WO2021027942A1

WO2021027942A1 - Method and apparatus for capability information transfer

Info

Publication number: WO2021027942A1
Application number: PCT/CN2020/109321
Authority: WO
Inventors: Zhang Zhang; Congchi ZHANG; Antonino ORSINO
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2019-08-15
Filing date: 2020-08-14
Publication date: 2021-02-18

Abstract

Various embodiments of the present disclosure provide a method for capability information transfer. The method which may be performed by a first terminal device comprises determining whether to transfer first capability information over a sidelink between the first terminal device and a second terminal device in a one-way manner or in a two-way manner, according to an information transfer rule. The method further comprises transmitting the first capability information to the second terminal device, according to the determination. In accordance with some embodiments of the present disclosure, sidelink capability information transfer may be performed adaptively with reduced signaling overhead and transmission latency.

Description

METHOD AND APPARATUS FOR CAPABILITY INFORMATION TRANSFER

FIELD OF THE INVENTION

The present disclosure generally relates to communication networks, and more specifically, to a method and apparatus for capability information transfer.

BACKGROUND

This section introduces aspects that may facilitate a better understanding of the disclosure. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art.

Communication service providers and network operators have been continually facing challenges to deliver value and convenience to consumers by, for example, providing compelling network services and performance. With the evolution of wireless communication, a requirement for supporting device-to-device (D2D) communication features in various applications is proposed. An extension for the D2D work may consist of supporting vehicle-to-everything (V2X) communication, which includes any combination of direct communications among vehicles, pedestrians and infrastructure. Wireless communication networks such as long-term evolution (LTE) and new radio (NR) networks may be expected to use V2X services and support communication for V2X capable user equipment (UE) .

SUMMARY

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

In a wireless communication network, V2X services may be used for various applications to meet different communication requirements. Direct unicast transmission over a sidelink between two V2X capable UEs may be needed in some applications such as platooning, cooperative driving, dynamic ride sharing, etc. When performing sidelink unicast, two UEs may exchange their capability information over the sidelink. On the other hand, sidelink UE capability information (also called sidelink capability information) may need to be transmitted to a network node in some cases. Therefore, it may be desirable to implement sidelink capability information transfer in an efficient way.

Various exemplary embodiments of the present disclosure propose a solution for capability information transfer, which can enable sidelink capability information to be transferred, in a manner determined according to a specific criterion, for example over a sidelink between two terminal devices and/or a cellular link between a network node and a terminal device, so as to reduce signaling overhead and optimize information exchange in a communication network.

According to a first aspect of the present disclosure, there is provided a method performed by a first terminal device such as a UE. The method comprises determining whether to transfer first capability information over a sidelink between the first terminal device and a second terminal device in a one-way manner or in a two-way manner, according to an information transfer rule. The method further comprises transmitting the first capability information to the second terminal device, according to the determination.

In accordance with some exemplary embodiments, the information transfer rule may indicate at least one of: which type of capability information is to be transferred in the one-way manner, and which type of capability information is to be transferred in the two-way manner.

In accordance with some exemplary embodiments, the information transfer rule may be based at least in part on one or more of: network configuration, predetermined provision, and an agreement between the first terminal device and the second terminal device.

In accordance with some exemplary embodiments, the transmission of the first capability information to the second terminal device according to the determination may comprise: transmitting, in response to determining to transfer the first capability information over the sidelink in the one-way manner, the first capability information to inform the second terminal device that one or more first capabilities related to the first capability information are supportable by the first terminal device.

In accordance with some exemplary embodiments, the transmission of the first capability information to the second terminal device according to the determination may comprise: transmitting, in response to determining to transfer the first capability information over the sidelink in the two-way manner, the first capability information to enquire capabilities supportable by the second terminal device (e.g., enquiring whether the second terminal device is able to support one or more first capabilities related to the first capability information and supportable by the first terminal device, or whether the second terminal device is able to support one or more second capabilities which may be different from the one or more first capabilities, etc. ) .

In accordance with some exemplary embodiments, the method according to the first aspect of the present disclosure may further comprise: receiving a first response from the second terminal device according to a first criterion. The first response may indicate that the second terminal device is able to support at least one of one or more first capabilities related to the first capability information.

In accordance with some exemplary embodiments, the at least one of the one or more first capabilities may be indicated by a bitmap in the first response.

In accordance with some exemplary embodiments, the first response may indicate a capability corresponding to a first bit in the bitmap.

In accordance with some exemplary embodiments, the first criterion may be based at least in part on one or more of: preference setting of the second terminal device, a time limit related to a first timer, and a manner in which the first capability information is transferred over the sidelink. Optionally, the time limit related to the first timer may be informed to the second terminal device by the first terminal device.

In accordance with some exemplary embodiments, the method according to the first aspect of the present disclosure may further comprise: receiving second capability information about one or more second capabilities supportable by the second terminal device from the second terminal device, according to the information transfer rule.

In accordance with some exemplary embodiments, the one or more second capabilities supportable by the second terminal device may not be indicated to the first terminal device previously by the second terminal device.

In accordance with some exemplary embodiments, the second capability information may be received from the second terminal device together with a first response.

In accordance with some exemplary embodiments, the method according to the first aspect of the present disclosure may further comprise: transmitting a second response to the second terminal device according to a second criterion. The second response may indicate that the first terminal device is able to support at least one of the one or more second capabilities.

In accordance with some exemplary embodiments, the second criterion may be based at least in part on one or more of: preference setting of the first terminal device, a time limit related to a second timer, and a manner in which the second capability information is transferred over the sidelink. Optionally, the time limit related to the second timer may be informed to the first terminal device by the second terminal device.

According to a second aspect of the present disclosure, there is provided an apparatus which may be implemented as a first terminal device. The apparatus may comprise one or more processors and one or more memories storing computer program codes. The one or more memories and the computer program codes may be configured to, with the one or more processors, cause the apparatus at least to perform any step of the method according to the first aspect of the present disclosure.

According to a third aspect of the present disclosure, there is provided a computer-readable medium having computer program codes embodied thereon which, when executed on a computer, cause the computer to perform any step of the method according to the first aspect of the present disclosure.

According to a fourth aspect of the present disclosure, there is provided an apparatus which may be implemented as a first terminal device. The apparatus may comprise a determining unit and a transmitting unit. In accordance with some exemplary embodiments, the determining unit may be operable to carry out at least the determining step of the method according to the first aspect of the present disclosure. The transmitting unit may be operable to carry out at least the transmitting step of the method according to the first aspect of the present disclosure.

According to a fifth aspect of the present disclosure, there is provided a method performed by a second terminal device such as a UE. The method comprises receiving first capability information from a first terminal device. It is determined according to an information transfer rule whether the first capability information is transferred over a sidelink between the first terminal device and the second terminal device in a one-way manner or in a two-way manner.

In accordance with some exemplary embodiments, the first and second terminal devices described according to the fifth aspect of the present disclosure may correspond to the first and second terminal devices described according to the first aspect of the present disclosure, respectively. To this regard, the second terminal device described according to the fifth aspect of the present disclosure may receive the first capability information from the first terminal device described according to the first aspect of the present disclosure.

In accordance with some exemplary embodiments, the method according to the fifth aspect of the present disclosure may further comprise: determining that one or more first capabilities related to the first capability information are supportable by the first terminal device, in response that the first capability information is transferred over the sidelink in the one-way manner.

In accordance with some exemplary embodiments, the method according to the fifth aspect of the present disclosure may further comprise: determining whether the second terminal device is able to support one or more first capabilities related to the first capability information and supportable by the first terminal device, in response that the first capability information is transferred over the sidelink in the two-way manner.

In accordance with some exemplary embodiments, the method according to the fifth aspect of the present disclosure may further comprise: transmitting a first response to the first terminal device according to a first criterion. The first response may indicate that the second terminal device is able to support at least one of one or more first capabilities related to the first capability information.

In accordance with some exemplary embodiments, the method according to the fifth aspect of the present disclosure may further comprise: transmitting second capability information about one or more second capabilities supportable by the second terminal device to the first terminal device, according to the information transfer rule.

In accordance with some exemplary embodiments, the method according to the fifth aspect of the present disclosure may further comprise: receiving a second response from the first terminal device according to a second criterion. The second response may indicate that the first terminal device is able to support at least one of the one or more second capabilities.

According to a sixth aspect of the present disclosure, there is provided an apparatus which may be implemented as a second terminal device. The apparatus may comprise one or more processors and one or more memories storing computer program codes. The one or more memories and the computer program codes may be configured to, with the one or more processors, cause the apparatus at least to perform any step of the method according to the fifth aspect of the present disclosure.

According to a seventh aspect of the present disclosure, there is provided a computer-readable medium having computer program codes embodied thereon which, when executed on a computer, cause the computer to perform any step of the method according to the fifth aspect of the present disclosure.

According to an eighth aspect of the present disclosure, there is provided an apparatus which may be implemented as a second terminal device. The apparatus may comprise a receiving unit and optionally a transmitting unit. In accordance with some exemplary embodiments, the receiving unit may be operable to carry out at least the receiving step of the method according to the fifth aspect of the present disclosure. The transmitting unit may be operable to carry out at least the transmitting step of the method according to the fifth aspect of the present disclosure.

According to a ninth aspect of the present disclosure, there is provided a method performed by a first terminal device such as a UE. The method comprises transmitting first information about one or more first sidelink capabilities of the first terminal device to a network node.

In accordance with some exemplary embodiments, the one or more first sidelink capabilities may be determined to be informed to the network node according to at least one of: scheduling signaling from the network node, network configuration, and coordination between the first terminal device and a second terminal device.

In accordance with some exemplary embodiments, the method according to the ninth aspect of the present disclosure may further comprise: notifying the network node that the first information is to be transmitted from the first terminal device to the network node, prior to the transmission of the first information to the network node.

In accordance with some exemplary embodiments, the transmission of the first information to the network node may be performed prior to establishment of a sidelink connection between the first terminal device and a second terminal device.

In accordance with some exemplary embodiments, the method according to the ninth aspect of the present disclosure may further comprise: receiving a notification from the network node to indicate that second information about one or more second sidelink capabilities of a second terminal device is obtainable from the network node.

In accordance with some exemplary embodiments, the method according to the ninth aspect of the present disclosure may further comprise: receiving second information about one or more second sidelink capabilities of a second terminal device from the network node.

In accordance with some exemplary embodiments, the reception of the second information from the network node may be performed in response to a sidelink connection between the first terminal device and the second terminal device being established or resumed.

In accordance with some exemplary embodiments, the method according to the ninth aspect of the present disclosure may further comprise: performing coordination with a second terminal device to determine which type of sidelink capability information is to be transferred between the first terminal device and the second terminal device through the network node.

According to a tenth aspect of the present disclosure, there is provided an apparatus which may be implemented as a first terminal device. The apparatus may comprise one or more processors and one or more memories storing computer program codes. The one or more memories and the computer program codes may be configured to, with the one or more processors, cause the apparatus at least to perform any step of the method according to the ninth aspect of the present disclosure.

According to an eleventh aspect of the present disclosure, there is provided a computer-readable medium having computer program codes embodied thereon which, when executed on a computer, cause the computer to perform any step of the method according to the ninth aspect of the present disclosure.

According to a twelfth aspect of the present disclosure, there is provided an apparatus which may be implemented as a first terminal device. The apparatus may comprise a transmitting unit and optionally a receiving unit. In accordance with some exemplary embodiments, the transmitting unit may be operable to carry out at least the transmitting step of the method according to the ninth aspect of the present disclosure. The receiving unit may be operable to carry out at least the receiving step of the method according to the ninth aspect of the present disclosure.

According to a thirteenth aspect of the present disclosure, there is provided a method performed by a network node such as a base station. The method comprises receiving, from a first terminal device, first information about one or more first sidelink capabilities of the first terminal device.

In accordance with some exemplary embodiments, the first terminal device and the network node described according to the thirteenth aspect of the present disclosure may correspond to the first terminal device and the network node described according to the ninth aspect of the present disclosure, respectively. To this regard, the network node described according to the thirteenth aspect of the present disclosure may receive the first information from the first terminal device described according to the ninth aspect of the present disclosure.

In accordance with some exemplary embodiments, the method according to the thirteenth aspect of the present disclosure may further comprise: receiving a notification from the first terminal device that the first information is to be transmitted from the first terminal device to the network node, prior to the reception of the first information from the first terminal device.

