WO2017115127A1

WO2017115127A1 - Method and apparatus for information transmission in a wireless communication system and method and apparatus for facilitating information transmission

Info

Publication number: WO2017115127A1
Application number: PCT/IB2016/001880
Authority: WO
Inventors: Yong Liu; Dong Li
Original assignee: Alcatel Lucent
Priority date: 2015-12-28
Filing date: 2016-12-07
Publication date: 2017-07-06
Also published as: CN106921932B; CN106921932A; TW201728217A

Abstract

The present invention provides a method and apparatus for transmitting information in a wireless communication system and a method and apparatus for facilitating information transmission in a wireless communication system. Particularly, the method of transmitting information in a relay device of a wireless communication system comprises: determining whether to transmit relay-related information according to a transmission probability; and transmitting the relay-related information when it is determined to transmit. Compared with the prior art, the present invention determines whether it is necessary for a relay device in a wireless communication system to transmit relay-related information according to a transmission probability; therefore, compared with the prior art, the present invention may improve the efficiency of a relay device in terms of energy conservation and resource utilization.

Description

METHOD AND APPARATUS FOR INFORMATION TRANSMISSION IN A WIRELESS COMMUNICATION SYSTEM AND METHOD AND APPARATUS FOR FACILITATING INFORMATION

TRANSMISSION

FIELD OF THE INVENTION

[1] The present invention relates to the field of wireless communication, and more specifically to a method and apparatus for information transmission in a relay device of a wireless communication system and a method and apparatus for facilitating a relay device to transmit information in a base station of a wireless communication system. BACKGROUND OF THE INVENTION

[2] Relay is one of key technologies of LTE-A (Long-Term Evolution-Advanced). Wireless relay may provide flexible and fast network deployment and can enhance network coverage and capacity.

[3] In the latest 3GPP (The 3 Generation Partnership Project) Release 13, U E-to-network relay is an important feature. In a mobile cellular network, a relay device may be fixed device or mobile device. Mobile relay is also a kind of relay devices. The mobile relay not only has features of a base station, but also has features of a user terminal. The mobile relay constantly receives to-be-relayed information from the base station and then sends it to the terminal. Therefore, energy conservation and resource consumption of the mobile relay are key issues to consider. The present invention provides a method for transmitting relay information, which may improve relay efficiency in energy conservation and resource consumption.

SUMMARY OF THE INVENTION

[4] An objective of the present invention is to provide a method and apparatus for transmitting information in a relay device of a wireless communication system, and a method and apparatus for facilitating a relay device to transmit information in a base station of a wireless communication system.

[5] According to one aspect of the present invention, there is provided a method of transmitting information in a relay device of a wireless communication system, wherein the method comprises:

[6] - determining whether to transmit relay-related information according to a transmission probability;

[7] - transmitting the relay-related information when it is determined to transmit.

[8] According to another aspect of the present invention, there is provided a method of facilitating a relay device to transmit information in a base station of a wireless communication system, wherein the method comprises:

[9] - determining a transmission probability;

[10] - transmitting a message containing the transmission probability to one or more relay devices.

[11] According to a further aspect of the present invention, there is provided an apparatus for transmitting information in a relay device of a wireless communication system, wherein the apparatus comprises:

[12] - a module configured to determine whether to transmit relay-related information according to a transmission probability; [13] - a module configured to transmit the relay-related information when it is determined to transmit.

[14] According to still further aspect of the present invention, there is provided an apparatus for facilitating a relay device to transmit information in a base station of a wireless communication system, wherein the apparatus comprises:

[15] - a module configured to determine a transmission probability;

[16] -a module configured to transmit a message containing the transmission probability to one or more relay devices.

[17] Compared with the prior art, the present invention determines whether it is necessary for a relay device in a wireless communication system to transmit relay-related information according to a transmission probability; therefore, compared with the prior art, the present invention may improve the efficiency of a relay device in terms of energy conservation and resource utilization, and keep the effectiveness of relay at the same time. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[18] The present invention will be understood more thoroughly through the detailed depictions and the accompanying drawings infra, wherein the same units are presented by the same reference numerals; the drawings are only provided for illustration, not intended to limit the present invention, wherein:

[19] Fig. 1 illustrates a schematic diagram of a wireless cellular network using relay technology;

[20] Fig. 2 illustrates a method of transmitting information in a relay device of a wireless communication system according to one aspect of the present invention.

[21] Fig. 3 illustrates a method of facilitating a relay device to transmit information in a base station of a wireless communication system according to another aspect of the present invention.

[22] Fig. 4 illustrates an apparatus for transmitting information in a relay device of a wireless communication system according to a further aspect of the present invention.

[23] Fig. 5 illustrates an apparatus for facilitating a relay device to transmit information in a base station of a wireless communication system according to a still further aspect of the present invention.

[24] It should be mentioned that these drawings intend to illustrate general characteristics of the methods, structures and/or materials used in some exemplary embodiments, and to make supplementations to the written depictions provided infra. However, these drawings are not drawn in proportion and might not accurately reflect a precise structure or performance feature of any given embodiment, and should not be interpreted as defining or limiting the scope of numerical values or attributes covered by exemplary embodiments. In various drawings, similar or complete identical reference numerals are used to indicate existence of similar or completely identical units or features.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[25] Although exemplary embodiments may have various modified and alternative manners, one some embodiments thereof are illustrated exemplarily, which will be described in detail here. However, it should be understood that the exemplary embodiments are not intended to be limited to the disclosed specific forms; on the contrary, the exemplary embodiments are intended to cover all modifications, equivalent solutions, and alternative solutions within the scope of the claims. Same reference numerals constantly refer to same units in depiction of respective drawings.

[26] It should be mentioned before discussing the exemplary embodiments in more detail that some exemplary embodiments are described as processing or methods in the form of flow diagrams. Although a flow diagram depicts respective operations as being sequentially processed, many operations therein may be implemented in parallel, concurrently or simultaneously. Besides, various operations may be re-ordered. When the operations are completed, the processing may be terminated. However, there may comprise additional steps not included in the accompanying drawings. The processing may correspond to a method, a function, a specification, a sub-routine, a sub-program, etc.

[27] The term "wireless device" or "device" used here may be regarded as synonymous to and will be sometimes referred to hereinafter as the following items: client, user equipment, mobile station, mobile user, mobile terminal, subscriber, user, remote station, access terminal, receiver, mobile unit, etc., which may also describe a remote user of wireless resources in a wireless communication network.

[28] Analogously, the term "base station" used here may be regarded synonymous to or sometimes referred to as the following terms hereinafter: node B, evolved node-B, eNodeB, transceiver base station (BTS), RNC, etc., and may also describe a transceiver that communicates with a mobile terminal and provide radio resources thereto in a wireless communication network that may span a plurality of technology generations. Besides the capability implemented by the method discussed here, the base station as discussed may have all functions associated with traditional well-known base stations.

[29] The methods discussed infra (some of which are illustrated through flow diagrams) may be implemented through hardware, software, firmware, middleware, microcode, hardware description language or any combination thereof. When they are implemented with software, firmware, middleware or microcode, the program code or code segment for executing essential tasks may be stored in a machine or a computer readable medium (e.g., storage medium). (One or more) processors may implement essential tasks.

[30] The specific structures and function details disclosed here are only representative, for a purpose of describing the exemplary embodiments of the present invention. Instead, the present invention may be specifically implemented through many alternative embodiments. Therefore, it should not be appreciated that the present invention is only limited to the embodiments illustrated here.

[31] However, it should be understood that although terms "first," "second" might be used here to describe respective units, these units should not be limited by these terms. Use of these terms is only for distinguishing one unit from another. For example, without departing from the scope of the exemplary embodiments, the first unit may be referred to as the second unit, and similarly the second unit may be referred to as the first unit. The term "and/or" used here includes any and all combinations of one or more associated items as listed.

