WO2018018602A1

WO2018018602A1 - Methods, terminals, and base stations for end-to-end communication

Info

Publication number: WO2018018602A1
Application number: PCT/CN2016/092250
Authority: WO
Inventors: Yueping WU; Xiang Chen; Eddy Chiu
Original assignee: Huizhou TCL Mobile Communication Co Ltd
Current assignee: Huizhou TCL Mobile Communication Co Ltd
Priority date: 2016-07-29
Filing date: 2016-07-29
Publication date: 2018-02-01
Anticipated expiration: 2019-01-29
Also published as: CN109417775B; CN109417775A

Abstract

A method for end-to-end communication is disclosed that includes: receiving an assigned first group index that corresponds to a communications resource set, wherein different group indices correspond to different communications resource sets; and transmitting a first message and/or forwarding a received second message using the communications resource set corresponding to the first group index. An associated terminal and a base station are also disclosed. According to the disclosure， other terminals belonging to the same group with the one sending the second message can receive the second message, thus the potential security risks can be eliminated, the reliability can be improved， and the transmission range for the messages can be effectively widened.

Description

METHODS， TERMINALS， AND BASE STATIONS FOR END-TO-END COMMUNICATION

TECHNICAL FIELD

This disclosure relates generally to communications， and more particularly， to methods， terminals， and base stations for end-to-end communication.

BACKGROUND

Vehicle-to-everything (V2X) communication is the passing of information from a vehicle to any entity that may affect the vehicle， e.g.， another vehicle， a pedestrian， or an infrastructure， and vice versa. The information exchange can help to warn drivers of potential risks and improve traffic efficiency， so the V2X communication has very broad application prospects.

Based on the previously developed device-to-device (D2D) technologies in Long Term Evolution (LTE) ， new functionalities of V2X communication have been investigated and the evolving LTE-based V2X communication has a high reliability and can re-use the existing LTE-based network infrastructure， and thus is advantageous to its promotion and maintenance.

However， LTE-based D2D communication is half-duplex rather than full duplex， so is the evolving LTE-based V2X communication， meaning if in V2X communication two terminals attempt to communicate messages therebetween over a same channel at the same time， neither shall be able to receive the message from the other， which may lead to security risks and even traffic accidents， severely affecting the reliability. In addition， fading of the propagation environment together with the terminals’limited transmission power collectively lead to a largely limited transmission range.

SUMMARY

A principle technical problem to be addressed by the disclosure is to provide methods， terminals， and base stations for end-to-end communication， to provide solutions for the half-duplex issues as well as short transmission range issues existing in the prior art.

According to an aspect of the disclosure， a method for end-to-end communication is provided that comprises： receiving an assigned first group index that corresponds to a communications resource set， where different group indices may correspond to different communications resource sets， respectively； and transmitting a first message and/or forwarding a received second message using the communication resource set corresponding to the first group index.

In some embodiments， the method may further comprise： using other resources outside of the resource set corresponding to the first group index for receiving.

In some embodiments， the second message may come from a terminal assigned a second group index， and forwarding the second message may enable another terminal also assigned the second group index to receive the second message.

In some embodiments， each communications resource set may comprise multiple transmission time intervals (TTIs) .

In some embodiments， each TTI may comprise one or more sub-frames or a portion of sub-frame.

In some embodiments， the block of transmitting the first message and forwarding the received second message may comprise： obtaining the information related to a resource used to transmit the second message； and selecting a first resource， which corresponds to the resource that is used to transmit the second message， to forward the second message， and selecting a second resource different from the first resource to transmit the first message.

In some embodiments， the block of transmitting the first message and forwarding the received second message may alternatively comprise： randomly selecting different resources to transmit the first message and forward the second message， respectively.

In some embodiments， the block of forwarding the received second message may comprise： forwarding the second message when the forwarding conditions are satisfied.

In some embodiments， the forwarding conditions for the second message may comprise at least one of： a number of the remaining forwarding times for the second message is greater than zero； a propagation distance of the second message is smaller than a preset threshold； a propagation duration of the second message is smaller than a predetermined value； and the second message is an emergency message.

In some embodiments， the block of transmitting the first message and/or forwarding the received second message using the communications resource set corresponding to the first group index may comprise： using every resource in the corresponding communications resource set to transmit the first message if an emergency event happens； otherwise， if an emergency event doesn’t happen， using only part of the resources in the corresponding communications resource set to transmit the first message.

In some embodiments， initial forwarding times for the first message may be set equal to a total number of all the group indices (i.e.， a total number of all the groups) minus one.

In some embodiments， the communications resource set corresponding to the first group index may comprise multiple SA resources configured to transmit the scheduling assignment (SA) information and multiple data resources configured to transmit data， and each SA resource is not later than the associated one or more data resources in the time domain.

In some embodiments， each SA resource and the associated data resource may correspond to different sub-carriers in the frequency domain， respectively.

In some embodiments， the different communications resource sets corresponding to different group indices may be interleaved with each other in the time and/or the frequency domain.

According to another aspect of the disclosure， another method for end-to-end communication is also provided that comprises： dividing the terminals under coverage into at least two groups each to be assigned a group index that corresponds to a communications resource set， where different group indices may correspond to different communications resource sets， respectively； and assigning a first group index to a terminal， so that the terminal can transmit a first message and/or forward a second message using the communications resource set corresponding to the first group index.

In some embodiments， each communications resource set may comprise multiple transmission time intervals.

In some embodiments， the number of terminals in at least one group may be greater than or equal to 2.

In some embodiments， the block of dividing the terminals under coverage into at least two groups may comprise： dividing the terminals under coverage into at least two groups according to a predetermined strategy and/or the terminals’positions， so as to enable at least one group of terminals to be substantially evenly distributed across the coverage area.

According to yet another aspect of the disclosure， a terminal is further provided that comprises： a receiving module configured to receive an assigned first group index that corresponds to a communications resource set， wherein different group indices may correspond to different communications resource sets， respectively； and a transmitting module configured to transmit a first message and/or forward a received second message using the communications resource set corresponding to the first group index.

In some embodiments， the receiving module may be further configured to use other resources outside of the resource set corresponding to the first group index for receiving.