In accordance with some exemplary embodiments, the reception of the first information from the first terminal device may be performed prior to establishment of a sidelink connection between the first terminal device and a second terminal device.

In accordance with some exemplary embodiments, the method according to the thirteenth aspect of the present disclosure may further comprise: storing the first information for a period of time, without considering a sidelink connection between the first terminal device and a second terminal device.

In accordance with some exemplary embodiments, the method according to the thirteenth aspect of the present disclosure may further comprise: receiving second information about one or more second sidelink capabilities of a second terminal device from at least one of: the second terminal device and one or more other communication devices.

In accordance with some exemplary embodiments, the method according to the thirteenth aspect of the present disclosure may further comprise performing at least one of: notifying the first terminal device that the second information is obtainable from the network node; and notifying the second terminal device that the first information is obtainable from the network node.

In accordance with some exemplary embodiments, the method according to the thirteenth aspect of the present disclosure may further comprise performing sidelink capability information transfer by carrying out at least one of: transmitting the second information to the first terminal device; and transmitting the first information to the second terminal device.

In accordance with some exemplary embodiments, the sidelink capability information transfer may be performed in response to a sidelink connection between the first terminal device and the second terminal device being established or resumed.

According to a fourteenth aspect of the present disclosure, there is provided an apparatus which may be implemented as a network node. The apparatus may comprise one or more processors and one or more memories storing computer program codes. The one or more memories and the computer program codes may be configured to, with the one or more processors, cause the apparatus at least to perform any step of the method according to the thirteenth aspect of the present disclosure.

According to a fifteenth aspect of the present disclosure, there is provided a computer-readable medium having computer program codes embodied thereon which, when executed on a computer, cause the computer to perform any step of the method according to the thirteenth aspect of the present disclosure.

According to a sixteenth aspect of the present disclosure, there is provided an apparatus which may be implemented as a network node. The apparatus may comprise a receiving unit and optionally a performing unit. In accordance with some exemplary embodiments, the receiving unit may be operable to carry out at least the receiving step of the method according to the thirteenth aspect of the present disclosure. The performing unit may be operable to carry out at least the performing step of the method according to the thirteenth aspect of the present disclosure.

According to a seventeenth aspect of the present disclosure, there is provided a method performed by a second terminal device such as a UE. The method comprises receiving first information about one or more first sidelink capabilities of a first terminal device from a network node.

In accordance with some exemplary embodiments, the method according to the seventeenth aspect of the present disclosure may further comprise: receiving a notification from the network node that the first information is obtainable from the network node, prior to the reception of the first information from the network node.

In accordance with some exemplary embodiments, the reception of the first information from the network node may be performed in response to a sidelink connection between the first terminal device and the second terminal device being established or resumed.

In accordance with some exemplary embodiments, the method according to the seventeenth aspect of the present disclosure may further comprise: transmitting second information about one or more second sidelink capabilities of the second terminal device to the network node.

In accordance with some exemplary embodiments, the one or more second sidelink capabilities may be determined to be informed to the network node according to at least one of: scheduling signaling from the network node, network configuration, and coordination between the first terminal device and the second terminal device.

In accordance with some exemplary embodiments, the transmission of the second information to the network node may be performed prior to establishment of a sidelink connection between the first terminal device and the second terminal device.

In accordance with some exemplary embodiments, the method according to the seventeenth aspect of the present disclosure may further comprise: performing coordination with the first terminal device to determine which type of sidelink capability information is to be transferred between the first terminal device and the second terminal device through the network node.

According to an eighteenth aspect of the present disclosure, there is provided an apparatus which may be implemented as a second terminal device. The apparatus may comprise one or more processors and one or more memories storing computer program codes. The one or more memories and the computer program codes may be configured to, with the one or more processors, cause the apparatus at least to perform any step of the method according to the seventeenth aspect of the present disclosure.

According to a nineteenth aspect of the present disclosure, there is provided a computer-readable medium having computer program codes embodied thereon which, when executed on a computer, cause the computer to perform any step of the method according to the seventeenth aspect of the present disclosure.

According to a twentieth aspect of the present disclosure, there is provided an apparatus which may be implemented as a second terminal device. The apparatus may comprise a receiving unit and optionally a transmitting unit. In accordance with some exemplary embodiments, the receiving unit may be operable to carry out at least the receiving step of the method according to the seventeenth aspect of the present disclosure. The transmitting unit may be operable to carry out at least the transmitting step of the method according to the seventeenth aspect of the present disclosure.

According to a twenty-first aspect of the present disclosure, there is provided a method performed by a first terminal device such as a UE. The method comprises receiving sidelink capability information from a second terminal device. The method further comprises transmitting the sidelink capability information of the second terminal device to a network node.

In accordance with some exemplary embodiments, the method according to the twenty-first aspect of the present disclosure may further comprise: transmitting an identifier of the second terminal device to the network node.

In accordance with some exemplary embodiments, the sidelink capability information of the second terminal device may be received by the first terminal device, in a response to an enquiry for the sidelink capability information of the second terminal device by the first terminal device.

In accordance with some exemplary embodiments, the enquiry for the sidelink capability information of the second terminal device may be performed by the first terminal device in response to reception of an enquiry message for the sidelink capability information of the second terminal device from the network node.

According to a twenty-second aspect of the present disclosure, there is provided an apparatus which may be implemented as a first terminal device. The apparatus may comprise one or more processors and one or more memories storing computer program codes. The one or more memories and the computer program codes may be configured to, with the one or more processors, cause the apparatus at least to perform any step of the method according to the twenty-first aspect of the present disclosure.

According to a twenty-third aspect of the present disclosure, there is provided a computer-readable medium having computer program codes embodied thereon which, when executed on a computer, cause the computer to perform any step of the method according to the twenty-first aspect of the present disclosure.

According to a twenty-fourth aspect of the present disclosure, there is provided an apparatus which may be implemented as a first terminal device. The apparatus may comprise a receiving unit and a transmitting unit. In accordance with some exemplary embodiments, the receiving unit may be operable to carry out at least the receiving step of the method according to the twenty-first aspect of the present disclosure. The transmitting unit may be operable to carry out at least the transmitting step of the method according to the twenty-first aspect of the present disclosure.

According to a twenty-fifth aspect of the present disclosure, there is provided a method performed by a network node such as a base station. The method comprises receiving sidelink capability information of a second terminal device from a first terminal device.

In accordance with some exemplary embodiments, the method according to the twenty-fifth aspect of the present disclosure may further comprise: receiving an identifier of the second terminal device from the first terminal device.

In accordance with some exemplary embodiments, the method according to the twenty-fifth aspect of the present disclosure may further comprise: transmitting an enquiry message for the sidelink capability information of the second terminal device to the first terminal device.

According to a twenty-sixth aspect of the present disclosure, there is provided an apparatus which may be implemented as a network node. The apparatus may comprise one or more processors and one or more memories storing computer program codes. The one or more memories and the computer program codes may be configured to, with the one or more processors, cause the apparatus at least to perform any step of the method according to the twenty-fifth aspect of the present disclosure.

According to a twenty-seventh aspect of the present disclosure, there is provided a computer-readable medium having computer program codes embodied thereon which, when executed on a computer, cause the computer to perform any step of the method according to the twenty-fifth aspect of the present disclosure.

According to a twenty-eighth aspect of the present disclosure, there is provided an apparatus which may be implemented as a network node. The apparatus may comprise a receiving unit and optionally a transmitting unit. In accordance with some exemplary embodiments, the receiving unit may be operable to carry out at least the receiving step of the method according to the twenty-fifth aspect of the present disclosure. The transmitting unit may be operable to carry out at least the transmitting step of the method according to the twenty-fifth aspect of the present disclosure.

According to a twenty-ninth aspect of the present disclosure, there is provided a method performed by a first terminal device such as a UE. The method comprises transmitting a capability enquiry message to a second terminal device. The capability enquiry message may include capability information about one or more capabilities for sidelink supportable by the first terminal device.

In accordance with some exemplary embodiments, the capability information may be included in an information element (IE) ueCapabilityInformationSidelink.

In accordance with some exemplary embodiments, the method according to the twenty-ninth aspect of the present disclosure may further comprise: receiving a response to the capability enquiry message from the second terminal device. The response may indicate that the second terminal device is able to support at least one of the one or more capabilities for sidelink.

According to a thirtieth aspect of the present disclosure, there is provided an apparatus which may be implemented as a first terminal device. The apparatus may comprise one or more processors and one or more memories storing computer program codes. The one or more memories and the computer program codes may be configured to, with the one or more processors, cause the apparatus at least to perform any step of the method according to the twenty-ninth aspect of the present disclosure.

According to a thirty-first aspect of the present disclosure, there is provided a computer-readable medium having computer program codes embodied thereon which, when executed on a computer, cause the computer to perform any step of the method according to the twenty-ninth aspect of the present disclosure.

According to a thirty-second aspect of the present disclosure, there is provided an apparatus which may be implemented as a first terminal device. The apparatus may comprise a transmitting unit and optionally a receiving unit. In accordance with some exemplary embodiments, the transmitting unit may be operable to carry out at least the transmitting step of the method according to the twenty-ninth aspect of the present disclosure. The receiving unit may be operable to carry out at least the receiving step of the method according to the twenty-ninth aspect of the present disclosure.

According to a thirty-third aspect of the present disclosure, there is provided a method performed by a second terminal device such as a UE. The method comprises receiving a capability enquiry message from a first terminal device. The capability enquiry message may include capability information about one or more capabilities for sidelink supportable by the first terminal device.

In accordance with some exemplary embodiments, the method according to the thirty-third aspect of the present disclosure may further comprise: transmitting a response to the capability enquiry message to the first terminal device. The response may indicate that the second terminal device is able to support at least one of the one or more capabilities for sidelink.

According to a thirty-fourth aspect of the present disclosure, there is provided an apparatus which may be implemented as a second terminal device. The apparatus may comprise one or more processors and one or more memories storing computer program codes. The one or more memories and the computer program codes may be configured to, with the one or more processors, cause the apparatus at least to perform any step of the method according to the thirty-third aspect of the present disclosure.

According to a thirty-fifth aspect of the present disclosure, there is provided a computer-readable medium having computer program codes embodied thereon which, when executed on a computer, cause the computer to perform any step of the method according to the thirty-third aspect of the present disclosure.

According to a thirty-sixth aspect of the present disclosure, there is provided an apparatus which may be implemented as a second terminal device. The apparatus may comprise a receiving unit and optionally a transmitting unit. In accordance with some exemplary embodiments, the receiving unit may be operable to carry out at least the receiving step of the method according to the thirty-third aspect of the present disclosure. The transmitting unit may be operable to carry out at least the transmitting step of the method according to the thirty-third aspect of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure itself, the preferable mode of use and further objectives are best understood by reference to the following detailed description of the embodiments when read in conjunction with the accompanying drawings, in which:

Fig. 1 is a diagram illustrating exemplary V2X scenarios for an LTE-based network (NW) according to an embodiment of the present disclosure;

Figs. 2A-2B are diagrams illustrating examples of uni-directional UE capability information transfer according to some embodiments of the present disclosure;

Figs. 3A-3B are diagrams illustrating examples of bi-directional UE capability information transfer according to some embodiments of the present disclosure;

Figs. 4A-4B are diagrams illustrating examples of peer UE capability information transfer to NW according to some embodiments of the present disclosure;

Fig. 5A is a flowchart illustrating a method according to some embodiments of the present disclosure;

Fig. 5B is a flowchart illustrating another method according to some embodiments of the present disclosure;

Fig. 5C is a flowchart illustrating another method according to some embodiments of the present disclosure;

Fig. 5D is a flowchart illustrating another method according to some embodiments of the present disclosure;

Fig. 6A is a flowchart illustrating another method according to some embodiments of the present disclosure;

Fig. 6B is a flowchart illustrating another method according to some embodiments of the present disclosure;

Fig. 6C is a flowchart illustrating another method according to some embodiments of the present disclosure;

Fig. 7A is a flowchart illustrating another method according to some embodiments of the present disclosure;

Fig. 7B is a flowchart illustrating another method according to some embodiments of the present disclosure;

Fig. 8 is a block diagram illustrating an apparatus according to some embodiments of the present disclosure;

Fig. 9 is a block diagram illustrating a telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments of the present disclosure;

Fig. 10 is a block diagram illustrating a host computer communicating via a base station with a UE over a partially wireless connection in accordance with some embodiments of the present disclosure;

Fig. 11 is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment of the present disclosure;

Fig. 12 is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment of the present disclosure;

Fig. 13 is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment of the present disclosure; and

Fig. 14 is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

The embodiments of the present disclosure are described in detail with reference to the accompanying drawings. It should be understood that these embodiments are discussed only for the purpose of enabling those skilled persons in the art to better understand and thus implement the present disclosure, rather than suggesting any limitations on the scope of the present disclosure. Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present disclosure should be or are in any single embodiment of the disclosure. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present disclosure. Furthermore, the described features, advantages, and characteristics of the disclosure may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the disclosure may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the disclosure.

