CN109391924B

CN109391924B - Method, device, and computer readable medium for device-to-device (D2D) communication

Info

Publication number: CN109391924B
Application number: CN201710672154.9A
Authority: CN
Inventors: 刘海静
Original assignee: Nokia Shanghai Bell Co Ltd
Current assignee: Nokia Shanghai Bell Co Ltd
Priority date: 2017-08-08
Filing date: 2017-08-08
Publication date: 2023-04-07
Anticipated expiration: 2037-08-08
Also published as: WO2019030576A1; CN109391924A

Abstract

Embodiments of the present disclosure relate to methods, devices, and computer-readable media for device-to-device (D2D) communication. According to embodiments of the present disclosure, the remote terminal device and the relay terminal device may obtain an association between channel conditions related to discovery of D2D communication and a set of resources for transmitting discovery messages. The remote terminal device may preferentially receive a response from the relay terminal device having the discovered channel condition of good D2D communication according to the association. Energy consumption of the remote terminal device and the relay terminal device can be saved. In addition, the embodiment of the disclosure can also avoid that relay terminal devices with different channel conditions select the same resource to respond.

Description

Method, device, and computer readable medium for device-to-device (D2D) communication

Technical Field

Embodiments of the present disclosure relate generally to communication technology and, more particularly, relate to a method, device, and computer-readable medium for device-to-device (D2D) communication.

Background

Currently, in the third generation partnership project (3 GPP) standardization for Long Term Evolution (LTE), further enhanced Device-to-Device (feD 2D) techniques have been proposed. For example, in the 3gpp RAN #72 and RAN #73 conferences, research technical topics have been proposed for D2D communication in Long Term Evolution (LTE) for internet of things (IoT) and user wearable mobile devices. The techniques can support sidelink (sidelink) communications with IoT devices with limited operating bandwidth and wearable devices in a relay environment. In a feD2D scenario, a far end terminal device (e.g., a wearable device) is in the vicinity of the relay terminal device. Therefore, power efficiency and resource utilization efficiency of relay terminal devices and remote terminal devices (e.g., user wearable mobile devices) are also important research topics.

Disclosure of Invention

In general, embodiments of the present disclosure relate to a method of D2D communication and a corresponding terminal device.

In a first aspect, embodiments of the present disclosure provide a method for device-to-device (D2D) communication. The method comprises the following steps: transmitting, at a remote terminal device in the D2D communication, a discovery request for the D2D communication to a relay terminal device in the D2D communication; obtaining an association of channel conditions related to discovery of D2D communication with at least one set of resources in a resource pool; and listening, on the resource pool, for a response to the discovery request from the relay terminal device based on the association.

In a second aspect, embodiments of the present disclosure provide a method for device-to-device (D2D) communication. The method comprises the following steps: obtaining, at a relay terminal device in D2D communication, an association of channel conditions related to discovery of D2D communication with at least one set of resources in a resource pool; in response to receiving a discovery request for D2D communication from a remote terminal device in the D2D communication, determining current channel conditions for discovery of the D2D communication; based on the association, a set of resources, corresponding to current channel conditions, of the at least one set of resources for a response to the discovery request is determined.

In a third aspect, embodiments of the present disclosure provide a remote terminal device. The remote terminal device includes: at least one processor; and a memory coupled to the at least one processor, the memory having instructions stored therein that, when executed by the at least one processing unit, cause the remote terminal device to perform actions comprising: transmitting a discovery request for D2D communication to a relay terminal device in the D2D communication; obtaining an association of channel conditions related to discovery of D2D communication with at least one set of resources in a resource pool; and listening, on the resource pool, for a response to the discovery request from the relay terminal device based on the association.

In a fourth aspect, an embodiment of the present disclosure provides a relay terminal device. The relay terminal device includes: at least one processor; and a memory coupled with the at least one processor, the memory having instructions stored therein that, when executed by the at least one processing unit, cause the relay terminal device to perform actions comprising: obtaining an association of channel conditions related to discovery of D2D communications with at least one set of resources in a resource pool; in response to receiving a discovery request for a D2D communication from a remote terminal device in the D2D communication, determining a current channel condition for discovery of the D2D communication; based on the association, a set of resources of the at least one set of resources corresponding to current channel conditions for a response to the discovery request is determined.

In a fifth aspect, embodiments of the present disclosure provide a computer-readable storage medium. The computer readable storage medium comprises program code stored thereon, which when executed by an apparatus, causes the apparatus to perform a method according to the first or second aspect.