[32] It should be understood that when one unit is "connected" or "coupled" to a further unit, it may be directly connected or coupled to the further unit or an intermediate unit may exist. In contrast, when a unit is "directly connected" or "directly coupled" to a further unit, an intermediate unit does not exist. Other terms (e.g., "disposed between" VS. "directly disposed between," "adjacent to" VS. "immediately adjacent to," and the like) for describing a relationship between units should be interpreted in a similar manner.

[33] The terms used here are only for describing preferred embodiments, not intended to limit exemplary embodiments. Unless otherwise indicated, singular forms "a" or "one" used here further intends to include plural forms. It should also be appreciated that the terms "comprise" and/or "include" used here prescribe existence of features, integers, steps, operations, units and/or components as stated, but do not exclude existence or addition of one or more other features, integers, steps, operations, units, components, and/or a combination thereof.

[34] It should also be noted that in some alternative embodiments, the functions/actions as mentioned may occur in an order different from what is indicated in the drawings. For example, dependent on the functions/actions involved, two successively illustrated diagrams may be executed substantially simultaneously or in a reverse order sometimes.

[35] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meanings as generally understood by those skilled in the art within the field of the exemplary embodiments. It should also be understood that unless explicitly defined here, those terms defined in a typical dictionary should be interpreted to have a meaning consistent with that in a context of a relevant field, and should not be interpreted according to an ideal or over formal meaning.

[36] Some parts of the exemplary embodiments and corresponding detailed depiction are provided through software or algorithm within a computer memory or through symbols for operating data bits. Such depictions and expressions are depictions and expressions used by those skilled in the art to effective convey their work essence to other skilled in the art. Like what are generally used, the term "algorithm" used here is envisaged to a sequence of steps for achieving a desired result. The steps are those steps that need to physically manipulate the physical amounts. Generally but not essentially, these numbers adopt forms of optical, electric or magnetic signals that can be stored, transported, combined, compared and manipulated by other manners. Mainly for the reasons of usual use, it has been proved that these signals are sometimes referred to as bits, numerical values, elements, symbols, characters, items, and digits, etc.

[37] In the depiction below, illustrate embodiments may be depicted with actions implemented as function modules or function processing and symbol expressions of operations (e.g., in the form of flow diagrams). The program module or function processing comprises a routine, program, object, assembly and data structure and the like that implements a specific task or implements a specific abstract data type, and may be implemented using existing hardware at the existing network unit. Such existing hardware may comprise one or more central processing units (CPUs), a digital signal processor (DSP), an application-specific integrated circuit, and a field programmable gate array (FPGA) computer, etc.

[38] However, it should be noted that all of these and similar terms should be associated with appropriate physical quantities and are only convenient labels applied to these quantities. Unless explicitly stated otherwise or clearly seen from the discussion, terms like "processing," "computing," "determining" or "displaying" refer to actions and processing of a computer system or a similar electronic computing device, which manipulate data expressed as physical and electronic quantities within the register and memory of the computer system and transform them into other data similarly expressed as the physical quantities within the computer system memory or register or other such kind of information storage, transmission or display devices. [39] It should also be noted that the software-implemented aspects of the exemplary embodiments are usually encoded on a certain form of program storage medium or implemented by a certain kind of transmission medium. The program storage medium may be magnetic (e.g., floppy disk or hard disk driver) or optical (e.g., compact disk read-only storage memory or "CD-ROM"), and may be read-only or random access storage medium. Similarly, the transmission medium may be twisted pair, co-axial cable, optical fiber or some other appropriate transmission medium known in the art. The exemplary embodiments are not limited to any of these aspects with given embodiments.

[40] The processor and memory may operate together to run functions of the apparatus. For example, the memory may store code segments about the apparatus functions. The code segments may also be executed by the processor. Besides, the memory may store processing variables and constants for the processor to use.

[41] Hereinafter, the present invention will be described in further detail with reference to the accompanying drawings.

[42] Fig. 1 illustrates a schematic diagram of a wireless cellular network using relay technology. The relay technology in the wireless cellular network refers to the technology of forwarding wireless signals one or more times by adding some relay devices based on the original base station services. These added relay devices and the base station are connected via wireless communication. Downlink data transmitted to the user equipment first arrive at relay devices through the base station, and then the relay devices transmit the data to terminal users; for uplink data, a reverse procedure. With the relay devices, the cell coverage area may be expanded and it can bring a higher system capacity and a larger network coverage to the cell. In the schematic diagram of Fig.l, user equipment-1, user equipment-2, relay device-1, and relay device-2 are within the coverage of the base station, while user equipment-a, user equipment-b, user equipment-c, user equipment-d, and user equipment-e are beyond the coverage of the base station. Suppose the base station needs to broadcast an important message to as many terminals as possible, including user equipments within and beyond the coverage. The base station broadcasts the important message within its coverage, such that the user equipment-1, user equipment-2, relay device-1 and relay device-2 may receive the important message. Then, the base station arranges relay device-1 and relay device-2 that are appropriate to extend the coverage to broadcast the message to the user equipment-a, user equipment-b, user equipment-c, user equipment-d, and user equipment-e that are beyond the coverage.

[43] A relay device refers to a device having relay capability; the relay capability refers to the capability of receiving downlink data transmitted from the base station and then forwarding data to the terminal user, or the capability of receiving the uplink data from the terminal user and then forwarding data to the base station. The relay device may be a relay node deployed at a relatively fixed scene such as a machine room, an office or a house, and the relay device may also be a vehicle mobile terminal, a data card, or a mobile phone, or other terminal device having relay capability.

[44] It should be noted that relevant depictions on the base station, relay device, relay node, and mobile terminal are only examples, and other existing or future possibly emerging base station, relay device, relay node, and mobile terminal, if applicable to the present invention, should also be included within the protection scope of the present invention and are incorporated here by reference. [45] Fig. 2 illustrates a method of transmitting information in a relay device of a wireless communication system according to an embodiment in one aspect of the present invention. The method according to the embodiment comprises step S21 and step S22.

[46] Particularly, the method according to the present invention is implemented by a relay device. The relay device in the present invention refers to a device that has relay capability. The relay device comprises at least one of the following items:

[47] - a terminal device having relay capability;

[48] - a relay node device having relay capability.

[49] The terminal device having relay capability refers to a terminal device integrated with relay function. This terminal may be a mobile phone, or a data card, a vehicle terminal, or other devices of the same kind. A terminal device having relay capability has both a relay function and a function of a common terminal. Any terminal having relay capability is a potential relay device in the network. A relay node device having relay capability is deployed at a machine room, an office or a house, etc., mainly responsible for data relay between the base station and the terminal in a wireless communication network. There comprise one or more relay node devices in a wireless communication network.

[50] It should be noted that the relay device is only an example, and other existing or future possibly emerging relay devices, if applicable to the present invention, should also be included within the protection scope of the present invention and are incorporated here by reference.

[51] Step S21 and step S22 performed by the relay device will be illustrated below.

[52] In step S21, the relay device determines whether to transmit relay-related information according to a transmission probability.

[53] The transmission probability refers to a probability followed by the relay device to transmit relay-related information. In the present invention, the transmission probability of the relay device may be pre-determined in the relay device, or autonomously determined by the relay device, or may be obtained from the base station. In one preferred embodiment, the relay device obtains the transmission probability from the base station. Firstly, the relay device receives a message containing the transmission probability transmitted from the base station. For example, while broadcasting the cell network configuration parameters, the base station may broadcast the information containing the transmission probability along with cell network configuration parameters. For another example, the base station may separately customize a message containing the transmission probability, and then broadcast the message to all relay devices within the cell. The relay device may receive these messages broadcast by the base station, including the message containing the transmission probability. Next, the relay device determines the transmission probability according to the message containing the probability. For example, the relay device decodes the message containing the transmission probability, obtains the information of the transmission probability therein, and then may determine the transmission probability followed to transmit the relay-related information.

