PATENT DOCUMENT

Publication Number: US-12096330-B2
Application Number: US-202117441389-A
Country: US
Kind Code: B2

Title: Quality of service (QOS) enhancement for a side-link relay

Abstract:
An approach is described for a user equipment (UE) comprising a transceiver configured to enable wireless communication with a second UE and a wireless device and a processor communicatively coupled to the transceiver. The processor is configured receive, from the second UE, an end-to-end (E2E) quality of service (QoS) requirement of an E2E connection between the second UE and the wireless device, wherein the E2E connection includes a first hop between the UE and the second UE and a second hop between the UE and the wireless device. The processor is further configured to obtain a first hop link condition and a second hop link condition; split the E2E QoS requirement into a first hop QoS requirement and a second hop QoS requirement based on the first hop link condition and the second hop link condition; and transmit, using the transceiver, the first hop QoS requirement to the second UE. The wireless device is a third UE or a base station.

Claims:
What is claimed is: 
     
       1. A user equipment (UE) comprising:
 a transceiver configured to enable wireless communication with a second UE and a wireless device; and 
 a processor, communicatively coupled to the transceiver, and configured to:
 receive, from the second UE, an end-to-end (E2E) quality of service (QOS) requirement of an E2E connection between the second UE and the wireless device, wherein the E2E connection includes a first hop between the UE and the second UE and a second hop between the UE and the wireless device; 
 obtain a first hop link condition and a second hop link condition; 
 split the E2E QOS requirement into a first hop QoS requirement and a second hop QOS requirement based on the first hop link condition and the second hop link condition; and 
 transmit, using the transceiver, the first hop QoS requirement to the second UE, 
 wherein the wireless device is a third UE or a base station. 
 
 
     
     
       2. The UE of  claim 1 , wherein the processor is further configured to split the E2E QOS requirement by:
 transmitting the first hop link condition and the second hop link condition to the base station; 
 transmitting the E2E QOS requirement to the base station; and 
 receiving the first hop QoS requirement and the second hop QOS requirement from the base station. 
 
     
     
       3. The UE of  claim 1 , wherein the processor is further configured to:
 receive a QoS enforcement configuration from the base station, 
 wherein the QoS enforcement configuration includes an indication of enabling or disabling splitting the E2E QOS requirement, and 
 wherein the QoS enforcement configuration further includes a splitting table. 
 
     
     
       4. The UE of  claim 3 , wherein the processor is further configured to split the E2E QOS requirement by accessing the splitting table based on the first hop link condition and the second hop link condition. 
     
     
       5. The UE of  claim 1 , wherein the processor is further configured to:
 receive a packet from the second UE; 
 determine a first hop QoS status based on the packet; 
 adjust the second hop QoS requirement based on the first hop QoS status; 
 allocate communication resources to the second hop based on the adjusted second hop QoS requirement; and 
 forward the packet to the wireless device based on the adjusted second hop QoS requirement using the communication resources. 
 
     
     
       6. The UE of  claim 5 , wherein the processor is further configured to adjust the second hop QoS requirement by:
 determining a remaining QoS requirement based on a difference between the first hop QoS status and the E 2 E QOS requirement; and 
 adjusting the second hop QoS requirement based on the remaining QoS requirement. 
 
     
     
       7. The UE of  claim 5 , wherein the processor is further configured to allocate the communication resources by:
 determining the communication resources based on the adjusted second hop QoS requirement; 
 sending a resource request indicating the communication resources to the base station; 
 receiving a resource allocation confirmation from the base station; and 
 allocating the communication resources to the second hop based on the resource allocation confirmation. 
 
     
     
       8. The UE of  claim 5 , wherein the processor is further configured to allocate the communication resources by:
 determining the communication resources based on the adjusted second hop QoS requirement; and 
 allocating the communication resources to the second hop. 
 
     
     
       9. A method of operating a user equipment (UE) as a relay between a base station and a second UE, the method comprising:
 obtaining a link condition of a second hop between the UE and the second UE of an end-to-end (E2E) connection, wherein the first hop of the E2E connection is between the base station and the UE; 
 transmitting the link condition of the second hop to the base station; and 
 receiving, from the base station, a second hop quality of service (QOS) requirement. 
 
     
     
       10. The method of  claim 9 , further comprising:
 receiving, from the base station, an E2E QOS requirement of the E2E connection between the base station and the second UE. 
 
     
     
       11. The method of  claim 10 , further comprising:
 receiving a packet from the base station; 
 determining a first hop QoS status based on the packet; 
 adjusting the second hop QoS requirement based on the first hop QoS status and the E2E QOS requirement; 
 allocating communication resources to the second hop based on the adjusted second hop QoS requirement; and 
 forwarding the packet to the second UE based on the adjusted second hop QoS requirement using the communication resources. 
 
     
     
       12. The method of  claim 11 , wherein the adjusting the second hop QOS requirement further comprises:
 determining a remaining QoS requirement based on a difference between the first hop QoS status and the E2E QOS requirement; and 
 adjusting the second hop QOS requirement based on the remaining QoS requirement. 
 
     
     
       13. The method of  claim 12 , wherein the allocating the communication resources further comprises:
 determining the communication resources based on the adjusted second hop QoS requirement; 
 sending a resource request indicating the communication resources to the base station; 
 receiving a resource allocation confirmation from the base station; and 
 allocating the communication resources to the second hop based on the resource allocation confirmation. 
 
     
     
       14. The method of  claim 12 , wherein the allocating the communication resources further comprises:
 determining the communication resources based on the adjusted second hop QoS requirement; and 
 allocating the communication resources to the second hop. 
 
     
     
       15. The method of  claim 9 ,
 wherein the second hop is a side-link connection, and 
 wherein the link condition includes a channel busy ratio (CBR) or a side-link reference signal received power (SL-RSRP). 
 
     
     
       16. A base station configured to serve a user equipment (UE) that is configured to provide a relay between a second UE and a wireless device, wherein an end-to-end (E2E) connection between the second UE and the wireless device includes a first hop between the second UE and the UE and a second hop between the UE and the wireless device, the base station comprising:
 a transceiver configured to enable wireless communication with the UE; and 
 a processor, communicatively coupled to the transceiver, and configured to:
 generate a quality of service (QOS) enforcement configuration; and 
 transmit the QoS enforcement configuration to the UE, 
 wherein the QoS enforcement configuration includes an indication of enabling or disabling the UE to split an E2E QoS requirement associated with the E2E connection. 
 
 
     
     
       17. The base station of  claim 16 , wherein the QoS enforcement configuration includes a splitting table. 
     
     
       18. The base station of  claim 16 , wherein the QoS enforcement configuration further includes a first hop QoS requirement and a second hop QOS requirement. 
     
     
       19. The base station of  claim 16 , wherein the wireless device is the base station, and the processor is further configured to:
 receive the E2E QOS requirement from the UE; 
 receive a first hop link condition from the UE; 
 determine a second hop link condition; 
 split the E2E QOS requirement into a first hop QoS requirement and a second hop QoS requirement based on the first hop link condition and the second hop link condition; and 
 transmit the first hop QoS requirement and the second hop QoS requirement to the UE.