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as new radio (NR) , long term evolution (LTE) , LTE-Advanced, wideband code division multiple access (WCDMA) , high-speed packet access (HSPA) , and so on. Furthermore, the communications between a terminal device and a network node in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , 4G, 4.5G, 5G communication protocols, and/or any other protocols either currently known or to be developed in the future.

The term “network node” refers to a network device in a communication network via which a terminal device accesses to the network and receives services therefrom. The network node may refer to a base station (BS) , an access point (AP) , a multi-cell/multicast coordination entity (MCE) , a controller or any other suitable device in a wireless communication network. The BS may be, for example, a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a next generation NodeB (gNodeB or gNB) , a remote radio unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a relay, a low power node such as a femto, a pico, and so forth.

Yet further examples of the network node comprise multi-standard radio (MSR) radio equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs) , base transceiver stations (BTSs) , transmission points, transmission nodes, positioning nodes and/or the like. More generally, however, the network node may represent any suitable device (or group of devices) capable, configured, arranged, and/or operable to enable and/or provide a terminal device access to a wireless communication network or to provide some service to a terminal device that has accessed to the wireless communication network.

The term “terminal device” refers to any end device that can access a communication network and receive services therefrom. By way of example and not limitation, the terminal device may refer to a mobile terminal, a user equipment (UE) , or other suitable devices. The UE may be, for example, a subscriber station, a portable subscriber station, a mobile station (MS) or an access terminal (AT) . The terminal device may include, but not limited to, portable computers, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, a mobile phone, a cellular phone, a smart phone, a tablet, a wearable device, a personal digital assistant (PDA) , a vehicle, and the like.

As yet another specific example, in an Internet of things (IoT) scenario, a terminal device may also be called an IoT device and represent a machine or other device that performs monitoring, sensing and/or measurements etc., and transmits the results of such monitoring, sensing and/or measurements etc. to another terminal device and/or a network equipment. The terminal device may in this case be a machine-to-machine (M2M) device, which may in a 3rd generation partnership project (3GPP) context be referred to as a machine-type communication (MTC) device.

As one particular example, the terminal device may be a UE implementing the 3GPP narrow band Internet of things (NB-IoT) standard. Particular examples of such machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances, e.g. refrigerators, televisions, personal wearables such as watches etc. In other scenarios, a terminal device may represent a vehicle or other equipment, for example, a medical instrument that is capable of monitoring, sensing and/or reporting etc. on its operational status or other functions associated with its operation.

As used herein, the terms “first” , “second” and so forth refer to different elements. The singular forms “a” and “an” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” as used herein, specify the presence of stated features, elements, and/or components and the like, but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof. The term “based on” is to be read as “based at least in part on” . The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment” . The term “another embodiment” is to be read as “at least one other embodiment” . Other definitions, explicit and implicit, may be included below.

Wireless communication networks are widely deployed to provide various telecommunication services such as voice, video, data, messaging and broadcasts. To meet dramatically increasing network requirements on traffic capacity and data rates, one interesting option for communication technique development is to allow V2X communications to be implemented in a wireless communication network such as 4G/LTE or 5G/NR network. V2X communications may take advantage of a network (NW) infrastructure, when available, but at least basic V2X connectivity needs to be possible even in case of lack of coverage. Providing an LTE-based V2X interface may be economically advantageous because of the LTE economies of scale and it may enable tighter integration between communications with the NW infrastructure (V2I) , pedestrian (V2P) and other vehicles (V2V) , as compared to using a dedicated V2X technology.

V2X communications may carry both non-safety and safety information, where each of the applications and services related to V2X communications may be associated with specific requirements sets, e.g., in terms of latency, reliability, data rates etc. Many use cases may be defined for V2X communications, for example:

● V2V (vehicle-to-vehicle) : covering LTE-based communication between vehicles, either via the cellular interface (known as Uu interface) or via the sidelink interface (known as PC5 interface) .

● V2P (vehicle-to-pedestrian) : covering LTE-based communication between a vehicle and a device carried by an individual (e.g., a handheld terminal carried by a pedestrian, cyclist, driver or passenger) , either via the Uu or sidelink (PC5) interface.

● V2I/N (vehicle-to-infrastructure/network) : covering LTE-based communication between a vehicle and a roadside unit/network. A roadside unit (RSU) may be a transportation infrastructure entity (e.g., an entity transmitting speed notifications) that communicates with V2X capable UEs over the sidelink (PC5) or Uu interface. For V2N, the communication may be performed on the Uu interface.

Fig. 1 is a diagram illustrating exemplary V2X scenarios for an LTE-based NW according to an embodiment of the present disclosure. Various embodiments of the present disclosure are described without limitation in the context of a communication system as illustrated in the diagram of Fig. 1. The communication system may include UEs that are configured for D2D, V2X, and/or other sidelink communications in accordance with various embodiments of the present disclosure. As shown in Fig. 1, the communication system can include a network node 101 (e.g., an eNB) , and a plurality of UEs 102a-102e. The UEs 102a-102e can be any type of electronic device or wireless communication device configured for D2D and/or V2X communications such as V2I, V2P, V2V communications or any combination thereof. As used herein, D2D is referred to in a broader sense to include communications between any type of UEs, and includes V2X communications between a vehicle UE and any other type of UE. D2D and/or V2X may be a component of many existing wireless technologies when it comes to direct communication between wireless devices. D2D and/or V2X communications as an underlay to cellular networks may be proposed as an approach to take advantage of the proximity of devices.

Although various embodiments are explained in the context of V2X communications, some embodiments can also be used for other types of direct communications, including D2D and other sidelink communications. Accordingly, the term “V2X” herein can be replaced with the term “D2D” for some exemplary embodiments. Moreover, although some embodiments are described in the context of LTE system, they may be used in other wireless systems, including systems that operate according to 5G standards, also referred to as NR, or future radio technologies and standards.

Various use cases for advanced V2X services with new service requirements may be applied in 4G/LTE and 5G/NR networks. For example, these use cases may be categorized into four use case groups: vehicles platooning, extended sensors, advanced driving and remote driving. Direct unicast (i.e. one-to-one) and/or multicast (i.e. one-to-many) transmissions over sidelink may be needed in some use cases. The advanced applications of V2X communications may have more stringent requirements on the needed data rate, capacity, reliability, latency, communication range and speed.

In accordance with some exemplary embodiments, sidelink transmissions may be associated with a source layer1/layer2 identifier (L1/L2 ID) and a destination L1/L2 ID. For sidelink unicast, the source L1/L2 ID represents the service type and/or transmitter UE ID, which may become the destination L1/L2 ID of the peer UE. A sidelink unicast link can be identified by the combination of the source L1/L2 ID and the destination L1/L2 ID. For sidelink groupcast, the source L1/L2 ID represents the transmitter UE ID, and the destination L1/L2 ID represents the group ID provided by the upper layer or the service type. For sidelink broadcast, the source L1/L2 ID represents the transmitter UE ID, and the destination L1/L2 ID represents the service type. According to an exemplary embodiment, a connected UE can report the destination L2 ID to its serving cell/node.

In accordance with some exemplary embodiments, some sidelink access stratum level (AS-level) information, such as UE capabilities and AS-layer configurations, may be exchanged between UEs performing sidelink unicast. For example, the AS-level information may be exchanged over sidelink using radio resource control (RRC) signaling such as PC5-RRC signaling. According to an embodiment, the PC5-RRC signaling may be sent during or after the sidelink unicast link setup. For an RRC connected UE, some sidelink AS-level information (e.g., one or more supported sidelink radio access technologies (RATs) , quality of service (QoS) related information and configurations, etc. ) may be exchanged between a gNB and the UE over the Uu interface.

Figs. 2A-2B are diagrams illustrating examples of uni-directional UE capability information transfer according to some embodiments of the present disclosure. The exemplary uni-directional UE capability information transfer may be performed over a sidelink between two sidelink capable UEs such as UE1 and UE2 shown in Figs. 2A-2B. In accordance with some exemplary embodiments, PC5-RRC based UE capability information transfer can be done in either one-way or two-way manner. In the one-way case as shown in Fig. 2A, a UE such as UE1 that wants to transfer its capability information can directly initiate the capability information transfer to its peer UE such as UE2. In the two-way case as shown in Fig. 2B, UE1 may first send a capability enquiry message (e.g., UECapabilityEnquirySidelink message, etc. ) to request capability information transfer from UE2, and then UE2 can send its capability information (e.g., in UECapabilityInformationSidelink message, etc. ) to UE1 according to the received capability enquiry.

In the case of the uni-directional UE capability information transfer as shown in Figs. 2A-2B, the capacity information may be only transferred in one direction (e.g., from UE1 to UE2, or from UE2 to UE1) . On the other hand, in some cases (e.g., when there are bi-directional sidelink traffics between the UEs) , a bi-directional procedure may be needed for UE capability information transfer. In this procedure, not only UE1 needs to transfer capability information to UE2, but also UE2 needs to transfer capability information to UE1.

Figs. 3A-3B are diagrams illustrating examples of bi-directional UE capability information transfer according to some embodiments of the present disclosure. The exemplary bi-directional UE capability information transfer may be performed over a sidelink between two sidelink capable UEs such as UE1 and UE2 shown in Figs. 3A-3B, for example, in either one-way or two-way manner. In the bi-directional procedure for one-way UE capability information transfer as shown in Fig. 3A, UE1 can directly initiate the capability information transfer to its peer UE such as UE2. Similarly, UE2 can also directly initiate the capability information transfer to its peer UE such as UE1. In the bi-directional procedure for two-way UE capability information transfer as shown in Fig. 3B, UE1 may first send a capability enquiry message (e.g., UECapabilityEnquirySidelink message, etc. ) to request capability information transfer from UE2, and then UE2 can send its capability information (e.g., in UECapabilityInformationSidelink message, etc. ) to UE1 according to the received capability enquiry. Correspondingly, UE2 can also send a capability enquiry message (e.g., UECapabilityEnquirySidelink message, etc. ) to request capability information transfer from UE1, and then UE1 can send its capability information (e.g., in UECapabilityInformationSidelink message, etc. ) to UE2 according to the received capability enquiry.

As mentioned previously, the sidelink UE capability information may be transferred in one-way and/or two-way manner, however there is no criterion/procedure to define when/whether to use one-way or two-way transfer. It may happen that for the same capabilities a UE transfers the related capability information in one-way manner, while another UE adopts two-way manner and sends a capability enquiry to the UE. This may lead to unnecessary signaling overhead and resource consumption. In addition, for the bi-directional capability information transfer, there may be often some overlap between the capabilities which are indicated by the capability information transferred in the two directions, especially when the bi-directional sidelink traffic is for the same application. The capability information transfer being performed by the UEs independently in the two directions may also lead to unnecessary signaling overhead and resource consumption.

Various exemplary embodiments of the present disclosure propose a solution to optimize sidelink capability transfer. In accordance with some exemplary embodiments, a terminal device such as a UE can determine when or whether to adopt one-way and/or two-way capability information transfer according to a specific criterion or procedure. According to the proposed solution, the UE can perform a common capability information transfer procedure for both bi-directional one-way capability information transfer and bi-directional two-way capability information transfer. Optionally, the UE can transmit capability information to indicate some (selected) sidelink capabilities by using Uu interface. According to an exemplary embodiment, the UE may forward some capability information of its peer UE to a gNB through the specific signaling and procedure, so as to enable the gNB to understand one or more capabilities of at least one of the two UEs with the sidelink unicast connection. Application of various embodiments can reduce the signaling overhead for transmitting sidelink capability information and decrease the transmission latency.