[54] Specifically, in step S21, the relay device may generate an output result according to a probability model or a probability generation function. The output result represents an indication of transmitting the relay-related information, wherein the generation probability representing the output result of the relay-related information corresponds to the transmission probability. For example, the relay device may use a random value generating function. The function output value ranges between [0, 1]. Suppose the transmission probability is 0.3, if an output value of the random value generating function is less than or equal to 0.3, the relay device determines that it is needed to transmit relay-related information; if the output value of the random value generating function is greater than 0.3, the relay device determines that it is not needed to transmit the relay-related information. It should be noted that the example above is only for better illustrating the technical solution of the present invention, not for limiting the present invention. Those skilled in the art should understand that any implementation manner of determining whether to transmit relay-related information according to the transmission probability should be included within the scope of the present invention.

[55] In the present invention, the relay-related information is any information related to the relay function. In one embodiment, the relay-related information includes at least any one of the following:

[56] - to-be-relayed broadcast message received from the base station;

[57] - autonomously transmitted relay-related information.

[58] The to-be-relayed broadcast message received from the base station refers to the relay-related information that needs to be relayed by a relay device. The broadcast message transmitted by the base station needs to be transmitted to as many terminal devices as possible; after receiving the broadcast message transmitted by the base station, the relay device relays the broadcast message to nearby out-of-coverage terminal devices so as to increase cell coverage. For a plurality of relay devices near to each other, because the terminal devices covered by the transmitted signal are identical, it is unnecessary to all relay devices performing relay transmission. Therefore, after the relay devices receive the to-be-relayed broadcast message transmitted from the base station, whether to transmit the broadcast message may be determined based on the transmission probability. According to the manner above, while guaranteeing validity of the relay function, because some relay devices are not needed to transmit the broadcast message, energy consumption needed by transmission is saved, and interference with other devices during transmission is also reduced.

[59] The relay-related message autonomously transmitted by the relay device refers to a message autonomously generated to complete relay transmission. For example, when a out-of-coverage terminal device

[60] e capable of being connected to the base station via the relay device, the terminal device initiates a relay request message to relay devices nearly. The relay devices near the terminal user receive the relay request message. After that, they may reply to the terminal device with a relay response message and confirm that they may act as a relay device for the terminal device. When a plurality of relay devices exist, it is unnecessary to activate all relay devices as relays for the terminal device. Therefore, after receiving the relay request message from the terminal user, the relay device may decide whether to transmit a relay request response message according to the transmission probability. A relay device that does not transmit the relay request response message will not act as a relay device for the terminal device to perform subsequent relay transmission. According to the manner above, while guaranteeing validity of the relay function, energy consumption needed by transmission is saved, and interference with other devices during transmission is also reduced.

[61] It should be noted that the relay-related information above is only an example, and other existing or future possibly emerging relay-related information, if applicable to the present invention, should also be included within the protection scope of the present invention and is incorporated here by reference.

[62] In step S22, when it is determined to transmit, the relay device transmits the relay-related information. Specifically, after the relay device determines in step S21 that the relay-related information needs to be transmitted according to the manner above, the relay device transmits the relay-related information that needs to be transmitted.

[63] In one embodiment, the step S22 comprises step S221 (not shown in the drawings); determining a relay transmission resource; and a step S222 (not shown in the figure): when it is determined to transmit, transmitting the relay-related information using the relay transmission resource. In the present invention, the relay transmission resource refers to a time frequency resource used when the relay device transmits the relay-related information. The relay transmission resource used by the relay device is originated from the time-frequency resource assigned by the base station to the relay device.

[64] In step S221, the relay device determines a relay transmission resource. In one embodiment, the relay transmission resource may be predetermined. In one preferred embodiment, the relay device may receive a message transmitted by the base station, containing relevant information about one or more relay transmission resources.

[65] The relay device may be synchronized with the base station by detecting a synchronization signal from the base station. If timing and frequency estimation of the relay devices is accurate enough, all relay devices may be synchronized with each other. In this way, the relay device may use the same time-frequency resource to transmit the relay information when transmitting the same message with a small mutual interference. Therefore, the base station is only needed to assign the same relay transmission resource to all relay devices. In this case, information about the transmission resource assigned by the base station to the relay devices includes one relevant information about the relay transmission resource, e.g., time and frequency information of the relay transmission resource.

[66] If the timing estimation or frequency estimation of the relay device is not accurate enough, the relay devices may interfere with each other when transmitting the relay information with the same time-frequency resource. In this case, the base station may assign a resource pool containing a plurality of relay transmission resources to the relay device. In this way, each relay device may autonomously select a relay transmission resource from the resource pool assigned by the base station, thereby reducing the conflict when the relay devices use the same relay transmission resources and reducing mutual interference. In this case, relevant information about the transmission resource assigned by the base station to the relay device includes relevant information about a plurality of relay transmission resources, e.g., time and frequency information of respective relay transmission resources.

[67] After the relay device receives the message containing relevant information about one or more relay transmission resources, the relay device determines a relay transmission resource used in transmitting the relay related information according to the message containing relevant information about one or more relay transmission resources. Specifically, after receiving the message containing relevant information about one or more relay transmission resources, the relay device decodes the message to obtain relevant information about the relay transmission resource in the message, e.g., the time and frequency information of the relay transmission resource. If the message only contains relevant information about one relay transmission resource, the relay device may determine using the transmission resource to transmit the relay-related information; if the message contains relevant information about a plurality of relay transmission resources, the relay device may select one relay transmission resource therefrom to transmit the relay-related information.

[68] Next, in step S222, when it is determined to transmit, the relay device uses the relay transmission resource to transmit the relay-related information. Specifically, after the relay device determines the relay transmission resource in step S221 according to the manner above, the relay device transmits the relay-related information that needs to be transmitted with the relay transmission resource.

[69] In the prior art, all relay devices transmit the relay-related information every time. When the number of relay devices at a cell edge is relatively large, if all relay devices transmit the relay-related information, utilization efficiency of the transmission resources and energy will not be high. In the present invention, the relay device determines whether to transmit the relay-related information according to the transmission probability, thereby reducing power consumption of the relay devices and the resources in use while guaranteeing validity of the relay function, and enhancing the efficiency of the relay device. When the relay device does not transmit the relay-related information, potential interference caused to other users during the transmission is also reduced.

[70] Fig. 3 illustrates a method of facilitating a relay device to transmit information in a base station of a wireless communication system. The method according to the present embodiment comprises steps S31 and S32.

[71] Particularly, the method in the present embodiment is mainly implemented through a base station.

[72] The "base station" used here may be regarded synonymous to or sometimes referred to as the following terms hereinafter: node B, evolved node-B, eNodeB, transceiver base station (BTS), RNC, etc., and may also describe a transceiver that communicates with a mobile terminal and provide radio resources thereto in a wireless communication network that may span a plurality of technology generations. It should be noted that relevant description of the base station is only exemplary, and any other existing or future possibly emerging base station, if applicable to the present invention, should also be included within the protection scope of the present invention and are incorporated here by reference.

[73] The relay device in the present invention refers to a device that has relay capability. The relay device comprises at least one of the following items:

[74] - a terminal device having relay capability;

[75] - a relay node device having relay capability.

[76] The terminal device having relay capability refers to a terminal device integrated with relay function. This terminal may be a mobile phone, or a data card, a vehicle terminal, or other devices of the same kind. A terminal device having relay capability has both a relay function and a function of a common terminal. Any terminal having relay capability is a potential relay device in the network. A relay node device having relay capability is deployed at a machine room, an office or a house, etc., mainly responsible for data relay between the base station and the terminal in a wireless communication network. There comprise one or more relay node devices in a wireless communication network.