Description:
This application is a U.S. National Phase of International Application No. PCT/CN2021/084512, filed Mar. 31, 2021, which is hereby incorporated by reference in its entirety. 
     BACKGROUND 
     Field 
     The described aspects generally relate to an enhancement on a quality of service (QoS) for side-link relay. 
     SUMMARY 
     Some aspects of this disclosure relate to apparatuses and methods for implementing a quality of service (QoS) enhancement for a side-link relay for 3rd Generation Partnership Project (3GPP) release 15 (Rel-15), release 16 (Rel-16), release 17 (Rel-17), and/or other 3GPP releases that support QoS splitting. For example, systems and methods are provided for implementing splitting an end-to-end QoS requirement based on link conditions. 
     Some aspects of this disclosure relate to a user equipment (UE) comprising a transceiver configured to enable wireless communication with a second UE and a wireless device and a processor communicatively coupled to the transceiver. The processor is configured receive, from the second UE, an end-to-end (E2E) quality of service (QoS) requirement of an E2E connection between the second UE and the wireless device, wherein the E2E connection includes a first hop between the UE and the second UE and a second hop between the UE and the wireless device. The processor is further configured to obtain a first hop link condition and a second hop link condition; split the E2E QoS requirement into a first hop QoS requirement and a second hop QoS requirement based on the first hop link condition and the second hop link condition; and transmit, using the transceiver, the first hop QoS requirement to the second UE. The wireless device is a third UE or a base station. 
     Some aspects of this disclosure relate to a method of operating operating a user equipment (UE) as a relay between a base station and a second UE. The method comprise obtaining a link condition of a second hop between UE and the second UE of an end-to-end (E2E) connection, wherein the first hop of the end-to-end (E2E) connection is between the base station and the UE. The method further comprises transmitting the link condition of the second hop to the base station and receiving, from the base station, a second hop quality of service (QoS) requirement. 
     Some aspects of this disclosure relate to a base station configured to serve a user equipment (UE) that is configured to provide a relay between a second UE and a wireless device, wherein an end-to-end (E2E) connection between the second UE and the wireless device includes a first hop between the second UE and the UE and a second hop between the UE and the wireless device, the base station comprising. The base station comprises a transceiver configured to enable wireless communication with the UE; and a processor, communicatively coupled to the transceiver. The processor is configured to generate a quality of service (QoS) enforcement configuration and transmit the QoS enforcement configuration to the UE. The QoS enforcement configuration includes an indication of enabling or disabling the UE to split an E2E QoS requirement associated with the E2E connection. 
     This Summary is provided merely for purposes of illustrating some aspects to provide an understanding of the subject matter described herein. Accordingly, the above-described features are merely examples and should not be construed to narrow the scope or spirit of the subject matter in this disclosure. Other features, aspects, and advantages of this disclosure will become apparent from the following Detailed Description, Figures, and Claims. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The accompanying drawings, which are incorporated herein and form part of the specification, illustrate the present disclosure and, together with the description, further serve to explain the principles of the disclosure and enable a person of skill in the relevant art(s) to make and use the disclosure. 
         FIG.  1    illustrates an example system implementing a quality of service (QoS) enhancement for a side-link relay, according to some aspects of the disclosure. 
         FIG.  2    illustrates a block diagram of an example system of an electronic device for the QoS enhancement, according to some aspects of the disclosure. 
         FIG.  3 A  illustrates an example of a side-link relay system connecting a user device (UE) and a base station, according to some aspects of the disclosure. 
         FIG.  3 B  illustrates an example of a side-link relay system connecting two UEs, according to aspects of the disclosure. 
         FIGS.  4 A and  4 B  illustrate an example method for assigning per-hop QoS based on instructions from a base station and adjusting communication resources, according to aspects of the disclosure. 
         FIGS.  5 A and  5 B  illustrate an example method for assigning per-hop QoS by a relay UE and adjusting communication resources, according to aspects of the disclosure. 
         FIG.  6    illustrates an example system for logical channel prioritization according to aspects of the disclosure. 
         FIG.  7    illustrates an example of a side-link relay system comprising a plurality of hops, according to aspects of the disclosure. 
         FIG.  8    is an example computer system for implementing some aspects of the disclosure or portion(s) thereof. 
     
    
    
