Embodiments of the present application generally relate to wireless communication technology, especially to methods and apparatuses for a failure handling procedure in a sidelink relay system.
Vehicle to everything (V2X) has been introduced into 5G wireless communication technology. In terms of a channel structure of V2X communication, the direct link between two user equipments (UEs) is called a sidelink. A sidelink is a long-term evolution (LTE) feature introduced in 3GPP Release 12, and enables a direct communication between proximal UEs, and data does not need to go through a base station (BS) or a core network.
In the 3rd Generation Partnership Project (3GPP), deployment of a relay node (RN) in a wireless communication system is promoted. One objective of deploying a RN is to enhance the coverage area of a BS by improving the throughput of a user equipment (UE) that is located in the coverage or far from the BS, which can result in relatively low signal quality. A RN may also be named as a relay UE in some cases. A 3GPP 5G sidelink system including a relay UE may be named as a sidelink relay system.
Currently, in a 3GPP 5G New Radio (NR) system or the like, details regarding how to provide a failure handling procedure in a sidelink relay system has not been specifically discussed yet.
Some embodiments of the present application provide a method for wireless communications. The method may be performed by a UE. The method includes: establishing a PC5 radio resource control (RRC) connection of a link between the UE and a relay UE, wherein a PC5 RRC connection of a link between the relay UE and another UE has been established; and receiving a failure notification from the relay UE, wherein the failure notification indicates an occurrence of a failure on the link between the relay UE and the abovementioned another UE.
Some embodiments of the present application also provide an apparatus for wireless communications. The apparatus includes: a non-transitory computer-readable medium having stored thereon computer-executable instructions; a receiving circuitry; a transmitting circuitry; and a processor coupled to the non-transitory computer-readable medium, the receiving circuitry and the transmitting circuitry, wherein the computer-executable instructions cause the processor to implement the above-mentioned method for receiving a failure notification performed by a UE.
Some embodiments of the present application provide a further method for wireless communications. The method may be performed by a relay UE. The method includes: detecting whether a failure occurs on a link between the relay UE and another UE, wherein a PC5 RRC connection of a link between a UE and the relay UE has been established, and wherein a PC5 RRC connection of the link between the relay UE and the abovementioned another UE has been established; and in response to detecting that the failure occurs on the link between the relay UE and the abovementioned another UE, transmitting a failure notification to the UE, wherein the failure notification indicates an occurrence of the failure on the link between the relay UE and the abovementioned another UE.
Some embodiments of the present application also provide an apparatus for wireless communications. The apparatus includes: a non-transitory computer-readable medium having stored thereon computer-executable instructions; a receiving circuitry; a transmitting circuitry; and a processor coupled to the non-transitory computer-readable medium, the receiving circuitry and the transmitting circuitry, wherein the computer-executable instructions cause the processor to implement the above-mentioned further method for transmitting a failure notification performed by a relay UE.
Some embodiments of the present application provide a further method for wireless communications. The method may be performed by a UE. The method includes: transmitting a RRC reconfiguration for relayed sidelink message to a relay UE, wherein a RRC relayed connection of a link between the UE and another UE has been established; starting a timer for controlling a reconfiguration procedure; and in response to an expiry of the timer or in response to receiving a RRC reconfiguration failure for relayed sidelink message from the relay UE, reporting failure information to a BS, wherein the failure information indicates a failure on the RRC relayed connection of the link between the UE and the abovementioned another UE.
Some embodiments of the present application also provide an apparatus for wireless communications. The apparatus includes: a non-transitory computer-readable medium having stored thereon computer-executable instructions; a receiving circuitry; a transmitting circuitry; and a processor coupled to the non-transitory computer-readable medium, the receiving circuitry and the transmitting circuitry, wherein the computer-executable instructions cause the processor to implement the above-mentioned further method for reporting failure information performed by a UE.
Some embodiments of the present application provide a further method for wireless communications. The method may be performed by a relay UE. The method includes: receiving a RRC reconfiguration for relayed sidelink message from a UE; starting a timer for controlling a reconfiguration procedure; and in response to receiving a RRC reconfiguration failure sidelink message from another UE, transmitting a RRC reconfiguration failure for relayed sidelink message to the UE.
Some embodiments of the present application also provide an apparatus for wireless communications. The apparatus includes: a non-transitory computer-readable medium having stored thereon computer-executable instructions; a receiving circuitry; a transmitting circuitry; and a processor coupled to the non-transitory computer-readable medium, the receiving circuitry and the transmitting circuitry, wherein the computer-executable instructions cause the processor to implement the above-mentioned further method for transmitting a RRC reconfiguration failure for relayed sidelink message performed by a relay UE.
The details of one or more examples are set forth in the accompanying drawings and the descriptions below. Other features, objects, and advantages will be apparent from the descriptions and drawings, and from the claims.