It should be understood that the statements herein reciting aspects are not intended to limit the critical or essential features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become apparent from the following description.

Drawings

The above and other features, advantages and aspects of various embodiments of the present disclosure will become more apparent by referring to the following detailed description when taken in conjunction with the accompanying drawings, in which:

fig. 1 illustrates a block diagram of an example communication system in which embodiments of the present disclosure may be implemented;

FIG. 2 illustrates an interaction diagram of communications, in accordance with certain embodiments of the present disclosure;

FIG. 3 illustrates a flow diagram of an example method in accordance with certain embodiments of the present disclosure;

FIG. 4 illustrates a flow diagram of an example method in accordance with certain embodiments of the present disclosure;

FIG. 5 illustrates a block diagram of a communication device, in accordance with certain embodiments of the present disclosure;

FIG. 6 illustrates a block diagram of a communication device, in accordance with certain embodiments of the present disclosure; and

fig. 7 illustrates a block diagram of a communication device, in accordance with certain embodiments of the present disclosure.

The same or similar reference numbers are used throughout the drawings to refer to the same or like elements.

Detailed Description

Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While certain embodiments of the present disclosure are shown in the drawings, it is to be understood that the present disclosure may be embodied in various forms and should not be construed as limited to the embodiments set forth herein, but rather are provided for a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the disclosure are for illustration purposes only and are not intended to limit the scope of the disclosure.

The term "network device" as used herein refers to any suitable entity or device capable of providing a cell or coverage such that a terminal device may access a network through or receive services from it. Examples of network devices include, for example, base stations. The term "base station" (BS) as used herein may refer to a node B (NodeB or NB), an evolved node B (eNodeB or eNB), a Remote Radio Unit (RRU), a Radio Head (RH), a Remote Radio Head (RRH), a relay, or a low power node such as a pico base station, a femto base station, or the like.

The terms "terminal device" or "user equipment" (UE) as used herein refer to any entity or device capable of wireless communication with network devices or with each other. As an example, the terminal device may include a Mobile Terminal (MT), a Subscriber Station (SS), a Portable Subscriber Station (PSS), a Mobile Station (MS) or an Access Terminal (AT), the above-mentioned device mounted in a vehicle, and a machine or an appliance having a communication function, and the like.

The terms "include" and variations thereof as used herein are inclusive and open-ended, i.e., "including but not limited to. The term "based on" is "based, at least in part, on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment". Relevant definitions for other terms will be given in the following description.

Fig. 1 illustrates an example communication system 100 in which embodiments of the present disclosure may be implemented. In this example, the communication system 100 includes a network device 110, a remote terminal device 120, and a relay terminal device 130. It will be appreciated that the term "far end terminal device" or "far end user device" as used herein refers to a terminal device that is in sidelink communication with a relay terminal device and may then relay communication with a network device via the relay terminal device. The term "relay terminal device" or "relay user equipment" as used herein refers to a relay terminal device capable of sidelink communication with a remote terminal device. Through this sidelink communication, the relay terminal device may provide a relay service for the remote terminal device, so that the remote terminal device can communicate with the network device by means of the relay service.

The network device 100 can communicate with the relay terminal device 130. The remote terminal device 120 and the relay terminal device 130 may be any suitable terminal devices whose role in network communications is determined by their relative locations. That is, the remote terminal device 120 is in the vicinity of the relay terminal device 130, and thus can perform D2D communication (e.g., sidelink communication) with the relay terminal device 130, and thereby communicate with the network device 110. It should be understood that the number of network devices, relay terminal devices and remote terminal devices shown in fig. 1 is for illustration purposes only and is not intended to be limiting. Communication system 100 may include any suitable number of network devices, relay terminal devices, and remote terminal devices.

Communications in communication system 100 may conform to any suitable wireless communication technology and corresponding communication standards. Examples of communication technologies include, but are not limited to, long Term Evolution (LTE), LTE-advanced (LTE-a), wideband Code Division Multiple Access (WCDMA), code Division Multiple Access (CDMA), global system for mobile communications (GSM), orthogonal frequency division multiple access (OFDM), wireless Local Area Network (WLAN), worldwide Interoperability for Microwave Access (WiMAX), bluetooth, zigbee technologies, machine Type Communication (MTC), D2D, or M2M, among others. Moreover, the communication may be performed according to any suitable communication protocol, including, but not limited to, transmission Control Protocol (TCP)/Internet Protocol (IP), hypertext transfer protocol (HTTP), user Datagram Protocol (UDP), session Description Protocol (SDP), and the like.