     The present disclosure is described with reference to the accompanying drawings. In the drawings, generally, like reference numbers indicate identical or functionally similar elements. Additionally, generally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears. 
     DETAILED DESCRIPTION 
     Some aspects of this disclosure include apparatuses and methods for implementing a quality of service (QoS) enhancement for a side-link relay for 3rd Generation Partnership Project (3GPP) release 15 (Rel-15), release 16 (Rel-16), release 17 (Rel-17), and/or other 3GPP releases. For example, systems and methods are provided for implementing designs for splitting an end-to-end QoS requirement based on link conditions. 
     According to some aspects, a user equipment (UE) that operates according to Release 15 (Rel-15), Release 16 (Rel-16), and/or Release 17 (Rel-17) and New Radio (NR) of 5 th  generation (5G) wireless technology for digital cellular networks as defined by 3rd Generation Partnership Project (3GPP) may support side-link connections with other UEs directly without connecting to a base station. For example, the UE connects with a second UE directly via a side-link connection. The UE also connects with a base station via a direct communication link, such as a Uu link. In some aspects, the second UE may be on a cell boundary of the base station or in a location not covered by the base station. The second UE may experience severe fading effects or interferences from other devices. In other words, the second UE is not able to connect with the base station directly. In some aspects, the UE relays packets between the second UE and the base station. For example, the second UE transmits a packet to the UE and the UE forwards the packet to the base station. The base station also transmits a packet to the second UE via the UE. In such a case, the second UE connects with the base station indirectly via the UE. 
     According to some aspects, the second UE connects with a third UE via the UE. For example, the UE connects with the third UE via a side-link connection. The second UE can transmit a packet to the UE, which forwards the packet to the third UE. In such a case, the second UE connects with the third UE indirectly via the UE. 
     According to some aspects, the second UE, the base station, and the third UE transmit packets with QoS requirements. For example, the QoS requirements include a priority, a packet delay budget (PDB), a packet error rate (PER), and others. A packet with a PDB of 10 ms is expected to be delivered to a destination within 10 ms. A packet may include a plurality of sub-packets. The packet is expected to have less than 10 −2  PER at the destination if the QoS requirements include a PER of 10 −2 . In some aspects, the QoS requirements also include a bit error rate (BER) and/or a symbol error rate (SER). 
     In some aspects, the base station assigns communication resources to a UE based on QoS requirements. For example, the UE transmits its QoS requirements to the base station, which assigns communication resources to the UE. The communication resources include bandwidth resources, scheduling resources, code resources, spatial resources, and others. The scheduling resources relate to a PDB requirement because the UE can schedule a packet transmission within the PDB with the scheduling resources. The bandwidth resources, the code resources, and the spatial resources relate to a PER requirement. However, for indirect connections, the communication resources may not be assigned properly. For example, the second UE determines an end-to-end (E2E) QoS requirement for the indirect connection between the second UE and the base station. The indirect connection includes the side-link connection between the second UE and the UE and the Uu link connection between the UE and the base station. The base station assigns communication resources to the UE, but not the second UE because the second UE locates outside a range of the base station. In addition, the second UE connects with the UE via the side-link connection directly, not via any base stations. 
     According to some aspects, the UE connects with a fourth UE. Similar to the second UE, the fourth UE connects with the base station via the UE indirectly. The UE multiplexes packets received from the second and the fourth UE and forwards them to the base station. In some aspects, the UE multiplexes the packets based on channel priorities. For example, the second UE transmits to the UE via a first channel and the fourth UE transmits to the UE via a second channel. The first channel has a higher priority than the second channel. In such a case, the UE prioritizes packets received via the first channel over packets received via the second channel. In some aspects, the first channel and the second channel have a same priority. In such a case, the UE prioritizes packets based on QoS statuses. For example, a first packet received via the first channel arrives at the UE with a 10 ms delay, while a second packet received via the second channel arrives at the UE on time. The UE prioritizes the first packet because the first packet has a more urgent latency. 
       FIG.  1    illustrates an example system  100  implementing designs of splitting an end-to-end QoS requirement based on link conditions, according to some aspects of the disclosure. Example system  100  is provided for the purpose of illustration only and does not limit the disclosed aspects. System  100  may include, but is not limited to, a base station  102 , such as a gNB, a UE  104 , a UE  106 , and a UE  108 . The UEs  104 ,  106 , and  108  may be implemented as electronic devices configured to operate based on a wide variety of wireless communication techniques. These techniques may include, but are not limited to, techniques based on 3rd Generation Partnership Project (3GPP) standards. For example, the UEs  104 ,  106 , and  108  may include electronic devices configured to operate using one or more 3GPP releases, such as Release 15 (Rel-15), Release 16 (Rel-16), Release 17 (Rel-17), or other 3GPP releases. The UEs  104 ,  106 , and  108  may include, but is not limited to, wireless communication devices, smartphones, laptops, desktops, tablets, personal assistants, monitors, televisions, wearable devices, Internet of Things (IoT) devices, vehicle communication devices, and the like. The base station  102  may include one or more nodes configured to operate based on a wide variety of wireless communication techniques such as, but not limited to, techniques based on 3GPP standards. For example, the base station  102  may include nodes configured to operate using Rel-15, Rel-16, Rel-17, or other 3GPP releases. In some aspects, the UE  104  is in a cell coverage of the base station  102  and connects with the base station  102  via a communication link  110 . The communication link  110  may be a Uu link. The UE  106  and the UE  108  locate outside the cell coverage of the base station  102 . For example, the UE  106  and the UE  108  may locate on a cell boundary of the base station  102  or in a location far away from the base station  102 . The UE  106  and the UE  108  may experience severe fading effects or interferences from other devices. Therefore, the UE  106  and the UE  108  cannot connect with the base station  102  directly. 
     According to some aspects, the UE  106  and the UE  108  connect with the UE  104  directly via a communication link  114  and a communication link  112 , respectively. The communication links  114  and  112  may be side-link connections. In some aspects, the UE  106  and the UE  108  can connect with the base station  102  indirectly via the UE  104 . For example, the UE  106  transmits a packet to the UE  104 , which forwards the packet to the base station  102 . The base station  102  transmits a second packet to the UE  104 , which forwards the second packet to the UE  106 . In other words, the UE  106  connects with the base station  102  via a two-hop connection, wherein the communication link  114  is a first hop and the communication link  110  is a second hop. 
     According to some aspects, the two-hop connection has one or more E2E QoS requirements. For example, the one or more E2E QoS requirements include a priority, a packet delay budget (PDB), a packet error rate (PER), and others. A packet with a PDB of 10 ms is expected to be delivered to a destination within 10 ms. A packet may include a plurality of sub-packets. The packet is expected to have less than 10 −2  PER at the destination if the one or more E2E QoS requirements include a PER of 10 −2 . In some aspects, the one or more E2E QoS requirements also include a bit error rate (BER) and/or a symbol error rate (SER). Because the two-hop connection includes the first and the second hops, transmissions of the first and the second hop needs to satisfy the one or more E2E QoS requirements. For example, the one or more E2E QoS requirements include a PDB of 100 ms. Therefore, a total transmission time of the first and the second hops needs to be less than 100 ms. 
     According to some aspects, the UE  104  splits each of the one or more E2E QoS requirements into two parts: a first hop QoS requirement corresponding to the communication link  114  and a second hop QoS requirement corresponding to the communication link  110 . In some aspects, the base station  102  splits the one or more E2E QoS requirements and transmits the firs hop and the second hop QoS requirements to the UE  104  and the UE  106 . 
     In some aspects, the UE  104  splits the one or more E2E QoS requirements with a constant ratio. For example, the UE  104  splits the E2E QoS requirement to the first hop QoS requirement and the second hop QoS requirement equally in embodiments. Alternatively, the UE  104  splits the one or more E2E QoS requirements to the first hop and the second hop QoS requirements unequally, but the QoS requirement is still represented as a ratio. 
     In some aspects, side-link connections, such as the communication link  114 , are subject to channel resource sharing and congestions. It is more challenging for the side-link connections to fulfill a QoS requirement than for Uu links, such as the communication link  110 . This is because the side-links and the Uu links have different channel environments, communication resources, power constraints, congestion scenarios, and others. Therefore, the UE  104  or the base station  102  can splits the one or more E2E QoS requirements based on link conditions of the side-links and the Uu links. For example, the one or more E2E QoS requirements include a PDB of 100 ms. The UE  104  can assign 70 ms to the communication link  114  and assign 30 ms to the communication link  110  based on link conditions of the communication link  114  and the communication link  110 . The link conditions include a channel busy ratio (CBR), signal strengths such as a reference signal received power (RSRP) and a reference signal received quality (RSRQ), interference conditions, available communication resources, fading conditions, and others. 
     According to some aspects, the link conditions of the communication link  114  and the communication link  110  are subject to change over time. For example, the interference conditions change according to a number of nearby devices that perform transmission. The fading conditions change according to positions of the UE  106  and the UE  104 . The CBR changes according to a number of packets that require transmission. Therefore, the communication link  114  and the communication link  110  may not satisfy the first hop and the second hop QoS requirements previously assigned. In such as case, the UE  104  adjusts the QoS requirements based on updated link conditions. 
     In some aspects, the UE  104  can adjust the first hop and the second hop QoS requirements for individual packets. For example, after the UE  104  receives a packet from the UE  106 , the UE  104  determines a QoS status of the communication link  114 . The QoS status indicates that the communication link  114  outperforms or underperforms the first hop QoS requirement. For example, referring to the previous example, the first hop QoS requirement is 70 ms, which means that the UE  104  needs to receive the packet within 70 ms after the UE  106  generates the packet. However, due to a change of the link condition of the communication link  114 , the UE  104  receives the packet at 80 ms. Therefore, the communication link  114  creates a 10 ms excess delay. If the second hop QoS requirement remains the same, the packet will arrive at the base station  102  with a 10 ms excess delay. 
     In some aspects, to compensate, the UE  104  adjusts the second hop QoS requirement based on the delay of the communication link  114 . For example, the UE  104  adjusts the second hop QoS requirement from 30 ms to 20 ms to mitigate the 10 ms excess. In such a case, if the communication link  110  fulfills the adjusted second hop QoS requirement, an E2E packet delivery time is 100 ms, which still satisfies the one or more E2E QoS requirements of 100 ms. 
     In some aspects, the UE  104  adjusts the second hop QoS requirement based on instructions of the base station  102 . For example, the UE  104  transmits the QoS status of the communication link  114  to the base station  102 . The base station  102  determines the adjusted second hop QoS requirement of the communication link  110  and transmits the adjusted second hop QoS requirement to the UE  104 . 
     In some aspects, the UE  104  adjusts communication resources of the communication link  110  to allow the communication link  110  to achieve the adjusted second hop QoS requirement. In some aspects, the adjusted second hop QoS requirement can be tighter than the second hop QoS requirement assigned previously. For example, referring to the example above, the UE  104  adjusts the second hop QoS requirement from 30 ms to 20 ms. The communication link  110  is required to deliver the packet in a shorter time. In such a case, the UE  104  schedules the packet for transmission in time frames that are sooner. In some aspects, the adjusted second hop QoS requirement can be looser than the second hop QoS requirement assigned previously. For example, the UE  104  adjusts the second hop QoS requirement from 30 ms to 40 ms. This is possible when the communication link  114  outperforms the first hop QoS requirement. In such a case, the UE  104  schedules the packet for transmission in time frames that are later. The UE  104  releases time frames that were originally assigned to the packet and can use the time frames to transmit other more packets. 
     According to some aspects, the UE  106  cannot connect with the UE  108  directly. For example, the UE  106  and the UE  108  are far away from each other. Because the UE  106  and the UE  108  both connect with the UE  104 , a two-hop connection via the UE  104  between the UE  106  and UE  108  is possible. For example, the UE  106  transmits a packet to the UE  104 , which forwards the packet to the UE  108 . Similar to the two-hop connection between the UE  106  and the base station  102  discussed above, the two-hop connection between the UE  106  and the UE  108  also has one or more E2E QoS requirements. The UE  104  can split the one or more E2E QoS requirements based on conditions of the communication link  114  and the communication link  112  in a similar way as discussed above. 
       FIG.  2    illustrates a block diagram of an example system  200  of an electronic device implementing a QoS enhancement for a side-link relay, according to some aspects of the disclosure. The system  200  may be any of the electronic devices (e.g., the base station  102  and the UEs  104 ,  106 , and  108 ) of the system  100 . The system  200  includes a processor  210 , one or more transceivers  220 , a communication infrastructure  240 , a memory  250 , an operating system  252 , an application  254 , and one or more antennas  260 . Illustrated systems are provided as exemplary parts of system  200 , and system  200  may include other circuit(s) and subsystem(s). Also, although the systems of system  200  are illustrated as separate components, the aspects of this disclosure may include any combination of these, e.g., less, or more components. 
     The memory  250  may include random access memory (RAM) and/or cache, and may include control logic (e.g., computer software) and/or data. The memory  250  may include other storage devices or memory. According to some examples, the operating system  252  may be stored in the memory  250 . The operating system  252  may manage transfer of data from the memory  250  and/or the one or more applications  254  to the processor  210  and/or the one or more transceivers  220 . In some examples, the operating system  252  maintains one or more network protocol stacks (e.g., Internet protocol stack, cellular protocol stack, and the like) that may include a number of logical layers. At corresponding layers of the protocol stack, the operating system  252  includes control mechanisms and data structures to perform the functions associated with that layer. 
     According to some examples, the application  254  may be stored in the memory  250 . The application  254  may include applications (e.g., user applications) used by wireless system  200  and/or a user of wireless system  200 . The applications in the application  254  may include applications such as, but not limited to. Siri™, FaceTime™, radio streaming, video streaming, remote control, and/or other user applications. 
     The system  200  may also include the communication infrastructure  240 . The communication infrastructure  240  provides communication between, for example, the processor  210 , the one or more transceivers  220 , and the memory  250 . In some implementations, the communication infrastructure  240  may be a bus. 
     The processor  210 , alone, or together with instructions stored in the memory  250  performs operations enabling system  200  of the system  100  to implement mechanisms for the QoS enhancement for the side-link relay, as described herein. Alternatively, or additionally, the processor  210  can be “hard coded” to implement mechanisms for the QoS enhancement for the side-link relay, as described herein 
     The one or more transceivers  220  transmit and receive communications signals support mechanisms for the QoS enhancement for the side-link relay. Additionally, the one or more transceivers  220  transmit and receive communications signals that support mechanisms for measuring communication link(s), generating and transmitting system information, and receiving the system information. According to some aspects, the one or more transceivers  220  may be coupled to antenna  260  to wirelessly transmit and receive the communication signals. Antenna  260  may include one or more antennas that may be the same or different types. The one or more transceivers  220  allow system  200  to communicate with other devices that may be wired and/or wireless. In some examples, the one or more transceivers  220  may include processors, controllers, radios, sockets, plugs, buffers, and like circuits/devices used for connecting to and communication on networks. According to some examples, the one or more transceivers  220  include one or more circuits to connect to and communicate on wired and/or wireless networks. 
     According to some aspects of this disclosure, the one or more transceivers  220  may include a cellular subsystem, a WLAN subsystem, and/or a Bluetooth™ subsystem, each including its own radio transceiver and protocol(s) as will be understood by those skilled in the arts based on the discussion provided herein. In some implementations, the one or more transceivers  220  may include more or fewer systems for communicating with other devices. 
     In some examples, the one or more the transceivers  220  may include one or more circuits (including a WLAN transceiver) to enable connection(s) and communication over WLAN networks such as, but not limited to, networks based on standards described in IEEE 802.11. 
     Additionally, or alternatively, the one or more the transceivers  220  may include one or more circuits (including a Bluetooth™ transceiver) to enable connection(s) and communication based on, for example, Bluetooth™ protocol, the Bluetooth™ Low Energy protocol, or the Bluetooth™ Low Energy Long Range protocol. For example, the transceiver  220  may include a Bluetooth™ transceiver. 
     Additionally, the one or more the transceivers  220  may include one or more circuits (including a cellular transceiver) for connecting to and communicating on cellular networks. The cellular networks may include, but are not limited to, 3G/4G/5G networks such as Universal Mobile Telecommunications System (UMTS), Long-Term Evolution (LTE), and the like. For example, the one or more transceivers  220  may be configured to operate according to one or more of Rel-15, Rel-16, Rel-17, or other releases of 3GPP standard. 
     As discussed in more detail below with respect to  FIGS.  3 - 8   , processor  210  may implement different mechanisms for the QoS enhancement for the side-link relay as discussed with respect to the system  100  of  FIG.  1   . 
       FIG.  3 A  illustrates an example system of a side-link relay system connecting a UE and a base station. Example system  300  is provided for the purpose of illustration only and does not limit the disclosed aspects. System  300  may include, but is not limited to, the UE  106 , the UE  104 , and the base station  102 . Similar to the discussion above, the UE  106  connects with the base station  102  via a two-hop connection  302 . The two-hop connection  302  includes a first hop  304  and a second hop  306 . 
     According to some aspects, the two-hop connection  302  has one or more E2E QoS requirements. For example, the one or more E2E QoS requirements include a priority, a PDB, a PER, and others. The first hop  304  and the second hop  306  also have one or more first hop QoS requirements and one or more second hop QoS requirements, respectively. A combination of the one or more first hop and second hop QoS requirements need to satisfy the one or more E2E QoS requirements. For example, the one or more E2E QoS requirements include a PDB of X 1  ms. The one or more first hop QoS requirements include a first PDB of X 1  ms and the one or more second hop QoS requirements include a second PDB of X 2  ms. To satisfy the PDB. X 1  and X 2  need to satisfy X 1 +X 2 ≤X. The one or more E2E QoS requirements may also include a PER of E. The one or more first hop QoS requirements include a first PER of E 1  and the one or more second hop QoS requirements include a second PER of E 2 . To satisfy the PER, E 1  and E 2  need to satisfy (1−E 1 )×(1−E 2 )≤(1−E). The one or more E 2 E QoS requirements may also include a priority of Y. The one or more first hop QoS requirements include a first priority of Y 1  and the one or more second hop QoS requirements include a second priority of Y 2 . To satisfy the priority, Y 2  needs to satisfy Y 2 ≤Y. Here, a lower priority value corresponds to a higher priority. 
     According to some aspects, the UE  104  determines the one or more first hop and second hop QoS requirements based on link conditions of the first hop  304  and the second hop  306 . For example, the link conditions include CBRs of the first hop  304  and the second hop  306 . A higher CBR value corresponds to a more severe congestion condition in a communication link. If a CBR of the first hop  304  is larger than a CBR of the second hop  306 , the UE  104  determines that the first PDB is larger than the second PDB, i.e., X 1 &gt;X 2 . This is because the first hop  304  is expected to experience a more severe congestion than the second hop  306 . Therefore, a looser QoS requirement of the PDB is assigned to the first hop  304 . In some aspects, the link conditions include signal strengths, such as an RSRP and an RSRQ, of the first hop  304  and the second hop  306 . A higher signal strength value may correspond to a higher signal-to-noise ratio (SNR) at a receiver side of a communication link. In addition, a higher SNR may correspond to a lower PER. If a signal strength of the first hop  304  is smaller than a signal strength of the second hop  306 , the UE  104  determines that the first PER is larger than the second PER, i.e., E 1 &gt;E 2 . This is because the PER of the first hop  304  is expected to be higher than the PER of the second hop  306 . Therefore, a looser QoS requirement of PER is assigned to the first hop  304 . 
     In some aspects, the UE  104  determines the one or more first hop and second hop QoS requirements proportionally to the link conditions. For example, the CBR of the first hop  304  is C 1  and the CBR of the second hop  306  is C 2 . The UE  104  determines that the 
     