[77] It should be noted that the relay device is only an example, and other existing or future possibly emerging relay devices, if applicable to the present invention, should also be included within the protection scope of the present invention and are incorporated here by reference.

[78] In step S31, the base station determines a transmission probability. The transmission probability refers to the probability followed by a relay device to transmit relay-related information. Specifically, various algorithms may exist for the base station to determine the transmission probability. For example, the base station may estimate efficiency of the relay devices based on a retransmission ratio of terminal users to which the relay device transmits data, thereby determining the transmission probability; the base station may determine the transmission probability based on the number of all relay devices in the cell; or the base station determines the transmission probability based on a density of relay devices at the edge of a cell .

[79] According to one preferred embodiment of the present invention, step S31 further comprises the following steps: determining, by the base station, a density of relay devices; then, determining, by the base station, the transmission probability according to the density of relay devices.

[80] First, the base station determines the density of relay devices. Various algorithms may exist for the base station to determine the density of relay devices. For example, the base station may use the number of relay stations at the edge of a cell to represent the density of relay devices, a larger number of relay devices represent a larger density of relay devices; a smaller number of relay devices represents a smaller density of relay devices. For another example, the base station may adjust the density of relay devices based on the number of existing relay devices within the cell and the number of all terminal users within the cell. For example, first, set reference default values of the number of existing relay devices and of the number of all terminal users within the cell, and a default value of the relay device density corresponding to the reference default value. When the number of relay devices increases or decreases, the value of the density of relay devices correspondingly increases or decreases; when the number of all terminal users within the cell increases or decreases, the value of density of relay devices correspondingly decreases or increases. For another example, the base station may estimate the size of a cell based on the magnitude of the transmit power of the base station and the number of users within the cell, and then adjust the density of the relay device according to the number of relay devices. For example, first set reference default values of the transmit power of the base station, the number of users within the cell, and the number of relay devices, and a default value of the density of the relay devices corresponding to the reference default values. When the number of relay devices increases or decreases, the density of the relay device correspondingly increases or decreases; when the number of users within the cell increases or decreases, the density of relay devices correspondingly decreases or increases; when the transmit power of the base station increases or decreases, the density of relay devices correspondingly decreases or increases. It should be noted that the above examples of determining, by the base station, the density of relay devices are only for better illustrating the technical solution of the present invention, not for limiting the present invention. Those skilled in the art should understand that any implementation manner of determining, by the base station, the density of the relay devices, should be included within the scope of the present invention. Next, the base station determines the transmission probability according to the density of the relay devices. Various algorithms may exist for the base station to determine the transmission probability according to the density of the relay devices. For example, two thresholds a and b (a<b) with default values exist in the base station. If the density of the relay devices is greater than or equal to threshold b, the transmission probability is 1/3; if the density of the relay device is smaller than or equal to threshold a, the transmission probability is 1; if the density of the relay device is greater than the threshold a but smaller than threshold b, the transmission probability is 2/3. It should be noted that the above examples of determining, by the base station, the transmission probability, are only for better illustrating the technical solution of the present invention, not for limiting the present invention. Those skilled in the art should understand that any implementation manner of determining, by the base station, the transmission probability, should be included within the scope of the present invention.

[81] In one embodiment, the method of facilitating a relay device to transmit information in a base station of the wireless communication system further comprises steps of: determining, by the base station, one or more relay transmission resources; and transmitting, by the base station, a message containing relevant information about the one or more relay transmission resources. In the present embodiment, the relay transmission resource refers to time-frequency resource used by the relay device when transmitting the relay-related information.

[82] First, the base station determines one or more relay transmission resources used by the relay device.

[83] The relay device may be synchronized with the base station by detecting a synchronization signal from the base station. If timing and frequency estimation of the relay devices is accurate enough, all relay devices may be synchronized with each other. In this way, the relay device may use the same time-frequency resource to transmit the relay information when transmitting the same message with a small mutual interference. Therefore, the base station is only needed to assign the same relay transmission resource to all relay devices. In this case, the base station determines one relay transmission resource for the relay devices to use.

[84] If the timing estimation or frequency estimation of the relay device is not accurate enough, the relay devices may interfere with each other when transmitting the relay information with the same time-frequency resource. In this case, the base station may assign a resource pool containing a plurality of relay transmission resources to the relay device. In this way, each relay device may autonomously select a relay transmission resource from the resource pool assigned by the base station, thereby reducing the conflict when the relay devices use the same relay transmission resources and reducing mutual interference. In this case, the base station determines many relay transmission resources for the relay device to use.

[85] Then, the base station transmits the message containing relevant information about the one or more relay transmission resources to the one or more relay devices, wherein the relevant information about the relay transmission resources refer to, time and frequency information for the relay transmission resources, for example. Specifically, the base station groups relevant information containing one or more relay transmission resources into a format of message, which may separately group the relevant information into one message containing the relay transmission resources, or incorporate the relevant information containing one or more relay transmission resources into other messages. Then, the base station transmits the messages to one or more relay devices in the cell.

[86] In one preferred embodiment, in step S31, the base station may determine a transmission probability according to the density of the relay devices and one or more relay transmission devices. Various manners exist for the base station to determine the transmission probability according to the density of the relay devices and one or more relay transmission resources. For example, the base station may first determine a interim value m of the transmission probability according to the density of relay devices: two thresholds a and b (a<b) with default values exist in the base station; if the density of the relay devices is greater than or equal to threshold b, the m is 1/3; if the density of the relay device is smaller than or equal to threshold a, the m is 1; if the density of the relay device is greater than the threshold a but smaller than threshold b, the m is 2/3. Then, the base station determines the transmission probability based on the information about the relay transmission resources: suppose the amount of relay transmission resources is n. If n is smaller than the predetermined threshold x, then the size of the transmission probability is m*(l-k%), where k is a preset adjustment parameter; if n is greater than the predetermined threshold y, the size of transmission probability is m*(l+k%), wherein k denotes a preset adjustment parameter; if n is greater than or equal to x, but smaller than or equal to y, x <y, then the transmission probability is m. It should be noted that the above examples of determining, by the base station, the transmission probability, are only for better illustrating the technical solution of the present invention, not for limiting the present invention. Those skilled in the art should understand that any implementation manner of determining, by the base station, the transmission probability, should be included within the scope of the present invention.

[87] Because many mobile relay devices possibly exist, e.g., mobile terminal devices having relay functionality, the density of relay devices within the cell constantly changes. In one embodiment, when the density of relay devices changes, the base station may re-determine the transmission probability. For example, the base station may set a change threshold for the density of relay devices, when the magnitude of the change of the density of relay devices exceeds a preset threshold, the base station re-determines the transmission probability. For another example, the base station may also set an update period for the transmission probability. During each period, the base station re-determines the transmission probability according to the latest density of the relay devices.

[88] After the base station determines the transmission probability in step S31 according to the method above, in step S32, the base station transmits a message containing the transmission probability to one or more relay devices. For example, while broadcasting cell network configuration parameters, the base station may broadcast the information of the transmission probability along with the cell network configuration parameters, such that the base station transmits the message containing the probability to one or more relay devices in a broadcast way. For another example, the base station may separately customize a message containing the probability information, and then transmits message, in the signaling of a common channel, to one or more relay devices within the cell. It should be noted that the example above is only for better understanding the technical solution of the present invention, not for limiting the present invention. Those skilled in the art should understand that any implementation manner in which the base station transmits a message containing the transmission probability to one or more relay devices should be included within the scope of the present invention.