The discovery process of the conventional D2D communication includes the following two modes: one mode (referred to as "mode a") requires the relay terminal device to broadcast the announcement message, while the other mode (referred to as "mode B") requires the relay terminal device to send a response message in response to a request message from the remote terminal device. In mode a, the relay terminal device broadcasts the announcement message using a plurality of frequency bands in one subframe. Therefore, the remote terminal device needs to monitor the entire operating frequency band of the relay terminal device to find a suitable relay terminal device. However, the operating band of the relay terminal device is far beyond the operating bandwidth of the narrowband remote terminal device. For this reason, the narrowband remote terminal device must monitor the operation band of the relay terminal device section by section in units of its own operation band. This takes a long time and consumes much energy and is therefore very inefficient.

In mode B, the remote terminal device sends a discovery request (e.g., a request Message) for D2D communication to initiate D2D communication. The relay terminal device receives the discovery request from the remote terminal device and then transmits a message responding to the request to the remote terminal device. Since the relay terminal device has no information about which resources should be utilized to respond to the request, the relay terminal device may randomly select resources to respond to the request. Therefore, the remote end device must listen to all resources to receive the response. Thereby causing a waste of energy and power for the remote terminal device. Further, since the relay terminal apparatus randomly selects a resource to respond to the request, there is a case where a plurality of relay terminal apparatuses select the same resource, and the remote terminal apparatus will not be able to correctly receive the response. The remote terminal device cannot preferentially receive a response from the relay terminal device having the discovered channel condition of the good D2D communication.

A method of associating resources used for transmitting discovery requests for D2D communication with resources responding to the requests has been proposed. In particular, the relay terminal device may determine the resource to respond to the request based on the resource for which the remote terminal device transmits the discovery request for D2D communication. Thus, the remote end terminal device will not have to listen to all resources to receive the response. However, there is still a case where a plurality of relay terminal devices select the same resource, and the remote terminal device will not be able to correctly receive the response. Further, the remote terminal device still cannot preferentially receive a response from the relay terminal device having the found channel condition of good D2D communication, and this method also has a case where energy is wasted.

To better enable the discovery process of D2D communication, embodiments of the present disclosure provide an association between channel conditions for discovery of D2D communication and a set of resources for transmission. Fig. 2 shows an interaction signaling diagram 200 between D2D communication entities according to an embodiment of the disclosure. The term "resource pool" as used herein refers to a collective term for a number of resources in the time and/or frequency domain that may be used to transmit information. The term "resource set" as used herein indicates a set of resources including a certain number (1 or more) of time and/or frequency domains for transmitting information.

In general, according to embodiments of the present disclosure, the remote terminal device 120 may transmit 210 a discovery request for D2D communication to the relay terminal device 130. Optionally, the network device 210 may transmit 220 to the remote terminal device 120 and the relay terminal device 130 an association of channel conditions related to discovery of D2D communication with at least one set of resources in the resource pool. This association indicates a correspondence between different channel conditions and different sets of resources. In other words, such an association indicates that for a particular channel condition, a particular set of resources may be used for D2D communication discovery. Channel conditions may be represented by channel-related parameters such as Sidelink Discovery Reference Signal Received Power (SD-RSRP). For example, table 1 below shows the correspondence of SD-RSRP to different sets of resources in the resource pool. The resource in the resource pool may be a resource used by a Physical Sidelink Discovery Channel (PSDCH), and the resource set may be a set of PSDCH resources.

TABLE 1

SD-RSRP	PSDCH resources
		[X ₀ ,X ₁ ]	1
[X ₁ ,X ₂ ]	2
		...	...
[X _n-1 ,X _n ]	N

In the example shown in Table 1, the channel conditions are represented by SD-RSRP, different values of SD-RSRP (e.g., X) ₀ ，X ₁ ，....,X _n ) Different cases of channel conditions may be represented, with a set of resources being represented by a set of PSDCH resources, with different sets of PSDCH resources having different reference numbers (e.g., 1,2. More specific description about table 1 will be given below.

Note that table 1 is merely exemplary, and the association may be represented by other forms, such as a tree structure or the like. It is to be understood that the manner of obtaining the association shown in fig. 2 is only an example, and the remote terminal device 120 and the relay terminal device 130 may obtain the association in any suitable manner. For example, the association may be stored in advance in the remote terminal device 120 and the relay terminal device 130. Alternatively, the association may also be stored in a database accessible by the remote terminal device 120 and the relay terminal device 130.

The relay terminal device 130 may determine 230 current channel conditions for D2D communication discovery in response to receiving a discovery request for D2D communication from the remote terminal device 120. For example, relay device 130 may determine channel conditions by measuring SD-RSRP of the current channel. The relay terminal device may also determine 240 a set of resources of the at least one set of resources corresponding to the current channel conditions for a response to the communication request based on the association. The remote end terminal device 120 may listen 250 for a response to the discovery request from the relay terminal device 130 on the resource pool based on the association.

According to the procedure illustrated in fig. 2, the remote terminal device 120 and the relay terminal device 130 are allowed to obtain an association between the discovered channel conditions of the D2D communication and the set of resources for transmission. The relay terminal device 130 may select a specific resource in response to the discovery request of the D2D communication according to the association and its current channel condition. The remote terminal device 120 may preferentially receive a response from a relay terminal device having a good channel condition for D2D communication discovery according to the association. The remote terminal device 120 can thus save energy and power consumption. In addition, the embodiment of the disclosure avoids relay terminal devices with different channel conditions from selecting the same resource to respond.

Certain example embodiments according to the present disclosure will now be described in detail. Fig. 3 illustrates a flow diagram of an example method 300 in accordance with certain embodiments of the present disclosure. The method 300 may be implemented at the remote terminal device 120 as shown in fig. 1.

At block 305, the remote terminal device 120 transmits a discovery request for D2D communication to the relay terminal device 130 in D2D communication. In some embodiments, the discovery request for D2D communication may be, for example, a request message. In an exemplary embodiment, the resources for transmitting the discovery request may be selected by the remote terminal device 120. Alternatively, the network device 110 may allocate resources to the remote terminal device 120 for transmitting the discovery request.

The remote terminal device 120 may transmit the discovery request for D2D communication to the relay terminal device 130 in any suitable manner. For example, in some embodiments, the remote end-point device 120 may broadcast the discovery request. Alternatively, the remote end device 120 may multicast the discovery request. The remote end device 120 may also unicast the discovery request. It is to be understood that the embodiments of the present disclosure are not limited in this respect.

At block 310, the remote terminal device 120 obtains an association of channel conditions related to discovery of D2D communications with at least one set of resources in the resource pool. The channel conditions related to the discovery of D2D communication may be any suitable information, for example, indicative of channel fading conditions. The channel conditions related to the discovery of D2D communications may also be any suitable information indicating the channel gain situation.

As described above, in some embodiments, the channel condition may be represented by SD-RSRP. In some embodiments, the resources in the resource pool may be PSDCH resources and the resource set may be a collection of PSDCH resources.

As shown in Table 1, for example only, when the value of SD-RSRP is [ X ] ₀ ,X ₁ ]In the interval, the channel condition is good, and the corresponding resource set is the first PSDCH resource set (denoted as 1_psdch). In other words, the set of resources corresponding to good channel conditions is 1\ PSDCH. When the value of SD-RSRP is [ X ] ₁ ,X ₂ ]In the interval, the channel condition is moderate, and the corresponding resource set is the second PSDCH resource set (denoted as 2_psdch). In other words, the set of resources corresponding to moderate channel conditions is 2\ u PSDCH. When the value of SD-RSRP is [ X ] _n-1 ,X _n ]In the interval, the channel condition is poor, and the corresponding resource set is the nth PSDCH resource set (denoted as N _ PSDCH). In other words, the set of resources corresponding to poor channel conditions is N _ PSDCH.

In some embodiments, remote terminal device 120 may receive the association (e.g., table 1) from network device 110 via radio resource control signaling (RRC). Alternatively, the association (e.g., table 1) may also be preconfigured in the remote terminal device 120. In another example embodiment, the association (e.g., table 1) may be transmitted by the network device 110 to the remote terminal device 120 periodically. In other embodiments, the association (e.g., table 1) may be stored in a database accessible by the remote terminal device 120.

In some embodiments, method 300 may also include block 315. At block 315, the remote end terminal device 120 sends an indication of the lower bound channel condition to the relay terminal device 130. In some embodiments, the indication of the lower bound channel condition may be transmitted by the remote terminal device 120 to the relay terminal device 130 along with the discovery request for D2D communication described above. Alternatively, the far-end terminal device 120 may separately transmit the indication of the lower limit channel condition to the relay terminal device 130. In an exemplary embodiment, the resource used to transmit the indication may be selected by the remote terminal device 120. Alternatively, the network device 110 may allocate resources to the remote terminal device 120 for sending the indication.

The remote terminal device 120 may send the indication of the lower bound channel condition to the relay terminal device 130 in any suitable manner. For example, in some embodiments, the remote end device 120 may broadcast the indication. Alternatively, the far end terminal device 120 may multicast the indication. The remote end device 120 may also unicast the indication. It is to be understood that the embodiments of the present disclosure are not limited in this respect.

At block 320, the remote end device 120 may listen on the resource pool for a response to the discovery request from the relay end device 130 based on the association. For example only, in some embodiments, as shown in table 1, resource set 1 \/psdch corresponds to good channel conditions. The remote terminal device 120 may preferentially listen for responses to discovery requests for D2D communications on resource set 1 \/psdch (referred to as the "first resource set"). If the remote end terminal device 120 successfully listens on the first set of resources for a response to the discovery request for D2D communication, the remote end terminal device 120 may not have to continue listening to the other set of resources. In this way, the remote terminal device 120 can establish D2D communication with the relay remote terminal device 130 whose channel condition is optimal, and thus the D2D communication quality therebetween can be secured. Furthermore, the remote end device 120 does not need to consume energy and power to continue listening to other sets of resources. This is advantageous for improving the power efficiency of the remote terminal apparatus 120.

In some embodiments, the remote end terminal device 120 does not hear the response on the first set of resources, the remote end terminal device 120 may continue to listen for the resource set 2 \/psdch (referred to as the "second set of resources") corresponding to the medium channel conditions. Similarly, if the remote end terminal device 120 successfully listens for the response on the second set of resources, the remote end terminal device 120 may not have to continue listening for other sets of resources. If the remote end terminal device 120 fails to hear the response on the second set of resources, the remote end terminal device 120 may continue to listen on the other set of resources.

Fig. 4 illustrates a flow diagram of an example method 400 in accordance with certain embodiments of the present disclosure. The method 400 may be implemented at the relay remote terminal device 130 as shown in fig. 1.

At block 405, the relay terminal device 130 may obtain an association of channel conditions related to discovery of D2D communication in combination with at least one resource in a resource pool. As described above, the channel conditions related to the discovery of D2D communication may be any suitable information, for example, indicative of channel fading conditions. The channel conditions related to the discovery of D2D communications may also be any suitable information indicating the channel gain situation.

Merely by way of example, in some embodiments, the relay terminal device 130 may obtain table 1 above, which illustrates the association of channel conditions related to discovery of D2D communications with at least one set of resources in a resource pool. Similarly, as shown in Table 1, for example only, when the value of SD-RSRP is [ X ] ₀ ,X ₁ ]In the interval, the channel condition is good, and the corresponding resource set is the first PSDCH resource set (denoted as 1_psdch). In other words, the set of resources corresponding to good channel conditions is 1\ PSDCH. When the value of SD-RSRP is [ X ] ₁ ,X ₂ ]In the interval, the channel condition is moderate, and the corresponding resource set is the second PSDCH resource set (denoted as 2_psdch). In other words, the set of resources corresponding to moderate channel conditions is 2\ u PSDCH. When the value of SD-RSRP is [ X ] _n-1 ,X _n ]In the interval, the channel condition is poor, and the corresponding resource set is the nth PSDCH resource set (denoted as N _ PSDCH). In other words, the set of resources corresponding to poor channel conditions is N _ PSDCH.

In some embodiments, relay terminal device 130 may receive the association (e.g., table 1) from network device 110 via radio resource control signaling (RRC). Alternatively, the association (e.g., table 1) may also be configured in advance in the relay terminal device 130. In another example embodiment, the association (e.g., table 1) may be transmitted by network device 110 to relay terminal device 130 periodically. In other embodiments, the association (e.g., table 1) may be stored in a database accessible by the relay terminal device 130.

At block 410, the relay terminal device 130 may determine current channel conditions for discovery of D2D communications in response to receiving a discovery request for D2D communications from the remote terminal device 120. The relay terminal device 130 may measure the channel fading condition of the discovery channel of the D2D communication between it and the remote terminal device 120. The relay terminal device 130 may measure the channel gain condition of the discovery channel of the D2D communication between it and the remote terminal device 120. Alternatively, by way of example only, in some embodiments, the relay terminal device 130 may measure the SD-RSRP of the discovery channel of the D2D communication between it and the remote terminal device 120 to determine the current channel conditions. For example, the relay terminal device 130 may determine that the value of SD-RSRP of the current channel is X'.

At block 415, the relay terminal device 130 may determine a set of resources corresponding to the current channel of the at least one set of resources for a response to the communication request based on the association. For example only, in some embodiments, the relay terminal device 130 may look up table 1 to determine the set of resources for the current channel condition. For example, if the value X' of SD-RSRP of the current channel is in the interval [ X ₀ ,X ₁ ]Which indicates that the current channel conditions are good, the relay terminal device 130 may determine that the aggregate resource for the response to the discovery request is 1 \ psdch. Similarly, if the value X' of SD-RSRP of the current channel is in the interval [ X ₁ ,X ₂ ]Which indicates current channel conditions are medium, the relay terminal device 130 may determine that the aggregate resource for the response to the discovery request is 2\ psdch. If the value X' of SD-RSRP of the current channel is in the interval [ X _N-1 ,X _N ]Which means that the current channel condition is poor, the relay terminal device 130 may determine that the aggregated resource for the response to the discovery request is N _ PSDCH. It will be appreciated that in some embodiments, the relay terminal device 130 may not transmit the response on the determined resources.

In some embodiments, the resource used for transmitting the discovery request of D2D communication may be associated with the resource responding to the request, and the relay terminal device 130 may preliminarily determine the resource set of the response to the request according to the resource receiving the discovery request, and then further determine the resource set of the response according to the association. Alternatively, the relay terminal device 130 may preliminarily determine the set of resources for the response to the request according to the association described above, and then further determine the set of resources for the response according to the resources for which the discovery request is received.

In some embodiments, method 400 may also include block 420. At block 420, the relay terminal device 130 may obtain an indication of the lower bound channel condition. In some embodiments, the relay terminal device 130 may receive an indication of the lower bound channel condition from the remote terminal device 120 together with a discovery request for D2D communication. Alternatively, the relay terminal device 130 may receive the indication of the lower bound channel condition separately from the remote terminal device 120. In other embodiments, the relay terminal device 130 may receive an indication of the lower bound channel condition from the network device 110.

In certain embodiments, method 400 further includes block 425. In block 425, the relay terminal device 130 may respond to the discovered request in response to the current channel condition exceeding the lower bound channel condition. In some embodiments, and by way of example only, the indication of the lower bound channel condition is assumed to be a value X of SD-RSRP _ref If the value of SD-RSRP of the current channel condition is X ', the relay terminal device 130 may compare the value X' with the value X _ref A comparison is made. If the value X' is greater than the value X _ref Which indicates that the current channel conditions are acceptable, the relay terminal device 130 may respond to the discovery request on resources corresponding to the current channel conditions. If the value X' is smaller than the value X _ref Which indicates that the current channel condition is relatively poor, the relay terminal device 130 may not respond to the discovery request. Therefore, the relay terminal device 130 can save energy consumption. While further reducing interference with the PC5 interface.

Fig. 5 is a block diagram of a device 500 that may implement embodiments in accordance with the present disclosure. As shown in fig. 5, the device 500 includes one or more processors 510, one or more memories 520 coupled to the processors 510, one or more transmitters and/or receivers 540 coupled to the processors 510

The processor 510 may be of any suitable type suitable to the local technical environment, and the processor 510 may include, by way of non-limiting example, one or more general purpose computers, special purpose computers, microprocessors, digital signal processors, and processors based on a multi-core processor architecture. The device 500 may have multiple processors, such as application specific integrated circuit chips, that are synchronized in time with the main processor.

The memory 520 may be of any suitable type suitable to the local technical environment and may be implemented using any suitable data storage technology, including but not limited to non-transitory computer-readable media, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems.

Memory 520 stores at least a portion of instructions 530. The transmitter/receiver 540 may be adapted for bi-directional communication. The transmitter/receiver 540 has at least one antenna for communication and the transmitter/receiver 540 may support fiber optic communication, but in practice there may be several access nodes referred to by the present disclosure. The communication interface may represent any necessary interface for communicating with other network elements.

The instructions 530 are assumed to comprise program instructions that, when executed by the associated processor 510, cause the device 500 to operate in accordance with the embodiments described in this disclosure with reference to fig. 3 and 4. That is, embodiments of the present disclosure may be implemented by the processor 510 of the device 500, or by hardware, or by a combination of software and hardware, as computer software execution.

Fig. 6 illustrates a block diagram of an apparatus 600, in accordance with certain embodiments of the present disclosure. It is understood that the apparatus 600 may be implemented on the remote terminal device 120 side shown in fig. 1. As shown in fig. 6, the apparatus 600 (e.g., the remote terminal device 120) includes a transmission unit 610, an obtaining unit 620, and a listening unit 630. The transmission unit 610 is configured to transmit a discovery request for D2D communication to a relay terminal device in D2D communication. The obtaining unit 620 is configured to obtain an association of channel conditions related to discovery of the D2D communication with at least one set of resources in a resource pool. The listening unit 630 is configured to listen on the resource pool for a response to the discovery request from the relay terminal device based on the association.

Fig. 7 illustrates a block diagram of an apparatus 700 according to certain embodiments of the present disclosure. It is to be appreciated that the apparatus 700 may be implemented on the side of the relay terminal device 130 shown in fig. 1. As shown, the apparatus 700 (e.g., the relay terminal device 130) includes an obtaining unit 710, a first determining unit 720, and a second determining unit 730. The obtaining unit 710 is configured to obtain an association of channel conditions related to discovery of D2D communication with at least one set of resources in a resource pool. The first determining unit 720 is configured to determine, in response to receiving a discovery request of a D2D communication from a remote terminal device, a current channel condition for discovery of the D2D communication. The second determining unit is configured to determine a set of resources of the at least one set of resources corresponding to the current channel condition for a response to the communication request based on the association.

It should be understood that means (not shown) for performing each step of the interaction 200, the method 300 and the method 400 described with reference to fig. 1 to 5 may also be comprised in the apparatus 600 and the apparatus 700. The operations and features described above in connection with fig. 1 to 7 are equally applicable to the

apparatuses

600 and 700 and the units included therein, and have the same effects, and detailed details are not repeated.

The elements included in apparatus 600 and apparatus 700 may be implemented in a variety of ways including software, hardware, firmware, or any combination thereof. In one embodiment, one or more of the units may be implemented using software and/or firmware, such as machine executable instructions stored on a storage medium. In addition to or in the alternative to machine-executable instructions, some or all of the elements in apparatus 600 and apparatus 700 may be implemented at least in part by one or more hardware logic components. By way of example, and not limitation, exemplary types of hardware logic components that may be used include Field Programmable Gate Arrays (FPGAs), application Specific Integrated Circuits (ASICs), application Specific Standards (ASSPs), systems on a chip (SOCs), complex Programmable Logic Devices (CPLDs), and so forth.

The elements shown in fig. 6 and 7 may be implemented partially or wholly as hardware modules, software modules, firmware modules, or any combination thereof. In particular, in certain embodiments, the processes, methods, or procedures described above may be implemented by a communication device or hardware in a communication device. For example, the relay terminal device and the remote terminal device may utilize their transmitters, receivers, transceivers and/or processors or controllers to implement the

methods

300 and 400.

In general, the various example embodiments of this disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Certain 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. While aspects of embodiments of the disclosure have been illustrated or described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that the 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.

By way of example, embodiments of the disclosure may be described in the context of machine-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. In various embodiments, the functionality of the program modules may be combined or divided between program modules as described. Machine-executable instructions for program modules may be executed within local or distributed devices. In a distributed facility, program modules may be located in both local and remote memory storage media.

Computer program code for implementing the methods of the present disclosure may be written in one or more programming languages. These computer program codes may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the computer or other programmable data processing apparatus, cause the functions/acts specified in the flowchart and/or block diagram block or blocks to be performed. The program code may execute entirely on the computer, partly on the computer, as a stand-alone software package, partly on the computer and partly on a remote computer or entirely on the remote computer or server.

In the context of this disclosure, a machine-readable medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination thereof. More detailed examples of a machine-readable storage medium include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical storage device, a magnetic storage device, or any suitable combination thereof.

Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In some cases, multitasking or parallel processing may be beneficial. Likewise, while the above discussion contains certain specific implementation details, this should not be construed as limiting the scope of any invention or claims, but rather as describing particular embodiments that may be directed to particular inventions. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination.

Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A method for device-to-device (D2D) communication, comprising:

transmitting, at a remote terminal device in the D2D communication, a discovery request for the D2D communication to a relay terminal device in the D2D communication;

obtaining, at a remote terminal device in the D2D communication, an association of channel conditions related to discovery of the D2D communication with at least one set of resources in a resource pool; and

at a remote terminal device in the D2D communication, listening on the resource pool for a response to the discovery request from the relay terminal device based on the association.

2. The method of claim 1, further comprising:

sending an indication of a lower bound channel condition to the relay terminal device such that the relay terminal device responds to the discovery request only if the channel condition exceeds the lower bound channel condition.

3. The method of claim 1, wherein determining the association comprises:

the association is received from a network device via radio resource control signaling (RRC).

4. The method of claim 1, wherein the at least one set of resources comprises a first set of resources associated with a first channel condition and a second set of resources associated with a second channel condition, and wherein listening for a response to the discovery request from a relay terminal device comprises:

in response to determining that the first channel condition is better than the second channel condition based on the association, listen for the response on the first set of resources; and

listening for the response on the second set of resources if the response is not listened to on the first set of resources.

5. A method for device-to-device (D2D) communication, comprising:

obtaining, at a relay terminal device in the D2D communication, an association of channel conditions related to discovery of the D2D communication with at least one set of resources in a resource pool;

determining, at a relay terminal device in the D2D communication, a current channel condition for discovery of the D2D communication in response to receiving a discovery request of the D2D communication from a remote terminal device in the D2D communication;

determining, at a relay terminal device in the D2D communication, a set of resources of the at least one set of resources corresponding to the current channel condition for a response to the discovery request based on the association,

wherein the association is obtained by a remote terminal device in the D2D communication, and

wherein the association is for listening, by a remote terminal device in the D2D communication, on the resource pool for a response to the discovery request from the relay terminal device based on the association.

6. The method of claim 5, further comprising:

obtaining an indication of a lower bound channel condition; and

responding to the discovery request in response to the current channel condition exceeding the lower bound channel condition.

7. The method of claim 6, wherein obtaining the indication of the lower bound channel condition comprises:

receiving the indication from the remote terminal device; or

Receiving the indication from a network device.

8. The method of claim 5, wherein obtaining the association comprises:

9. A remote terminal device comprising:

at least one processor; and

a memory coupled with the at least one processor, the memory having instructions stored therein that, when executed by the at least one processing unit, cause the remote terminal device to perform actions comprising:

transmitting a discovery request for D2D communication to a relay terminal device in the D2D communication;

obtaining an association of channel conditions related to discovery of the D2D communication with at least one set of resources in a resource pool; and

listening, on the resource pool, for a response to the discovery request from the relay terminal device based on the association.

10. The remote terminal device of claim 9, wherein the actions further comprise:

11. The remote terminal device of claim 9, wherein determining the association comprises:

the association is received from the network device via radio resource control signaling (RRC).

12. The remote terminal device of claim 9, wherein the at least one set of resources comprises a first set of resources associated with a first channel condition and a second set of resources associated with a second channel condition, and wherein listening for a response from a relay terminal device to the discovery request comprises:

in response to determining, based on the association, that the first channel condition is better than the second channel condition, listening for the response on the first set of resources; and

13. A relay terminal device, comprising:

at least one processor; and

a memory coupled with the at least one processor, the memory having instructions stored therein that, when executed by the at least one processing unit, cause the relay terminal device to perform acts comprising:

obtaining an association of channel conditions related to discovery of D2D communication with at least one set of resources in a resource pool;

in response to receiving a discovery request for the D2D communication from a remote terminal device in the D2D communication, determining current channel conditions for discovery of the D2D communication;

determining a set of resources of the at least one set of resources corresponding to the current channel condition for a response to the discovery request based on the association,

14. The relay terminal device of claim 13, the acts further comprising:

obtaining an indication of a lower bound channel condition; and

15. The relay terminal device of claim 14, wherein obtaining the indication of the lower bound channel condition comprises:

receiving the indication from the remote terminal device; or

Receiving the indication from a network device.

16. The relay terminal device of claim 13, wherein obtaining the association comprises:

17. A computer-readable medium having instructions stored thereon, which, when executed by at least one processing unit of a machine, cause the machine to implement the method recited by any one of claims 1-4.

18. A computer-readable medium having instructions stored thereon, which, when executed by at least one processing unit of a machine, cause the machine to implement the method recited by any one of claims 5-8.