       
         
           
             
               X 
               1 
             
             = 
             
               
                 
                   
                     
                       C 
                       1 
                     
                     ⁢ 
                     X 
                   
                   
                     
                       C 
                       1 
                     
                     + 
                     
                       C 
                       2 
                     
                   
                 
                 ⁢ 
                     
                 and 
                 ⁢ 
                     
                 
                   X 
                   2 
                 
               
               = 
               
                 
                   
                     
                       C 
                       2 
                     
                     ⁢ 
                     X 
                   
                   
                     
                       C 
                       1 
                     
                     + 
                     
                       C 
                       2 
                     
                   
                 
                 . 
               
             
           
         
       
     
     In some aspects, the UE  104  determines the one or more first hop and second hop QoS requirements based on a splitting table. The splitting table includes a plurality of dimensions. Each dimension corresponds to one kind of first hop and second hop QoS requirements. For example, Table 1 shown below corresponds to the PDB QoS requirements. If the first hop  304  has a CBR value of C 1 −3 and the second hop  306  has a CBR value of C 2 −4, the UE  104  determines that the first PDB of the first hop  304  is X 1 −34 and the second PDB of the second hop  306  is X 2 −34. In other words, the UE  104  determines the one or more first hop and second hop QoS requirements by accessing the splitting table. In some aspects, a CBR value may not be listed in the splitting table. For example, the first hop  304  has a CRB value C 1 −n, wherein C 1 −1&lt;C 1 −n&lt;C 1 −2. The second hop  306  has a CRB value C 2 −1. The UE  104  determines that the first PDB to be a value between X 1 −11 and X 1 −21 and the second PDB to be a value between X 2 −11 and X 2 −21. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Splitting Table. 
               