In some embodiments， the second message may come from a terminal assigned a second group index， and the transmitting module may be configured to forward the second message to enable another terminal also assigned the second group index to receive the second message.

In some embodiments， each communications resource set may comprise multiple transmission time intervals (TTIs)

In some embodiments， the transmitting module may comprise： an acquisition unit configured to obtain the information of a resource used to transmit the second message； and a selection unit configured to select a first resource corresponding to the resource used to transmit the second message to forward the second message， and select a second resource different from the first resource to transmit the first message.

In some embodiments， the transmitting module may be configured to select randomly different resources to transmit the first message and forward the second message， respectively.

In some embodiments， the transmitting module may be configured to forward the second message when the forwarding conditions for the second message are satisfied.

In some embodiments， the transmitting module may be configured to use every resource in the corresponding communications resource set to transmit the first message if an emergency event happens； and， otherwise if an emergency event doesn’t happen， use only part of the resources in the corresponding communications resource set to transmit the first message.

In some embodiments， each SA and the associated data resource may correspond to different sub-carriers in the frequency domain， respectively.

According to still another aspect of the disclosure， a base station is provided that comprises： a division module configured to divide the terminals under coverage into at least two groups each to be assigned a group index that corresponds to a communications resource set， where different group indices may correspond to different communications resource sets， respectively； and an assignment module configured to assign a first group index to a terminal， so that the terminal can transmit a first message and/or forward a second message using the communications resource set corresponding to the first group index.

In some embodiments， the division module may be configured to divide the terminals under coverage into at least two groups according to a predetermined strategy and/or the terminals’positions， so as to enable at least one group of terminals to be substantially evenly distributed across the coverage area.

According to yet another aspect of the disclosure， a terminal is further provided that comprises a processor and a communication circuit coupled to the processor， the processor configured to： receive， via the communication circuit， an assigned first group index that corresponds to a communications resource set， wherein different group indices may correspond to different communications resource sets， respectively； and transmit a first message and/or forward a received second message via the communication circuit using the communications resource set corresponding to the first group index.

In some embodiments， the processor may be further configured to use other resources outside of the resource set corresponding to the first group index for receiving.

In some embodiments， the second message may come from a terminal assigned a second group index， and the processor configured to forward the second message may enable another terminal also assigned the second group index to receive the second message.

In some embodiments， each communications resource set may comprise multiple transmission time intervals (TTIs) . The second message may come from a terminal assigned a second group index， and the processor may be configured to forward the second message via the communication circuit in order to allow another terminal also assigned the second group index to receive the second message.

In some embodiments， the processor may be configured to： obtain the information related to the resource used to transmit the second message； and select a first resource corresponding to the resource used to transmit the second message to forward the second message via the communication circuit， and select a second resource different from the first resource to transmit the first message via the communication circuit.

In some embodiments， the processor may be configured to select randomly different resources to transmit the first message and forward the second message via the communication circuit， respectively.

In some embodiments， the processor may be configured to forward via the communication circuit the second message when the forwarding conditions for the second message are satisfied.

In some embodiments， the processor may be further configured to： use every resource in the corresponding communications resource set to transmit the first message via the communication circuit if an emergency event happens； and， otherwise if an emergency event doesn’t happen， use only part of the resources in the corresponding communications resource set to transmit the first message via the communication circuit.

In some embodiments， each SA resource and the associated data resource may correspond to different sub-carriers in the frequency domain.

According to still another aspect of the disclosure， a base station is provided that comprises a processor and a transceiver coupled to the processor， the processor configured to： divide the terminals under coverage into at least two groups each belonging to a group index that corresponds to a communications resource set， where different group indices may correspond to a different communications resource set， respectively； and assign a first group index to a terminal via the transceiver， so that the terminal can transmit a first message and/or forward a second message using the communications resource set corresponding to the first group index.

In some embodiments， the processor may be configured to divide the terminals under coverage into at least two groups according to a predetermined strategy and/or the terminals’positions， so as to enable at least one group of terminals to be substantially evenly distributed across the coverage area.

Advantages of the disclosure may follow： by forwarding a received second message， the other terminals belonging to the same group with the one sending the second message would be able to receive the second message， which can thus help to eliminate the potential security risks， improve the reliability， and can also effectively increase the transmission range of the messages.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart illustrating a first embodiment of a method for end-to-end communication according to the disclosure.

FIG. 2 is a flowchart illustrating a second embodiment of a method for end-to-end communication according to the disclosure.

FIG. 3 is a flowchart illustrating a third embodiment of a method for end-to-end communication according to the disclosure.

FIG. 4 is a flowchart illustrating a fourth embodiment of a method for end-to-end communication according to the disclosure.

FIG. 5 is a schematic diagram illustrating the comparison between an emergency mode and an ordinary mode in a fifth embodiment of a method for end-to-end communication.

FIG. 6 illustrates that a communications resource set comprises multiple SA resources and data resources in an embodiment of a method for end-to-end communication.

FIG. 7 illustrates that different communications resource sets are interleaved in the time or the frequency domain in an embodiment of a method for end-to-end communication.

FIG. 8 is a flowchart illustrating a sixth embodiment of a method for end-to-end communication according to the disclosure.

FIG. 9 is a block diagram of a first embodiment of a terminal according to the disclosure.

FIG. 10 is a block diagram of a second embodiment of a terminal according to the disclosure.

FIG. 11 is a block diagram of a third embodiment of a terminal according to the disclosure.

FIG. 12 is a block diagram of a first embodiment of a base station according to the disclosure.

FIG. 13 is a block diagram of a second embodiment of a base station according to the disclosure.

This disclosure includes references to “one embodiment， ” “a particular embodiment， ” “some embodiments， ” “various embodiments， ” or “an embodiment. ” The appearances of the phrases “in one embodiment， ” “in a particular embodiment， ” “in some embodiments， ” “in various embodiments， ” or “in an embodiment， ” do not necessarily refer to the same embodiment. Particular features， structures， or characteristics may be combined in any suitable manner consistent with this disclosure.