[89] In one embodiment, the method of facilitating a relay device to transmit information in a base station of a wireless transmission system further comprises a step in which the base station transmits a to-be-relayed broadcast message to the one or more relay devices. The broadcast message transmitted by the base station needs to be transmitted to as many terminal devices as possible; after receiving the broadcast message transmitted by the base station, the relay device relays the broadcast message to nearby out-of-coverage terminal devices so as to enhance cell coverage. For a plurality of relay devices near to each other, because the terminal devices covered by the transmitted signal are identical, it is unnecessary to all relay devices performing relay transmission. Therefore, after the relay devices receive the to-be-relayed broadcast message transmitted from the base station, whether to transmit the broadcast message may be determined based on the transmission probability. According to the manner above, while guaranteeing validity of the relay function, because some relay devices are not needed to transmit the broadcast message, energy consumption needed by transmission is saved, and interference with other devices during transmission is also reduced.

[90] In the prior art, all relay devices transmit the relay-related information. When the number of relay devices at a cell edge is relatively large, if all relay devices transmit the relay-related information, utilization efficiency of the transmission resources and energy will not be high. The base station according to the embodiment of the present invention may determine a transmission probability, used by the relay devices, to transmit the relay-related information, and then transmits the message containing the transmission probability to the relay devices. The relay device can then transmit the relay-related information according to the transmission probability, which, while guaranteeing validity of the relay function, enhances the energy efficiency of transmitting the relay-related information and improve the utilization of the relay transmission resources.

[91] Fig. 4 illustrates an apparatus for transmitting information in a relay device of a wireless communication system according to a further aspect of the present invention. The apparatus according to the present embodiment comprises: a module configured to determine whether to transmit relay-related information according to a transmission probability, hereinafter referred to as a first determining module 41; and a module configured to transmit the relay-related information when it is determined to transmit, hereinafter referred to as a first transmitting module 42.

[92] Particularly, the apparatus according to the present invention is implemented in a relay device. The relay device in the present invention refers to a device that has relay capability. The relay device comprises at least one of the following items:

[93] - a terminal device having relay capability;

[94] - a relay node device having relay capability.

[95] The terminal device having relay capability refers to a terminal device integrated with relay function. This terminal may be a mobile phone, or a data card, a vehicle terminal, or other devices of the same kind. A terminal device having relay capability has both a relay function and a function of a common terminal. Any terminal having relay capability is a potential relay device in the network. A relay node device having relay capability is deployed at a machine room, an office or a house, etc., mainly responsible for data relay between the base station and the terminal in a wireless communication network. There comprise one or more relay node devices in a wireless communication network.

[96] It should be noted that the relay device is only an example, and other existing or future possibly emerging relay devices, if applicable to the present invention, should also be included within the protection scope of the present invention and are incorporated here by reference.

[97] Hereinafter, the first determining module 41 and the first transmitting module 42 included in the apparatus for transmitting information in a relay device will be illustrated.

[98] The transmission probability refers to a probability followed by the relay device to transmit relay-related information. In the present invention, the transmission probability of the relay device may be pre-determined in the relay device, or autonomously determined by the relay device, or may be obtained from the base station. In one preferred embodiment, the relay device obtains the transmission probability from the base station. The apparatus for transmitting information in the relay device further comprises a module (hereinafter referred to as first receiving module 43) for receiving a message containing the transmission probability transmitted by the base station, and a module (hereinafter referred to as a second determining module 44) configured to determine the transmission probability according to the message containing the transmission probability. Firstly, the first receiving module 43 receives a message containing the transmission probability transmitted from the base station. For example, while broadcasting the cell network configuration parameters, the base station may broadcast the information containing the transmission probability along with cell network configuration parameters. For another example, the base station may separately customize a message containing the transmission probability, and then broadcast the message to all relay devices within the cell. The first receiving module 43 may receive these messages broadcast by the base station, including the message containing the transmission probability. Next, the second determining module 44 determines the transmission probability according to the message containing the probability. For example, the second determining module 44 decodes the message containing the transmission probability, obtains the information of the transmission probability therein, and then may determine the transmission probability followed to transmit the relay-related information.

[99] The first determining module 41 of the relay device determines whether to transmit relay-related information according to the transmission probability. Specifically, the first determining module 41 may generate an output result according to a probability model or a probability generation function. The output result represents an indication of transmitting the relay-related information, wherein the generation probability representing the output result of the relay-related information corresponds to the transmission probability. For example, the first determining module 41 may use a random value generating function. The function output value ranges between [0, 1]. Suppose the transmission probability is 0.3, if an output value of the random value generating function is less than or equal to 0.3, the first determining module 41 determines that it is needed to transmit relay-related information; if the output value of the random value generating function is greater than 0.3, the first determining module 41 determines that it is not needed to transmit the relay-related information. It should be noted that the example above is only for better illustrating the technical solution of the present invention, not for limiting the present invention. Those skilled in the art should understand that any implementation manner of the module configured to determine whether to transmit relay-related information according to the transmission probability should be included within the scope of the present invention.

[100] In the present invention, the relay-related information is any information related to the relay function. In one embodiment, the relay-related information includes at least any one of the following:

[101] - to-be-relayed broadcast message received from the base station;

[102] - autonomously transmitted relay-related information.

[103] The to-be-relayed broadcast message received from the base station refers to the relay-related information that needs to be relayed by a relay device. The broadcast message transmitted by the base station needs to be transmitted to as many terminal devices as possible; after receiving the broadcast message transmitted by the base station, the relay device relays the broadcast message to nearby out-of-coverage terminal devices so as to increase cell coverage. For a plurality of relay devices near to each other, because the terminal devices covered by the transmitted signal are identical, it is unnecessary to all relay devices performing relay transmission. Therefore, after the relay devices receive the to-be-relayed broadcast message transmitted from the base station, whether to transmit the broadcast message may be determined based on the transmission probability. According to the manner above, while guaranteeing validity of the relay function, because some relay devices are not needed to transmit the broadcast message, energy consumption needed by transmission is saved, and interference with other devices during transmission is also reduced.

[104] The relay-related message autonomously transmitted by the relay device refers to a message autonomously generated to complete relay transmission. For example, when a out-of-coverage terminal device intends to find a delay device so as to be capable of being connected to the base station via the relay device, the terminal device initiates a relay request message to relay devices nearly. The relay devices near the terminal user receive the relay request message. After that, they may reply to the terminal device with a relay response message and confirm that they may act as a relay device for the terminal device. When a plurality of relay devices exist, it is unnecessary to activate all relay devices as relays for the terminal device. Therefore, after receiving the relay request message from the terminal user, the relay device may decide whether to transmit a relay request response message according to the transmission probability. A relay device that does not transmit the relay request response message will not act as a relay device for the terminal device to perform subsequent relay transmission. According to the manner above, while guaranteeing validity of the relay function, energy consumption needed by transmission is saved, and interference with other devices during transmission is also reduced.

[105] It should be noted that the relay-related information above is only an example, and other existing or future possibly emerging relay-related information, if applicable to the present invention, should also be included within the protection scope of the present invention and is incorporated here by reference.

[106] The first transmitting module 42 is configured to, when it is determined to transmit, transmit the relay-related information. Specifically, after the first determining module 41 determines that the relay-related information needs to be transmitted according to the manner above, the first transmitting module 42 transmits the relay-related information that needs to be transmitted.

[107] In one embodiment, the first transmitting module 42 comprises a module configured to determine a relay transmission resource (hereinafter referred to as a third determining module 421, not shown in the drawings); and a module configured to: when it is determined to transmit, transmit the relay-related information using the relay transmission resource (hereinafter referred to as a second transmitting module 422, not shown in the figure). In the present invention, the relay transmission resource refers to a time frequency resource used when the relay device transmits the relay-related information. The relay transmission resource used by the relay device is originated from the time-frequency resource assigned by the base station to the relay device.