            
           
           
               
               
            
               
                 Second 
                 First hop 
               
            
           
           
               
               
               
               
               
               
            
               
                 hop 
                 C 1 -1 
                 C 1 -2 
                 C 1 -3 
                 C 1 -4 
                 C 1 -5 
               
               
                   
               
               
                 C 2 -1 
                 X 1 -11, X 2 -11 
                 X 1 -21, X 2 -21 
                 X 1 -31, X 2 -31 
                 X 1 -41, X 2 -41 
                 X 1 -51, X 2 -51 
               
               
                 C 2 -2 
                 X 1 -12, X 2 -12 
                 X 1 -22, X 2 -22 
                 X 1 -32, X 2 -32 
                 X 1 -42, X 2 -42 
                 X 1 -52, X 2 -52 
               
               
                 C 2 -3 
                 X 1 -13, X 2 -13 
                 X 1 -23, X 2 -23 
                 X 1 -33, X 2 -33 
                 X 1 -43, X 2 -43 
                 X 1 -53, X 2 -53 
               
               
                 C 2 -4 
                 X 1 -14, X 2 -14 
                 X 1 -24, X 2 -24 
                 X 1 -34, X 2 -34 
                 X 1 -44, X 2 -44 
                 X 1 -54, X 2 -54 
               
               
                 C 2 -5 
                 X 1 -15, X 2 -15 
                 X 1 -25, X 2 -25 
                 X 1 -35, X 2 -35 
                 X 1 -45, X 2 -45 
                 X 1 -55, X 2 -55 
               
               
                   
               
            
           
         
       
     
     In some aspects, the splitting table also includes the one or more first hop and second hop QoS requirements, such as the PER and the priority. For example, the UE  104  determines the PER of the first hop  304  and the PER of the second hop  306  based on the splitting table similarly as discussed above. 
     In some aspects, the UE  104  receives the splitting table from the base station  102 . The base station  102  generates the splitting table. In other aspects, the base station  102  receives the splitting table from a core network. For example, the base station  102  receives the splitting table from a policy control function (PFC) of the core network. 
     In some aspects, the UE  104  determines the one or more first hop and second hop QoS requirements based on instructions received from the base station  102 . For example, the UE  104  transmits the link conditions of the first hop  304  and the second hop  306  to the base station  102 . The base station  102  determines the one or more first hop and second hop QoS requirements and transmits them to the UE  104 . 
     In some aspects, the UE  104  measures the link conditions of the first hop  304  and the second hop  306 . For example, the UE  104  measures the signal strength of the first hop  304  by measuring received signals from the UE  106 . The UE  104  also measures the CBR of the second hop  306  by measuring a number of nearby devices and their transmission rates. In some aspects, the UE  104  receives the link conditions from other devices such as the UE  106  and the base station  102 . For example, the UE  104  receives the CBR of the first hop  304  from the UE  106  and receives the signal strength of the second hop  306  from the base station  102 . In some aspects, the UE  104  transmits the link conditions that are unknown to the base station  102  to the base station  102  for determining the one or more first hop and second hop QoS requirements. For example, the UE  104  transmits the CBR of the second hop  306  to the base station  102 . 
     In some aspects, the UE  104  updates the one or more first hop and second hop QoS requirements based on updated link conditions of the first hop  304  and the second hop  306 . For example, the CBR of the first hop  304  and the CBR of the second hop  306  are updated periodically or on-demand when the CBRs change. In some aspects, the first hop  304  is less capable or stable than the second hop  306 . For example, the first hop  304  is subjected to a more strict power constraint than the second hop  306 . The first hop  304  may suffer from a more severe fading effect than the second hop  306  because both the UE  106  and the UE  104  of the first hop  304  are mobile. Therefore, the UE  104  updates the one or more first hop and second hop QoS requirements based solely on the link conditions of the first hop  304 . In other words, the UE  104  presumes that the link conditions of the second hop  306  do not change. In some aspects, because the second hop  306  is more stable as explained above, the UE  104  determines that the one or more first hop QoS requirements are looser than the one or more second hop QoS requirements even if the link conditions of the first hop  304  and the second hop  306  are the same. For example, as shown in Table 1, the UE  104  determines that X 1 −33 is greater than X 2 −33, even if C 1 −3=C 2 −3. 
       FIG.  3 B  illustrates an example system of a side-link relay system connecting multiple UEs. Example system  300  is provided for the purpose of illustration only and does not limit the disclosed aspects. System  300  may include, but is not limited to, the UE  104 , the UE  106 , and the UE  108 . Similar to the discussion above, the UE  106  connects with the UE  108  via a two-hop connection  308 . The two-hop connection  308  includes a first hop  310  and a second hop  312 . 
     According to some aspects, similar as discussed above, the two-hop connection  308  has one or more E 2 E QoS requirements. For example, the one or more E 2 E QoS requirements include a priority, a PDB, a PER, and others. The first hop  310  and the second hop  312  also have one or more first hop QoS requirements and one or more second hop QoS requirements, respectively. A combination of the one or more first hop and second hop QoS requirements need to satisfy the one or more E 2 E QoS requirements. Regarding the PDB and the PER. The one or more first hop and second hop QoS requirements satisfy the one or more E 2 E QoS requirements in a same way as described in  FIG.  3 A  discussed above. Regarding the priority, the one or more E 2 E QoS requirements may include a priority of Y. The one or more first hop QoS requirements include a first priority of Y 1  and the one or more second hop QoS requirements include a second priority of Y 2 . To satisfy the priority, Y 1  and Y 2  need to satisfy Y 2 ≤Y and Y 1 ≤Y. Here, a lower priority value corresponds to a higher priority. 
     In some aspects, the UE  104  determines the one or more first hop and second hop QoS requirements similarly as discussed in  FIG.  3 A  above. For example, the UE  104  determines the one or more first hop and second hop QoS requirements based on relative values of link conditions of the first hop  310  and the second hop  312 . The UE  104  determines the one or more first hop and second hop QoS requirements based on a ratio between the link conditions of the first hop  310  and the second hop  312 . The UE  104  determines the one or more first hop and second hop QoS requirements based on a second splitting table. The UE  104  receives the second splitting table from the base station  102 . In some aspects, the second splitting table has a similar structure to the splitting table discussed in  FIG.  3 A . For example, for each kind of QoS requirement, such as the PDB, the UE  104  looks up the second splitting table based on the link conditions to determine a first PDB of the first link  310  and a second PDB of the second link  312 . On the other hand, unlike the two-hop connection  302  of  FIG.  3 A , which includes the second hop  306  that is a Uu link connection, the two-hop connection  308  of  FIG.  3 B  includes the first hop  310  and the second hop  312  that are both side-link connections. Therefore, in the second splitting table, if the channel conditions of the first hop  310  and the second hop  312  are the same, the one or more first hop and second hop QoS requirements are the same. 
     In some aspects, the UE  104  determines the one or more first hop and second hop QoS requirements based on instructions received from the base station  102 . For example, the UE  104  transmits the link conditions of the first hop  310  and the second hop  312  to the base station  102 . The base station  102  determines the one or more first hop and second hop QoS requirements and transmits them to the UE  104 . In some aspects, because the base station  102  is not a part of the two-hop connection  308 , the UE  104  gathers all the link conditions of the first hop  310  and the second hop  312  and transmits them to the base station  102 . 
       FIGS.  4 A- 4 B  illustrate an example method  400  for a system implementing a QoS enhancement for a side-link relay. As a convenience and not a limitation,  FIG.  4    may be described with regard to elements of  FIGS.  1 ,  2 ,  3 , and  8   . Method  400  may represent the operation of electronic devices (for example, the base stations  102 , the UE  104 , and the UE  106  of  FIG.  1   ) implementing the QoS enhancement for the side-link relay. For the sake of demonstration, the UE  104  is referred to as a relay UE  104  and the UE  106  is referred to as a remote UE  106 . The remote UE  106  connects with the base station  102  by a two-hop connection via the relay UE  104 . The two-hop connection includes a first hop between the remote UE  106  and the relay UE  104  and a second hop between the relay UE  104  and the base station  102 . Method  400  may also be performed by system  200  of  FIG.  2    and/or computer system  800  of  FIG.  8   . But method  400  is not limited to the specific aspects depicted in those figures and other systems may be used to perform the method, as will be understood by those skilled in the art. It is to be appreciated that not all operations may be needed, and the operations may not be performed in the same order as shown in  FIG.  4   . 
     At  402 , the relay UE  104  transmits an enhanced relay QoS capability message to the base station  102 . The enhanced relay QoS capability message indicates that the relay UE  104  is capable of splitting one or more E 2 E QoS requirements for a multi-hop connection, such as the two-hop connection between the remote UE  106  and the base station  102 , as discussed above. In addition, the enhanced relay QoS capability message also indicates that the relay UE  104  is capable of adjusting QoS requirements for a hop connection, such as the second hop, based on a received packet. 
     At  404 , the relay UE  104  transmits the enhanced relay QoS capability message to the remote UE  106 . The enhanced relay QoS capability message may be identical to the one that is sent to the base station  102  in  402 . In response to receiving the enhanced relay QoS capability, the remote UE  106  enables an outlier mode by transmitting packets when the remote UE  106  expects that the packets do not meet QoS requirements of the first hop. For example, the remote UE  106  transmits a packet even when the remote UE  106  expects that the packet will arrive at the relay UE  104  with an excess delay, such as a 10 ms delay. This is because the remote UE  106  expects that the second hop will make up for the 10 ms delay based on the enhanced relay QoS capability message. 
     At  406 , the base station  102  obtains an E 2 E QoS requirement corresponding to the two-hop connection between the remote UE  106  and the base station  102 . The E 2 E QoS requirement includes a priority, a PDB, a PER, or others. In an uplink scenario, the remote UE  106  determines the E 2 E QoS requirement. The remote UE  106  can determine the E 2 E QoS requirement based on instructions received from an application of the remote UE  106 , such as the application  254  of the  FIG.  2   . The remote UE  106  can also receive the E 2 E QoS requirement from a user of the remote UE  106 . Furthermore, the remote UE  106  transmits the E 2 E QoS requirement to the base station  102  via the relay UE  104 . In a downlink scenario, the base station  102  determines the E 2 E QoS requirement. The base station  102  may also transmits the E 2 E QoS requirement to the relay UE  104 . 
     At  408 , the relay UE  104  transmits a first hop link condition measurement to the base station  102 . The first hop link condition measurement includes a CBR of the first hop, a signal strength of the first hop, i.e., a side-link reference signal received power (SL-RSRP), an interference level of the first hop, and others. The relay UE  104  measures a first hop link condition at the relay UE  104 . For example, the relay UE  104  measures a signal strength of the first hop based on signals received at the relay UE  104 . The relay UE  104  also receives the first hop link condition from the remote UE  106 . For example, the remote UE  106  measures a CBR of the first hop and transmits the CBR to the relay UE  104 . 
     At  410 , the base station  102  measures a second hop link condition. For example, the base station  102  measures a signal strength of the second hop based on signals received at the base station  102 . In some aspects, the base station  102  receives the second hop link condition. For example, the base station  102  receives a CBR of the second hop from the relay UE  104 . In some aspects, the second hop is a Uu link. The second hop link condition is measured based on radio resource measurement (RRM). 
     At  412 , the base station  102  assigns QoS requirements for the first hop and the second hop based on the link conditions of the first hop and the second hop. The base station  102  can assign the QoS requirements based on a splitting table as discussed above in  FIG.  3 A . In some aspects, the base station  102  transmits the splitting table to the relav UE  104  and the relay UE  104  assigns the QoS requirements based on the splitting table. 
     At  414 , the base station  102  transmits the QoS requirement of the second hop to the relay UE  104 . In some aspects, the base station  102  also assigns corresponding communication resources to the second hop and notifies the relay UE  104 . The relay UE  104  adjusts the second hop connection based on the QoS requirement and the communication resources. 
     At  416 , the base station  102  transmits the QoS requirement of the first hop to the remote UE  106  via the relay UE  104 . The remote UE  106  and the relay UE  104  adjust the first hop connection based on the QoS requirement. In some aspects, the remote UE  106  and the relay UE  104  adjust communication resources of the first hop based on the QoS requirement. 
     At  418 , the relay UE  104  receives a packet. The packet has information corresponding to the E 2 E QoS requirement. For example, the information includes a packet generating time and an expected arrival time at a destination. The difference between the packet generating time and the expected arrival time at the destination is less than the PDB of the E 2 E QoS requirement. In other words, the packet needs to be delivered to the destination within the PDB of the E 2 E QoS requirement. In some aspects, the relay UE  104  receives the packet from the remote UE  106 . In such a case, the packet is an uplink packet and the destination is the base station  102 . In other aspects, the relay UE  104  receives the packet from the base station  102 . In such a case, the packet is a downlink packet and the destination is the remote UE  106 . 
     At  420 , the relay UE  104  determines a hop QoS status. In the uplink scenario, the hop QoS status is a first hop QoS status. The first hop QoS status indicates whether or not the first hop fulfills the QoS requirement of the first hop. For example, the QoS requirement of the first hop includes a PDB of 70 ms. The relay UE  104  determines a current time of receiving the packet and subtracts the packet generating time included in the packet to obtain a first hop transmission time of 80 ms. In such a case, the first hop QoS status indicates an excess delay of 10 ms. In the downlink scenario, the hop QoS status is a second hop QoS status corresponding the second hop. The relay UE  104  determines the second hop QoS status similarly as the first hop QoS status. 
     At  422 , the relay UE  104  determines an updated QoS requirement. For example, in the uplink scenario, the QoS requirement of the second hop includes a PDB of 30 ms. Based on the delay of the first hop QoS status, the relay UE  104  updates the QoS requirement of the second hop to be 20 ms. In this way, the second hop makes up the excess delay of the first hop and the packet is expected to arrive at the base station  102  within an expected delay. On the other hand, in the downlink scenario, the relay UE  104  updates the QoS requirement of the first hop similarly as discussed above. 
     At  424 , the relay UE  104  determines communication resources based on the updated QoS requirement. For example, in the uplink scenario, the relay UE  104  updates the QoS requirement of the second hop from 30 ms to 20 ms to mitigate the excess 10 ms delay per the continuing example. The relay UE  104  determines that time frames closer to the current time are needed for transmitting the packet in the second hop. In the downlink scenario, the relay UE  104  may also determine communication resources of the first hop. 
     At  426 , the relay UE  104  transmits a communication resource request to the base station  102 . The communication resource request indicates the communication resources. In some aspects, the relay UE  104  connects with the base station via a first channel and a second channel. The first channel corresponds to a first logical channel group and the second channel corresponds to a second logical channel group. The first logical channel group has a higher priority than the second logical channel group. For example, if the communication resource request corresponds to the first logical channel group, the base station  102  is more likely to grant the communication resources. Otherwise, the base station  102  may ignore the communication resource request. The relay UE  104  indicates in the communication resource request whether the communication resources correspond to the first logical channel group or the second logical channel group. The relay UE  104  can improve a chance of receiving the communication resources by indicating the first logical channel group in the communication resource request regardless. For example, the communication resources correspond to the second logical channel group. Nevertheless, the relay UE  104  indicates in the communication resource request that the communication resources correspond to the first logical channel group. In some aspects, the relay UE  104  assigns the communication resources to the second hop without permission from the base station  102 . 
     At  428 , the base station  102  assigns the communication resources to the second hop or the first hop based on the communication resource request. In some aspects, the base station  102  assigns based on the logical channel group corresponding to the communication resources. 
     At  430 , the base station  102  transmits a confirmation of the communication resources to the relay UE  104 . The confirmation indicates the communication resources of the communication resource request are granted. In some aspects, the confirmation indicates communication resources that are different from the communication resources of the communication resource request. For example, the base station  102  determines that the communication resources indicated by the communication resource request are not available or not suitable. 
     At  432 , the relay UE  104  forwards the packet using the communication resources that are granted by the base station. For example, in the uplink scenario, the relay UE  104  adjusts the second hop connection based on the communication resources and the updated QoS requirement of the second hop and transmits the packet using the adjusted second hop connection. In the downlink scenario, the relay UE  104  forwards the packet to the remote UE  106  using the communication resources assigned. 
       FIGS.  5 A- 5 B  illustrate an example method  500  for a system implementing a QoS enhancement for a side-link relay. As a convenience and not a limitation,  FIG.  5    may be described with regard to elements of  FIGS.  1 ,  2 ,  3 , and  8   . Method  500  may represent the operation of electronic devices (for example, the base stations  102 , the UE  104 , the UE  106 , and the UE  108  of  FIG.  1   ) implementing the QoS enhancement for the side-link relay. For the sake of demonstration, the UE  104  is referred to as a relay UE  104 ; the UE  106  is referred to as a remote UE  106 ; and the UE  108  is referred to as a target UE  108 . The remote UE  106  connects with the target UE  108  by a two-hop connection via the relay UE  104 . The two-hop connection includes a first hop between the remote UE  106  and the relay UE  104  and a second hop between the relay UE  104  and the target UE  108 . Method  500  may also be performed by system  200  of  FIG.  2    and/or computer system  800  of  FIG.  8   . But method  500  is not limited to the specific aspects depicted in those figures and other systems may be used to perform the method, as will be understood by those skilled in the art. It is to be appreciated that not all operations may be needed, and the operations may not be performed in the same order as shown in  FIG.  5   . 
     At  502 , the relay UE  104  transmits an enhanced relay QoS capability message to the base station  102 . The enhanced relay QoS capability message indicates that the relay UE  104  is capable of splitting one or more E 2 E QoS requirements for a multi-hop connection, such as the two-hop connection between the remote UE  106  and the target UE  108 , as discussed above. In addition, the enhanced relay QoS capability, message also indicates that the relay UE  104  is capable of adjusting QoS requirements for a hop connection, such as the second hop, based on a received packet. 
     At  504 , the relay UE  104  transmits the enhanced relay QoS capability message to the remote UE  106 . The enhanced relay QoS capability message may be identical to the one that is sent to the base station  102  in  402 . In response to receiving the enhanced relay QoS capability, the remote UE  106  enables an outlier mode by transmitting packets even when the remote UE  106  expects that the packets do not meet QoS requirements of the first hop. For example, the remote UE  106  transmits a packet even when the remote UE  106  expects that the packet will arrive at the relay UE  104  with an excess delay, e.g., 10 ms delay. This is because the remote UE  106  expects that the second hop will make up for the 10 ms delay based on the enhanced relay QoS capability message. 
     At  506 , the base station  102  transmits a QoS enforcement configuration to the relay UE  104 . In some aspects, the QoS enforcement configuration enables or disables enhanced relay QoS functions of the relay UE  104 . For example, the QoS enforcement configuration instructs the relay UE  104  whether to split one or more E 2 E QoS requirements of the two-hop connection. In addition, the QoS enforcement configuration instructs the relay UE  104  whether to adjust QoS requirements of the second hop based on the received packet. In some aspects, the QoS enforcement configuration further includes a splitting table as discussed in  FIG.  3 A . The relay UE  104  can split the one or more E 2 E QoS requirements based on the splitting table. In some aspects, if a radio resource control (RRC) connection between the relay UE  104  and the base station  102  is idle or inactive, the base station  102  includes the QoS enforcement configuration in a system information block (SIB) and transmits the SIB to the relay UE  104 . If the RRC connection is active, the base station  102  transmits the QoS enforcement configuration through a dedicated RRC connection. If the relay UE  104  is out of coverage of the base station  102 , the relay UE  104  uses a QoS enforcement configuration previously received or pre-configured. 
     At  508 , the remote UE  106  transmits an E 2 E QoS requirement to the relay UE  104 . The E 2 E QoS requirement includes a priority, a PDB, a PER, or others. The remote UE  106  receives the E 2 E QoS requirement from an application of the remote UE  106 , such as the application  254  of the  FIG.  2   . The remote UE  106  can also receive the E 2 E QoS requirement from a user of the remote UE  106 . 
     At  510 , the relay UE  104  measures a first hop link condition at the relay UE  104 . The first hop link condition includes a CBR of the first hop, a signal strength of the first hop, an interference level of the first hop, and others. For example, the relay UE  104  measures a signal strength of the first hop based on signals received at the relay UE  104 . The relay UE  104  also receives the first hop link condition from the remote UE  106 . For example, the remote UE  106  measures a CBR of the first hop and transmits the CBR to the relay UE  104 . 
     At  512 , the target UE  108  measures a second hop link condition. For example, the target UE  108  measures a signal strength of the second hop based on signals received at the target UE  108 . 
     At  514 , the target UE  108  transmits the second hop link condition to the relay UE  104 . In some aspects, the target UE  108  only transmits the second link condition that is unknown to the relay UE  104 . For example, the target UE  108  does not transmit a CBR of the second hop because the relay UE  104  can measure the CBR of the second hop. 
     At  516 , the relay UE  104  determines the QoS requirements to the first hop and the second hop based on the link conditions of the first hop and the second hop. The relay UE  104  can assign the QoS requirements based on the splitting table received from the base station  102 . In some aspects, the relay UE  104  determines the QoS requirements based on instructions from the base station  102 . For example, the relay UE  104  transmits the link conditions of the first and the second hops to the base station  102 . The base station  102  determines the QoS requirements based on the link conditions and transmits the QoS requirements to the relay UE  104 . 
     At  518 , the relay UE  104  transmits the QoS requirement of the first hop to the remote UE  106 . The remote UE  106  and the relay UE  104  adjust the first hop connection based on the QoS requirement of the first hop. In some aspects, the remote UE  106  and the relay UE  104  adjust communication resources of the first hop based on the QoS requirement. 
     At  520 , the remote UE  106  transmits a packet to the relay UE  104 . The packet has information corresponding to the E 2 E QoS requirement. For example, the information includes a packet generating time and an expected arrival time at the base station  102 . The difference between the packet generating time and the expected arrival time at the base station  102  is less than the PDB of the E 2 E QoS requirement. In other words, the packet needs to be delivered to the base station  102  within the PDB of the E 2 E QoS requirement. 
     At  522 , the relay UE  104  determines a first hop QoS status. In some aspects, the first hop QoS status indicates whether or not the first hop fulfills the QoS requirement of the first hop. For example, the QoS requirement of the first hop includes a PDB of 70 ms. The relay UE  104  determines a current time of receiving the packet and subtracts the packet generating time included in the packet to obtain a first hop transmission time of 80 ms. In such a case, the first hop QoS status indicates an excess delay of 10 ms. 
     At  524 , the relay UE  104  determines an updated QoS requirement of the second hop. For example, the QoS requirement of the second hop includes a PDB of 30 ms. Based on the delay of the first hop QoS status, the UE  104  determines that the updated QoS requirement of the second hop be 20 ms. In this way, the second hop makes up the excess delay of the first hop and the packet is expected to arrive at the base station  102  without a delay. 
     At  526 , the relay UE  104  determines communication resources of the second hop based on the updated QoS requirement of the second hop. For example, the relay UE  104  updates the QoS requirement of the second hop from 30 ms to 20 ms. The relay UE  104  determines that time frames closer to the current time are needed for transmitting the packet. 
     At  528 , the relay UE  104  transmits a communication resource request to the base station  102 . The communication resource request indicates the communication resources of the second hop. In some aspects, the relay UE  104  connects with the base station via a first channel and a second channel. The first channel corresponds to a first logical channel group and the second channel corresponds to a second logical channel group. The first logical channel group has a higher priority than the second logical channel group. For example, if the communication resource request corresponds to the first logical channel group, the base station  102  is more likely to grant the communication resources. Otherwise, the base station  102  may ignore the communication resource request. The relay UE  104  indicates in the communication resource request whether the communication resources correspond to the first logical channel group or the second logical channel group. The relay UE  104  can improve a chance of receiving the communication resources by indicating first logical channel group in the communication resource request regardless. For example, the communication resources correspond to the second logical channel group. Nevertheless, the relay UE  104  indicates in the communication resource request that the communication resources correspond to the first logical channel group. In some aspects, the relay UE  104  assigns the communication resources to the second hop without permission from the base station  102 . 
     At  530 , the base station  102  assigns the communication resources to the second hop based on the communication resource request. In some aspects, the base station  102  assigns based on the logical channel group corresponding to the communication resources. 
     At  532 , the base station  102  transmits a confirmation of the communication resources to the relay UE  104 . The confirmation indicates the communication resources of the communication resource request are granted. In some aspects, the confirmation indicates communication resources that are different from the communication resources of the communication resource request. For example, the base station  102  determines that the communication resources indicated by the communication resource request are not available or not suitable. 
     At  534 , the relay UE  104  forwards the packet to the target UE  108  using the granted communication resources. For example, the relay UE  104  adjusts the second hop connection based on the communication resources and the updated QoS requirement of the second hop and transmits the packet using the adjusted second hop connection. 
       FIG.  6    illustrates an example system for logical channel prioritization. Example system  600  is provided for the purpose of illustration only and does not limit the disclosed aspects. System  600  may include, but is not limited to, the UE  106 , the UE  104 , a UE  602 , and the base station  102 . Similar to the discussion above, the UE  106  connects with the base station  102  via a hop  606  and a hop  608 . The UE  602  also connects with the base station  102  via a hop  604  and the hop  608 . 
     According to some aspects, the UE  104  multiplexes packets received from the UE  106  and the UE  602  and forwards them to the base station  102 . The UE can multiplex the packets based on channel priorities. For example, the UE  106  transmits to the UE  104  via a first channel and the UE  602  transmits to the UE  104  via a second channel. The first channel has a higher priority than the second channel. The UE  104  prioritizes packets received via the first channel over packets received via the second channel. For example, the UE  104  multiplexes two packets received from the UE  106  for every packet received from the UE  602 . In other words, the packets from the UE  106  are forwarded more frequently than the packets from the UE  602 . In some aspects, the first channel and the second channel have a same priority. In such a case, the UE prioritizes packets based on QoS statuses. For example, the hop  606  is free of congestion, while the hop  604  is in congestion. As a result, the packets from the UE  602  likely have delays. For example, a first packet from the UE  602  arrives at the UE  104  with a 10 ms delay, while a second packet from the UE  106  arrives at the UE  104  on time. The UE  104  prioritizes the first packet because the first packet has a more urgent latency. 
       FIG.  7    illustrates an example of a side-link relay system comprising a plurality of hops. Example system  700  is provided for the purpose of illustration only and does not limit the disclosed aspects. System  700  may include, but is not limited to, the UE  106 , a UE  702 , the UE  104 , and the base station  102 . The UE  106  connects with the base station  102  via a three-hop connection  710 . The three-hop connection  710  includes a hop  704 , a hop  706 , and a hop  708 . 
     According to some aspects, the three-hop connection has one or more E 2 E QoS requirements. For example, as discussed above, a packet transmitted from the UE  106  is expected to arrive at the base station  102  before a time point. The UE  104  can split the one or more E 2 E QoS requirements into three parts for the hop  704 , the hop  706 , and the hop  708  based on link conditions of the hops. For example, the UE  104  splits the one or more E 2 E QoS requirements based on a three-dimensional splitting table. The three-dimensional splitting table is a three-dimensional version of the splitting table described in the  FIG.  3 A , where the link conditions of three hops, instead of two hops, are included in the three-dimensional splitting table. In some aspects, the UE  104  can split the one or more E 2 E QoS requirements into N parts for an N-hop connection based on an N-dimensional splitting table, wherein N is a positive integer. 
     In some aspects, the UE  104  considers the hop  704  and the hop  706  as a single hop  712 . In such a case, the UE  104  splits the one or more E 2 E QoS requirements into two parts for the hop  712  and the hop  708  as discussed above in  FIG.  3 A . For example, the hop  712  can be treated as the hop  304  and the hop  708  can be treated as the hop  306 . The UE  702  further splits QoS requirements of the hop  712  into two parts for the hop  704  and the hop  706  as discussed above in  FIG.  3 B . For example, the hop  704  can be treated as the hop  310  and the hop  706  can be treated as the hop  312 . In such a case, the UE  104  and the UE  702  split the one or more E 2 E QoS requirements for hops  704 ,  706 ,  708  in two steps. In addition, the two-step splitting can be extended to split the N-hop connection. In other words, the two-hop connection of  FIG.  3 A  and the two-hop connection of  FIG.  3 B  can be used as basic elements of the N-hop connection. 
     Various aspects may be implemented, for example, using one or more computer systems, such as computer system  800  shown in  FIG.  8   . Computer system  800  may be any well-known computer capable of performing the functions described herein such as electronic devices  104 ,  106 ,  108 , and  102  of  FIG.  1   , or  200  of  FIG.  2   . Computer system  800  includes one or more processors (also called central processing units, or CPUs), such as a processor  804 . Processor  804  is connected to a communication infrastructure  806  (e.g., a bus.) Computer system  800  also includes user input/output device(s)  803 , such as monitors, keyboards, pointing devices, etc., that communicate with communication infrastructure  806  through user input/output interface(s)  802 . Computer system  800  also includes a main or primary memory  808 , such as random access memory (RAM). Main memory  808  may include one or more levels of cache. Main memory  808  has stored therein control logic (e.g., computer software) and/or data. 
     Computer system  800  may also include one or more secondary storage devices or memory  810 . Secondary memory  810  may include, for example, a hard disk drive  812  and/or a removable storage device or drive  814 . Removable storage drive  814  may be a floppy disk drive, a magnetic tape drive, a compact disk drive, an optical storage device, tape backup device, and/or any other storage device/drive. 
     Removable storage drive  814  may interact with a removable storage unit  818 . Removable storage unit  818  includes a computer usable or readable storage device having stored thereon computer software (control logic) and/or data. Removable storage unit  818  may be a floppy disk, magnetic tape, compact disk, DVD, optical storage disk, and/any other computer data storage device. Removable storage drive  814  reads from and/or writes to removable storage unit  818  in a well-known manner. 
     According to some aspects, secondary memory  810  may include other means, instrumentalities or other approaches for allowing computer programs and/or other instructions and/or data to be accessed by computer system  800 . Such means, instrumentalities or other approaches may include, for example, a removable storage unit  822  and an interface  820 . Examples of the removable storage unit  822  and the interface  820  may include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an EPROM or PROM) and associated socket, a memory stick and USB port, a memory card and associated memory card slot, and/or any other removable storage unit and associated interface. 
     Computer system  800  may further include a communication or network interface  824 . Communication interface  824  enables computer system  800  to communicate and interact with any combination of remote devices, remote networks, remote entities, etc. (individually and collectively referenced by reference number  828 ). For example, communication interface  824  may allow computer system  800  to communicate with remote devices  828  over communications path  826 , which may be wired and/or wireless, and which may include any combination of LANs, WANs, the Internet, etc. Control logic and/or data may be transmitted to and from computer system  800  via communication path  826 . 
     The operations in the preceding aspects may be implemented in a wide variety of configurations and architectures. Therefore, some or all of the operations in the preceding aspects may be performed in hardware, in software or both. In some aspects, a tangible, non-transitory apparatus or article of manufacture includes a tangible, non-transitory computer useable or readable medium having control logic (software) stored thereon is also referred to herein as a computer program product or program storage device. This includes, but is not limited to, computer system  800 , main memory  808 , secondary memory  810  and removable storage units  818  and  822 , as well as tangible articles of manufacture embodying any combination of the foregoing. Such control logic, when executed by one or more data processing devices (such as computer system  800 ), causes such data processing devices to operate as described herein. 
     Based on the teachings contained in this disclosure, it will be apparent to persons skilled in the relevant art(s) how to make and use aspects of the disclosure using data processing devices, computer systems and/or computer architectures other than that shown in  FIG.  8   . In particular, aspects may operate with software, hardware, and/or operating system implementations other than those described herein. 
     It is to be appreciated that the Detailed Description section, and not the Summary and Abstract sections, is intended to be used to interpret the claims. The Summary and Abstract sections may set forth one or more, but not all, exemplary aspects of the disclosure as contemplated by the inventor(s), and thus, are not intended to limit the disclosure or the appended claims in any way. 
     While the disclosure has been described herein with reference to exemplary aspects for exemplary fields and applications, it should be understood that the disclosure is not limited thereto. Other aspects and modifications thereto are possible, and are within the scope and spirit of the disclosure. For example, and without limiting the generality of this paragraph, aspects are not limited to the software, hardware, firmware, and/or entities illustrated in the figures and/or described herein. Further, aspects (whether or not explicitly described herein) have significant utility to fields and applications beyond the examples described herein. 
     Aspects have been described herein with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined as long as the specified functions and relationships (or equivalents thereof) are appropriately performed. In addition, alternative aspects may perform functional blocks, steps, operations, methods, etc. using orderings different from those described herein. 
     References herein to “one embodiment,” “an embodiment,” “an example embodiment,” or similar phrases, indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it would be within the knowledge of persons skilled in the relevant art(s) to incorporate such feature, structure, or characteristic into other aspects whether or not explicitly mentioned or described herein. 
     The breadth and scope of the disclosure should not be limited by any of the above-described exemplary aspects, but should be defined only in accordance with the following claims and their equivalents. 
     It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users. 
     The present disclosure contemplates that the entities responsible for the collection, analysis, disclosure, transfer, storage, or other use of such personal information data will comply with well-established privacy policies and/or privacy practices. In particular, such entities should implement and consistently use privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining personal information data private and secure. Such policies should be easily accessible by users, and should be updated as the collection and/or use of data changes. Personal information from users should be collected for legitimate and reasonable uses of the entity and not shared or sold outside of those legitimate uses. Further, such collection/sharing should only occur after receiving the informed consent of the users. Additionally, such entities should consider taking any needed steps for safeguarding and securing access to such personal information data and ensuring that others with access to the personal information data adhere to their privacy policies and procedures. Further, such entities can subject themselves to evaluation by third parties to certify their adherence to widely accepted privacy policies and practices. In addition, policies and practices should be adapted for the particular types of personal information data being collected and/or accessed and adapted to applicable laws and standards, including jurisdiction-specific considerations. For instance, in the US, collection of, or access to, certain health data may be governed by federal and/or state laws, such as the Health Insurance Portability and Accountability Act (HIPAA); whereas health data in other countries may be subject to other regulations and policies and should be handled accordingly. Hence different privacy practices should be maintained for different personal data types in each country.

Metadata:
Filing Date: 20210331
Publication Date: 20240917
Grant Date: 20240917
Priority Date: 20210331
Inventors: SUN, HAITONG
YE, CHUNXUAN
WU, ZHIBIN
CHEN, YUQIN
XU, FANGLI
HU, HAIJING
ZHANG, DAWEI
ZENG, WEI
VAMANAN, Sudeep Manithara
Assignee: APPLE INC
CPC Classifications: [{"code": "H04W40/22", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W28/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/543", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W88/04", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W40/12", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W28/24", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W40/22", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W28/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W40/12", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 83455409