EP-4190120-B1 - MECHANISMS FOR MANAGING USER EQUIPMENT ON SIDELINK COMMUNICATION

Inventors

• SUN, HAITONG
• YE, CHUNXUAN
• HU, HAIJING
• ZENG, WEI
• ZHANG, DAWEI
• CHEN, YUQIN
• XU, FANGLI
• WU, ZHIBIN

Dates

Publication Date

20260506

Application Date

20200925

Claims (14)

1. A user equipment, UE, comprising: a transceiver configured to wirelessly communicate through a first interface for sidelink communication with one or more UEs including a receiver UE; and a processor communicatively coupled to the transceiver and configured to: determine (402) a discontinuous reception, DRX, cycle of the receiver UE that includes a first number of slots; determine (404) a sidelink on-duration period within the DRX cycle of the receiver UE, wherein the sidelink on-duration period contains a single slot, wherein the receiver UE is in an active state to listen to a Physical Sidelink Control Channel, PSCCH, during the single slot of the sidelink on-duration period, and the PSCCH occupies a plurality of symbols of the single slot but not all symbols of the single slot; and send a message (408), using the transceiver, to the receiver UE during the single slot of the sidelink on-duration period, wherein the message includes a configuration to define one or more slots for the receiver UE to respond to the UE.
2. The UE of claim 1, wherein the transceiver is further configured to wirelessly communicate with a base station through a second interface supporting uplink and downlink transmissions between the base station and the UE, wherein the first interface is a PC5 interface and the second interface is a Uu interface.
3. The UE of claim 1, wherein the DRX cycle of the receiver UE further includes a power saving state having a third number of slots, and wherein the receiver UE refrains from listening to the PSCCH during the power saving state.
4. The UE of claim 1, wherein the message to the receiver UE is carried in a sidelink medium access control, MAC, Control Element, MAC CE.
5. The UE of claim 1, wherein the message is sent to the receiver UE by a broadcast transmission, a groupcast transmission, or a unicast transmission.
6. The UE of claim 1, wherein the receiver UE is an in-coverage UE, an out-of-coverage UE, or a partial-coverage UE.
7. The UE of claim 1, wherein the DRX cycle of the receiver UE is a first DRX cycle, the one or more UEs further include a second receiver UE, and the processor is further configured to: determine a second DRX cycle of the second receiver UE; determine a second sidelink on-duration period within the second DRX cycle, wherein during the second sidelink on-duration period, the second receiver UE is in an active state to listen to the PSCCH; determine one or more slots when the first receiver UE and the second receiver UE are both in the active state; and send a message, using the transceiver, to the first receiver UE and the second receiver UE in a one-to-many communication during the one or more slots when the first receiver UE and the second receiver UE are both in the active state.
8. The UE of claim 7, wherein the first DRX cycle of the first receiver UE has a same time period as the second DRX cycle of the second receiver UE with respect to a timing reference, and the first sidelink on-duration period has a same time period as the second sidelink on-duration period with respect to the timing reference.
9. The UE of claim 7, wherein the first DRX cycle of the first receiver UE has a first offset with respect to a timing reference, and the second DRX cycle of the second receiver UE has a second offset with respect to the timing reference, and wherein the first offset has a length different from a length of the second offset.
10. The UE of claim 7, wherein the first DRX cycle of the first receiver UE has a first length, the second DRX cycle of the second receiver UE has a second length, and the first length is ½ of the second length or ¼ of the second length.
11. The UE of claim 7, wherein the first sidelink on-duration period has a length different from a length of the second sidelink on-duration period.
12. A method for operating a user equipment, UE, comprising: receiving (502) a configuration for a discontinuous reception, DRX, cycle having a sidelink on-duration period within the DRX cycle, wherein the sidelink on-duration period contains a single slot, wherein the UE is in an active state during the single slot of the sidelink on-duration period, and the UE is in a power saving state outside the sidelink on-duration period; listening (504) to a Physical Sidelink Control Channel, PSCCH, during the single slot within the sidelink on-duration period for a message from an other UE that wirelessly communicates through a PC5 interface for sidelink communication with the UE, wherein the PSCCH occupies a plurality of symbols of the single slot but not all symbols of the single slot, wherein the UE refrains from listening to PSCCH when the UE is in the power saving state; and receiving the message from the other UE during the sidelink on-duration period, wherein the message includes a configuration to define one or more slots for the UE to respond to the other UE.
13. The method of claim 12, further comprising: receiving (506) the message from the other UE through the PC5 interface for sidelink communication when the UE is in the active state.
14. The method of claim 13, further comprising: determining, based on the received message, the configuration that defines one or more slots for the UE to respond to the other UE; and sending a response message to the other UE based on the determined configuration.

