and UE  4 . RE  3  exchanges user data using DL CA with another RE and UE. The macro eNodeB determines its loading by UE and RE numbers, although other factors could be considered. The macro eNodeB compares the RE/UE load to number thresholds to determine if macro network DL CA should be turned off and where. 
     In this example, macro eNodeB determines that it will initially terminate DL CA for the UEs it serves. The macro eNodeB now exchanges user data with UE  1  without using DL CA. The macro eNodeB and RE  2  still exchange user data using DL CA. RE  2  and RE  3  exchange user data with DL CA. RE  3  and UE  4  exchange user data using DL CA. RE  3  exchanges user data using DL CA with another RE and UE. 
     Referring to  FIG. 6 , the macro eNodeB continues to compare its loading to thresholds, and in this example, the macro eNodeB determines that it will now terminate CA for the UEs that are served by RE  2 . The macro eNodeB transfers an instruction to RE  2  to terminate DL CA to for the macro PLMN ID. The macro eNodeB still exchanges user data with UE  1  without using DL CA. The macro eNodeB still exchanges user data with RE  2  with DL CA. RE  2  and RE  3  still exchange user data with DL CA. RE  2  and UE  4  now exchange user data without using DL CA. RE  3  exchanges user data with another RE and UE using DL CA. 
     The macro eNodeB continues to compare loading to thresholds, and in this example, the macro eNodeB determines that it will now terminate CA for the UEs that are served by RE  3 . The macro eNodeB transfers an instruction to RE  3  to terminate DL CA to for the macro PLMN ID. The macro eNodeB exchanges user data with UE  1  without DL CA. The macro eNodeB exchanges user data with RE  2  with DL CA. RE  2  and RE  3  exchange user data with DL CA. RE  2  and UE  4  exchange user data without using DL CA. RE  3  exchanges user data with the other RE using DL CA, however, RE  3  now exchanges user data with the other UE without DL CA. 
       FIG. 7  illustrates wireless relay  700  to control CA. Wireless relay  700  comprises data communication interface  701  and data processing system  702 . Data communication interface  701  comprises communication transceivers  711 - 713 . Data processing system  702  comprises processing circuitry  703  and storage system  704 . Storage system  704  stores software  705 . Software  705  includes respective software modules  706 - 709 . 
     Communication transceivers  711 - 713  comprise pilot transceiver  711 , UE Radio Resource Control (RRC) transceiver  712 , and network RRC transceiver  713 . Pilot transceiver  711  broadcasts one or more macro network IDs and relay network IDs. Communication transceivers  711 - 713  include communication components, such as antennas, amplifiers, filters, modulators, bus interfaces, signal processors, baseband controllers, memory, software, and the like. Processing circuitry  703  comprises circuit boards, bus interfaces, integrated micro-processing circuitry, and associated electronics. Storage system  704  comprises non-transitory, machine-readable, data storage media, such as flash drives, disc drives, memory circuitry, servers, and the like. Software  705  comprises machine-readable instructions that control the operation of processing circuitry  703  when executed. 
     Software  705  includes software modules  706 - 709  and may also include operating systems, hypervisors, applications, data structures, virtual network elements, utilities, and the like. Wireless relay  700  may be centralized or distributed. All or portions of software  706 - 709  may be externally stored on one or more storage media, such as circuitry, discs, and the like. Some conventional aspects of wireless relay  700  are omitted for clarity, such as power supplies, enclosures, and the like. 
     When executed by processing circuitry  703 , software modules  706 - 709  direct circuitry  703  to perform the following operations. UE modules  706  interact with UEs and relays over UE RRC transceiver  712 —typically using CA. Network modules  707  interact with wireless base stations and relays over network RRC transceiver  713 —typically using CA. User data modules  708  exchange user data and associated control signaling between UE modules  706  and Network modules  707 . CA modules  709  perform threshold analysis and interact with UE modules  706  and network modules  707  to drive RRC transceivers  712 - 713  to use CA and to implement CA on/off instructions. 
       FIG. 8  illustrates macrocell base station  800  to control CA at wireless relays. Macrocell base station  800  comprises data communication interface  801  and data processing system  802 . Data communication interface  801  comprises communication transceivers  811 - 813 . Data processing system  802  comprises processing circuitry  803  and storage system  804 . Storage system  804  stores software  805 . Software  805  includes respective software modules  806 - 809 . 
     Communication transceivers  811 - 813  comprise pilot transceiver  811 , Radio Resource Control (RRC) transceiver  812 , and network transceiver  813 . Pilot transceiver  811  broadcasts one or more macro network IDs and relay network IDs. Communication transceivers  811 - 813  include communication components, such as antennas, ports, amplifiers, filters, modulators, bus interfaces, signal processors, baseband controllers, memory, software, and the like. Processing circuitry  803  comprises circuit boards, bus interfaces, integrated micro-processing circuitry, and associated electronics. Storage system  804  comprises non-transitory, machine-readable, data storage media, such as flash drives, disc drives, memory circuitry, servers, and the like. Software  805  comprises machine-readable instructions that control the operation of processing circuitry  803  when executed. 
     Software  805  includes software modules  806 - 809  and may also include operating systems, hypervisors, applications, data structures, virtual network elements, utilities, and the like. Macrocell base station  800  may be centralized or distributed. All or portions of software  806 - 809  may be externally stored on one or more storage media, such as circuitry, discs, and the like. Some conventional aspects of macrocell base station  800  are omitted for clarity, such as power supplies, enclosures, and the like. 
     When executed by processing circuitry  803 , software modules  806 - 809  direct circuitry  803  to perform the following operations. UE modules  806  interact with UEs and relays over RRC transceiver  812 —typically using CA. Network modules  807  interact with network gateways and controllers over network transceiver  813 . User data modules  808  exchange user data and associated control signaling between UE modules  806  and Network modules  807 . CA modules  809  perform threshold analysis and interact with UE modules  806  to drive RRC transceiver  812  to use CA and to implement CA on/off instructions. 
     The above description and associated figures teach the best mode of the invention. The following claims specify the scope of the invention. Note that some aspects of the best mode may not fall within the scope of the invention as specified by the claims. Those skilled in the art will appreciate that the features described above can be combined in various ways to form multiple variations of the invention. As a result, the invention is not limited to the specific embodiments described above, but only by the following claims and their equivalents.