[108] First, the third determining module 421 determines a relay transmission resource. In one embodiment, the third determining module 421 may predetermine the relay transmission resource. In one preferred embodiment, the third determining module 421 comprises a module configured to receive a message containing relevant information about one or more relay transmission resources, hereinafter referred to as resource-related information receiving module 4211 (not shown), and a module configured to determine a relay transmission resource based on the message containing the relevant information about one or more relay transmission resources, hereinafter referred to as a resource determining module 4212 (not shown).

[109] The relay device may be synchronized with the base station by detecting a synchronization signal from the base station. If timing and frequency estimation of the relay devices is accurate enough, all relay devices may be synchronized with each other. In this way, the relay device may use the same time-frequency resource to transmit the relay information when transmitting the same message with a small mutual interference. Therefore, the base station is only needed to assign the same relay transmission resource to all relay devices. In this case, information about the transmission resource assigned by the base station to the relay devices includes one relevant information about the relay transmission resource, e.g., time and frequency information of the relay transmission resource.

[110] If the timing estimation or frequency estimation of the relay device is not accurate enough, the relay devices may interfere with each other when transmitting the relay information with the same time-frequency resource. In this case, the base station may assign a resource pool containing a plurality of relay transmission resources to the relay device. In this way, each relay device may autonomously select a relay transmission resource from the resource pool assigned by the base station, thereby reducing the conflict when the relay devices use the same relay transmission resources and reducing mutual interference. In this case, relevant information about the transmission resource assigned by the base station to the relay device includes relevant information about a plurality of relay transmission resources, e.g., time and frequency information of respective relay transmission resources.

[111] Specifically, after receiving the message containing relevant information about one or more relay transmission resources, the resource-related information receiving module 4211 decodes the message to obtain relevant information about the relay transmission resource in the message, e.g., the time and frequency information of the relay transmission resource. If the message only contains relevant information about one relay transmission resource, the resource determining module 4212 may determine using the transmission resource to transmit the relay-related information; if the message contains relevant information about a plurality of relay transmission resources, the resource determining module 4212 may select one relay transmission resource therefrom to transmit the relay-related information.

[112] Next, when the first determining module 41 determines transmitting, the second transmitting module 422 uses the relay transmission resource to transmit the relay-related information. Specifically, after the third determining module 421 determines the relay transmission resource according to the manner above, the second transmitting module 422 transmits the relay-related information that needs to be transmitted with the relay transmission resource.

[113] In the prior art, all relay devices transmit the relay-related information every time. When the number of relay devices at a cell edge is relatively large, if all relay devices transmit the relay-related information, utilization efficiency of the transmission resources and energy will not be high. In the present invention, the relay device determines whether to transmit the relay-related information according to the transmission probability, thereby reducing power consumption of the relay devices and the resources in use while guaranteeing validity of the relay function, and enhancing the efficiency of the relay device. When the relay device does not transmit the relay-related information, potential interference caused to other users during the transmission is also reduced.

[114] Fig. 5 illustrates an apparatus for facilitating a relay device to transmit information in a base station of a wireless communication system. The apparatus according to the present embodiment comprises a module (hereinafter referred to as fourth determining module 51) configured to determine a transmission probability; and a module (hereinafter referred to as third transmitting module 52) configured to transmit a message containing the transmission probability to one or more relay devices.

[115] Particularly, the apparatus in the present embodiment is mainly implemented through a base station.

[116] The "base station" used here may be regarded synonymous to or sometimes referred to as the following terms hereinafter: node B, evolved node-B, eNodeB, transceiver base station (BTS), RNC, etc., and may also describe a transceiver that communicates with a mobile terminal and provide radio resources thereto in a wireless communication network that may span a plurality of technology generations. It should be noted that relevant description of the base station is only exemplary, and any other existing or future possibly emerging base station, if applicable to the present invention, should also be included within the protection scope of the present invention and are incorporated here by reference.

[117] The relay device in the present invention refers to a device that has a relay capability. The relay device comprises at least one of the following items:

[118] - a terminal device having relay capability;

[119] - a relay node device having relay capability.

[120] The terminal device having relay capability refers to a terminal device integrated with relay function. This terminal may be a mobile phone, or a data card, a vehicle terminal, or other devices of the same kind. A terminal device having relay capability has both a relay function and a function of a common terminal. Any terminal having relay capability is a potential relay device in the network. A relay node device having relay capability is deployed at a machine room, an office or a house, etc., mainly responsible for data relay between the base station and the terminal in a wireless communication network. There comprise one or more relay node devices in a wireless communication network.

[121] It should be noted that the relay device is only an example, and other existing or future possibly emerging relay devices, if applicable to the present invention, should also be included within the protection scope of the present invention and are incorporated here by reference.

[122] First, the fourth determining module 51 determines a transmission probability. The transmission probability refers to the probability followed by a relay device to transmit relay-related information. Specifically, various algorithms may exist for the fourth determining module 51 to determine the transmission probability. For example, the fourth determining module 51 may estimate efficiency of the relay devices based on a retransmission ratio of terminal users to which the relay device transmits data, thereby determining the transmission probability; the fourth determining module 51 may determine the transmission probability based on the number of all relay devices in the cell; or the fourth determining module 51 determines the transmission probability based on a density of relay devices at the edge of a cell. [123] According to one preferred embodiment of the present invention, the fourth determining module 51 further comprises the following modules: a module (hereinafter referred to as a fifth determining module 511) configured to determine a density of relay devices; and a module (hereinafter referred to as a sixth determining module 512) configured to determine a transmission probability according to the density of relay devices.

[124] First, the fifth determining module 511 determines the density of relay devices. Various algorithms may exist for the fifth determining module 511 to determine the density of relay devices. For example, the fifth determining module 511 may use the number of relay stations at the edge of a cell to represent the density of relay devices, a larger number of relay devices represent a larger density of relay devices; a smaller number of relay devices represents a smaller density of relay devices. For another example, the fifth determining module 511 may adjust the density of relay devices based on the number of existing relay devices within the cell and the number of all terminal users within the cell. For example, the fifth determining module 511 may first set reference default values of the number of existing relay devices and of the number of all terminal users within the cell, and a default value of the relay device density corresponding to the reference default value. When the number of relay devices increases or decreases, the fifth determining module 511 correspondingly increases or decreases the value of the density of relay devices; when the number of all terminal users within the cell increases or decreases, the fifth determining module 511 correspondingly increases or decreases the value of density of relay devices. For another example, the fifth determining module 511 may estimate the size of a cell based on the magnitude of the transmit power of the base station and the number of users within the cell, and then adjust the density of the relay device according to the number of relay devices. For example, the fifth determining module 511 first set reference default values of the transmit power of the base station, the number of users within the cell, and the number of relay devices, and a default value of the density of the relay devices corresponding to the reference default values. When the number of relay devices increases or decreases, the fifth determining module 511 correspondingly increases or decreases the density of the relay device; when the number of users within the cell increases or decreases, the fifth determining module 511 correspondingly decreases or increases the density of relay devices; when the transmit power of the base station increases or decreases, the fifth determining module 511 correspondingly decreases or increases the density of relay devices. It should be noted that the above examples of determining the density of relay devices are only for better illustrating the technical solution of the present invention, not for limiting the present invention. Those skilled in the art should understand that any implementation manner of a module configured to determine the density of the relay devices should be included within the scope of the present invention.

[125] Next, the sixth determining module 512 determines the transmission probability according to the density of the relay devices. Various algorithms may exist for the sixth determining module 512 to determine the transmission probability according to the density of the relay devices. For example, the sixth determining module 512 has two thresholds a and b (a<b) with default values. If the density of the relay devices is greater than or equal to threshold b, the sixth determining module 512 determines that the transmission probability is 1/3; if the density of the relay device is smaller than or equal to threshold a, the sixth determining module 512 determines that the transmission probability is 1; if the density of the relay device is greater than the threshold a but smaller than threshold b, the sixth determining module 512 determines that the transmission probability is 2/3. It should be noted that the above examples of determining the transmission probability are only for better illustrating the technical solution of the present invention, not for limiting the present invention. Those skilled in the art should understand that any implementation manner of determining, by the sixth determining module 512, the transmission probability, should be included within the scope of the present invention.