Description

BACKGROUND Field The described aspects generally relate to managing user equipments on sidelink communication in a wireless communication system. Related Art A user equipment (UE) communicates with a base station (for example, an evolved Node B (eNB), a next generation node B (gNB), or other base station) in a wireless communication network or system. In addition, device-to-device (D2D) or sidelink communication among UEs is becoming more and more important for information exchange in wireless communication systems. Sidelink communication enables direct communication between proximate devices, e.g., multiple UEs, without going through the base station, leading to lower latency for communication among UEs. However, there are various issues to be resolved for sidelink communication among UEs in a wireless communication system. EP3 500 028 discloses a set of network nodes which can communicate using sidelink connections. WO2018/064477 discloses a discontinuous reception system for device-to-device communications including coordination of resources of a relay UE. SUMMARY The invention is defined by the independent claims. A selection of optional features of the invention is set out in the dependent claims. Insofar as the term embodiment is used in the following, or features are presented as being optional, this should be interpreted in such a way that the only protection sought is that of the invention claimed (with due regard to Article 69 EPC and the protocol thereto). References to "embodiment(s)" throughout the description which are not under the scope of the appended claims merely represent possible exemplary executions and are not part of the present invention. 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 wireless system implementing designs for sidelink communications among multiple user equipments (UEs), according to some aspects of the disclosure.FIGS. 2A-2C illustrate an example wireless system including multiple UEs operating according to discontinuous reception (DRX) cycles containing sidelink on-duration periods for sidelink communications, according to some aspects of the disclosure.FIGS. 3A-3C illustrates example DRX cycles with sidelink on-duration periods for sidelink communications among multiple UEs, according to some aspects of the disclosure.FIG. 4 illustrates an example method for a device supporting sidelink communications among multiple UEs, according to some aspects of the disclosure.FIGS. 5A-5B illustrate example methods for a device supporting sidelink communications among multiple UEs, according to some aspects of the disclosure.FIG. 6 illustrates a block diagram of an example system of an electronic device implementing designs for sidelink communications among multiple UEs, according to some aspects of the disclosure.FIG. 7 is an example computer system for implementing some aspects or portion(s) thereof of the disclosure provided herein. 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 In a wireless system, a user equipment (UE) can communicate via uplink and downlink with a base station (for example, an evolved Node B (eNB), a next generation node B (gNB), or other base station) in a wireless communication network or system. In addition, a UE can communicate with one or more UEs directly by device-to-device (D2D) or sidelink (SL) communication through sidelink channels. Various sidelink channels are defined in an interface for sidelink communication, e.g., Physical Sidelink Control Channel (PSCCH) in a PC5 interface. Compared to the conventional cellular communication, sidelink communication can have many advantages, e.g., more efficient and transparent to achieve higher spectral efficiency and low latency. Other terms have been used to describe SL related communication systems, e.g., proximity service (ProSe) communication, D2D communication. Even though those terms, e.g., SL communication, D2D communication, ProSe communication, can differ from each other in some aspects. In the current disclosure, SL, D2D, and ProSe are used interchangeably. SL communication can operate using both licensed cellular spectrum (known as in-band communication) and unlicensed spectrum (known as out-band communication). Power management is an important issue for UEs. To conserve battery of a UE, the UE can enter an idle mode with reduced communication or computation activities. If a UE is in co