Various modules， units， circuits， or other components may be described or claimed as “configured to” perform a task or tasks. In such contexts， “configured to” is used to connote structure by indicating that the modules/units/circuits/components include structure (e.g.， circuitry) that performs those task or tasks during operation. As such， the modules/units/circuits/components can be said to be configured to perform the task even when the specified module/unit/circuit/component is not currently operational (e.g.， is not on) . The modules/units/circuits/components used with the “′configured to” language include hardware-for example， circuits， memory storing program instructions executable to implement the operation， etc. Reciting that a module/unit/circuit/component is “configured to” perform one or more tasks is expressly intended not to invoke 35 U.S.C. §112 (f) ， for that module/unit/circuit/component. Additionally， “configured to” can include a generic structure (e.g.， generic circuitry) that is manipulated by software and/or firmware (e.g.， an FPGA or a general-purpose processor executing software) to operate in a manner that is capable of performing the task (s) at issue. “Configured to” may also include adapting a manufacturing process (e.g.， a semiconductor fabrication facility) to fabricate devices (e.g.， integrated circuits) that are adapted to implement or perform one or more tasks.

As used herein， the term “based on” describes one or more factors that affect a determination. This term does not foreclose additional factors that may affect the determination. That is， a determination may be solely based on those factors or based， at least in part， on those factors. Consider the phrase “determine A based on B. ” While in this case， B is a factor that affects the determination of A， such a phrase does not foreclose the determination of A from also being based on C. In other instances， A may be determined based solely on B.

DETAILED DESCRIPTION

FIG. I is a flowchart illustrating a first embodiment of a method for end-to-end communication. For purposes of illustration， the method is illustrated as being sequential. However， portions of the method may be performed in other orders or in parallel (e.g.， simultaneously) . The method can be implemented by any number of terminals. The terminals can be stationary at a fixed position or mobile from place to place， including， but not limited to， cellular phones， personal digital assistants (PDA) ， wireless modems， tablet computers， notebook computers， cordless phones， and so forth. The method according to this embodiment can comprise the following block.

At block S11， the method includes receiving an assigned first group index.

The first group index may correspond to a communications resource set， and different group indices can correspond to different communications resource sets， respectively. In general， a subject terminal can receive from a base station the assigned first group index and the information of the corresponding communications resource set.

The resources in each communications resource set can comprise one or more resource blocks， or one or more portions of a resource block. The resources in a communications resource set can be continuous in the time domain while occupy part of the system bandwidth in the frequency domain， and each communications resource set， in this case， can be represented as one or more carriers or sub-carriers. Alternatively， the resources in each communications resource set may be not continuous in the time domain while occupy the whole system bandwidth in the frequency domain， and each communications resource set， in this case， may be referred to as and comprise multiple transmission time intervals (TTIs) ， where each TTI can be one or more sub-frames， or a portion of a sub-frame. Alternatively， the resources in each communications resource set may be non-continuous in the time domain and occupy part of the system bandwidth in the frequency domain.

At block S12， the method includes transmitting a first message and/or forwarding a received second message using the communications resource set corresponding to the first group index.

The subject terminal can transmit and/or forward a message in a broadcast mode， or in a directed manner.

The first message may be a message the terminal actively transmits， and may generally contains the identification information of the terminal itself. And the first message as transmitted from the terminal can also be received and forwarded by another terminal belonging to another group. While the second message may come from a terminal having been assigned a second group index. The first group index may be different from the second group index， thus it can be inferred that forwarding the second message may allow another terminal also assigned the second group index to be able to receive the second message.

The terminal can of course use all the resources in the communications resource set corresponding to the first group index to transmit the first message and/or forward the received second message， or use only part of the resources in the communications resource set to transmit the first message and/or forward the second message， while use the remaining part to receive messages.

According to the current embodiment， it can be concluded that forwarding the received second message can allow another terminal in the same group with the terminal sending the second message to be able to receive the second message， which thus can help to eliminate the potential security risks existing in half-duplex communication， improve the reliability， and can also effectively increase the transmission range for the messages.

Turning to FIG. 2， a flowchart of a second embodiment of a method for end-to-end communication is depicted. The second embodiment of the method for end-to-end communication is based on the above first embodiment， and further comprises the following blocks.

At block S13， the method includes using other resources outside of the resource set corresponding to the first group index for receiving.

This block can be performed simultaneously with or independently of block S12. When it is performed independently from block S12， the sequence of performance of the two blocks shall not be limited.

Turning to FIG. 3， a flowchart of a third embodiment of a method for end-to-end communication is depicted. The second embodiment is based on the first embodiment described above and additionally adopts collision avoidance to forward the received second message， in order to achieve multipath diversity and thus further improve the reliability. For purposes of illustration， the method is illustrated as being sequential. However， portions of the method may be performed in other orders or in parallel (e.g.， simultaneously) . The method according to this embodiment may comprise the following blocks.

At block S111， the method includes obtaining the information of a resource that is used to transmit the second message.

In general， depending on the type of the corresponding communications resource set， time and/or frequency domain information of the resource used to transmit the second message can be obtained.

At block S112， the method includes selecting a first resource corresponding to the resource used to transmit the second message to forward the second message， and selecting a second resource different from the first resource to transmit the first message.

The first resource can be such selected from the communications resource set corresponding to the first group index that it can correspond to the resource used to transmit the second message in the time and/or frequency domain. For example， they can correspond to a same TTI in the time domain， to a same carrier or sub-carrier in the frequency domain， et cetera.

If there are occasions that the first message needs not be sent， the collision avoidance scheme can still be adopted， i.e.， a first resource corresponding to the resource used to transmit the second message may still be selected to forward the second message.

When the collision avoidance scheme is adopted， a message can be transmitted multiple times using the same resource in different paths by terminals belong to the same group， and the multipath diversity can be achieved.

Turning to FIG. 4， a flowchart of a fourth embodiment of a method for end-to-end communication is depicted. The third embodiment is based on the first embodiment described above and additionally adopts a random selection scheme to forward the received second message， so as to achieve macro diversity and thus improve the received signal quality. The method according to this embodiment can comprise the following steps.

At block S121， the method includes randomly selecting different resources to transmit the first message and forward the second message， respectively.

From the corresponding communications resource set of the first group index， different resources can be selected and used to respectively transmit different messages. If there is more than one of such second message to be forwarded， then for each second message a different resource may be selected. Even though there is not a first message to be transmitted， the random selection scheme can still be adopted to select the resources by chance to forward the second message.

When the random selection scheme is adopted， a message can be transmitted multiple times using different randomly selected resources. In this case， if some signal processing technique is utilized at the receiver side， e.g.， coherence combining， a diversity gain called macro diversity can be achieved.

In various embodiments， when the second message satisfies the predetermined forwarding conditions， the terminal can forward its received second message， otherwise the second message might not be forwarded. The forwarding conditions for the second message may comprise at least one of： a number of the remaining forwarding times for the second message is greater than zero； a propagation distance of the second message is smaller than a preset threshold； a propagation duration of the second message is smaller than a predetermined value； and the second message is an emergency message.

The relevant information of the forwarding conditions can be contained in and transmitted along with the second message. For example， various flag bits can be set in the second message to indicate the remaining forwarding times， propagation distance， propagation time， or its emergency status. After the second message is received， the flag bits can be read to determine whether the forwarding conditions are still satisfied. If the answer is yes， the flag bits might be adaptively modified， for example， the remaining forwarding times can be decremented by one， the propagation distance can be adjusted according to the terminals’positions， et cetera. The second message can be then further forwarded to the next terminal or terminated when the forwarding conditions are no longer satisfied. The relevant information of the forwarding conditions can certainly be transmitted independently.

If， regarding a same message， a terminal has received it more than once， then there may exist multiple options to determine whether the forwarding conditions are satisfied. For example， assume there are three groups of terminals-A， B， and C， assigned their respective communications resource sets that occupy the time domain in turn. Now a terminal in group A sends out a message m， when another terminal in group B receives the message m and forwards it as a message m’， then a terminal in group C may as a result receive messages m and m’. Actually， in deciding whether to forward the messages， the terminal in the group C may consider only one of the two messages. For example， it may consider only the message that is later received， or the one with a better signal quality， et cetera. Alternatively， the terminal can also simultaneously consider both of the messages and determine whether their forwarding conditions are met， and may only forward the messages when the forwarding conditions are met-for example， the two messages may be forwarded as one message only when both messages m and m’satisfy the forwarding conditions， or when either of the messages satisfies.

FIG. 5 shows a schematic diagram illustrating the comparison between an emergency mode and an ordinary mode of a terminal in a fifth embodiment of a method for end-to-end communication. The method according to this embodiment is based on the first embodiment and can combine with any of the embodiments discussed above.

Typically， when an emergency event happens to a vehicle， such as loss of control or car accident， the terminal may enter an emergency mode and so use every source in the corresponding communications resource set to actively transmit messages， meanwhile the terminal can still forward its received messages or simply terminate forwarding. Until the emergency dismisses， the terminal would transit from the emergency mode to the normal mode and so use only part of the resources in the corresponding communications resource set to transmit messages. Alternatively， when the terminal enters the emergency mode， it can also use only part of the resources in the corresponding communications resource set to send messages. In contrast with the normal mode， under the emergency mode more resources are available， which can be marked by a higher transmission frequency and/or a wider occupied bandwidth. In one embodiment， the forwarding times for the message actively transmitted under the emergency mode can be set equal to a total number of all the group indices minus one， i.e.， a total number of all the groups， in order to ensure that terminals of all the other groups other than the group where the present terminal belongs， shall forward the emergency message.

As illustrated in FIG. 5， a communications resource set corresponding to the first group index assigned to the terminal includes multiple TTIs， which are represented by the ones filled with patterns. The ones filled with blanks represent the other TTIs outside of the communications resource set -the terminal may use these blank TTIs for receiving. Among the TTIs the ones stuffed with grids may suggest that the terminal actively transmits a first message during these grids-filled TTIs， while the ones depicted with slant lines may suggest that during these slant lines-filled TTIs the terminal may not actively send a first message， but only forward a received second message or simply receive a message.

In the beginning the terminal may run in a normal mode， and use part of the corresponding TTIs to transmit messages with a comparatively lower transmission frequency， while may only forward a received second message or simply receive messages during other TTIs. At time t1， when an emergency event happens， the terminal enters the emergency mode and begins to use every available TTI to send messages. Then at time t2， the emergency dismisses， the terminal restores to the normal mode.

In various embodiment， the corresponding communications resource set of the first group index may comprise multiple SA resources configured to transmit the scheduling assignment (SA) information and multiple data resources configured to transmit data， and each SA resource is not later than the associated one or more data resources in the time domain.

The SA may comprise the time and frequency domain information of the data resources used to transmit the corresponding data， so that the receiving terminal can accurately obtain the corresponding data. One SA resource can correspond to at least one data resource.

If a SA resource is earlier than the associated one or more data resources in the time domain， then it can be the same or different with each data resource in the frequency domain. Or， if the SA resource is the same with the associated data resource in the time domain， then it would be different from the associated data resource in the frequency domain.

Turning to FIG. 6， for example， each communications resource set comprises multiple TTIs， which are represented by the ones filled with patterns. The ones filled with blanks represent the other TTIs outside of the communications resource set -the terminal may use these blank TTIs for receiving. The communications resource set a as shown can be divided into an SA set and a data set interleaved in the time domain. Each SA set may comprise at least two TTIs used to transmit the SA， while each data set may comprise at least two TTIs used to transmit data. Therefore， after having sent the SA， resources can be selected from the following data set in a more flexible manner as the data resource for transmission of corresponding data.

Alternatively， one TTI used to transmit the SA and the several following TTIs used to transmit the corresponding data can form a complete message TTI. Multiple message TTIs can be sequentially arranged in the time domain to form the communications resource set b as shown in FIG. 6. While this may reduce the flexibility， it can make possible an even lower latency.

Considering now the communications resource set c shown in FIG. 6， one SA resource used to transmit the SA and one data resource used to transmit the corresponding data may correspond to a same TTI in the time domain， while correspond to different sub-carriers in the frequency domain respectively， so that the transmission latency can be further reduced.

In various embodiments， different communications resource sets may be interleaved in the time and/or the frequency domain.

Turning now to FIG. 7， for example， the communications resource sets 1 corresponding to the group index I are interleaved with the communications resource set 2 corresponding to the group index 2 in the time domain. In contrast， the communications resource set 3 corresponding to the group index 3 are interleaved with the communications resource set 4 corresponding to the group index 4 in the frequency domain.

FIG. 8 is a flowchart illustrating a sixth embodiment of a method for end-to-end communication. For purposes of illustration， the method is illustrated as being sequential. However， portions of the method may be performed in other orders or in parallel (e.g.， simultaneously) . The method can be implemented by a base station that is connected to a core network and can perform wireless communication with the terminals， to provide communication coverage for the corresponding geographical area. The base station can include， but not limited to， macro base stations， micro base stations， or pico base stations. In some embodiments， a base station can also be interchangeably referred to as a wireless base station， an access point， a Node B， an evolved Node B (eNodeB or eNB) ， and so forth. The method according to this embodiment can comprise the following steps.

At block S21， the method includes dividing the terminals under coverage into at least two groups.

Each group may be assigned a group index that corresponds to a communications resource set. Different groups may correspond to different communications resource sets， respectively.

The resources in each communications resource set can comprise one or more resource blocks， or one or more portions of a resource block. The resources in a communications resource set can be continuous in the time domain while occupy part of the system bandwidth in the frequency domain， and each communications resource set， in this case， can be represented as one or more carriers or sub-carriers. Alternatively， the resources in each communications resource set may be not continuous in the time domain while occupy the whole system bandwidth in the frequency domain， and each communications resource set， in this case， may be referred to as and comprise multiple transmission time intervals (TTIs) ， where each TTI can be one or more sub-frames， or a part of one sub-frame. Alternatively， the resources in each communications resource set may be non-continuous in the time domain and occupy part of the system bandwidth in the frequency domain.

At block S22， the method includes sending an assigned first group index to a terminal.

According to the first group index， the terminal can transmit a first message and/or forward a received second message using the communications resource set corresponding to the first group index. For more details of the terminal， see the relevant description of the first embodiment of the method for end-to-end communication.

According to the current embodiment， it can be concluded that grouping the terminals and forwarding the received second message can allow another terminal in the same group with the terminal sending the second message to be able to receive the second message， which thus can help to eliminate the potential security risks existing in half-duplex communication， improve the reliability， and can also effectively increase the transmission range for the messages.

A sixth embodiment of a method for end-to-end communication is the same as the fifth embodiment discussed above， except that at least one group comprises at least two terminals. Consider an extreme case， assume every terminal under coverage is divided into a different group， namely each group includes only one terminal， then even though the message forwarding mechanism is removed-i.e.， no terminal will forward any of its received messages-each terminal would be able to receive the messages from all other terminals. This， however， may introduce new issues when the number of the terminals under coverage is huge.

For example， if the communications resource sets are divided in terms of the time domain， the more terminals under coverage， the larger the intervals between resources assigned to each terminal， that is， the longer time the terminal needs to wait to transmit the next message and thus the greater the latency. Hence， the terminal may not be able to send messages in time when necessary， so this cannot meet the low-latency requirements for V2X communication， and may thus probably lead to security risks.

On the other hand， if the communications resource sets are divided in terms of the frequency domain， since the frequency bandwidth allocated for V2X communication is limited， the more terminals under coverage， the smaller the number of carriers/sub-carriers assigned to each terminal， i.e.， the narrower the bandwidth， this may lead to the reduction of the transmission rate and may cause interference between different terminals.

According to the current embodiment， the terminals under coverage can be divided into at least two groups each including at least two terminals， so that each group， but not each terminal， would be assigned a communications resource set. In addition， having the terminals to forward their received messages can solve the issue in half-duplex communication that terminals belonging to a same group cannot smoothly communicate messages with each other， this can improve the reliability and meanwhile avoid the problems introduced when there are many terminals under coverage， including high latency， reduction of transmission rate， or inter-terminals interference.

In one embodiment， the terminals may be divided into at least two groups according to a predetermined strategy and/or to the terminals’positions， in order to make at least one group of terminals substantially evenly distributed across the area of coverage. Thus， the transmission range for the messages can be further widened.

Turning now to FIG. 9， a block diagram of a first embodiment of a terminal is depicted. The terminal according to this embodiment may comprise a receiving module 11 and a transmitting module 12.

Receiving module 11 may be configured to receive an assigned first group index that corresponds to a communications resource set. Different group indices may correspond to different communications resource sets， respectively.

Transmission module 12 may be configured to transmit a first message and/or forward a received second message using the communications resource set corresponding to the first group index.

Various modules of the terminal according to this embodiment may be configured to perform the corresponding steps of the first embodiment of the method for end-to-end communication as illustrated in FIG. 1； for more details， see FIG. 1 and relevant description.

Specifically， the receiving module may be further configured to use other resources outside of the resource set corresponding to the first group index for receiving.

Specifically， the second message may come from a terminal assigned a second group index， and the transmitting module may be configured to forward the second message to enable another terminal also assigned the second group index to receive the second message.

Specifically， each communications resource set may comprise multiple transmission time intervals (TTIs) .

Specifically， each TTI may comprise one or more sub-frames or a portion of sub-frame.

Turning to FIG. 10， a block diagram of a second embodiment of the terminal is depicted. The second embodiment is based on the first embodiment， in which the transmitting module 12 comprises an acquisition unit 121 and a selection unit 122.

The acquisition unit 121 may be configured to obtain the information of a resource that is used to transmit the second message.

And the selection unit 122 may be configured to select a first resource corresponding to the resource used to transmit the second message to forward the second message， and select a second resource different from the first resource to transmit the first message.

Various modules of the terminal according to this embodiment may be configured to perform the corresponding steps of the second embodiment of the method for end-to-end communication as illustrated in FIG. 3； for more details， see FIG. 3 and relevant description.

Specifically， the transmitting module may be configured to select randomly different resources to transmit the first message and forward the second message， respectively.

Specifically， the transmitting module may be configured to forward the second message when the forwarding conditions for the second message are satisfied.

Specifically， the forwarding conditions for the second message may comprise at least one of： a number of the remaining forwarding times for the second message is greater than zero； a propagation distance of the second message is smaller than a preset threshold； a propagation duration of the second message is smaller than a predetermined value； and the second message is an emergency message.

Specifically， the transmitting module may be configured to use every resource in the corresponding communications resource set to transmit the first message if an emergency event happens； and， otherwise if an emergency event doesn’t happen， use only part of the resources in the corresponding communications resource set to transmit the first message.

Specifically， initial forwarding times for the first message may be set equal to a total number of all the group indices minus one.

Specifically， the corresponding communications resource set of the first group index may comprise multiple SA resources configured to transmit the scheduling assignment (SA) information and multiple data resources configured to transmit data， and each SA resource is not later than the associated one or more data resources in the time domain.

Specifically， each SA and the associated data resource may correspond to different sub-carriers in the frequency domain， respectively.

Specifically， the different communications resource sets corresponding to different group indices may be interleaved with each other in the time and/or the frequency domain.

Turning to FIG. 11， a block diagram of third embodiment of a terminal is depicted. The terminal according to this embodiment includes a processor 110 and a communication circuit 120 coupled to the processor 110 via a bus.

The communication circuit 120 may be configured to transmit and receive data. It can be regarded as an interface through which the terminal communicates with other communication equipment.

Processor 110 may control operations of the terminal， and can also be referred to as a central processing unit (CPU) . Processor 110 can be an integrated circuit chip with signal processing capabilities. It can also be a general-purpose processor， a digital signal processor (DSP) ， an application specific integrated circuit (ASIC) ， a field programmable gate array (FPGA) ， or other programmable logic devices， discrete gates， transistor logic devices， discrete hardware components. The general-purpose processor can be a microprocessor or any conventional processor.

The terminal may further include a memory storage (not shown) used to store commands and data necessary for operations of processor 110. The memory storage can also store the data received by the communication circuit 120.

Processor 110 may be configured to： receive via communication circuit 120 an assigned first group index that corresponds to a communications resource set， wherein different group indices may correspond to different communications resource sets， respectively； and transmit a first message and/or forward a received second message via communication circuit 120 using the communications resource set corresponding to the first group index.

Specifically， the processor 110 may be further configured to use other resources outside of the resource set corresponding to the first group index for receiving.

Specifically， the second message may come from a terminal assigned a second group index， and the processor 110 configured to forward the second message may enable another terminal also assigned the second group index to receive the second message.

Specifically， processor 110 may be configured to： obtain the information of a resource used to transmit the second message； and select a first resource corresponding to the resource used to transmit the second message to forward the second message via communication circuit 120， and select a second resource different from the first resource to transmit the first message via communication circuit 120.

Specifically， processor 110 may be configured to randomly select different resources to transmit the first message and forward the second message via communication circuit 120， respectively.

Specifically， processor 110 may be configured to forward via communication circuit 120 the second message when the forwarding conditions for the second message are satisfied.

Specifically， processor 110 may be further configured to： use every resource in the corresponding communications resource set to transmit via communication circuit 120 the first message if an emergency event happens； and， otherwise if an emergency event doesn′t happen， use only part of the resources in the corresponding communications resource set to transmit the first message via communication circuit 120.

Specifically， the initial forwarding times for the first message may be set equal to a total number of all the group indices minus one.

Turning to FIG. 12， a block diagram of a first embodiment of a base station is depicted. The base station according to this embodiment may comprise a division module 21 and an assignment module 22.

Division module 21 may be configured to divide the terminals under coverage into at least two groups each belonging to a group index and corresponding to a communications resource set. Different groups may correspond to different communications resource sets， respectively.

Assignment module 22 may be configured to send an assigned first group index to a terminal， so that the terminal can use the communications resource set corresponding to the first group index to transmit a first message and/or forward a received second message.

Various modules of the base station according to this embodiment may be configured to perform the corresponding steps of the fifth embodiment of the method for end-to-end communication as illustrated in FIG. 8； for more details， see FIG. 8 and relevant description.

Specifically， the number of terminals in at least one group may be greater than or equal to 2.

Specifically， the division module 21 may be configured to divide the terminals under coverage into at least two groups according to a predetermined strategy and/or the terminals’positions， so as to enable at least one group of terminals to be substantially evenly distributed across the coverage area.

Turning to FIG 13， a block diagram of a second embodiment of a base station is depicted. The base station according to this embodiment may comprise a processor 210 and a transceiver 220 coupled to processor 210 via a bus.

Transceiver 220 may be configured to transmit and receive data， which can be regarded as an interface through which the base station communicates with other communication equipment.

Processor 210 may control operations of the base station， and can also be referred to as a central processing unit (CPU) . Processor 210 may be an integrated circuit chip with signal processing capabilities， or a general-purpose processor， a digital signal processor (DSP) ， an application specific integrated circuit (ASIC) ， a field programmable gate array (FPGA) ， or any other programmable logic devices， discrete gates， transistor logic devices， discrete hardware components. The general-purpose processor can be a microprocessor or any conventional processor.

The base station may further comprise a memory storage (not shown) used to store the commands and data necessary for operations of processor 210. The memory storage can also store the data received by the transceiver 220.

Processor 210 may be configured to： divide the terminals under coverage into at least two groups each belonging to a group index that corresponds to a communications resource set， where different group indices may correspond to different communications resource sets， respectively； and assign via transceiver 220 a first group index to a terminal， so that the terminal can transmit a first message and/or forward a second message using the communications resource set corresponding to the first group index.

Specifically， processor 210 may be configured to divide the terminals under coverage into at least two groups according to a predetermined strategy and/or the terminals’positions， so as to enable at least one group of terminals to be substantially evenly distributed across the coverage area.

It should be appreciated that the terminals， base stations， and methods as disclosed can also be implemented in other forms. Actually， the base stations and terminals described are merely illustrative， for example， the division of modules or units is based solely on logic functions， thus in actual implementations there may be other division manners， e.g.， multiple units or components may be combined or integrated onto another system， or some system features may be ignored or simply not executed. In addition， mutual couplings， direct couplings， or communication connections as displayed or discussed may be achieved through some interfaces， devices， or units， and may be achieved electrically， mechanically or in other forms.

Separated units as described may or may not be physically separated. Components displayed as units may or may not be physical units， and may reside at one location or may be distributed to multiple networked units. Part or all of the units may be selectively adopted according to actual requirements to achieve objectives of the disclosure.

Additionally， various function units in the disclosure may be integrated into one processing unit， or may be presented as various physically separated units， or two or more units may be integrated into one unit. The integrated units may be implemented by hardware， or may be implemented as software functional units.

If the integrated units are implemented as software function units and sold or used as standalone products， they can be stored in a computer readable storage medium. On the basis of such an understanding， the substantial technical solution， or the part which contributes to the prior art， or all or part of the technical solution， of the disclosure， may be embodied as software products. Computer software products can be stored in a storage medium and can include multiple instructions enabling a computing device (for example， a personal computer， a server， a network device， etc. ) or a processor to execute all or part of the methods as described in various embodiments. The storage medium may include all kinds of medium that can store program codes， such as a USB flash disk， a mobile hard drive， a read-only memory (ROM) ， a random access memory (RAM) ， a magnetic disk or an optical disk.

The above description merely depicts some exemplary embodiments of the disclosure， and is not meant to limit the scope of the disclosure. Any equivalent structure or flow transformations made to the disclosure， or any direct or indirect applications of the disclosure on any other related fields， shall all be covered within the protection of the disclosure.

Claims

A method for end-to-end communication, comprising:

receiving an assigned first group index that corresponds to a communicationsresource set, wherein different group indices correspond to different communications resource sets, respectively； and

at least transmitting a first message or forwarding a received second messageusing the communications resource set corresponding to the first group index.
The method according to claim 1, further comprising:

using other resources outside of the resource set corresponding to the first group index for receiving.
The method according to claim 1, wherein the second message comes from a terminal assigned a second group index, and forwarding the second message enables another terminal also assigned the second group index to receive the second message.
The method according to claim 1, wherein each communications resource set comprises a plurality of transmission time intervals (TTIs) .
The method according to claim 4, wherein each TTI comprises one or more sub-frames or a portion of a sub-frame.
The method according to claim 1, wherein the block of transmitting the first message and forwarding the received second message comprises:

obtaining information of a resource used to transmit the second message； and

selecting a first resource corresponding to the resource used to transmit the second message to forward the second message, and selecting a second resource different from the first resource to transmit the first message.
The method according to claim 1, wherein the block of transmitting the first message and forwarding the received second message comprises:

randomly selecting different resources to transmit the first message and forward the second message, respectively.
The method according to claim 1, wherein the block of forwarding the received second message comprises:

forwarding the second message when predetermined forwarding conditions for the second message are satisfied.
The method according to claim 8, wherein the predetermined forwarding conditions comprise at least one of:

a number of remaining forwarding times for the second message is greater than zero； a propagation distance of the second message is smaller than a preset threshold； a propagation duration of the second message is smaller than a predetermined value； and the second message is an emergency message.
The method according to any one of claims 1-9, wherein the block of at least transmitting the first message or forwarding the received second message using the communications resource set corresponding to the first group index comprises:

when an emergency event happens, using every resource in the corresponding communications resource set to transmit the first message； otherwise using only part of the resources in the corresponding communications resource set to transmit the first message.
The method according to claim 10, wherein a number of initial forwarding times for the first message is set equal to a total number of all the group indices minus one.
The method according to any one of claims 1-9, wherein the communications resource set corresponding to the first group index comprises a plurality of SA resources configured to transmit scheduling assignment (SA) information and a plurality of associated data resources configured to transmit data, and each SA resource is not later than the associated at least one data resource in time domain.
The method according to claim 12, wherein each SA resource and the associated data resource correspond to different sub-carriers in frequency domain, respectively.
The method according to any one of claims 1-9, wherein different communications resource sets corresponding to different group indices are interleaved with one another in at least time or frequency domain.
A method for end-to-end communication, comprising:

dividing terminals under coverage into at least two groups each belonging to a group index and corresponding to a communications resource set, wherein different group indices correspond to different communications resource sets, respectively； and

transmitting an assigned first group index to a terminal, so that the terminal at least transmits a first message or forwards a received second message using the communications resource set corresponding to the first group index.
The method according to claim 15, wherein different communications resource sets corresponding to different group indices are interleaved with one another in at least time or frequency domain.
The method according to claim 15, wherein each communications resource set comprises a plurality of transmission time intervals (TTIs) .
The method according to claim 17, wherein each TTI comprises one or more sub-frames or a portion of a sub-frame.
The method according to any one of claims 15-18, wherein a number of the terminals in at least one group is greater than or equal to two.
The method according to any one of claims 15-18, wherein the block of dividing the terminals under coverage into at least two groups comprises:

dividing the terminals under coverage into at least two groups according to at least a predetermined strategy or the terminals'positions, so as to enable at least one group of terminals to be substantially evenly distributed across a current coverage area.
Aterminal, comprising:

a receiving module configured to receive an assigned first group index that corresponds to a communications resource set, wherein different group indices correspond to different communications resource sets, respectively； and

a transmitting module configured to at least transmit a first message or forward a received second message using the communications resource set corresponding to the first group index.
The terminal according to claim 21, wherein the receiving module is further configured to use other resources outside of the resource set corresponding to the first group index for receiving.
The terminal according to claim 21, wherein the second message comes from a terminal assigned a second group index, and the transmitting module is configured to forward the second message to enable another terminal also assigned the second group index to receive the second message.
The terminal according to claim 21, wherein each communications resource set comprises a plurality of transmission time intervals (TTIs) .
The terminal according to claim 24, wherein each TTI comprises one or more sub-frames or a portion of a sub-frame.
The terminal according to claim 21, wherein the transmitting module comprises:

an acquisition unit configured to obtain information of a resource used to transmit the second message； and

a selection unit configured to select a first resource corresponding to the resource used to transmit the second message to forward the second message, and select a second resource different from the first resource to transmit the first message.
The terminal according to claim 21, wherein the transmitting module is configured to randomly select different resources to transmit the first message and forward the second message, respectively.
The terminal according to claim 21, wherein the transmitting module is configured to forward the second message when predetermined forwarding conditions for the second message are satisfied.
The terminal according to claim 28, wherein the predetermined forwarding conditions comprises at least one of:

a number of remaining forwarding times for the second message is greater than zero； a propagation distance of the second message is smaller than a preset threshold； a propagation duration of the second message is smaller than a predetermined value； and the second message is an emergency message.
The terminal according to any one of claims 21-29, wherein the transmitting module is configured to use every resource in the corresponding communications resource set to transmit the first message if an emergency event happens, and, otherwise if an emergency event doesn't happen, use only part of the resources in the corresponding communications resource set to transmit the first message.
The terminal according to claim 30, wherein a number of initial forwarding times for the first message is set equal to a total number of all the group indices minus one.
The terminal according to any one of claims 21-29, wherein the communications resource set corresponding to the first group index comprises a plurality of SA resources configured to transmit scheduling assignment (SA) information and a plurality of associated data resources configured to transmit data, and each SA resource is not later than the associated at least one data resource in time domain.
The terminal according to claim 32, wherein each SA resource and the associated data resource correspond to different sub-carriers in frequency domain, respectively.
The terminal according to any one of claims 21-29, wherein different communications resource sets corresponding to different group indices are interleaved with one another in at least time or frequency domain.
Abase station, comprising:

a division module configured to divide terminals under coverage into at least two groups each belonging to a group index and corresponding to a communications resource set, wherein different groups correspond to different communications resource sets, respectively； and

an assignment module configured to send an assigned first group index to a terminal, so that the terminal at least transmits a first message or forwards a received second message using the communications resource set corresponding to the first group index.
The base station according to claim 35, wherein different communications resource sets corresponding to different group indices are interleaved with each other in at least time or frequency domain.
The base station according to claim 35, wherein each communications resource set comprises a plurality of transmission time intervals (TTIs) .
The base station according to claim 37, wherein each TTI comprises one or more sub-frames or a portion of a sub-frame.
The base station according to any one of claims 35-38, wherein a number of the terminals in at least one group is greater than or equal to two.
The base station according to any one of claims 35-38, wherein the division module is configured to divide the terminals under coverage into at least two groups according to at least a predetermined strategy or the terminals'positions, so as to enable at least one group of terminals to be substantially evenly distributed across a current coverage area.
A terminal, comprising a processor and a communication circuit coupled to the processor, wherein the processor is configured to:

receive via the communication circuit an assigned first group index that corresponds to a communications resource set, wherein different group indices correspond to different communications resource sets, respectively； and at least transmit a first message or forward a received second message via the communication circuit using the communications resource set corresponding to the first group index.
The terminal according to claim 41, wherein the processor is further configured to use other resources outside of the resource set corresponding to the first group index for receiving.
The terminal according to claim 41, wherein the second message comes from a terminal assigned a second group index, and the processor configured to forward the second message enables another terminal also assigned the second group index to receive the second message.
The terminal according to claim 41, wherein each communications resource set comprises a plurality of transmission time intervals (TTIs) .
The terminal according to claim 44, wherein each TTI comprises one or more sub-frames or a portion of a sub-frame.
The terminal according to claim 41, wherein the processor is further configured to:

obtain information of a resource used to transmit the second message； and

select a first resource corresponding to the resource used to transmit the second message to forward the second message via the communication circuit, and select a second resource different from the first resource to transmit the first message via the communication circuit.
The terminal according to claim 41, wherein the processor is configured to randomly select different resources to transmit the first message and forward the second message via the communication circuit, respectively.
The terminal according to claim 41, wherein the processor is configured to forward the second message via the communication circuit when predetermined forwarding conditions for the second message are satisfied.
The terminal according to claim 48, wherein the predetermined forwarding conditions comprises at least one of:

a number of remaining forwarding times for the second message is greater than zero； a propagation distance of the second message is smaller than a preset threshold； a propagation duration of the second message is smaller than a predetermined value； and the second message is an emergency message.
The terminal according to any one of claims 41-49, wherein the processor is further configured to:

use every resource in the corresponding communications resource set to transmit the first message via the communication circuit if an emergency event happens； and, otherwise if an emergency event doesn't happen, use only part of the resources in the corresponding communications resource set to transmit the first message via the communication circuit.
The terminal according to claim 50, wherein a number of initial forwarding times for the first message is set equal to a total number of all the group indices minus one.
The terminal according to any one of claims 41-49, wherein the communications resource set corresponding to the first group index comprises a plurality of SA resources configured to transmit scheduling assignment (SA) information and a plurality of associated data resources configured to transmit data, and each SA resource is not later than the associated at least one data resource in time domain.
The terminal according to claim 52, wherein each SA and the associated data resource correspond to different sub-carriers in frequency domain, respectively.
The terminal according to any one of claims 41-49, wherein different communications resource sets corresponding to different group indices are interleaved with one another in at least time or frequency domain.
A base station, comprising a processor and a transceiver coupled to the processor, wherein the processor is configured to:

divide terminals under coverage into at least two groups each belonging to a group index that corresponds to a communications resource set, wherein different group indices correspond to different communications resource sets； and send an assigned first group index to a terminal via the transceiver, so that the terminal at least transmits a first message or forward a second message using the communications resource set corresponding to the first group index.
The base station according to claim 55, wherein different communications resource sets corresponding to different group indices are interleaved with one another in at least time or frequency domain.
The base station according to claim 55, wherein each communications resource set comprises a plurality of transmission time intervals (TTIs) .
The base station according to claim 57, wherein each TTI comprises one or more sub-frames or a portion of a sub-frame.
The base station according to any one of claims 55-58, wherein a number of terminals in at least one group is greater than or equal to two.
The base station according to any one of claims 55-58, wherein the processor is configured to divide the terminals under coverage into at least two groups according to at least a predetermined strategy or the terminals′positions, so as to enable at least one group of terminals to be substantially evenly distributed across a current coverage area.