In accordance with some exemplary embodiments, UE capability information may be exchanged over sidelink. Various criteria/procedures may be applied to determine when or whether to adopt one-way and/or two-way capability information transfer. For instance, a specific criterion may be defined to indicate that information about the following kind of capabilities can be transmitted in one-way manner:

● Fundamental capabilities to support advanced V2X services over sidelink, e.g., the supported RATs and the corresponding release, the maximum supported data rate (per RAT) , vehicle UE or pedestrian UE, etc.

● Capabilities that need to be known for basic AS layer configurations, e.g., UE category, including power class, number of transmission/reception (Tx/Rx) antennas, number of Tx/Rx chains, etc.

In accordance with some exemplary embodiments, the NW may configure which (kind of) capability information need to be transferred in one-way manner or in two-way manner, for example, by using dedicated or common control signaling. The NW configuration may also be delivered to a UE by provisioning, for example, predefined in the UE or obtained over the top from the relevant server (s) .

In accordance with some exemplary embodiments, a common capability information transfer procedure can be adopted for the enhancement of the capability information transfer. The common capability information transfer procedure may be applicable for any of uni-directional/bi-directional one-way capability information transfer and uni-directional/bi-directional two-way capability information transfer.

According to the common capability information transfer procedure, one of the two UEs engaged in sidelink unicast communication may initiate capability information transfer to the peer UE. The initiating UE (e.g., UE1 as shown in Figs. 2A-2B and Figs. 3A-3B) can send to the peer UE (e.g., UE2 as shown in Figs. 2A-2B and Figs. 3A-3B) a capability transfer message (e.g., UECapabilityEnquirySidelink message, etc. ) indicating the capabilities (e.g., by ueCapabilityInformationSidelink, etc. ) that UE1 wants to inform (e.g., in one-way case) or enquire (e.g., in two-way case) . Optionally, UE1 may only inform or enquire the capabilities that it own can support, e.g., by UECapabilityInformationSidelink message which may be optionally sent together with UECapabilityEnquirySidelink message. UE2 can send a response to indicate which of the capabilities indicated by the message (s) received from UE1 can also be supported by UE2. According to an exemplary embodiment, a bitmap may be used to indicate the capabilities supported by UE2. Optionally, the response signaled by UE2 may also include the capability corresponding to the first bit in the bitmap, by which UE1 can figure out the capability corresponding to each bit in the bitmap.

In accordance with some exemplary embodiments, for one-way capability information transfer, UE2 may not send the response right after receiving the capability transfer message from UE1. Optionally, UE2 may send the response when UE2 wants to inform capabilities to UE1, or after receiving at most N capability transfer message (s) from UE1, where N is configurable, etc.

In accordance with some exemplary embodiments, for two-way capability information transfer, UE2 may send the response shortly after receiving the capability transfer message from UE1. Optionally, a timer may be (pre) defined and/or included in the capability transfer message to indicate the maximum time limit within which the response is expected to be received. Absence of this timer or the value of the timer larger than a certain threshold may imply that it is the one-way capability information transfer from UE1. Alternatively or additionally, a type/manner indicator may be included in the capability transfer message to indicate whether the capability transfer message is related to the one-way or two-way capability information transfer.

In accordance with some exemplary embodiments, UE2 may act as an initiating UE of capability information transfer to its peer UE such as UE1, if needed. For example, UE2 may send a capability transfer message to UE1, e.g. UECapabilityEnquirySidelink message which may include ueCapabilityInformationSidelink to indicate UE2’s capabilities for sidelink. Optionally, the capability transfer message sent by UE2 may exclude the capabilities that UE2 has sent in the previous response message (s) to UE1. According to an exemplary embodiment, the capability transfer message may be sent by UE2 together with a response to the capability transfer message from UE1, or sent separately. Similarly, UE1 may send a response to indicate which of the capabilities indicated by the message (s) received from UE2 can also be supported by UE1.

By using the common capability information transfer procedure, the signaling overhead can be reduced, especially in case of bi-directional and/or two-way capability information transfer, and also the latency can be reduced especially for bi-directional two-way capability information transfer.

In accordance with some exemplary embodiments, the peer UE capability information can be obtained from the NW (e.g., through a serving cell/node) . As a further enhancement of capability information transfer, the Uu interface may be used for transmitting sidelink capability information, for example, when both UEs engaged in sidelink unicast communication are in connected mode. In addition to reporting the destination L2 ID, a connected UE can also report its own L2 ID (for sidelink) to the serving cell/node, if needed. Optionally, the source and destination L2 IDs may be further forwarded to mobility management entity/access and mobility management function (MME/AMF) , by which the NW can know which UE pair is performing unicast communication (for a certain service) over sidelink. Furthermore, the NW may keep the mapping between radio network temporary identifier (RNTI) and source/destination (SRC/DST) IDs. According to an exemplary embodiment, the UE can inform its sidelink capabilities to the NW such as a base station, which may be triggered by signaling from the NW and/or configuration provided by the NW or predefined in the NW/UE.

In accordance with some exemplary embodiments, the NW may only trigger the sidelink capability information transfer when both UEs engaged in sidelink unicast communication are in connected mode. The signaling and the configuration from the NW such as a gNB may indicate which (type of) sidelink capabilities the UE may inform to the NW. Optionally, the UE may confirm which capabilities it may inform to the NW. Based on this, the NW may inform each UE performing sidelink unicast communication: which sidelink capability information related to the peer UE can be obtained over the Uu interface. Optionally, the UE may know this implicitly from the relevant triggering signaling and/or the configuration as described previously. Alternatively or additionally, the two UEs engaged in sidelink unciast communication may coordinate over the sidelink which (type of) capability information can be obtained over the Uu interface.

In accordance with some exemplary embodiments, after receiving the sidelink capability information from a UE, the NW such as a gNB can store the capability information in the UE context and forward them to the peer UE. Optionally, the capability information may be kept in the UE context for a configurable time period even when a radio link failure (RLF) occurs in the sidelink. When the sidelink connection is resumed, the UE can obtain the relevant sidelink capability information related to the peer UE from the NW over the Uu interface.

In accordance with some exemplary embodiments, the sidelink capability information can be sent to the NW by the UE even before the unicast sidelink connection of the UE is setup. This may enable the latency to be reduced compared to transmitting the capability information over the sidelink which can only be performed when a PC5-RRC connection is setup, especially when the UEs engaged in sidelink unicast communication are served by the same cell/node.

In accordance with some exemplary embodiments, the peer UE capability information can be sent to the NW such as a gNB. For a scenario where the sidelink unicast AS layer configuration is provided by the gNB, it is benefitial for the gNB of the initiating UE to understand the capability of the peer UE. As such, the gNB can determine the AS layer configuration that is suitable for both UEs with the sidelink unicast link.

Figs. 4A-4B are diagrams illustrating examples of peer UE capability information transfer to NW according to some embodiments of the present disclosure. For simplicity, Fig. 4A and Fig. 4B only depict some exemplary network elements such as UE1, UE2 and a gNB. It can be recognized that signaling messages and network elements shown in Figs. 4A-4B are just as examples, and more or less alternative signaling messages and network elements may be involved in the capability information transfer procedure according to some embodiments of the present disclosure. In the scenarios as shown in Figs. 4A-4B, UE1 may be controlled/configured by the gNB. Irrespective of the connect mode of UE2, the gNB can understand from sidelink UE information sent by UE1 that UE1 establishes a sidelink unicast connection with UE2, e.g., represented by the destination L2 ID in the sidelink UE information.

In accordance with an exemplary embodiment, one-way UE capability information transfer may occur over the sidelink between UE1 and UE2. For example, UE2 may transfer UE2 capability related information over the sidelink to UE1 (as shown in step 1 of Fig. 4A) , and UE1 can forward the UE2 capability related information to the associated gNB via an RRC message over the Uu interface (as shown in step 2 of Fig. 4A) . Optionally, the identifier (e.g. L2 ID) of UE2 may also be included in the same RRC message to help mapping the UE capability to the correct peer UE (e.g., UE2 in this case) .

It can be appreciated that although Fig. 4A merely shows the case of one-way UE capability information transfer, two-way UE capability information transfer may also occur over the sidelink between UE1 and UE2. In the case of two-way UE capability information transfer, UE1 may send an enquiry message to UE2 via the sidelink to enquiry UE2 capability. In response to the enquiry message, UE2 may transfer UE2 capability related information over the sidelink to UE1, and UE1 can forward the UE2 capability related information to the associated gNB via an RRC message over the Uu interface.

In accordance with an exemplary embodiment, the gNB may not have (complete) UE capability information of the peer UE (e.g., UE2 identified by L2 ID) in an existing sidelink unicast connection. The gNB can send an RRC enquiry message to UE1 via the Uu interface (as shown in step 1 of Fig. 4B) , for example, including the identifier of the peer UE (e.g., L2 ID of UE2) as well as the enquired UE capability elements. Optionally, UE1 may forward the UE2 capability enquiry message to UE2 via the sidelink (as shown in step 2 of Fig. 4B) . In response to the enquiry message, UE2 may transfer its UE capability information over the sidelink to UE1 (as shown in step 3 of Fig. 4B) . Then UE1 can forward UE2 capability related information to the associated gNB via an RRC message over the Uu interface (as shown in step 4 of Fig. 4B) . Optionally, the identifier (e.g. L2 ID) of UE2 may also be included in the same RRC message to help mapping the UE capability to the correct peer UE (e.g., UE2 in this case) .

It is noted that some embodiments of the present disclosure are mainly described in relation to 4G/LTE or 5G/NR specifications being used as non-limiting examples for certain exemplary network configurations and system deployments. As such, the description of exemplary embodiments given herein specifically refers to terminology which is directly related thereto. Such terminology is only used in the context of the presented non-limiting examples and embodiments, and does naturally not limit the present disclosure in any way. Rather, any other system configuration or radio technologies may equally be utilized as long as exemplary embodiments described herein are applicable.

Fig. 5A is a flowchart illustrating a method 510 according to some embodiments of the present disclosure. The method 510 illustrated in Fig. 5A may be performed by a first terminal device or an apparatus communicatively coupled to the first terminal device. In accordance with an exemplary embodiment, the first terminal device (e.g., UE1 shown in Figs. 2A-2B, Figs. 3A-3B and Figs. 4A-4B) may be configured to support V2X or sidelink communication with a second terminal device (e.g., UE2 shown in Figs. 2A-2B, Figs. 3A-3B and Figs. 4A-4B) . Optionally, the first terminal device may be configured to communicate with a network node such as a base station.

According to the exemplary method 510 illustrated in Fig. 5A, the first terminal device can determine whether to transfer first capability information over a sidelink between the first terminal device and a second terminal device in a one-way manner or in a two-way manner, according to an information transfer rule, as shown in block 512. According to the determination, the first terminal device can transmit the first capability information to the second terminal device, as shown in block 514.

In accordance with some exemplary embodiments, the information transfer rule may indicate which type of capability information is to be transferred in the one-way manner. Alternatively or additionally, the information transfer rule may indicate which type of capability information is to be transferred in the two-way manner. In accordance with some exemplary embodiments, the information transfer rule may be determined or configured based at least in part on one or more of: network configuration, predetermined provision, and an agreement between the first terminal device and the second terminal device.

In accordance with some exemplary embodiments, the transmission of the first capability information to the second terminal device according to the determination may comprise transmitting, in response to determining to transfer the first capability information over the sidelink in the one-way manner, the first capability information to inform the second terminal device that one or more first capabilities related to the first capability information are supportable by the first terminal device.

In accordance with some exemplary embodiments, the transmission of the first capability information to the second terminal device according to the determination may comprise transmitting, in response to determining to transfer the first capability information over the sidelink in the two-way manner, the first capability information to enquire capabilities supportable by the second terminal device (e.g., enquiring whether the second terminal device is able to support one or more first capabilities related to the first capability information and supportable by the first terminal device, or whether the second terminal device is able to support one or more second capabilities which may be different from the one or more first capabilities, etc. ) . In an embodiment, the first capability information may be included in an IE ueCapabilityInformationSidelink of a message such as UECapabilityEnquirySidelink transmitted by the first terminal device.