In order to describe the manner in which advantages and features of the application can be obtained, a description of the application is rendered by reference to specific embodiments thereof, which are illustrated in the appended drawings. These drawings depict only example embodiments of the application and are not therefore to be considered limiting of its scope.
The detailed description of the appended drawings is intended as a description of preferred embodiments of the present application and is not intended to represent the only form in which the present application may be practiced. It should be understood that the same or equivalent functions may be accomplished by different embodiments that are intended to be encompassed within the spirit and scope of the present application.
Reference will now be made in detail to some embodiments of the present application, examples of which are illustrated in the accompanying drawings. To facilitate understanding, embodiments are provided under specific network architecture and new service scenarios, such as 3GPP 5G, 3GPP LTE Release 8 and so on. It is contemplated that along with developments of network architectures and new service scenarios, all embodiments in the present application are also applicable to similar technical problems; and moreover, the terminologies recited in the present application may change, which should not affect the principle of the present application.
As shown in
Due to a far distance between UE 101a and UE 101b, these two UEs communicate with each other via the relay UE 103. UE 101a and UE 101b may be connected to the relay UE 103 via a network interface, for example, a PC5 interface as specified in 3GPP standard documents. UE 101a may be connected to the BS 102 via a network interface, for example, a Uu interface as specified in 3GPP standard documents. Referring to
In some embodiments of the present application, UE 101a, UE 101b, or the relay UE 103 may include computing devices, such as desktop computers, laptop computers, personal digital assistants (PDAs), tablet computers, smart televisions (e.g., televisions connected to the Internet), set-top boxes, game consoles, security systems (including security cameras), vehicle on-board computers, network devices (e.g., routers, switches, and modems), or the like.
In some further embodiments of the present application, UE 101a, UE 101b, or the relay UE 103 may include a portable wireless communication device, a smart phone, a cellular telephone, a flip phone, a device having a subscriber identity module, a personal computer, a selective call receiving circuitry, or any other device that is capable of sending and receiving communication signals on a wireless network.
In some other embodiments of the present application, UE 101a, UE 101b, or the relay UE 103 may include wearable devices, such as smart watches, fitness bands, optical head-mounted displays, or the like. Moreover, UE 101a, UE 101b, or the relay UE 103 may be referred to as a subscriber unit, a mobile, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a fixed terminal, a subscriber station, a user terminal, or a device, or described using other terminology used in the art.
BS(s) 102 may be distributed over a geographic region. In certain embodiments of the present application, each of the BS(s) 102 may also be referred to as an access point, an access terminal, a base, a base unit, a macro cell, a Node-B, an evolved Node B (eNB), a gNB, a Home Node-B, a relay node, or a device, or described using other terminology used in the art. BS(s) 102 is generally a part of a radio access network that may include one or more controllers communicably coupled to one or more corresponding BS(s) 102.
The wireless communication system 100 may be compatible with any type of network that is capable of sending and receiving wireless communication signals. For example, the wireless communication system 100 is compatible with a wireless communication network, a cellular telephone network, a Time Division Multiple Access (TDMA)-based network, a Code Division Multiple Access (CDMA)-based network, an Orthogonal Frequency Division Multiple Access (OFDMA)-based network, an LTE network, a 3GPP-based network, a 3GPP 5G network, a satellite communications network, a high altitude platform network, and/or other communications networks.
In some embodiments of the present application, the wireless communication system 100 is compatible with the 5G NR of the 3GPP protocol, wherein BS(s) 102 transmit data using an OFDM modulation scheme on the downlink (DL), and UE(s) 101 (e.g., UE 101a, UE 101b, or other similar UE) transmit data on the uplink (UL) using a Discrete Fourier Transform-Spread-Orthogonal Frequency Division Multiplexing (DFT-S-OFDM) or cyclic prefix-OFDM (CP-OFDM) scheme. More generally, however, the wireless communication system 100 may implement some other open or proprietary communication protocols, for example, WiMAX, among other protocols.
In some embodiments of the present application, BS(s) 102 may communicate using other communication protocols, such as the IEEE 802.11 family of wireless communication protocols. Further, in some embodiments of the present application, BS(s) 102 may communicate over licensed spectrums, whereas in other embodiments, BS(s) 102 may communicate over unlicensed spectrums. The present application is not intended to be limited to the implementation of any particular wireless communication system architecture or protocol. In yet some embodiments of present application, BS(s) 102 may communicate with UE(s) 101 using the 3GPP 5G protocols.
UE(s) 101 may access BS(s) 102 to receive data packets from BS(s) 102 via a downlink channel and/or transmit data packets to BS(s) 102 via an uplink channel. In normal operation, since UE(s) 101 does not know when BS(s) 102 will transmit data packets to it, UE(s) 101 has to be awake all the time to monitor the downlink channel (e.g., a Physical Downlink Control Channel (PDCCH)) to get ready for receiving data packets from BS(s) 102. However, if UE(s) 101 keeps monitoring the downlink channel all the time even when there is no traffic between BS(s) 102 and UE(s) 101, it would result in significant power waste, which is problematic to a power limited UE or a power sensitive UE.
As shown in
If the sidelink RRC reconfiguration procedure is successfully completed, in step 202, UE (b) may transmit “a RRC reconfiguration complete sidelink message” to UE (a), e.g., a RRCReconfigurationCompleteSidelink message as specified in 3GPP standard documents. Alternatively, if the sidelink RRC reconfiguration procedure is not successfully completed, in step 202, UE (b) may transmit “a RRC reconfiguration failure sidelink message” to UE (a), e.g., a RRCReconfigurationFailureSidelink message as specified in 3GPP standard documents.
The purpose of a sidelink RRC reconfiguration procedure is to modify a PC5 RRC connection, e.g., to establish, modify, or release sidelink data radio bearers (DRBs), to configure NR sidelink measurement and reporting, and to configure sidelink channel state information (CSI) reference signal resources.
A UE (e.g., UE (a) as illustrated and shown in
A UE capable of NR sidelink communication may initiate a procedure of sidelink UE information for NR, to report to a network or a B S that a sidelink radio link failure (RLF) (e.g., timer T400 expiry) or a sidelink RRC reconfiguration failure has been declared.
The following table shows an introduction of timer T400 as specified in 3GPP standard documents, including a starting condition, a stop condition, an operation at expiry, and a possible general name for the timer.
As shown in
Currently, in a sidelink relay system under 3GPP 5G NR, details regarding how to provide a failure handling procedure has not been specifically discussed yet. Embodiments of the present application provide a failure handling procedure in a sidelink relay system, for example, whether a relay UE reports a failure notification to a UE when a RLF of the link between the relay UE and another UE happens or when the relay UE receives a RRCReconfigurationFailureSidelink message from another UE. More details will be illustrated in the following text in combination with the appended drawings.
In the exemplary method 400 as shown in
In an example, the UE further establishes a RRC relayed connection of a link between the UE and the abovementioned another UE. The RRC relayed connection of the link is a logical link and may also be named as “an end-to-end link” between the UE and the abovementioned another UE.
In operation 402, the UE receives a failure notification from the relay UE. The failure notification indicates an occurrence of a failure on the link between the relay UE and the abovementioned another UE. The failure notification may be included in: a RRC signaling, a control packet data unit (PDU) in a sidelink adaptation protocol (SLAP) layer, and a MAC control element (CE).
In an embodiment, the failure notification includes the abovementioned another UE's ID, which may also be named as a destination ID. For instance, with reference to
In a further embodiment, the failure notification includes a failure cause. The failure cause may be “a sidelink radio link failure (RLF)” or “a configuration failure”. For instance, a RLF is included in the failure notification for the sidelink RLF, and a configuration failure is included in the failure notification for a sidelink RRC reconfiguration failure. The failure notification may further include at least one failure cause of:
According to some embodiments, the UE further declares a sidelink RLF of the link between the UE and the relay UE. If a RRC relayed connection of a link between the UE and the abovementioned another UE is established, the UE may further declare a sidelink RLF of the link between the UE and the abovementioned another UE.
According to some embodiments, the UE further releases DRBs and signaling radio bearers (SRBs) of the link between the UE and the relay UE, and discards sidelink communication configuration information of the link between the UE and the relay UE. If a RRC relayed connection of a link between the UE and the abovementioned another UE is established, the UE may further release DRBs and SRBs of the link between the UE and the abovementioned another UE, and the UE may further discard sidelink communication configuration information of the link between the UE and the abovementioned another UE.
According to some embodiments, the UE further:
If a RRC relayed connection of a link between the UE and the abovementioned another UE is established, the UE may further:
According to some embodiments, the UE further determines whether the UE is in coverage of a BS (e.g., the BS 102 illustrated and shown in
For instance, the failure information may include: a status of the link between the UE and the relay UE; and a status of the link between the relay UE and the abovementioned another UE. The status of the link between the UE and the relay UE may represent “an occurrence of a RLF” or “a link being available”. Similarly, the status of the link between the relay UE and the abovementioned another UE may represent “an occurrence of a RLF” or “a link being available”.
According to some embodiments, the UE further receives a RRC reconfiguration message from a BS and performs a relay reselection procedure. The RRC reconfiguration message instructs the UE to perform the relay reselection procedure. According to some other embodiments, the UE performs a relay reselection procedure upon receiving the failure notification.
During performing the relay reselection procedure, the UE monitors a discovery resource pool to find one or more relay UEs, and selects one relay UE within the found one or more relay UEs. The UE may further establish a PC5 RRC connection of a link between the UE and the selected relay UE.