[126] In one embodiment, the method of facilitating a relay device to transmit information in a base station of the wireless communication system further comprises a module (hereinafter referred to as seventh determining module 53, not shown) configured to determine one or more relay transmission resources; and a module (hereinafter referred to as fourth transmitting module 54, not shown) configured to transmit a message containing relevant information about the one or more relay transmission resources. In the present embodiment, the relay transmission resource refers to time-frequency resource used by the relay device when transmitting the relay-related information.

[127] First, the seventh determining module 53 determines one or more relay transmission resources used by the relay device.

[128] The relay device may be synchronized with the base station by detecting a synchronization signal from the base station. If timing and frequency estimation of the relay devices is accurate enough, all relay devices may be synchronized with each other. In this way, the relay device may use the same time-frequency resource to transmit the relay information when transmitting the same message with a small mutual interference. Therefore, the seventh determining module 53 is only needed to assign the same relay transmission resource to all relay devices. In this case, the seventh determining module 53 determines one relay transmission resource for the relay devices to use.

[129] If the timing estimation or frequency estimation of the relay device is not accurate enough, the relay devices might be interfered with each other when transmitting the relay information with the same time-frequency resource. In this case, the seventh determining module 53 may assign a resource pool containing a plurality of relay transmission resources to the relay device. In this way, each relay device may autonomously select a relay transmission resource from the resource pool assigned by the seventh determining module 53, thereby reducing the conflict when the relay devices use the same relay transmission resources and reducing mutual interference. In this case, the seventh determining module 53 determines many relay transmission resources for the relay device to use.

[130] Then, the fourth transmitting module 54 transmits the message containing relevant information about the one or more relay transmission resources to the one or more relay devices, wherein the relevant information about the relay transmission resources refer to, time and frequency information for the relay transmission resources, for example. Specifically, the fourth transmitting module 54 groups relevant information containing one or more relay transmission resources into a format of message, which may separately group the relevant information into one message containing the relay transmission resources, or incorporate the relevant information containing one or more relay transmission resources into other messages. Then, the fourth transmitting module 54 transmits the messages to one or more relay devices in the cell.

[131] In one preferred embodiment, the sixth determining module 512 comprises a module (hereinafter referred to as an eighth determining module 5121, not shown) configured to determine the transmission probability according to the density of the relay devices and one or more relay transmission devices. Various manners exist for the eighth determining module 5121 to determine the transmission probability according to the density of the relay devices and one or more relay transmission resources. For example, the eighth determining module 5121 may first determine a interim value m of the transmission probability according to the density of relay devices: two thresholds a and b (a<b) with default values exist in the base station; if the density of the relay devices is greater than or equal to threshold b, the m is 1/3; if the density of the relay device is smaller than or equal to threshold a, the m is 1; if the density of the relay device is greater than the threshold a but smaller than threshold b, the m is 2/3. Then, the eighth determining module 5121 determines the transmission probability based on the information about the relay transmission resources: suppose the amount of relay transmission resources is n. If n is smaller than the predetermined threshold x, then the size of the transmission probability is m*(l-k%), where k is a preset adjustment parameter; if n is greater than the predetermined threshold y, the size of transmission probability is m*(l+k%), wherein k denotes a preset adjustment parameter; if n is greater than or equal to x, but smaller than or equal to y, x <y, then the transmission probability is m. It should be noted that the above examples of determining the transmission probability, are only for better illustrating the technical solution of the present invention, not for limiting the present invention. Those skilled in the art should understand that any implementation manner of a module configured to determine the transmission probability, should be included within the scope of the present invention.

[132] Because many mobile relay devices possibly exist, e.g., mobile terminal devices having relay functionality, the density of relay devices within the cell constantly changes. In one embodiment, the fourth determining module 51 comprises a module (hereinafter referred to as re-determining module 513, not shown) configured to, when the density of relay devices changes, re-determine the transmission probability. When the density of the relay device changes, the re-determining module 513 may re-determine the transmission probability. For example, the re-determining module 513 may set a change threshold for the density of relay devices, when the magnitude of the change of the density of relay devices exceeds a preset threshold, the re-determining module 513 re-determines the transmission probability. For another example, the re-determining module 513 may also set an update period for the transmission probability. During each period, the re-determining module 513 re-determines the transmission probability according to the latest density of the relay devices.

[133] After the fourth determining module 51 determines the transmission probability according to the method above, the third transmitting module 52 transmits a message containing the transmission probability to one or more relay devices. For example, while broadcasting cell network configuration parameters, the third transmitting module 52 may broadcast the information of the transmission probability along with the cell network configuration parameters, so as to transmit the message containing the probability to one or more relay devices in a broadcast way. For another example, the third transmitting module 52 may separately customize a message containing the probability information, and then transmits message, in the signaling of a common channel, to one or more relay devices within the cell. It should be noted that the example above is only for better understanding the technical solution of the present invention, not for limiting the present invention. Those skilled in the art should understand that any implementation manner in which a module configured to transmit a message containing the transmission probability to one or more relay devices should be included within the scope of the present invention.

[134] In one embodiment, the apparatus for facilitating a relay device to transmit information in a base station of a wireless transmission system further comprises a module (hereinafter referred to as broadcast transmitting module 55, not shown) configured to transmit a to-be-relayed broadcast message to the one or more relay devices. The broadcast message transmitted by the broadcast transmitting module 55 needs to be transmitted to as many terminal devices as possible; after receiving the broadcast message transmitted by the broadcast transmitting module 55, the relay device relays the broadcast message to nearby out-of-coverage terminal devices so as to enhance cell coverage. For a plurality of relay devices near to each other, because the terminal devices covered by the transmitted signal are identical, it is unnecessary to all relay devices performing relay transmission. Therefore, after the relay devices receive the to-be-relayed broadcast message transmitted from the broadcast transmitting module 55, whether to transmit the broadcast message may be determined based on the transmission probability. According to the manner above, while guaranteeing validity of the relay function, because some relay devices are not needed to transmit the broadcast message, energy consumption needed by transmission is saved, and interference with other devices during transmission is also reduced.

[135] In the prior art, all relay devices transmit the relay-related information. When the number of relay devices at a cell edge is relatively large, if all relay devices transmit the relay-related information, utilization efficiency of the transmission resources and energy will not be high. The base station according to the embodiment of the present invention may determine a transmission probability, used by the relay devices, to transmit the relay-related information, and then transmits the message containing the transmission probability to the relay devices. The relay device can then transmit the relay-related information according to the transmission probability, which, while guaranteeing validity of the relay function, enhances the energy efficiency of transmitting the relay-related information and improve the utilization of the relay transmission resources.

[136] It should be noted that the present disclosure may be implemented in software or a combination of software and hardware; for example, it may be implemented by a dedicated integrated circuit (ASIC), a general-purpose computer, or any other similar hardware device. In an embodiment, the software program of the present disclosure may be executed by a processor so as to implement the above steps or functions. Likewise, the software program of the present disclosure (including relevant data structure) may be stored in a computer readable recording medium, for example, a RAM memory, a magnetic or optical driver, or a floppy disk, and similar devices. Besides, some steps of functions of the present disclosure may be implemented by hardware, for example, a circuit cooperating with the processor to execute various functions or steps.