In accordance with some exemplary embodiments, the first terminal device may receive a first response from the second terminal device according to a first criterion. The first criterion may be based at least in part on one or more of: preference setting of the second terminal device (e.g., whether the second terminal device wants to inform its capability to the first terminal device, etc. ) , a time limit related to a first timer (e.g., whether the second terminal device is required to inform its capability to the first terminal device within a specific period of time, etc. ) , and a manner in which the first capability information is transferred over the sidelink (e.g., whether the first capability information is transferred to inform or enquiry the second terminal device, etc. ) . Optionally, the time limit related to the first timer may be informed to the second terminal device by the first terminal device (e.g., together with the first capability information) .

In accordance with some exemplary embodiments, the first response may indicate that the second terminal device is able to support at least one of the one or more first capabilities related to the first capability information. In an embodiment, the one or more first capabilities may be supported by the first terminal device. According to an exemplary embodiment, the at least one of the one or more first capabilities may be indicated by a bitmap in the first response. Optionally, the first response may indicate a capability corresponding to a first bit in the bitmap.

In accordance with some exemplary embodiments, the first terminal device may receive second capability information about one or more second capabilities supportable by the second terminal device from the second terminal device, according to the information transfer rule. In an embodiment, the second capability information may be included in an IE ueCapabilityInformationSidelink of a message such as UECapabilityEnquirySidelink transmitted by the second terminal device. According to an exemplary embodiment, the one or more second capabilities supportable by the second terminal device may not be indicated to the first terminal device previously by the second terminal device. Optionally, the second capability information may be received from the second terminal device together with the first response.

In accordance with some exemplary embodiments, the first terminal device may transmit a second response to the second terminal device according to a second criterion. Similar to the first criterion, the second criterion may be based at least in part on one or more of: preference setting of the first terminal device, a time limit related to a second timer, and a manner in which the second capability information is transferred over the sidelink. According to an exemplary embodiment, the second response may indicate that the first terminal device is able to support at least one of the one or more second capabilities supportable by the second terminal device.

Fig. 5B is a flowchart illustrating a method 520 according to some embodiments of the present disclosure. The method 520 illustrated in Fig. 5B may be performed by a second terminal device or an apparatus communicatively coupled to the second terminal device. In accordance with an exemplary embodiment, the second terminal device (e.g., UE2 shown in Figs. 2A-2B, Figs. 3A-3B and Figs. 4A-4B) may be configured to support V2X or sidelink communication with a first terminal device (e.g., UE1 shown in Figs. 2A-2B, Figs. 3A-3B and Figs. 4A-4B) which may be configured to perform the method 510 as illustrated in Fig. 5A. Optionally, the second terminal device may be configured to communicate with a network node such as a base station. It can be realized that the first terminal device and the second terminal device may be served by the same base station or different base stations.

According to the exemplary method 520 illustrated in Fig. 5B, the second terminal device can receive first capability information from a first terminal device, as shown in block 522. It can be determined, according to an information transfer rule, whether the first capability information is transferred over a sidelink between the first terminal device and the second terminal device in a one-way manner or in a two-way manner. As described with respect to Fig. 5A, the information transfer rule may indicate the type of capability information that is to be transferred in the one-way manner or the two-way manner. Optionally, the information transfer rule can be determined according to network configuration, predetermined provision, and/or an agreement between the first terminal device and the second terminal device.

In response that the first capability information is transferred over the sidelink in the one-way manner, the second terminal device can determine that one or more first capabilities related to the first capability information are supportable by the first terminal device. In response that the first capability information is transferred over the sidelink in the two-way manner, the second terminal device can determine whether the second terminal device is able to support one or more first capabilities related to the first capability information and supportable by the first terminal device.

Optionally, the second terminal device may transmit a first response to the first terminal device according to a first criterion (e.g., the first criterion as describe in connection with Fig. 5A) , as shown in block 524. The first response may indicate that the second terminal device is able to support at least one of one or more first capabilities related to the first capability information. In an embodiment, the one or more first capabilities may be supported by the first terminal device. According to an exemplary embodiment, the second terminal device may set a bitmap in the first response to indicate the at least one of the one or more first capabilities supported by the second terminal device. Optionally, a capability corresponding to a first bit in the bitmap may be indicated by the first response.

In accordance with some exemplary embodiments, the second terminal device may transmit second capability information about one or more second capabilities supportable by the second terminal device (e.g., capabilities which are not indicated to the first terminal device previously by the second terminal device) to the first terminal device, according to the information transfer rule. Optionally, the second capability information may be transmitted to the first terminal device together with the first response.

In accordance with some exemplary embodiments, the second terminal device may receive a second response from the first terminal device according to a second criterion (e.g., the second criterion as described in connection wit Fig. 5A) . The second response may indicate that the first terminal device is able to support at least one of the one or more second capabilities supportable by the second terminal device.

It can be appreciated that the first terminal device as described with respect to Fig. 5A may also be configured to perform the method 520 illustrated in Fig. 5B. Similarly, the second terminal device as described with respect to Fig. 5B may also be configured to perform the method 510 as illustrated in Fig. 5A.

Fig. 5C is a flowchart illustrating a method 530 according to some embodiments of the present disclosure. The method 530 illustrated in Fig. 5C may be performed by a first terminal device or an apparatus communicatively coupled to the first terminal device. In accordance with an exemplary embodiment, the first terminal device (e.g., UE1 shown in Figs. 2A-2B, Figs. 3A-3B and Figs. 4A-4B) may be configured to support V2X or sidelink communication with a second terminal device (e.g., UE2 shown in Figs. 2A-2B, Figs. 3A-3B and Figs. 4A-4B) . Optionally, the first terminal device may be configured to communicate with a network node such as a base station.

According to the exemplary method 530 illustrated in Fig. 5C, the first terminal device may transmit a capability enquiry message (e.g., UECapabilityEnquirySidelink message, etc. ) to a second terminal device, as shown in block 532. The capability enquiry message may include capability information about one or more capabilities for sidelink supportable by the first terminal device. In an embodiment, the capability information may be included in an IE ueCapabilityInformationSidelink.

In accordance with some exemplary embodiments, the first terminal device may optionally receive a response to the capability enquiry message from the second terminal device, as shown in block 534. The response may indicate that the second terminal device is able to support at least one of the one or more capabilities for sidelink.

Fig. 5D is a flowchart illustrating a method 540 according to some embodiments of the present disclosure. The method 540 illustrated in Fig. 5D may be performed by a second terminal device or an apparatus communicatively coupled to the second terminal device. In accordance with an exemplary embodiment, the second terminal device (e.g., UE2 shown in Figs. 2A-2B, Figs. 3A-3B and Figs. 4A-4B) may be configured to support V2X or sidelink communication with a first terminal device (e.g., UE1 shown in Figs. 2A-2B, Figs. 3A-3B and Figs. 4A-4B) which may be configured to perform the method 530 as illustrated in Fig. 5C. Optionally, the second terminal device may be configured to communicate with a network node such as a base station. It can be realized that the first terminal device and the second terminal device may be served by the same base station or different base stations.

According to the exemplary method 540 illustrated in Fig. 5D, the second terminal device may receive a capability enquiry message (e.g., UECapabilityEnquirySidelink message, etc. ) from a first terminal device (e.g., the first terminal device as describe with respect to Fig. 5C) , as shown in block 542. The capability enquiry message may include capability information about one or more capabilities for sidelink supportable by the first terminal device. In an embodiment, the capability information may be included in an IE ueCapabilityInformationSidelink.

In accordance with some exemplary embodiments, the second terminal device may optionally transmit a response to the capability enquiry message to the first terminal device, as shown in block 544. The response may indicate that the second terminal device is able to support at least one of the one or more capabilities for sidelink.

It can be appreciated that the first terminal device as described with respect to Fig. 5C may also be configured to perform the method 540 illustrated in Fig. 5D. Similarly, the second terminal device as described with respect to Fig. 5D may also be configured to perform the method 530 as illustrated in Fig. 5C.

Fig. 6A is a flowchart illustrating a method 610 according to some embodiments of the present disclosure. The method 610 illustrated in Fig. 6A may be performed by a first terminal device or an apparatus communicatively coupled to the first terminal device. In accordance with an exemplary embodiment, the first terminal device (e.g., UE1 shown in Figs. 2A-2B, Figs. 3A-3B and Figs. 4A-4B) may be configured to communicate with a network node such as a base station. Optionally, the first terminal device may be configured to support V2X or sidelink communication with a second terminal device (e.g., UE2 shown in Figs. 2A-2B, Figs. 3A-3B and Figs. 4A-4B) . It can be realized that the first terminal device and the second terminal device may be served by the same base station or different base stations.

According to the exemplary method 610 illustrated in Fig. 6A, the first terminal device can transmit first information about one or more first sidelink capabilities of the first terminal device to a network node, as shown in block 612. In accordance with some exemplary embodiments, it can be determined that the one or more first sidelink capabilities are to be informed to the network node, for example, according to at least one of: scheduling signaling from the network node (e.g., indicating which type of sidelink capabilities need to be informed to the network node by the first terminal device, etc. ) , network configuration, and/or coordination between the first terminal device and a second terminal device (e.g., indicating which sidelink capabilities are to be transferred over the Uu interface, etc. ) .

In accordance with some exemplary embodiments, the first terminal device may notify the network node that the first information is to be transmitted from the first terminal device to the network node, prior to the transmission of the first information to the network node. For example, the first terminal device may send a confirm message to the network node to notify the subsequent transmission of the first information, in response to reception of signaling from the network node to schedule sidelink capability information of the first terminal device. In some exemplary embodiments, the transmission of the first information to the network node may be performed prior to establishment of a sidelink connection between the first terminal device and a second terminal device.

Optionally, the first terminal device may receive second information about one or more second sidelink capabilities of a second terminal device from the network node, as shown in block 614. In accordance with some exemplary embodiments, the first terminal device may receive a notification from the network node to indicate that the second information about one or more second sidelink capabilities of the second terminal device is obtainable from the network node. Optionally, the reception of the second information from the network node may be performed in response to a sidelink connection between the first terminal device and the second terminal device being established or resumed.

In accordance with some exemplary embodiments, the first terminal device may perform coordination with the second terminal device to determine which type of sidelink capability information is to be transferred between the first terminal device and the second terminal device through the network node. As such, at least part of the sidelink capability information may be transferred over the Uu interface. From the perspective of a terminal device, it may be possible to transmit/receive the sidelink capability information to/from the peer device through the network node in the case that the sidelink connection is not established or resumed.

Fig. 6B is a flowchart illustrating a method 620 according to some embodiments of the present disclosure. The method 620 illustrated in Fig. 6B may be performed by a network node or an apparatus communicatively coupled to the network node. In accordance with an exemplary embodiment, the network node such as a base station may be configured to serve one or more terminal devices such as the first terminal device previously described with respect to Fig. 6A and/or the second terminal device described later with respect to Fig. 6C.

According to the exemplary method 620 illustrated in Fig. 6B, the network node can receive, from a first terminal device (e.g., the first terminal device as described with respect to Fig. 6A) , first information about one or more first sidelink capabilities of the first terminal device, as shown in block 622. According to an exemplary embodiment, the reception of the first information from the first terminal device may be performed by the network node prior to establishment of a sidelink connection between the first terminal device and a second terminal device. Optionally, the network node may receive a notification from the first terminal device that the first information is to be transmitted from the first terminal device to the network node, prior to the reception of the first information from the first terminal device.

In accordance with some exemplary embodiments, the network node may store the first information for a period of time, without considering a sidelink connection between the first terminal device and a second terminal device. For example, the first information can be stored as context information of the first terminal device for a configurable period of time, regardless of whether there is an RLF in the sidelink of the first terminal device.

In accordance with some exemplary embodiments, the network node may receive second information about one or more second sidelink capabilities of a second terminal device from at least one of the second terminal device and one or more other communication devices (e.g., another network node, an MME/AMF, a third terminal device or the first terminal device) . According to an exemplary embodiment, the network node may collect sidelink capability information of other terminal devices in addition to the first and second terminal devices, and optionally forward the collected sidelink capability information to another network node/entity (e.g., MME/AMF, etc. ) .

In accordance with some exemplary embodiments, the network node may perform at least one of: notifying the first terminal device that the second information is obtainable from the network node, and notifying the second terminal device that the first information is obtainable from the network node. As such, the first terminal device and/or the second terminal device may know which type of sidelink capability information related to the peer terminal device can be obtained over the Uu interface.

Optionally, the network node may perform sidelink capability information transfer, as shown in block 624, for example, by carrying out at least one of: transmitting the second information to the first terminal device, and transmitting the first information to the second terminal device. In accordance with some exemplary embodiments, the sidelink capability information transfer may be performed in response to a sidelink connection between the first terminal device and the second terminal device being established or resumed.

Fig. 6C is a flowchart illustrating a method 630 according to some embodiments of the present disclosure. The method 630 illustrated in Fig. 6C may be performed by a second terminal device or an apparatus communicatively coupled to the second terminal device. In accordance with an exemplary embodiment, the second terminal device (e.g., UE2 shown in Figs. 2A-2B, Figs. 3A-3B and Figs. 4A-4B) may be configured to communicate with a network node such as a base station. Optionally, the second terminal device may be configured to support V2X or sidelink communication with a first terminal device (e.g., UE1 shown in Figs. 2A-2B, Figs. 3A-3B and Figs. 4A-4B) . It can be realized that the first terminal device and the second terminal device may be served by the same base station or different base stations.

According to the exemplary method 630 illustrated in Fig. 6C, the second terminal device can receive first information about one or more first sidelink capabilities of a first terminal device (e.g., the first terminal device as described with respect to Fig. 6A) from a network node (e.g., the network node as described with respect to Fig. 6B) , as shown in block 632. Optionally, the second terminal device may receive a notification from the network node that the first information is obtainable from the network node, prior to the reception of the first information from the network node. In accordance with some exemplary embodiments, the reception of the first information from the network node may be performed in response to a sidelink connection between the first terminal device and the second terminal device being established or resumed.

Optionally, the second terminal device can transmit second information about one or more second sidelink capabilities of the second terminal device to the network node, as shown in block 634. According to an exemplary embodiment, the transmission of the second information to the network node may be performed prior to establishment of a sidelink connection between the first terminal device and the second terminal device. Similar to the situation described in connection with Fig. 6A, the one or more second sidelink capabilities may be determined to be informed to the network node according to at least one of: scheduling signaling from the network node, network configuration, and coordination between the first terminal device and the second terminal device.

In accordance with some exemplary embodiments, the second terminal device can perform coordination with the first terminal device to determine which type of sidelink capability information is to be transferred between the first terminal device and the second terminal device through the network node. As such, a certain type of sidelink capability information can be transferred over the Uu interface.

It can be appreciated that the second terminal device as described with respect to Fig. 6C may also be configured to perform the method 610 illustrated in Fig. 6A, and the first terminal device as described with respect to Fig. 6A may also be configured to perform the method 630 illustrated in Fig. 6C. On the other hand, the network node as described with respect to Fig. 6B can provide sidelink capability information related to other terminal device to the first/second terminal device over the Uu interface, in addition to the sidelink capability information related to the second/first terminal device.

Fig. 7A is a flowchart illustrating a method 710 according to some embodiments of the present disclosure. The method 710 illustrated in Fig. 7A may be performed by a first terminal device or an apparatus communicatively coupled to the first terminal device. In accordance with an exemplary embodiment, the first terminal device (e.g., UE1 shown in Figs. 2A-2B, Figs. 3A-3B and Figs. 4A-4B) may be configured to communicate with a network node such as a base station. Optionally, the first terminal device may be configured to support V2X or sidelink communication with a second terminal device (e.g., UE2 shown in Figs. 2A-2B, Figs. 3A-3B and Figs. 4A-4B) . It can be realized that the first terminal device and the second terminal device may be served by the same base station or different base stations.

According to the exemplary method 710 illustrated in Fig. 7A, the first terminal device can receive sidelink capability information from a second terminal device, as shown in block 712. In accordance with some exemplary embodiments, the first terminal device may transmit the sidelink capability information of the second terminal device to a network node, as shown in block 714. Optionally, the first terminal device may transmit an identifier of the second terminal device to the network node. In this way, the network node can understand some sidelink capabilities of the peer device (e.g., the second terminal device in this embodiment) of the first terminal device, and determine the relevant configurations for the first and second terminal devices accordingly.

In accordance with some exemplary embodiments, the sidelink capability information may be transferred from the second terminal device to the first terminal device in a one-way manner or a two-way manner. For example, the first terminal device may receive the sidelink capability information of the second terminal device without enquiring the second terminal device. Alternatively or additionally, the sidelink capability information may be received from the second terminal device in a response to an enquiry for the sidelink capability information of the second terminal device by the first terminal device.

In accordance with some exemplary embodiments, the enquiry for the sidelink capability information of the second terminal device may be performed by the first terminal device in response to reception of an enquiry message for the sidelink capability information of the second terminal device from the network node. In this case, the first terminal device may forward the enquiry message for the sidelink capability information of the second terminal device from the network node to the second terminal device.

Fig. 7B is a flowchart illustrating a method 720 according to some embodiments of the present disclosure. The method 720 illustrated in Fig. 7B may be performed by a network node or an apparatus communicatively coupled to the network node. In accordance with an exemplary embodiment, the network node such as a base station may be configured to serve one or more terminal devices such as the first terminal device described with respect to Fig. 7A.

According to the exemplary method 720 illustrated in Fig. 7B, the network node may receive sidelink capability information of a second terminal device from a first terminal device (e.g., the first terminal device as described with respect to Fig. 7A) , as shown in block 724. Optionally, the network node may receive an identifier of the second terminal device from the first terminal device. As such, the network node can determine that a sidelink connection is established between the first terminal device and the second terminal device.

As mentioned previously, the transmission of the sidelink capability information of the second terminal device to the network node may be initiated by the first terminal device (as shown in Fig. 4A) , or performed in response to an enquiry by the network node (as shown in Fig. 4B) . In accordance with some exemplary embodiments, the network node may optionally transmit an enquiry message for the sidelink capability information of the second terminal device to the first terminal device, as shown in block 722. In response to the enquiry message, the first terminal device may transmit the sidelink capability information of the second terminal device to the network node.

It can be appreciated that some exemplary embodiments of the present disclosure may be implemented in combination. For example, the first terminal device as described with respect to Fig. 5A may also be configured to perform the method 610 as illustrated in Fig. 6A and/or the method 710 as illustrated in Fig. 7A. In this case, the first terminal device can determine whether and/or how to perform sidelink capability information transfer, for example, whether to transmit sidelink capability information (e.g., capability information related to the first terminal device and/or the second terminal device) to a network node over the Uu interface, or to the second terminal device over the sidelink interface in a one-way or two-way manner. Similarly, the second terminal device as described with respect to Fig. 5B may also be configured to perform the method 630 as illustrated in Fig. 6C. In this case, the second terminal device can obtain sidelink capability information of its peer device (e.g., the first terminal device) via the Uu interface and/or the sidelink interface. Correspondingly, the network node as described with respect to Fig. 6B may also be configured to perform the method 720 as illustrated in Fig. 7B. In this case, the network node can obtain and/or deliver sidelink capability information of at least one of the first terminal device and the second terminal device over the Uu interface.

The various blocks shown in Figs. 5A-5D, Figs. 6A-6C and Figs. 7A-7B may be viewed as method steps, and/or as operations that result from operation of computer program code, and/or as a plurality of coupled logic circuit elements constructed to carry out the associated function (s) . The schematic flow chart diagrams described above are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of specific embodiments of the presented methods. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated methods. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown.

Fig. 8 is a block diagram illustrating an apparatus 800 according to various embodiments of the present disclosure. As shown in Fig. 8, the apparatus 800 may comprise one or more processors such as processor 801 and one or more memories such as memory 802 storing computer program codes 803. The memory 802 may be non-transitory machine/processor/computer readable storage medium. In accordance with some exemplary embodiments, the apparatus 800 may be implemented as an integrated circuit chip or module that can be plugged or installed into a first terminal device as described with respect to any of Fig. 5A, Fig. 5C, Fig. 6A and Fig. 7A, a second terminal device as described with respect to any of Fig. 5B, Fig. 5D and Fig. 6C, or a network node as described with respect to any of Fig. 6B and Fig. 7B. In such cases, the apparatus 800 may be implemented as a first terminal device as described with respect to any of Fig. 5A, Fig. 5C, Fig. 6A and Fig. 7A, a second terminal device as described with respect to any of Fig. 5B, Fig. 5D and Fig. 6C, or a network node as described with respect to any of Fig. 6B and Fig. 7B.

In some implementations, the one or more memories 802 and the computer program codes 803 may be configured to, with the one or more processors 801, cause the apparatus 800 at least to perform any operation of the method as described in connection with any of Fig. 5A, Fig. 5C, Fig. 6A and Fig. 7A. In other implementations, the one or more memories 802 and the computer program codes 803 may be configured to, with the one or more processors 801, cause the apparatus 800 at least to perform any operation of the method as described in connection with any of Fig. 6B and Fig. 7B. In other implementations, the one or more memories 802 and the computer program codes 803 may be configured to, with the one or more processors 801, cause the apparatus 800 at least to perform any operation of the method as described in connection with any of Fig. 5B, Fig. 5D and Fig. 6C. Alternatively or additionally, the one or more memories 802 and the computer program codes 803 may be configured to, with the one or more processors 801, cause the apparatus 800 at least to perform more or less operations to implement the proposed methods according to the exemplary embodiments of the present disclosure.

According to some embodiments of the present disclosure, an apparatus comprising a determining unit and a transmitting unit may be provided. In an exemplary embodiment, the apparatus may be implemented in a first terminal device such as a UE. The determining unit may be operable to carry out the operation in block 512, and the transmitting unit may be operable to carry out the operation in block 514. Optionally, the determining unit and/or the transmitting unit may be operable to carry out more or less operations to implement the proposed methods according to the exemplary embodiments of the present disclosure.

According to some embodiments of the present disclosure, an apparatus comprising a receiving unit and optionally a transmitting unit may be provided. In an exemplary embodiment, the apparatus may be implemented in a second terminal device such as a UE. The receiving unit may be operable to carry out the operation in block 522, and the transmitting unit may be operable to carry out the operation in block 524. Optionally, the receiving unit and/or the transmitting unit may be operable to carry out more or less operations to implement the proposed methods according to the exemplary embodiments of the present disclosure.

According to some embodiments of the present disclosure, an apparatus comprising a transmitting unit and optionally a receiving unit may be provided. In an exemplary embodiment, the apparatus may be implemented in a first terminal device such as a UE. The transmitting unit may be operable to carry out the operation in block 532, and the receiving unit may be operable to carry out the operation in block 534. Optionally, the transmitting unit and/or the receiving unit may be operable to carry out more or less operations to implement the proposed methods according to the exemplary embodiments of the present disclosure.

According to some embodiments of the present disclosure, an apparatus comprising a receiving unit and optionally a transmitting unit may be provided. In an exemplary embodiment, the apparatus may be implemented in a second terminal device such as a UE. The receiving unit may be operable to carry out the operation in block 542, and the transmitting unit may be operable to carry out the operation in block 544. Optionally, the receiving unit and/or the transmitting unit may be operable to carry out more or less operations to implement the proposed methods according to the exemplary embodiments of the present disclosure.

According to some embodiments of the present disclosure, an apparatus comprising a transmitting unit and optionally a receiving unit may be provided. In an exemplary embodiment, the apparatus may be implemented in a first terminal device such as a UE. The transmitting unit may be operable to carry out the operation in block 612, and the receiving unit may be operable to carry out the operation in block 614. Optionally, the transmitting unit and/or the receiving unit may be operable to carry out more or less operations to implement the proposed methods according to the exemplary embodiments of the present disclosure.

According to some embodiments of the present disclosure, an apparatus comprising a receiving unit and optionally a performing unit may be provided. In an exemplary embodiment, the apparatus may be implemented in a network node such as a base station. The receiving unit may be operable to carry out the operation in block 622, and the performing unit may be operable to carry out the operation in block 624. Optionally, the receiving unit and/or the performing unit may be operable to carry out more or less operations to implement the proposed methods according to the exemplary embodiments of the present disclosure.

According to some embodiments of the present disclosure, an apparatus comprising a receiving unit and optionally a transmitting unit may be provided. In an exemplary embodiment, the apparatus may be implemented in a second terminal device such as a UE. The receiving unit may be operable to carry out the operation in block 632, and the transmitting unit may be operable to carry out the operation in block 634. Optionally, the receiving unit and/or the transmitting unit may be operable to carry out more or less operations to implement the proposed methods according to the exemplary embodiments of the present disclosure.

According to some embodiments of the present disclosure, an apparatus comprising a receiving unit and a transmitting unit may be provided. In an exemplary embodiment, the apparatus may be implemented in a first terminal device such as a UE. The receiving unit may be operable to carry out the operation in block 712, and the transmitting unit may be operable to carry out the operation in block 714. Optionally, the receiving unit and/or the transmitting unit may be operable to carry out more or less operations to implement the proposed methods according to the exemplary embodiments of the present disclosure.

According to some embodiments of the present disclosure, an apparatus comprising a receiving unit and optionally a transmitting unit may be provided. In an exemplary embodiment, the apparatus may be implemented in a network node such as a base station. The transmitting unit may be operable to carry out the operation in block 722, and the receiving unit may be operable to carry out the operation in block 724. Optionally, the receiving unit and/or the transmitting unit may be operable to carry out more or less operations to implement the proposed methods according to the exemplary embodiments of the present disclosure.

Fig. 9 is a block diagram illustrating a telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments of the present disclosure.

With reference to Fig. 9, in accordance with an embodiment, a communication system includes a telecommunication network 910, such as a 3GPP-type cellular network, which comprises an access network 911, such as a radio access network, and a core network 914. The access network 911 comprises a plurality of

base stations

912a, 912b, 912c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a

corresponding coverage area

913a, 913b, 913c. Each

base station

912a, 912b, 912c is connectable to the core network 914 over a wired or wireless connection 915. A first UE 991 located in a coverage area 913c is configured to wirelessly connect to, or be paged by, the corresponding base station 912c. A second UE 992 in a coverage area 913a is wirelessly connectable to the corresponding base station 912a. While a plurality of

UEs

991, 992 are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station 912.

The telecommunication network 910 is itself connected to a host computer 930, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. The host computer 930 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider.

Connections

921 and 922 between the telecommunication network 910 and the host computer 930 may extend directly from the core network 914 to the host computer 930 or may go via an optional intermediate network 920. An intermediate network 920 may be one of, or a combination of more than one of, a public, private or hosted network; the intermediate network 920, if any, may be a backbone network or the Internet; in particular, the intermediate network 920 may comprise two or more sub-networks (not shown) .

The communication system of Fig. 9 as a whole enables connectivity between the connected

UEs

991, 992 and the host computer 930. The connectivity may be described as an over-the-top (OTT) connection 950. The host computer 930 and the connected

UEs

991, 992 are configured to communicate data and/or signaling via the OTT connection 950, using the access network 911, the core network 914, any intermediate network 920 and possible further infrastructure (not shown) as intermediaries. The OTT connection 950 may be transparent in the sense that the participating communication devices through which the OTT connection 950 passes are unaware of routing of uplink and downlink communications. For example, the base station 912 may not or need not be informed about the past routing of an incoming downlink communication with data originating from the host computer 930 to be forwarded (e.g., handed over) to a connected UE 991. Similarly, the base station 912 need not be aware of the future routing of an outgoing uplink communication originating from the UE 991 towards the host computer 930.

Fig. 10 is a block diagram illustrating a host computer communicating via a base station with a UE over a partially wireless connection in accordance with some embodiments of the present disclosure.

Example implementations, in accordance with an embodiment, of the UE, base station and host computer discussed in the preceding paragraphs will now be described with reference to Fig. 10. In a communication system 1000, a host computer 1010 comprises hardware 1015 including a communication interface 1016 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of the communication system 1000. The host computer 1010 further comprises a processing circuitry 1018, which may have storage and/or processing capabilities. In particular, the processing circuitry 1018 may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. The host computer 1010 further comprises software 1011, which is stored in or accessible by the host computer 1010 and executable by the processing circuitry 1018. The software 1011 includes a host application 1012. The host application 1012 may be operable to provide a service to a remote user, such as UE 1030 connecting via an OTT connection 1050 terminating at the UE 1030 and the host computer 1010. In providing the service to the remote user, the host application 1012 may provide user data which is transmitted using the OTT connection 1050.

The communication system 1000 further includes a base station 1020 provided in a telecommunication system and comprising hardware 1025 enabling it to communicate with the host computer 1010 and with the UE 1030. The hardware 1025 may include a communication interface 1026 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of the communication system 1000, as well as a radio interface 1027 for setting up and maintaining at least a wireless connection 1070 with the UE 1030 located in a coverage area (not shown in Fig. 10) served by the base station 1020. The communication interface 1026 may be configured to facilitate a connection 1060 to the host computer 1010. The connection 1060 may be direct or it may pass through a core network (not shown in Fig. 10) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, the hardware 1025 of the base station 1020 further includes a processing circuitry 1028, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. The base station 1020 further has software 1021 stored internally or accessible via an external connection.

The communication system 1000 further includes the UE 1030 already referred to. Its hardware 1035 may include a radio interface 1037 configured to set up and maintain a wireless connection 1070 with a base station serving a coverage area in which the UE 1030 is currently located. The hardware 1035 of the UE 1030 further includes a processing circuitry 1038, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. The UE 1030 further comprises software 1031, which is stored in or accessible by the UE 1030 and executable by the processing circuitry 1038. The software 1031 includes a client application 1032. The client application 1032 may be operable to provide a service to a human or non-human user via the UE 1030, with the support of the host computer 1010. In the host computer 1010, an executing host application 1012 may communicate with the executing client application 1032 via the OTT connection 1050 terminating at the UE 1030 and the host computer 1010. In providing the service to the user, the client application 1032 may receive request data from the host application 1012 and provide user data in response to the request data. The OTT connection 1050 may transfer both the request data and the user data. The client application 1032 may interact with the user to generate the user data that it provides.

It is noted that the host computer 1010, the base station 1020 and the UE 1030 illustrated in Fig. 10 may be similar or identical to the host computer 930, one of

base stations

912a, 912b, 912c and one of

UEs

991, 992 of Fig. 9, respectively. This is to say, the inner workings of these entities may be as shown in Fig. 10 and independently, the surrounding network topology may be that of Fig. 9.

In Fig. 10, the OTT connection 1050 has been drawn abstractly to illustrate the communication between the host computer 1010 and the UE 1030 via the base station 1020, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from the UE 1030 or from the service provider operating the host computer 1010, or both. While the OTT connection 1050 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network) .

Wireless connection 1070 between the UE 1030 and the base station 1020 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the UE 1030 using the OTT connection 1050, in which the wireless connection 1070 forms the last segment. More precisely, the teachings of these embodiments may improve the latency and the power consumption, and thereby provide benefits such as lower complexity, reduced time required to access a cell, better responsiveness, extended battery lifetime, etc.

A measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection 1050 between the host computer 1010 and the UE 1030, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection 1050 may be implemented in software 1011 and hardware 1015 of the host computer 1010 or in software 1031 and hardware 1035 of the UE 1030, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which the OTT connection 1050 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which the

software

1011, 1031 may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 1050 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect the base station 1020, and it may be unknown or imperceptible to the base station 1020. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating the host computer 1010’s measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that the

software

1011 and 1031 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection 1050 while it monitors propagation times, errors etc.

Fig. 11 is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Fig. 9 and Fig. 10. For simplicity of the present disclosure, only drawing references to Fig. 11 will be included in this section. In step 1110, the host computer provides user data. In substep 1111 (which may be optional) of step 1110, the host computer provides the user data by executing a host application. In step 1120, the host computer initiates a transmission carrying the user data to the UE. In step 1130 (which may be optional) , the base station transmits to the UE the user data which was carried in the transmission that the host computer initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1140 (which may also be optional) , the UE executes a client application associated with the host application executed by the host computer.

Fig. 12 is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Fig. 9 and Fig. 10. For simplicity of the present disclosure, only drawing references to Fig. 12 will be included in this section. In step 1210 of the method, the host computer provides user data. In an optional substep (not shown) the host computer provides the user data by executing a host application. In step 1220, the host computer initiates a transmission carrying the user data to the UE. The transmission may pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1230 (which may be optional) , the UE receives the user data carried in the transmission.

Fig. 13 is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Fig. 9 and Fig. 10. For simplicity of the present disclosure, only drawing references to Fig. 13 will be included in this section. In step 1310 (which may be optional) , the UE receives input data provided by the host computer. Additionally or alternatively, in step 1320, the UE provides user data. In substep 1321 (which may be optional) of step 1320, the UE provides the user data by executing a client application. In substep 1311 (which may be optional) of step 1310, the UE executes a client application which provides the user data in reaction to the received input data provided by the host computer. In providing the user data, the executed client application may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the UE initiates, in substep 1330 (which may be optional) , transmission of the user data to the host computer. In step 1340 of the method, the host computer receives the user data transmitted from the UE, in accordance with the teachings of the embodiments described throughout this disclosure.

Fig. 14 is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Fig. 9 and Fig. 10. For simplicity of the present disclosure, only drawing references to Fig. 14 will be included in this section. In step 1410 (which may be optional) , in accordance with the teachings of the embodiments described throughout this disclosure, the base station receives user data from the UE. In step 1420 (which may be optional) , the base station initiates transmission of the received user data to the host computer. In step 1430 (which may be optional) , the host computer receives the user data carried in the transmission initiated by the base station.

According to some exemplary embodiments, there is provided a method implemented in a communication system which may include a host computer, a base station and a UE. The method may comprise providing user data at the host computer. Optionally, the method may comprise, at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station which may perform any step of the exemplary method 620 as describe with respect to Fig. 6B and/or any step of the exemplary method 720 as describe with respect to Fig. 7B.

According to some exemplary embodiments, there is provided a communication system including a host computer. The host computer may comprise processing circuitry configured to provide user data, and a communication interface configured to forward the user data to a cellular network for transmission to a UE. The cellular network may comprise a base station having a radio interface and processing circuitry. The base station’s processing circuitry may be configured to perform any step of the exemplary method 620 as describe with respect to Fig. 6B and/or any step of the exemplary method 720 as describe with respect to Fig. 7B.

According to some exemplary embodiments, there is provided a method implemented in a communication system which may include a host computer, a base station and a UE. The method may comprise providing user data at the host computer. Optionally, the method may comprise, at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station. The UE may perform any step of the exemplary method 510 as describe with respect to Fig. 5A, any step of the exemplary method 520 as describe with respect to Fig. 5B, any step of the exemplary method 530 as describe with respect to Fig. 5C, any step of the exemplary method 540 as describe with respect to Fig. 5D, any step of the exemplary method 610 as describe with respect to Fig. 6A, any step of the exemplary method 630 as describe with respect to Fig. 6C and/or any step of the exemplary method 710 as describe with respect to Fig. 7A.

According to some exemplary embodiments, there is provided a communication system including a host computer. The host computer may comprise processing circuitry configured to provide user data, and a communication interface configured to forward user data to a cellular network for transmission to a UE. The UE may comprise a radio interface and processing circuitry. The UE’s processing circuitry may be configured to perform any step of the exemplary method 510 as describe with respect to Fig. 5A, any step of the exemplary method 520 as describe with respect to Fig. 5B, any step of the exemplary method 530 as describe with respect to Fig. 5C, any step of the exemplary method 540 as describe with respect to Fig. 5D, any step of the exemplary method 610 as describe with respect to Fig. 6A, any step of the exemplary method 630 as describe with respect to Fig. 6C and/or any step of the exemplary method 710 as describe with respect to Fig. 7A.

According to some exemplary embodiments, there is provided a method implemented in a communication system which may include a host computer, a base station and a UE. The method may comprise, at the host computer, receiving user data transmitted to the base station from the UE which may perform any step of the exemplary method 510 as describe with respect to Fig. 5A, any step of the exemplary method 520 as describe with respect to Fig. 5B, any step of the exemplary method 530 as describe with respect to Fig. 5C, any step of the exemplary method 540 as describe with respect to Fig. 5D, any step of the exemplary method 610 as describe with respect to Fig. 6A, any step of the exemplary method 630 as describe with respect to Fig. 6C and/or any step of the exemplary method 710 as describe with respect to Fig. 7A.

According to some exemplary embodiments, there is provided a communication system including a host computer. The host computer may comprise a communication interface configured to receive user data originating from a transmission from a UE to a base station. The UE may comprise a radio interface and processing circuitry. The UE’s processing circuitry may be configured to perform any step of the exemplary method 510 as describe with respect to Fig. 5A, any step of the exemplary method 520 as describe with respect to Fig. 5B, any step of the exemplary method 530 as describe with respect to Fig. 5C, any step of the exemplary method 540 as describe with respect to Fig. 5D, any step of the exemplary method 610 as describe with respect to Fig. 6A, any step of the exemplary method 630 as describe with respect to Fig. 6C and/or any step of the exemplary method 710 as describe with respect to Fig. 7A.

According to some exemplary embodiments, there is provided a method implemented in a communication system which may include a host computer, a base station and a UE. The method may comprise, at the host computer, receiving, from the base station, user data originating from a transmission which the base station has received from the UE. The base station may perform any step of the exemplary method 620 as describe with respect to Fig. 6B and/or any step of the exemplary method 720 as describe with respect to Fig. 7B.

According to some exemplary embodiments, there is provided a communication system which may include a host computer. The host computer may comprise a communication interface configured to receive user data originating from a transmission from a UE to a base station. The base station may comprise a radio interface and processing circuitry. The base station’s processing circuitry may be configured to perform any step of the exemplary method 620 as describe with respect to Fig. 6B and/or any step of the exemplary method 720 as describe with respect to Fig. 7B.

In general, the various exemplary embodiments may be implemented in hardware or special purpose chips, circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the disclosure is not limited thereto. While various aspects of the exemplary embodiments of this disclosure may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

As such, it should be appreciated that at least some aspects of the exemplary embodiments of the disclosure may be practiced in various components such as integrated circuit chips and modules. It should thus be appreciated that the exemplary embodiments of this disclosure may be realized in an apparatus that is embodied as an integrated circuit, where the integrated circuit may comprise circuitry (as well as possibly firmware) for embodying at least one or more of a data processor, a digital signal processor, baseband circuitry and radio frequency circuitry that are configurable so as to operate in accordance with the exemplary embodiments of this disclosure.

It should be appreciated that at least some aspects of the exemplary embodiments of the disclosure may be embodied in computer-executable instructions, such as in one or more program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types when executed by a processor in a computer or other device. The computer executable instructions may be stored on a computer readable medium such as a hard disk, optical disk, removable storage media, solid state memory, random access memory (RAM) , etc. As will be appreciated by one of skill in the art, the function of the program modules may be combined or distributed as desired in various embodiments. In addition, the function may be embodied in whole or partly in firmware or hardware equivalents such as integrated circuits, field programmable gate arrays (FPGA) , and the like.

The present disclosure includes any novel feature or combination of features disclosed herein either explicitly or any generalization thereof. Various modifications and adaptations to the foregoing exemplary embodiments of this disclosure may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings. However, any and all modifications will still fall within the scope of the non-limiting and exemplary embodiments of this disclosure.

Claims

A method (510) performed by a first terminal device, comprising:

determining (512) whether to transfer first capability information over a sidelink between the first terminal device and a second terminal device in a one-way manner or in a two-way manner, according to an information transfer rule; and

transmitting (514) the first capability information to the second terminal device, according to the determination.
The method according to claim 1, wherein the transmission of the first capability information to the second terminal device according to the determination comprises:

transmitting, in response to determining to transfer the first capability information over the sidelink in the one-way manner, the first capability information to inform the second terminal device that one or more first capabilities related to the first capability information are supportable by the first terminal device.
The method according to claim 1, wherein the transmission of the first capability information to the second terminal device according to the determination comprises:

transmitting, in response to determining to transfer the first capability information over the sidelink in the two-way manner, the first capability information to enquire capabilities supportable by the second terminal device.
The method according to any of claims 1-3, further comprising:

receiving a first response from the second terminal device according to a first criterion, wherein the first response indicates that the second terminal device is able to support at least one of one or more first capabilities related to the first capability information.
The method according to any of claims 1-4, further comprising:

receiving second capability information about one or more second capabilities supportable by the second terminal device from the second terminal device, according to the information transfer rule.
The method according to claim 5, further comprising:

transmitting a second response to the second terminal device according to a second criterion, wherein the second response indicates that the first terminal device is able to support at least one of the one or more second capabilities.
A first terminal device (800) , comprising:

one or more processors (801) ; and

one or more memories (802) storing computer program codes (803) ,

the one or more memories (802) and the computer program codes (803) configured to, with the one or more processors (801) , cause the first terminal device (800) at least to perform the method according to any one of claims 1-6.
A computer-readable medium having computer program codes (803) embodied thereon which, when executed on a computer, cause the computer to perform any step of the method according to any one of claims 1-6.
A method (520) performed by a second terminal device, comprising:

receiving (522) first capability information from a first terminal device, wherein whether the first capability information is transferred over a sidelink between the first terminal device and the second terminal device in a one-way manner or in a two-way manner is determined according to an information transfer rule.
The method according to claim 9, further comprising:

transmitting (524) a first response to the first terminal device according to a first criterion, wherein the first response indicates that the second terminal device is able to support at least one of one or more first capabilities related to the first capability information.
The method according to claim 9 or 10, further comprising:

transmitting second capability information about one or more second capabilities supportable by the second terminal device to the first terminal device, according to the information transfer rule.
The method according to claim 11, further comprising:

receiving a second response from the first terminal device according to a second criterion, wherein the second response indicates that the first terminal device is able to support at least one of the one or more second capabilities.
A second terminal device (800) , comprising:

one or more processors (801) ; and

one or more memories (802) storing computer program codes (803) ,

the one or more memories (802) and the computer program codes (803) configured to, with the one or more processors (801) , cause the second terminal device (800) at least to perform the method according to any one of claims 9-12.
A computer-readable medium having computer program codes (803) embodied thereon which, when executed on a computer, cause the computer to perform any step of the method according to any one of claims 9-12.
A method (610) performed by a first terminal device, comprising:

transmitting (612) first information about one or more first sidelink capabilities of the first terminal device to a network node.
The method according to claim 15, wherein the transmission of the first information to the network node is performed prior to establishment of a sidelink connection between the first terminal device and a second terminal device.
The method according to claim 15 or 16, further comprising:

receiving (614) second information about one or more second sidelink capabilities of a second terminal device from the network node.
The method according to claim 17, wherein the reception of the second information from the network node is performed in response to a sidelink connection between the first terminal device and the second terminal device being established or resumed.
A first terminal device (800) , comprising:

one or more processors (801) ; and

one or more memories (802) storing computer program codes (803) ,

the one or more memories (802) and the computer program codes (803) configured to, with the one or more processors (801) , cause the first terminal device (800) at least to perform the method according to any one of claims 15-18.
A computer-readable medium having computer program codes (803) embodied thereon which, when executed on a computer, cause the computer to perform any step of the method according to any one of claims 15-18.
A method (620) performed by a network node, comprising:

receiving (622) , from a first terminal device, first information about one or more first sidelink capabilities of the first terminal device.
The method according to claim 21, wherein the reception of the first information from the first terminal device is performed prior to establishment of a sidelink connection between the first terminal device and a second terminal device.
The method according to claim 21 or 22, further comprising:

receiving second information about one or more second sidelink capabilities of a second terminal device from at least one of: the second terminal device and one or more other communication devices.
The method according to claim 23, further comprising performing (624) sidelink capability information transfer by carrying out at least one of:

transmitting the second information to the first terminal device; and

transmitting the first information to the second terminal device.
The method according to claim 24, wherein the sidelink capability information transfer is performed in response to a sidelink connection between the first terminal device and the second terminal device being established or resumed.
A network node (800) , comprising:

one or more processors (801) ; and

one or more memories (802) storing computer program codes (803) ,

the one or more memories (802) and the computer program codes (803) configured to, with the one or more processors (801) , cause the network node (800) at least to perform the method according to any one of claims 21-25.
A computer-readable medium having computer program codes (803) embodied thereon which, when executed on a computer, cause the computer to perform any step of the method according to any one of claims 21-25.
A method (630) performed by a second terminal device, comprising:

receiving (632) first information about one or more first sidelink capabilities of a first terminal device from a network node.
The method according to claim 28, wherein the reception of the first information from the network node is performed in response to a sidelink connection between the first terminal device and the second terminal device being established or resumed.
The method according to claim 28 or 29, further comprising:

transmitting (634) second information about one or more second sidelink capabilities of the second terminal device to the network node.
The method according to claim 30, wherein the transmission of the second information to the network node is performed prior to establishment of a sidelink connection between the first terminal device and the second terminal device.
A second terminal device (800) , comprising:

one or more processors (801) ; and

one or more memories (802) storing computer program codes (803) ,

the one or more memories (802) and the computer program codes (803) configured to, with the one or more processors (801) , cause the second terminal device (800) at least to perform the method according to any one of claims 28-31.
A computer-readable medium having computer program codes (803) embodied thereon which, when executed on a computer, cause the computer to perform any step of the method according to any one of claims 28-31.
A method (710) performed by a first terminal device, comprising:

receiving (712) sidelink capability information from a second terminal device; and

transmitting (714) the sidelink capability information of the second terminal device to a network node.
The method according to claim 34, further comprising:

transmitting an identifier of the second terminal device to the network node.
The method according to claim 34 or 35, wherein the sidelink capability information is received in a response to an enquiry for the sidelink capability information of the second terminal device by the first terminal device.
The method according to claim 36, wherein the enquiry for the sidelink capability information of the second terminal device is performed by the first terminal device in response to reception of an enquiry message for the sidelink capability information of the second terminal device from the network node.
A first terminal device (800) , comprising:

one or more processors (801) ; and

one or more memories (802) storing computer program codes (803) ,

the one or more memories (802) and the computer program codes (803) configured to, with the one or more processors (801) , cause the first terminal device (800) at least to perform the method according to any one of claims 34-37.
A computer-readable medium having computer program codes (803) embodied thereon which, when executed on a computer, cause the computer to perform any step of the method according to any one of claims 34-37.
A method (720) performed by a network node, comprising:

receiving (724) sidelink capability information of a second terminal device from a first terminal device.
The method according to claim 40, further comprising:

receiving an identifier of the second terminal device from the first terminal device.
The method according to claim 40 or 41, further comprising:

transmitting (722) an enquiry message for the sidelink capability information of the second terminal device to the first terminal device.
A network node (800) , comprising:

one or more processors (801) ; and

one or more memories (802) storing computer program codes (803) ,

the one or more memories (802) and the computer program codes (803) configured to, with the one or more processors (801) , cause the network node (800) at least to perform the method according to any one of claims 40-42.
A computer-readable medium having computer program codes (803) embodied thereon which, when executed on a computer, cause the computer to perform any step of the method according to any one of claims 40-42.
A method (530) performed by a first terminal device, comprising:

transmitting (532) a capability enquiry message to a second terminal device, wherein the capability enquiry message includes capability information about one or more capabilities for sidelink supportable by the first terminal device.
The method according to claim 45, wherein the capability information is included in an information element ueCapabilityInformationSidelink.
The method according to claim 45 or 46, further comprising:

receiving (534) a response to the capability enquiry message from the second terminal device, wherein the response indicates that the second terminal device is able to support at least one of the one or more capabilities for sidelink.
A first terminal device (800) , comprising:

one or more processors (801) ; and

one or more memories (802) storing computer program codes (803) ,

the one or more memories (802) and the computer program codes (803) configured to, with the one or more processors (801) , cause the first terminal device (800) at least to perform the method according to any of claims 45-47.
A computer-readable medium having computer program codes (803) embodied thereon which, when executed on a computer, cause the computer to perform any step of the method according to any of claims 45-47.
A method (540) performed by a second terminal device, comprising:

receiving (542) a capability enquiry message from a first terminal device, wherein the capability enquiry message includes capability information about one or more capabilities for sidelink supportable by the first terminal device.
The method according to claim 50, wherein the capability information is included in an information element ueCapabilityInformationSidelink.
The method according to claim 50 or 51, further comprising:

transmitting (544) a response to the capability enquiry message to the first terminal device, wherein the response indicates that the second terminal device is able to support at least one of the one or more capabilities for sidelink.
A second terminal device (800) , comprising:

one or more processors (801) ; and

one or more memories (802) storing computer program codes (803) ,

the one or more memories (802) and the computer program codes (803) configured to, with the one or more processors (801) , cause the first terminal device (800) at least to perform the method according to any of claims 50-52.
A computer-readable medium having computer program codes (803) embodied thereon which, when executed on a computer, cause the computer to perform any step of the method according to any of claims 50-52.