Details described in all other embodiments of the present application (for example, details of how to handle a failure on a link between a relay UE and a UE) are applicable for the embodiments of
In the exemplary method 500 as shown in
In an example, the failure is a sidelink RLF of the link between the relay UE and the abovementioned another UE. In a further example, the failure is a failure during a RRC reconfiguration procedure between the relay UE and the abovementioned another UE, and the failure notification is “a RRC reconfiguration failure for relayed sidelink message”.
The failure notification in the embodiments of
According to some embodiments, the failure notification in the embodiments of
Details described in all other embodiments of the present application (for example, details of how to handle a failure on a link between a relay UE and a UE) are applicable for the embodiments of
The following texts describe specific Embodiments 1 and 2 of the methods as shown and illustrated in
According to Embodiment 1, a UE (e.g., UE 101a as shown and illustrated in
Similar to Embodiment 1, according to Embodiment 2, a UE (e.g., UE 101a as shown and illustrated in
In the exemplary method 600 as shown in
In operation 602, the UE starts a timer for controlling a reconfiguration procedure. In operation 603, if the timer expiries or the UE receives a RRC reconfiguration failure for relayed sidelink message from the relay UE, the UE reports failure information to a BS (e.g., the BS 102 illustrated and shown in
The failure information in the embodiments of
According to some embodiments, the UE receives a RRC reconfiguration message from the BS and performs the relay reselection procedure. The RRC reconfiguration message instructs the UE to perform a relay re-selection procedure. According to some other embodiments, the UE autonomously performs a relay reselection procedure. For example, the UE autonomously performs a relay reselection procedure upon reporting the failure information to the B S. The relay reselection procedure in the embodiments of
In an example, the failure information includes the abovementioned another UE's ID, which may also be named as a destination ID. For instance, with reference to
In an example, the failure information includes a failure cause. For instance, the failure cause may be a sidelink RLF of the RRC relayed connection of the link between UE 101a and UE 101b. The failure cause may be a configuration failure of the RRC relayed connection of the link between UE 101a and UE 101b.
In an embodiment, the UE declares a sidelink RLF of the link between the UE and the abovementioned another UE. For instance, UE 101a declares a sidelink RLF of the link between UE 101a and UE 101b.
In a further embodiment, the UE further performs the following operations:
Details described in all other embodiments of the present application (for example, details of how to handle a failure on a link between a relay UE and a UE) are applicable for the embodiments of
In the exemplary method 700 as shown in
In an embodiment, the relay UE further transmits “the RRC reconfiguration for relayed sidelink message” to the abovementioned another UE. For instance, “the RRC reconfiguration failure for relayed sidelink message” includes the abovementioned another UE's ID, which may also be named as a destination ID. With reference to
In an example, “the RRC reconfiguration failure for relayed sidelink message” includes a failure cause. Similar to the failure cause in the failure notification of the embodiments of
Details described in all other embodiments of the present application (for example, details of how to handle a failure on a link between a relay UE and a UE) are applicable for the embodiments of
The following texts describe specific Embodiment 3 of the methods as shown and illustrated in
According to Embodiment 3, a UE (e.g., UE 101a as shown and illustrated in
In some embodiments of the present application, the apparatus 800 may be a UE (e.g., UE 101a or UE 101b as illustrated and shown in
In some other embodiments of the present application, the apparatus 800 may be a relay UE (e.g., the relay UE 103 as illustrated and shown in
In some additional embodiments of the present application, the apparatus 800 may be a BS (e.g., the BS 102 as illustrated and shown in
As shown in
Although in
In some embodiments of the present application, the at least one non-transitory computer-readable medium 806 may have stored thereon computer-executable instructions which are programmed to implement the operations of the methods, for example as described in view of any one of
Those having ordinary skills in the art would understand that the operations of a method described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. Additionally, in some aspects, the operations of a method may reside as one or any combination or set of codes and/or instructions on a non-transitory computer-readable medium, which may be incorporated into a computer program product.
While this disclosure has been described with specific embodiments thereof, it is evident that many alternatives, modifications, and variations may be apparent to those skilled in the art. For example, various components of the embodiments may be interchanged, added, or substituted in the other embodiments. Also, all of the elements of each figure are not necessary for operation of the disclosed embodiments. For example, those having ordinary skills in the art would be enabled to make and use the teachings of the disclosure by simply employing the elements of the independent claims. Accordingly, embodiments of the disclosure as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the disclosure.
In this document, the terms “includes,” “including,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “a,” “an,” or the like does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that includes the element. Also, the term “another” is defined as at least a second or more. The term “having” and the like, as used herein, are defined as “including.”
Filing Document | Filing Date | Country | Kind |
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PCT/CN2020/107421 | 8/6/2020 | WO |