[137] To those skilled in the art, it is apparent that the present disclosure is not limited to the details of the above exemplary embodiments, and the present disclosure may be implemented with other forms without departing from the spirit or basic features of the present disclosure. Thus, in any way, the embodiments should be regarded as exemplary, not limitative; the scope of the present disclosure is limited by the appended claims, instead of the above depiction. Thus, all variations intended to fall into the meaning and scope of equivalent elements of the claims should be covered within the present disclosure. No reference signs in the claims should be regarded as limiting the involved claims. Besides, it is apparent that the term "comprise/comprising/include/including" does not exclude other units or steps, and singularity does not exclude plurality. A plurality of units or means stated in the apparatus claims may also be implemented by a single unit or means through software or hardware. Terms such as the first and the second are used to indicate names, but do not indicate any particular sequence.

[138] Although exemplary embodiments have been specifically illustrated and described above, those skilled in the art will understand that without departing from the spirit and scope of the claims, their forms and details may change somewhat. Here, the protection as sought is defined in the appended claims. These and other aspects of respective embodiments are prescribed in the following numbered clauses:

1. A method of transmitting information in a relay device of a wireless communication system, wherein the method comprises:

- determining whether to transmit relay-related information according to a transmission probability;

- transmitting the relay-related information when it is determined to transmit.

2. The method according to clause 1, wherein the method further comprises:

- receiving a message containing the transmission probability transmitted by a base station;

- determining the transmission probability according to the message containing the transmission probability.

3. The method according to clause 1 or 2, wherein when it is determined to transmit, the step of transmitting the relay-related information comprises:

- determining a relay transmission resource;

- when it is determined to transmit, transmitting the relay-related information using the relay transmission resource.

4. The method according to clause 3, wherein the step of determining a relay transmission resource comprises:

- receiving a message containing relevant information about one or more relay transmission resources transmitted by the base station;

- determining the relay transmission resource according to the message containing relevant information about one or more relay transmission resources. 5. The method according to any one of clauses 1-4, wherein the relay-related information comprises at least one of the following:

- to-be-relayed broadcast message received from the base station;

- autonomously transmitted relay-related message. 6. The method according to any one of clauses 1-5, wherein the relay device comprises at least any one of the following:

- a terminal device having relay capability;

- a relay node device having relay capability. 7. A method of facilitating a relay device to transmit information in a base station of a wireless communication system, wherein the method comprises:

- determining a transmission probability;

- transmitting a message containing the transmission probability to one or more relay devices.

8. The method according to clause 7, wherein the step of determining a transmission probability comprises:

- determining a density of relay devices;

- determining the transmission probability according to the density of the relay devices.

9. The method according to clause 7 or 8, wherein the method further comprises:

- determining one or more relay transmission resources;

- transmitting a message containing the relevant information about one or more relay transmission resources to the one or more relay devices.

10. The method according to clause 9, wherein the step of determining the transmission probability according to the density of relay devices comprises:

- determining the transmission probability according to the density of relay devices and the one or more relay transmission resources.

11. The method according to clause 8 or 10, wherein the method further comprises:

- re-determining the transmission probability when the density of the relay devices changes. 12. The method according to any one of clauses 7-12, wherein the method further comprises:

- transmitting to-be-relayed broadcast message to the one or more relay devices.

13. The method according to any one of clauses 7-12, wherein the relay device comprises at least any one of the following:

- a terminal device having relay capability;

- a relay node device having relay capability.

14. An apparatus for transmitting information in a relay device of a wireless communication system, wherein the apparatus comprises:

- a module configured to determine whether to transmit relay-related information according to a transmission probability;

- a module configured to transmit the relay-related information when it is determined to transmit. 15. The apparatus according to clause 1, wherein the apparatus further comprises:

- a module configured to receive a message containing the transmission probability transmitted by a base station;

- a module configured to determine the transmission probability according to the message containing the transmission probability. 16. The apparatus according to clause 14 or 15, wherein the module configured to transmit the relay-related information when it is determined to transmit comprises:

- a module configured to determine a relay transmission resource;

- a module configured to, when it is determined to transmit, transmit the relay-related information using the relay transmission resource.

17 The apparatus according to clause 16, wherein the module configured to determine a relay transmission resource comprises:

- a module configured to receive a message containing relevant information about one or more relay transmission resources transmitted by the base station;

- a module configured to determine the relay transmission resource according to the message containing relevant information about one or more relay transmission resources. 18. The apparatus according to any one of clauses 14-17, wherein the relay-related information comprises at least one of the following:

- to-be-relayed broadcast message received from the base station;

- autonomously transmitted relay-related message. 19. The apparatus according to any one of clauses 14-18, wherein the relay device comprises at least any one of the following:

- a terminal device having relay capability;

- a relay node device having relay capability. 20. An apparatus for facilitating a relay device to transmit information in a base station of a wireless communication system, wherein the apparatus comprises:

- a module configured to determine a transmission probability;

- a module configured to transmit a message containing the transmission probability to one or more relay devices.

21. The apparatus according to clause 20, wherein the module configured to determine a transmission probability comprises:

- a module configured to determine a density of relay devices;

- a module configured to determine the transmission probability according to the density of the relay devices.

22. The apparatus according to clause 20 or 21, wherein the apparatus further comprises:

- a module configured to determine one or more relay transmission resources;

- a module configured to transmit a message containing the relevant information about one or more relay transmission resources to the one or more relay devices.

23. The apparatus according to clause 22, wherein the module configured to determine the transmission probability according to the density of relay devices comprises:

- a module configured to determine the transmission probability according to the density of relay devices and the one or more relay transmission resources.

24. The apparatus according to clause 21 or 23, wherein the apparatus further comprises:

- a module configured to re-determine the transmission probability when the density of the relay devices changes.

25. The apparatus according to any one of clauses 20-24, wherein the apparatus further comprises:

- a module configured to transmit to-be-relayed broadcast message to the one or more relay devices.

26. The apparatus according to any one of clauses 20-25, wherein the relay device comprises at least any one of the following:

- a terminal device having relay capability;

- a relay node device having relay capability.

Claims

- transmitting the relay-related information when it is determined to transmit.

2. The method according to claim 1, wherein the method further comprises:

3. A method of facilitating a relay device to transmit information in a base station of a wireless communication system, wherein the method comprises:

- determining a transmission probability;

4. The method according to claim 3, wherein the step of determining a transmission probability comprises:

- determining a density of relay devices;

5. An apparatus for transmitting information in a relay device of a wireless communication system, wherein the apparatus comprises:

- a module configured to transmit the relay-related information when it is determined to transmit.

6. The apparatus according to claim 5, wherein the apparatus further comprises:

- a module configured to determine the transmission probability according to the message containing the transmission probability.

7. The apparatus according to claim 5 or 6, wherein the module configured to transmit the relay-related information when it is determined to transmit comprises:

- a module configured to determine a relay transmission resource;

8. The apparatus according to claim 7, wherein the module configured to determine a relay transmission resource comprises: - a module configured to receive a message containing relevant information about one or more relay transmission resources transmitted by the base station;

- a module configured to determine the relay transmission resource according to the message containing relevant information about one or more relay transmission resources.

9. The apparatus according to any one of claims 5 to 8, wherein the relay-related information comprises at least one of the following:

- to-be-relayed broadcast message received from the base station;

- autonomously transmitted relay-related message.

10. The apparatus according to any one of claims 5 to 9, wherein the relay device comprises at least any one of the following:

- a terminal device having relay capability;

- a relay node device having relay capability.

11. An apparatus for facilitating a relay device to transmit information in a base station of a wireless communication system, wherein the apparatus comprises:

- a module configured to determine a transmission probability;

12. The apparatus according to claim 11, wherein the module configured to determine a transmission probability comprises:

- a module configured to determine a density of relay devices;

13. The apparatus according to claim 11 or 12, wherein the apparatus further comprises:

- a module configured to determine one or more relay transmission resources;

14. The apparatus according to claim 13, wherein the module configured to determine the transmission probability according to the density of relay devices comprises:

15. The apparatus according to claim 12 or 14, wherein the apparatus further comprises: