WO2016038451A1

WO2016038451A1 - Method and apparatus for charging proximity based services

Info

Publication number: WO2016038451A1
Application number: PCT/IB2015/001882
Authority: WO
Inventors: Xiangyang Li; Yigang Cai
Original assignee: Alcatel Lucent
Priority date: 2014-09-12
Filing date: 2015-09-04
Publication date: 2016-03-17
Also published as: CN105407472A

Abstract

The present invention provides a method and apparatus for charging a proximity based service in a wireless communication network. The method of the present invention comprises: obtaining charging related information sent by a user equipment, about a proximity based service used by the user equipment; obtaining charging derivative information based on the charging related information; generating a charging request for the proximity based service used by the user equipment based on the charging related information and the charging derivative information. Compared with the prior art, the solution of the present invention can charge a proximity service used by a user equipment having or not having a connection to the wireless communication network, thereby forming a more effective charging solution.

Description

Method and Apparatus for Charging Proximity Based

Services

FIDLD OF THE INVENTION

The present invention relates to the field of wireless communication, and more specifically, to a method and apparatus for charging a proximity based service in wireless communication.

BACKGROUND OF THE INVENTION

ProSe (Proximity based Services) is a new technology in LTE-A; when mobile devices are proximate to each other, they may connect and communicate directly using ProSe. ProSe enables communication between mobile devices to occur directly between mobile devices, without via a wireless access network and a core network, thereby offloading traffic load of the wireless access network and the core network. Further, because ProSe is based on the LTE technology and works at an LTE licensed frequency band, such that it is a part of the wires communication, it may provide a higher communication quality than technologies such as Bluetooth, WiFi Direct. It should be noted that when the mobile device moves beyond the coverage of an LTE network, it can still use ProSe on the licensed frequency band based on the LTE technology.

At present, the standard organization is still in an initial stage in the study on ProSe, and a detailed solution for charging Prose has not been formed yet. Because a direct device-to-device communication may be performed

immediately without network interference after a connection is established between mobile devices using ProSe, even the mobile devices using ProSe might not be in the network coverage of wireless communication, it is an imminent problem to solve how to charge ProSe. SUMMARY OF THE INVENTION

An objective of the present invention is to provide a method and apparatus for charging a proximity based service in a wireless communication network.

According to one aspect of the present invention, there is provided a method for charging a proximity based service in a wireless communication network, comprising:

- obtaining charging related information sent by a user equipment, about a proximity based service used by the user equipment;

- obtaining charging derivative information based on the charging related information;

- generating a charging request for the proximity based service used by the user equipment based on the charging related information and the charging derivative information.

According to another aspect, there is provided an apparatus for charging a proximity based service in a wireless communication network, comprising:

- means for obtaining charging related information sent by a user equipment, about a proximity based service used by the user equipment;

- means for obtaining charging derivative information based on the charging related information;

- means for generating a charging request for the proximity based service used by the user equipment based on the charging related information and the charging derivative information.

Compared with the prior art, the solution of the present invention can charge a proximity service used by a user equipment having or not having a connection to the wireless communication network, thereby forming a more effective charging solution.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features, objectives and advantages of the present invention will become more apparent through reading the following detailed description of the non-limiting embodiments with reference to the following accompanying drawings:

Fig. 1 shows a schematic diagram of a proximity based service in a wireless communication network;

Fig. 2 shows a flow diagram of a method for charging a proximity based service in a wireless communication network according to embodiments in one aspect of the present invention;

Fig. 3 shows a schematic diagram of an apparatus for charging a proximity based service in a wireless communication network according to embodiments in one aspect of the present invention.

Same or similar reference numerals in the accompanying drawings represent the same or similar components.

DETAILED DESCRIPTION OF THE INVENTION

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

The wireless communication herein includes a communication manner performed through radio signals based on a 3GPP protocol, e.g., LTE, wherein the wireless communication network includes a communication network based on a 3GPP protocol, e.g., LTE, and generally, a plurality of base stations, each base station providing a wireless coverage of the cell where it is located. The base station includes, but not limited to, NodeB, eNodeB. Besides, the wireless communication network supports a plurality of user equipments. Each user equipment may move within or between different cells, or move out of the coverage of the wireless communication network. When the user equipment is in a wireless coverage of a base station, it may communicate with the base station and then communicates with the wireless communication network. Besides, the user equipment may also indirectly establish an IP connection with a corresponding entity of the wireless communication network through other relaying node, thereby communicating with the wireless communication network. Here, the user equipment may be any electronic device that may communicate with a base station directly or indirectly in a wireless manner, including, but not limited to, a mobile phone, a PDA, etc. Preferably, each user equipment and base station in the wireless communication network may transmit and receive information in a time-division duplexing mode (TDD mode) and transmit and receive information in a frequency-division duplexing mode (FDD mode). Those skilled in the art should understand that the wireless communication technology and the modes in which each user equipment and base station transmit and receive information are not limited to the above, and any other existing or future possibly emerging wireless communication technology and information transceiving modes, if applicable to the present invention, should also be included within the protection scope of the present invention, and are incorporated here by reference.

Fig. 1 shows a schematic diagram of a proximity based service in a wireless communication network. As shown in the figure, within the coverage of the wireless communication network, and beyond the coverage, there are distributed a plurality of user equipments (UEs), wherein UE1 , UE2 and UE9 are located within the coverage of the wireless communication network and have a connection to the base station eNodeB. While UE3-UE8 are all located beyond the coverage of the wireless communication network. Device-to-device (D2D) communication may be performed using a proximity based service between respective proximate user equipments in Fig. 1. In Fig. 1 , a connection marked with D2D indicates that a proximity based service is used between user equipments, and there is a D2D direct connection therebetween. For example, there is a D2D connection between UE1 and UE2, between UE2 and UE3, among UE3, UE4 and UE5, and between UE6 and UE7.

Besides, communication between user equipments using proximity based services may be divided into the following four types according to the connection condition between the user equipments and the wireless communication network:

1. Both of two user equipments in communication are located within the coverage of the wireless communication network, e.g., the proximity based service communication between UE1 and UE2;

2. Only one of two user equipments in communication is located within the coverage of the wireless communication network, for example, the proximity based service communication between UE2 and UE8;

3. Neither of two user equipments in communication is located within the coverage of the wireless communication network, but one or two of the user equipments may establish a connection with another user equipment located in the coverage of the wireless communication network, which may be used as a relaying node to connect to the wireless communication network, e.g., the proximity based service communication between UE3 and UE4 or between UE3 and UE5, wherein UE3 uses UE2 as a relaying node to connect to the wireless communication network; or, in another case, neither of the two user equipments in communication is located within the coverage of the wireless communication network, but one or two of the user equipments may establish an IP connection (not shown) with a relevant entity of the wireless communication network through a relay manner such as WLAN;

4. Neither of two user equipments in communication is located within a coverage of the wireless communication network, and neither of the two user equipments can establish a connection with the wireless communication network via a relaying node, e.g., the proximity based service communication between UE6 and UE7.

Among the above four types of proximity based service communications, for the first to third type, the wireless communication network may control the proximity service communication of the user equipment through a direct (first type) or relayed (second type, third type) connection. The relayed control link is shown in dotted-line in Fig. 1. However, for the fourth type of proximity based service communication, the wireless communication network cannot control it.

Correspondingly, for the first to third types of proximity based service communications, the user equipment may transmit charging related information to the wireless communication network directly or via a relaying node when performing proximity based service communication,. However, for the fourth type of proximity based service communication, the user equipment will not be able to transmit the charging related information to the wireless communication network when performing proximity based service communication. At this point, the user equipment may store the charging related information of the proximity service it uses, and transmits the charging related information of the proximity service stored thereby to the wireless communication network when the user equipment can be connected to the wireless communication network directly or via the relaying node, wherein the charging related information may also comprise one or more pieces of charging related information of one or more times of proximity services.

It should be noted that in this description, the charging related information contains various information which can be used for charging proximity based services.

In the prior art, it is usually a charging trigger function (CTF) that obtains the charging related information, generates a charging request, and transmits it to the charging system. The CTF is generally located in the ProSe function of a network device. Hereinafter, for the sake of simplicity, relevant function supporting charging a proximity based service in the present invention is called CTF. Those skilled in the art should understand, although it is named "CTF," it is only for the purpose of facilitating understanding, rather than any limitation to the application scope of the present invention. And those skilled in the art should understand, said CTF which the present application relates to is not limited to locating in the ProSe function of a network device, and it can be integrated in any other component of a network device, or it can also be a standalone device.

Fig. 2 shows a schematic diagram of a method for charging a proximity based service in a wireless communication network according to embodiments in one aspect of the present invention.

In step S21 , CTF obtains charging related information sent by a user equipment, about a proximity based service used by the user equipment. Specifically, the user equipment generates charging related information for a proximity based service used by the user equipment, and directly or via a relaying node transmits the charging related information to a CTF or other relevant network devices or components of the wireless communication network. The CTF may directly obtain the charging related information or obtain the charging related information through interaction with other relevant network devices or components. In one embodiment, as described above, CTF locates in the ProSe function of a network device. The user equipment can directly or via a relaying node transmit charging related information to the ProSe function. In addition, based on the charging related information transmitted by the user equipment, ProSe function can also generate additional charging related information. Therefore, here, CTF can obtain the charging related information transmitted by the user equipment directly or via a relaying node from ProSe function, and CTF can obtain the additional charging related information generated by ProSe function from said ProSe function.

In one embodiment, the CTF may obtain the charging related information, sent by the user equipment during the proximity based service, about the proximity based service used by the user equipment, and/or obtain delayed charging related information, sent by the user equipment, after using the proximity based service, about the proximity based service used by the user equipment, wherein the delayed charging related information may include one or more pieces of charging related information of one or more proximity based services.

During and/or after use of the proximity based service, the user equipment may send charging related information about the proximity based service it uses/used for multiple times, e.g., the user equipment may send the corresponding charging related information at the start of the proximity based service, during the proximity based service, and at the end of the proximity based service, or the user equipment may also send the corresponding charging related information for multiple times after using the proximity based service. Correspondingly, CTF may obtain a plurality of pieces of charging related information sent by the user equipment during and/or after use of the proximity based service.

As mentioned above, the user equipment may send the corresponding charging related information to the wireless communication network through a direct connection to the wireless communication network or via a relaying node. In one preferred embodiment, for the user equipment located within coverage of the wireless communication network, the CTF may obtain the charging related information sent by the user equipment during use of the proximity based service via the wireless communication network, about the proximity based service used by the user equipment. Besides, for the user equipment not located within the coverage of the wireless communication network, the CTF may obtain the related charging related information sent by the user equipment via other communication manner during use of the proximity based service, the relayed charging related information about the proximity based service it uses. Besides, the other communication manner may include for example, relaying via the user equipment having a direct connection to the wireless communication network, or relaying via WLAN to transmit the charging related information. Those skilled in the art should understand that the other communication manner as listed here is only exemplary, not limitative; any manner suitable for the present invention should be included within the protection scope of the present invention and is incorporated here by reference.

As mentioned above, for the fourth type of proximity based service, the user equipment may store the charging related information of the proximity based service which it uses, and transmits the proximity charging related information stored thereby to the wireless communication network when the user equipment can directly or via a relay be connected to the wireless commutation information, and the charging related information may also include one or more pieces of charging related information of one or more proximity based services. In one embodiment, the CTF may obtain the delayed charging related information, sent by a user equipment that is not connected to the wireless communication network during use of the proximity based service but is connected to the wireless communication network after using the proximity based service, about the proximity based service used by the user equipment. Here, the manner in which the user equipment is connected to the wireless communication network includes connection using the wireless communication service provided by the wireless communication network or connection with the wireless communication network via other communication manner. Here, as mentioned above, other communication manner may include, for example, relay via a user equipment having a direct connection to the wireless communication network, or via WLAN to perform relay so as to connect to the wireless communication network.

Next, in step S22, the CTF determines charging derivative information based on the charging related information, wherein the charging derivative information includes at least any of the following:

- proximity based service event information and/or proximity based service session information;

- start time of the proximity based service event and/or proximity based service session;

- information indicating whether the charging related information is delayed charging related information;

- charging mode;

- information indicating whether the charging related information is relayed charging related information; - calling party related information of the proximity based service;

- one or more called parties related information of the proximity based service.

The charging derivative information may include proximity based service event information and/or proximity based service session information. The proximity based service may be divided into two types: proximity based service event and proximity based service session, and wherein the proximity based service session type may includes proximity based voice call session type and proximity based application data service flow session type. Here, the proximity based service event information refers to information about a proximity based service event that is related to the charging related information and needs to be charged; the proximity based service session information refers to information about a proximity based service session that is related to the charging related information and needs to be charged. The CTF may obtain an identifier of a proximity based service event or an identifier of a proximity based service session which is related to the charging related information from the charging related information so as to further obtain information about the proximity based service event or proximity based service session to which the charging related information is related, as the charging derivative information, through interaction with a corresponding entity of the wireless communication network.

Besides, as above mentioned, for the fourth type of proximity based service, after establishing the connection to the wireless communication network, the user equipment may send the charging related information of the proximity based service as stored thereby to the wireless communication network, and the charging related information may include charging related information of one or more times of proximity based services, which may not only includes the proximity based service event but also includes the charging related information of the proximity based service session. In other words, the CTF may obtain one or more pieces of proximity based service event information and/or proximity bases service session information as the charging derivative information based on the charging related information.

The charging derivative information may include the start time of the proximity based service event and/or proximity based service session. The CTF obtains the proximity service event information and/or proximity service session information through the above manner based on the charging related information, such that it may obtain the start time of the proximity based service event and/or proximity service session as the charging derivative information.

The charging derivative information may also include information indicating whether the charging related information is delayed charging related information. As mentioned above, for the fourth type of proximity based service, since the user equipment transmits the corresponding charging related information after the proximity based service and after it is connected to the wireless communication network, the charging related information is delayed charging related information. Based on the charging related information, the CTF may obtain the start time of the proximity based service event and/or the proximity based service session to which the charging related information is related in the above manner based on the charging related information. Then, the CTF may determine whether the charging related information is delayed charging related information based on whether the time interval between the time of receiving the charging related information and the start time exceeds a predetermined threshold. In other words, if the time interval between the time of receiving the charging related information and the start time of the proximity based service event and/or the proximity based service session to which the charging related information is related exceeds the predetermined threshold, it may be determined that the charging related information is delayed charging related information; otherwise, it is determined that it is not delayed charging related information. Besides, the CTF takes the information indicating a result of whether the above charging related information is delayed charging related information as the charging derivative information.

The charging derivative information may also include a charging mode. The charging mode here includes an offline charging mode and an online charging mode. The CTF may obtain whether the charging mode is an offline charging mode or an online charging mode according to an agreement between a user from which the charging related information comes and a carrier of the wireless communication network. Or, the CTF may determine whether the charging related information is delayed charging related information based on the above method, and when it is the delayed charging related information, the CTF determines that the charging mode is an offline charging mode. After determining the charging mode, the CTF takes the charging mode as the charging derivative information.

The charging derivative information may also include information indicating whether the charging related information is relayed charging related information. As mentioned above, the user equipment may directly establish a connection with the wireless communication network through using a wireless communication service of the wireless communication network, or the user equipment may establish a connection to the wireless communication network through other communication manner, e.g., through other relaying node such as a relaying user equipment or WLAN. When the user equipment sends the charging related information to the wireless communication network through a relaying node, the relaying node adds its own information (e.g., relaying node identifier, relay hop number, relay authentication state, relay type, etc.) in the charging related information. In this way, the CTF may determine whether it is relayed charging related information based on whether the charging related information includes information of a relaying node and takes the information indicating whether the charging related information is relayed charging related information as the charging derivative information.

The charging derivative information may also include calling party related information of the proximity based service. In the charging related information sent by the user equipment, it will include an identifier of the entity originating the proximity based service, i.e., the calling party identifier. The CTF may obtain relevant information of the calling party based on the calling party identifier included in the charging related information through communication with a relevant network device in the wireless communication network, and takes it as charging derivative information.

Besides, the charging derivative information may also include one or more called parties related information of the proximity based service. The proximity based service communication may be one-to-one proximity based service communication originated by one user equipment to another user equipment, or one-to-many proximity based service communication originated by one user equipment to more user equipments. Therefore, the charging related information may include identifiers of one or more called parties. Based on the identifiers of the one or more called parties included in the charging related information, the CTF may obtain relevant information of one or more called parties through, for example, communicating with relevant network device in the wireless communication network, and takes it as charging derivative information.

Those skilled in the art should understand that the list of charging derivative information mentioned here and the manners of obtaining the derivative information are only exemplary and non-limitative; any charging derivation information and its obtaining manner, if applicable to the present invention, should fall within the protection scope of the present invention and is incorporated here by reference.

In step S23, the CTF generates a charging request for the proximity based service used by the user equipment based on the charging related information and the charging derivative information.

In one instance, the charging derivative information includes proximity based service event information and/or proximity based service session information. The CTF generates a charging request for the proximity based service event and/or proximity based service session based on the charging related information and the proximity based service event information and/or the proximity based service session information. For the proximity based service session, as mentioned above, the CTF may obtain the corresponding charging related information for multiple times. In one embodiment, the CTF may generate a plurality of charging requests for multiple pieces of charging related information of the proximity based service session. In another embodiment, for the multiple pieces of charging related information as obtained for multiple times for the proximity based service session, the CTF may only generate one charging request corresponding to the multiple pieces of charging related information.

In one example, the charging derivative information includes information indicating whether the charging related information is delayed charging related information. When it is delayed charging related information, as mentioned above, the delayed charging related information may include information of one or more proximity based service events and/or proximity based service sessions. In one embodiment, the CTF generates a corresponding charging request for each of the one or more proximity based service events and/or proximity based service sessions. In another embodiment, the CTF only generates one charging request for all proximity based service events and/or proximity based service sessions for the one or more proximity based service events and/or proximity based service sessions. In another embodiment, the CTF may generate a charging request for some proximity based service events and/or proximity based service sessions in the one or more proximity based service events and/or proximity based service sessions, while generate a charging request for other proximity based service events and/or proximity based service sessions therein, respectively.

Besides, as mentioned above, the delayed charging related information may include one or more pieces of charging related information. In one embodiment, for respective charging related information therein, the CTF may generate a charging request, separately. In another embodiment, for respective charging related information of a certain proximity based service session included in the charging related information, the CTF may only generate one charging request.

In one instance, the charging derivative information includes a charging mode. When the charging mode is an offline charging mode, the CTF generates an offline charging request for the proximity based service used by the user equipment based on the charging related information and the charging derivative information; when the charging mode is an online charging mode, the CTF generates an online charging request for the proximity based service used by the user equipment based on the charging related information and the charging derivative information.

In one instance, the charging derivative information includes information indicating whether the charging related information is relayed charging related information. In one embodiment, the CTF generates a charging request based on the relayed charging related information, which charging request will further include information related to the relay, e.g., a relaying node identification, a relay hop number, a relay authentication state, a relay type, etc.

In one instance, the charging derivative information includes calling party related information of the proximity based service. Based on the charging related information and the charging derivative information, the CTF will generate a charging request including the calling party related information, in one instance, the charging derivative information includes one or more pieces of called parties related information of the proximity based service. In one embodiment, the CTF generates a charging request for respective called party among the one or more called parties based on the charging related information and the charging derivative information. In another embodiment, the CTF generates a charging request for respective called party among one or more called parties based on the charging related information and the charging derivative information.

Those skilled in the art should understand that the manners of generating the charging request based on the charging related information and different charging derivative information may be used in cooperation with each other; besides, they are only exemplary, rather than limitative, depictions, and any manner, if applicable to the present invention, should fall within the protection scope of the present invention, and is incorporated here by reference.

In one preferred embodiment, the CTF obtains respective charging related information, sent by a plurality of user equipments, about the proximity based services used by the user equipments respectively, and obtains the corresponding charging derivative information based on respective charging related information of the plurality of users. Then, the CTF obtains associated charging related information by associating respective charging related information from the same charging identifier from the plurality of user equipments based on respective charging related information of the plurality of user equipments and the charging derivative information. Then, the CTF generates a charging request for the proximity based services used by the plurality of user equipments based on respective charging related information of the plurality of user equipments, the charging derivative information, and the associated charging related information.

Here, the charging identifier refers to a charging identifier of an entity using the proximity based service.

Hereinafter, illustration will be made with an example that user equipment A and user equipment B use a proximity based service to perform a D2D session. First, the CTF obtains charging related information CI_A and charging related information CI_B from user equipment A and user equipment B, respectively, according to the above method. Moreover, the CTF obtains charging derivative information respectively corresponding to CI_A and CI_B according to the method mentioned above. In this example, the CTF obtains the proximity based service session information of CI_A and CI_B, respectively, and determines that it is a proximity based service session S_AB between the same user equipment A and user equipment B . the CTF obtains that the charging identifiers of CI_A and CI_B related to S_AB are identifier UE_A of user equipment A and identifier UE_B of user equipment B based on CI_A, CI_B and their respective charging derivative information. In this way, the CTF associates CI_A and CI_B, thereby obtaining, for S_AB, the associated charging information CI_AB for UE_A and UE_B. Next, CTF may uniformly generate a charging request for the proximity based service session S_AB based on CI_A, CI_b, and their respectively charging derivative information and associated charging information CI_AB - In another preferred embodiment, the CTF obtains a plurality of pieces of charging related information, sent by the user equipment within a second threshold time range, about the proximity based service as used by the user equipment, obtains the corresponding charging related information based on the plurality of pieces of charging related information, and determines whether the plurality of pieces of charging related information form complete session charging related information based on the plurality of pieces of charging related information and the charging derivative information. Next, the CTF generates a charging request for a proximity based service used by the user equipment based on the plurality of pieces of charging related information and the charging derivative information and based on a result of determining whether the plurality of pieces of charging related information form a complete session charging related information.

For example, the user equipment A and the user equipment B use a proximity based service to perform a D2D session. Hereinafter, the illustration will be made with user equipment A as an example, during the period when user equipment A uses the proximity based service, the CTF obtains a plurality of pieces of charging related information, sent by the user equipment A within the second threshold time range, about the proximity based service used by the user equipment A according to the method described above, which may include a plurality of pieces of charging related information sent at the start of the proximity based service, during the proximity based service, and at the end of the proximity based service. Here, the second threshold time range is a predetermined value set for example according to an empirical value, which may be dynamically adjusted according to the actual needs. Then, the CTF obtains corresponding charging derivative information based on the plurality of charging related information according to the method depicted above. For example, in this example, the CTF obtains that the identifier of the proximity based service session is S_AB, and obtains that the S_AB session already ended according to the method depicted above; besides, the plurality of pieces of charging related information reflect the procedure of the S_AB from the start to the end. In this way, the CTF determines that the plurality of pieces of charging related information form complete session charging related information for S_AB- Next, the CTF generates a complete session charging request for S_AB based on the plurality of pieces of charging related information and the charging derivative information and based on the complete session charging related information formed for the S_AB based on the plurality of pieces of charging related information, and the charging request includes information indicating that it is a complete session request. In another instance, suppose the CTF determines that the plurality of pieces of charging related information cannot form complete session charging related information for the proximity based service session. Correspondingly, the CTF generates an incomplete session charging request including information indicating that it is an incomplete session charging request. It should be noted that the complete session charging request or the incomplete session charging request is a uniform charging request generated for the plurality of charging related information.

Fig. 3 shows a schematic diagram of an apparatus for charging a proximity based service in a wireless communication network according to embodiments in another aspect of the present invention. The apparatus comprises: means 31 (hereinafter referred to as first charging related information obtaining module 31) for obtaining charging related information, sent by a user equipment, about a proximity based service used by the user equipment; means 32 (hereinafter referred to as first charging derivative information obtaining module 32) for obtaining charging derivative information based on the charging related information; means 33 (hereinafter referred to as first charging request generating module 33) for generating a charging request for the proximity based service used by the user equipment based on the charging related information and the charging derivative information.

First, the first charging related information obtaining module 31 obtains charging related information sent by a user equipment, about a proximity based service used by the user equipment. Specifically, the user equipment generates charging related information for the proximity based service used by the user equipment, and directly or via a relaying node sends it to other relevant network devices or components of the wireless communication network. The first charging related information obtaining module 31 may directly obtains the charging related information, or obtain the charging related information through interacting with other relevant network devices or components. In one embodiment, as described above, CTF locates in the ProSe function of a network device. The first charging related information obtaining module 31 can directly or via a relaying node transmit charging related information to the ProSe function. In addition, based on the charging related information transmitted by the user equipment, ProSe function can also generate additional charging related information. Therefore, here, The first charging related information obtaining module 31 can obtain the charging related information transmitted by the user equipment directly or via a relaying node from ProSe function, and The first charging related information obtaining module 31 can obtain the additional charging related information generated by ProSe function from said ProSe function.

In one embodiment, means 311 (not shown, hereinafter referred to as second charging related information obtaining module 311), of the first charging related information obtaining module 31 , for obtaining the charging related information, sent by the user equipment during using the proximity based service, about the proximity based service used by the user equipment, may obtain the charging related information, sent by the user equipment during using the proximity based service, about the proximity based service used by the user equipment. Means 312 (not shown, hereinafter referred to as the first charging related information obtaining module 312), of the first charging related information obtaining module 31 , for obtaining delayed charging related information, sent by the user equipment after using the proximity based service, about the proximity based service used by the user equipment, may obtain delayed charging related information, sent by the user equipment after using the proximity based service, about the proximity based service used by the user equipment, which may include one or more pieces of charging related information of one or more times of proximity based services.

During and/or after use of the proximity based service, the user equipment may send charging related information about the proximity based service it uses for multiple times, e.g., the user equipment may send the corresponding charging related information at the start of the proximity based service, during the proximity based service, and at the end of the proximity based service, or the user equipment may also send the corresponding charging related information for multiple times after using the proximity based service. Correspondingly, the second charging related information obtaining module 311 may obtain a plurality of pieces of charging related information sent by the user equipment during and/or after use of the proximity based service.

As mentioned above, the user equipment may send the corresponding charging related information to the wireless communication network through a direct connection to the wireless communication network or via a relaying node. In one preferred embodiment, for the user equipment located within coverage of the wireless communication network, the second charging related information obtaining module 311 may obtain the charging related information, sent by the user equipment during use of the proximity based service via the wireless communication network, about the proximity based service used by the user equipment. Besides, for the user equipment not located within the coverage of the wireless communication network, the second charging related information obtaining module 311 may obtain the related charging related information, sent by the user equipment via other communication manner during use of the proximity based service, the relayed charging related information about the proximity based service it uses. Here, the other communication manner may include for example, relaying via the user equipment having a direct connection to the wireless communication network, or relaying via WLAN to transmit the charging related information. Those skilled in the art should understand that the other communication manner as listed here is only exemplary, not limitative; any manner suitable for the present invention should be included within the protection scope of the present invention and is incorporated here by reference.

As mentioned above, for the fourth type of proximity based service, the user equipment may store the charging related information of the proximity based service which it uses, and transmits the proximity charging related information stored thereby to the wireless communication network when the user equipment can directly or via a relay be connected to the wireless commutation information, and the charging related information may also include one or more pieces of charging related information of one or more proximity based services. In one embodiment, the third charging related information obtaining module 312 may obtain the delayed charging related information, sent by a user equipment that is not connected to the wireless communication network during use of the proximity based service but is connected to the wireless communication network after using the proximity based service, about the proximity based service used by the user equipment. Here, the manner in which the user equipment is connected to the wireless communication network includes connection using the wireless communication service provided by the wireless communication network or connection with the wireless communication network via other communication manner. Here, as mentioned above, other communication manner may include, for example, relay via a user equipment having a direct connection to the wireless communication network, or via WLAN to perform relay so as to connect to the wireless communication network.

Next, the first charging derivative information obtaining module 32 determines charging derivative information based on the charging related information, wherein the charging derivative information includes at least any of the following:

- charging mode;

- information indicating whether the charging related information is relayed charging related information;

- calling party related information of the proximity based service;

The charging derivative information may include proximity based service event information and/or proximity based service session information. The proximity based service may be divided into two types: proximity based service event and proximity based service session, and wherein the proximity based service session type may includes proximity based voice call session type and proximity based application data service flow session type. Here, the proximity based service event information refers to information about a proximity based service event that is related to the charging related information and needs to be charged; the proximity based service session information refers to information about a proximity based service session that is related to the charging related information and needs to be charged. The first charging derivative information obtaining module 32 may obtain an identifier of a proximity based service event or an identifier of a proximity based service session which is related to the charging related information from the charging related information so as to further obtain information about the proximity based service event or proximity based service session to which the charging related information is related, as the charging derivative information, through interaction with a corresponding entity of the wireless communication network.

Besides, as above mentioned, for the fourth type of proximity based service, after establishing the connection to the wireless communication network, the user equipment may send the charging related information of the proximity based service as stored thereby to the wireless communication network, and the charging related information may include charging related information of one or more times of proximity based services, which may not only includes the proximity based service event but also includes the charging related information of the proximity based service session. In other words, the first charging derivative information obtaining module 32 may obtain one or more pieces of proximity based service event information and/or proximity bases service session information as the charging derivative information based on the charging related information.

The charging derivative information may include the start time of the proximity based service event and/or proximity based service session. The first charging derivative information obtaining module 32 obtains the proximity service event information and/or proximity service session information through the above manner based on the charging related information, such that it may obtain the start time of the proximity based service event and/or proximity service session as the charging derivative information.

The charging derivative information may also include information indicating whether the charging related information is delayed charging related information. As mentioned above, for example, for the fourth type of proximity based service, since the user equipment transmits the corresponding charging related information after the proximity based service and after it is connected to the wireless communication network, the charging related information is delayed charging related information. Based on the charging related information, the first charging derivative information obtaining module 32 may obtain the start time of the proximity based service event and/or the proximity based service session to which the charging related information is related in the above manner based on the charging related information. Then, the first charging derivative information obtaining module 32 may determine whether the charging related information is delayed charging related information based on whether the time interval between the time of receiving the charging related information and the start time exceeds a predetermined threshold. In other words, if the time interval between the time of receiving the charging related information and the start time of the proximity based service event and/or the proximity based service session to which the charging related information is related exceeds the predetermined threshold, the first charging derivative information obtaining module 32 may determine that the charging related information is delayed charging related information; otherwise, the first charging derivative information obtaining module 32 determines that it is not delayed charging related information. Besides, the first charging derivative information obtaining module 32 takes the information indicating a result of whether the above charging related information is delayed charging related information as the charging derivative information. The charging derivative information may also include a charging mode. The charging mode here includes an offline charging mode and an online charging mode. The first charging derivative information obtaining module 32 may obtain whether the charging mode is an offline charging mode or an online charging mode according to an agreement between a user from which the charging related information comes and a carrier of the wireless communication network. Or, the first charging derivative information obtaining module 32 may determine whether the charging related information is delayed charging related information based on the above method, and when it is the delayed charging related information, the first charging derivative information obtaining module 32 determines that the charging mode is an offline charging mode. After determining the charging mode, the first charging derivative information obtaining module 32 takes the charging mode as the charging derivative information.

The charging derivative information may also include information indicating whether the charging related information is relayed charging related information. As mentioned above, the user equipment may directly establish a connection with the wireless communication network through using a wireless communication service of the wireless communication network, or the user equipment may establish a connection to the wireless communication network through other communication manner, e.g., through other relaying node such as a relaying user equipment or WLAN. When the user equipment sends the charging related information to the wireless communication network through a relaying node, the relaying node adds its own information (e.g., relaying node identifier, relay hop number, relay authentication state, relay type, etc.) in the charging related information. In this way, the first charging derivative information obtaining module 32may determine whether it is relayed charging related information based on whether the charging related information includes information of a relaying node and the first charging derivative information obtaining module 32 takes the information indicating whether the charging related information is relayed charging related information as the charging derivative information.

The charging derivative information may also include calling party related information of the proximity based service. In the charging related information sent by the user equipment, it will include an identifier of the entity originating the proximity based service, i.e., the calling party identifier. The first charging derivative information obtaining module 32 may obtain relevant information of the calling party based on the calling party identifier included in the charging related information through communication with a relevant network device in the wireless communication network, and takes it as charging derivative information.

Besides, the charging derivative information may also include one or more called parties related information of the proximity based service. The proximity based service communication may be one-to-one proximity based service communication originated by one user equipment to another user equipment, or one-to-many proximity based service communication originated by one user equipment to more user equipments. Therefore, the charging related information may include identifiers of one or more called parties. Based on the identifiers of the one or more called parties included in the charging related information, the first charging derivative information obtaining module 32 may obtain relevant information of one or more called parties through, for example, communicating with relevant network device in the wireless communication network, and takes it as charging derivative information.

Next, the first charging request generating module 33 generates a charging request for the proximity based service used by the user equipment based on the charging related information and the charging derivative information.

In one instance, the charging derivative information includes proximity based service event information and/or proximity based service session information. The first charging request generating module 33 generates a charging request for the proximity based service event and/or proximity based service session based on the charging related information and the proximity based service event information and/or the proximity based service session information. For the proximity based service session, as mentioned above, the first charging related information obtaining module 31 may obtain the corresponding charging related information for multiple times. In one embodiment, the first charging request generating module 33 may generate a plurality of charging requests for multiple pieces of charging related information of the proximity based service session. In another embodiment, for the multiple pieces of charging related information as obtained for multiple times for the proximity based service session, the first charging request generating module 33 may only generate one charging request corresponding to the multiple pieces of charging related information.

In one example, the charging derivative information includes information indicating whether the charging related information is delayed charging related information. When it is delayed charging related information, as mentioned above, the delayed charging related information may include information of one or more proximity based service events and/or proximity based service sessions. In one embodiment, the first charging request generating module 33 generates a corresponding charging request for each of the one or more proximity based service events and/or proximity based service sessions. In another embodiment, the first charging request generating module 33 only generates one charging request for all proximity based service events and/or proximity based service sessions for the one or more proximity based service events and/or proximity based service sessions. In another embodiment, the first charging request generating module 33 may generate a charging request for some proximity based service events and/or proximity based service sessions in the one or more proximity based service events and/or proximity based service sessions, while the first charging request generating module 33 generates a charging request for other proximity based service events and/or proximity based service sessions therein, respectively.

Besides, as mentioned above, the delayed charging related information may include one or more pieces of charging related information. In one embodiment, for respective charging related information therein, the first charging request generating module 33 may generate a charging request, separately. In another embodiment, for respective charging related information of a certain proximity based service session included in the charging related information, the first charging request generating module 33 may only generate one charging request.

In one instance, the charging derivative information includes a charging mode. When the charging mode is an offline charging mode, the first charging request generating module 33 generates an offline charging request for the proximity based service used by the user equipment based on the charging related information and the charging derivative information; when the charging mode is an online charging mode, the first charging request generating module 33 generates an online charging request for the proximity based service used by the user equipment based on the charging related information and the charging derivative information.

In one instance, the charging derivative information includes information indicating whether the charging related information is relayed charging related information. In one embodiment, the first charging request generating module 33 generates a charging request based on the relayed charging related information, which charging request will further include information related to the relay, e.g., a relaying node identification, a relay hop number, a relay authentication state, a relay type, etc.

In one instance, the charging derivative information includes calling party related information of the proximity based service. Based on the charging related information and the charging derivative information, the first charging request generating module 33 will generate a charging request including the calling party related information, in one instance, the charging derivative information includes one or more called parties related information of the proximity based service. In one embodiment, the first charging request generating module 33 generates a charging request for respective called party among the one or more called parties based on the charging related information and the charging derivative information. In another embodiment, the first charging request generating module 33 generates a charging request for respective called party among one or more called parties based on the charging related information and the charging derivative information.

In one preferred embodiment, means 313 (not shown, hereinafter referred to as fourth charging related information obtaining module 313), of the first charging related information obtaining module 31 , for obtaining respective charging related information, sent by a plurality of user equipments, about the proximity based services used by the user equipments respectively, obtains respective charging related information, sent by a plurality of user equipments, about the proximity based services used by the user equipments respectively. And means 321 (not shown, hereinafter referred to as second charging derivative information obtaining module 321), of the first charging derivative information obtaining module, for obtaining the corresponding charging derivative information based on respective charging related information of the plurality of user equipments, obtains the corresponding charging derivative information based on respective charging related information of the plurality of use equipments. Then, means 331 (not shown, hereinafter referred to as associated charging related information obtaining module 331), of the first charging request generating module 33, for obtaining associated charging related information by associating respective charging related information from the same charging identifier from the plurality of user equipments based on respective charging related information of the plurality of user equipments and the charging derivative information, obtains associated charging related information by associating respective charging related information from the same charging identifier from the plurality of user equipments based on respective charging related information of the plurality of user equipments and the charging derivative information. Then, means 332 (not shown, hereinafter referred to as second charging request generating module 332), of the first charging request generating module 33, for generating a charging request for the proximity based services used by the plurality of user equipments based on respective charging related information of the plurality of user equipments, the charging derivative information, and the associated charging related information, generates a charging request for the proximity based services used by the plurality of user equipments based on respective charging related information of the plurality of users, the charging derivative information, and the associated charging related information.

Hereinafter, illustration will be made with an example that user equipment A and user equipment B use a proximity based service to perform a D2D session. First, the fourth charging related information obtaining module 313 obtains charging related information CI_A and charging related information CI_B from user equipment A and user equipment B, respectively, according to the above method. Moreover, the second charging derivative information obtaining module 321 obtains charging derivative information respectively corresponding to CI_A and CI_B according to the method mentioned above. In this example, the second charging derivative information obtaining module 321 obtains the proximity based service session information of CI_A and CI_B, respectively, and determines that it is a proximity based service session S_AB between the same user equipment A and user equipment B . The associated charging related information obtaining module 331 obtains that the charging identifiers of CI_A and CI_B related to S_AB are identifier UE_A of user equipment A and identifier UE_B of user equipment B based on CI_A, CI_b and their respective charging derivative information. In this way, the associated charging related information obtaining module 33 1 associates CI_A and CI_B, thereby obtaining, for S_AS, the associated charging information CI_AB for UE_A and UE_B. Next, second charging request generating module 332 may uniformly generate a charging request for the proximity based service session S_AB based on CI_A, CI_b, and their respectively charging derivative information and associated charging information CI_AB -

In another preferred embodiment, means 314 (not shown, hereinafter referred to as fifth charging related information obtaining module 314), of the first charging related information obtaining module 31 , for obtaining a plurality of pieces of charging related information, sent by the user equipment within a second threshold time range, about the proximity based service as used by the user equipment, obtains a plurality of pieces of charging related information, sent by the user equipment within a second threshold time range, about the proximity based service as used by the user equipment. Then, means 322 (now shown, hereinafter referred to as third charging derivative information obtaining module 322), of the first charging derivative information obtaining module 32, for obtaining the corresponding charging related information based on the plurality of pieces of charging related information, obtains the corresponding charging related information based on the plurality of pieces of charging related information. Moreover, means 333 (not shown, hereinafter referred to as complete session charging related information obtaining module 333), of the first charging request generating module 33, for determining whether the plurality of pieces of charging related information form complete session charging related information based on the plurality of pieces of charging related information and the charging derivative information, determines whether the plurality of pieces of charging related information form complete session charging related information based on the plurality of pieces of charging related information and the charging derivative information. Next, means 334 (not shown, hereinafter referred to as third charging request generating module 334), of the first charging request generating module 33, for generating a charging request for a proximity based service used by the user equipment based on the plurality of pieces of charging related information and the charging derivative information and based on a result of determining whether the plurality of pieces of charging related information form a complete session charging related information, generates a charging request for a proximity based service used by the user equipment based on the plurality of pieces of charging related information and the charging derivative information and based on a result of determining whether the plurality of pieces of charging related information form a complete session charging related information.

For example, the user equipment A and the user equipment B use a proximity based service to perform a D2D session. Hereinafter, the illustration will be made with user equipment A as an example. During the period when user equipment A uses the proximity based service, the fifth charging related information obtaining module 314 obtains a plurality of pieces of charging related information, sent by the user equipment A within the second threshold time range, about the proximity based service used by the user equipment A according to the method described above, which may include a plurality of pieces of charging related information sent at the start of the proximity based service, during the proximity based service, and at the end of the proximity based service. Here, the second threshold time range is a predetermined value set for example according to an empirical value, which may be dynamically adjusted according to the actual needs. Then, the third charging derivative information obtaining module 322 obtains corresponding charging derivative information based on the plurality of charging related information according to the method depicted above. For example, in this example, the third charging derivative information obtaining module 322 obtains that the identifier of the proximity based service session is S_AB, and the complete session charging related information determining module 333 obtains that the S_AB session already ended according to the method depicted above; besides, the plurality of pieces of charging related information reflect the procedure of the S_AB from the start to the end. In this way, the complete session charging related information determining module 333 determines that the plurality of pieces of charging related information form complete session charging related information for S_AB- Next, the third charging request generating module 334 generates a complete session charging request for S_AB based on the plurality of pieces of charging related information and the charging derivative information and based on the complete session charging related information formed for the S_AB based on the plurality of pieces of charging related information, and the charging request includes information indicating that it is a complete session request. In another instance, suppose the complete session charging related information determining module 333 determines that the plurality of pieces of charging related information cannot form complete session charging related information for the proximity based service session. Correspondingly, the third charging request generating module 334 generates an incomplete session charging request including information indicating that it is an incomplete session charging request. It should be noted that the complete session charging request or the incomplete session charging request is a uniform charging request generated for the plurality of charging related information.

It should be noted that the present invention may be implemented in software and/or a combination of software and hardware. For example, each module of the present invention may be implemented by an application-specific integrated circuit (ASIC) or any other similar hardware device. In one embodiment, the software program of the present invention may be executed through a processor to implement the steps or functions as mentioned above. Likewise, the software program (including relevant data structure) of the present invention may be stored in a computer readable recording medium, e.g., RAM memory, magnetic or optic driver or soft floppy or similar devices. Additionally, some steps or functions of the present invention may be implemented by hardware, for example, a circuit cooperating with the processor so as to implement various steps of functions.

Additionally, a part of the present invention may be applied as a computer program product, e.g., a computer program instruction, which, when being executed by the computer, may invoke or provide a method and/or technical solution according to the present invention. Further, the program instruction invoking the method of the present invention may be stored in a fixed or mobile recording medium, and/or communicated through broadcast or data stream in other signal carrying media, and/or stored in a work memory of a computer device running based on the program instruction. Here, one embodiment according to the present invention comprises an apparatus that includes a memory storing the computer program instruction and a processor executing the program instruction, wherein when being executed by the processor, the computer program instruction triggers the apparatus to operate the method and/or technical solution according to a plurality of embodiments of the present invention as mentioned above.

To those skilled in the art, it is apparent that the present invention is not limited to the details of the above exemplary embodiments, and the present invention may be implemented with other embodiments without departing from the spirit or basic features of the present invention. Thus, in any way, the embodiments should be regarded as exemplary, not limitative; the scope of the present invention 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 invention. No reference signs in the claims should be regarded as limiting the involved claims. Besides, it is apparent that the term "comprise" or "include" does not exclude other units or steps, and singularity does not exclude plurality. A plurality of units or modules stated in a system claim may also be implemented by a single unit or module through software or hardware. Terms such as the first and the second are used to indicate names, but do not indicate any particular sequence.

Claims

1. A method for charging a proximity based service in a wireless communication network, comprising:

- obtaining charging related information sent by a user equipment about a proximity based service used by the user equipment;

2. The method according to claim 1 , wherein the obtaining charging related information sent by a user equipment about a proximity based service used by the user equipment comprises any one or more of the following:

- obtaining the charging related information sent by the user equipment during using the proximity based service, about the proximity based service used by the user equipment;

- obtaining delayed charging related information sent by the user equipment after using the proximity based service, about the proximity based service used by the user equipment.

3. The method according to claim 2, wherein the obtaining the charging related information sent by the user equipment during using the proximity based service, about the proximity based service used by the user equipment comprises:

- for the user equipment located within the coverage area of the wireless communication network, obtaining charging related information transmitted by the user equipment via the wireless communication network during using the proximity based service, about the proximity based service used by the user equipment;

- for the user equipment not located within the coverage area of the wireless communication network, obtaining relayed charging related information sent by the user equipment via other communication manner during using the proximity based service, about the proximity based service used by the user equipment.

4. The method according to claim 2, wherein the obtaining delayed charging related information sent by the user equipment after using the proximity based service, about the proximity based service used by the user equipment comprises:

- obtaining delayed charging related information, sent by the user equipment that is not connected to the wireless communication network during the proximity based service but is connected to the wireless communication network after using the proximity based service, about the proximity based service used by the user equipment.

5. The method according to any one of claims 1 to 4, wherein the charging derivative information includes at least any one of the following:

- information indicating whether the charging related information is delayed charging related information; - charging mode;

- calling party related information of the proximity based service;

6. The method according to any one of claim 1 to 5, wherein, said charging derivative information includes charging mode,

Wherein, the generating a charging request for the proximity based service used by the user equipment based on the charging related information and the charging derivative information comprises:

- when the charging mode is an online charging mode, generating an online charging request for the proximity based service used by the user equipment based on the charging related information and the charging derivative information;

- when the charging mode is an offline charging mode, generating an offline charging request for the proximity based service used by the user equipment based on the charging related information and the charging derivative information.

7. The method according to any one of claims 1 to 6, wherein the obtaining charging related information sent by a user equipment, about a proximity based service used by the user equipment comprises:

- obtaining respective charging related information, sent by a plurality of user equipments, about respective proximity based services used by the plurality of user equipments;

wherein the obtaining charging derivative information based on the charging related information comprises:

- obtaining corresponding charging derivative information based on respective charging related information of the plurality of user equipments; wherein the generating a charging request for the proximity based service used by the user equipment based on the charging related information and the charging derivative information comprises:

- obtaining associated charging related information by associating respective charging related information having an identical charging identifier from the plurality of user equipments based on respective charging related information and the charging derivative information;

- generating a charging request for the proximity based services used by the plurality of user equipments based on respective charging related information of the plurality of user equipments, the charging derivative information, and the associated charging related information.

8. The method according to any one of claims 1 to 7, wherein the obtaining charging related information, sent by a user equipment, about a proximity based service used by the user equipment comprises:

- obtaining a plurality of pieces of charging related information, sent by the user equipment within a second threshold time range, about the proximity based service used by the user equipment;

- obtaining corresponding charging derivative information based on the plurality of pieces of charging related information;

wherein the generating a charging request for the proximity based service used by the user equipment based on the charging related information and the charging derivative information comprises:

- determining whether the plurality of pieces of charging related information forming a complete session charging related information based on the plurality of pieces of charging related information and the charging derivative information;

- generating a complete session charging request or an incomplete session charging request for the proximity based service used by the user equipment based on the plurality of pieces of charging related information and the charging derivative information and based on a result of determining whether the plurality of pieces of charging related information forming a complete session charging related information.

9. A apparatus for charging a proximity based service in a wireless communication network, comprising:

10. The apparatus according to claim 9, wherein the means for obtaining charging related information sent by a user equipment about a proximity based service used by the user equipment comprises any one or more of the following:

- means for obtaining the charging related information sent by the user equipment during using the proximity based service, about the proximity based service used by the user equipment;

- means for obtaining delayed charging related information sent by the user equipment after using the proximity based service, about the proximity based service used by the user equipment.

11. The apparatus according to claim 10, wherein the means for obtaining the charging related information sent by the user equipment during using the proximity based service, about the proximity based service used by the user equipment is configured to:

- for the user equipment located within the coverage area of the wireless communication network, obtain charging related information transmitted by the user equipment via the wireless communication network during using the proximity based service, about the proximity based service used by the user equipment;

- for the user equipment not located within the coverage area of the wireless communication network, obtain relayed charging related information sent by the user equipment via other communication manner during using the proximity based service, about the proximity based service used by the user equipment.

12. The apparatus according to claim 10, wherein the means for obtaining delayed charging related information sent by the user equipment after using the proximity based service, about the proximity based service used by the user equipment is configured to:

- obtain delayed charging related information, sent by the user equipment that is not connected to the wireless communication network during the proximity based service but is connected to the wireless communication network after using the proximity based service, about the proximity based service used by the user equipment.

13. The apparatus according to any one of claims 9 to 12, wherein the charging derivative information includes at least any one of the following: - proximity based service event information and/or proximity based service session information;

- charging mode;

- calling party related information of the proximity based service;

14. The apparatus according to any one of claims 9 to 13, wherein, said charging derivative information includes charging mode,

Wherein, the means for generating a charging request for the proximity based service used by the user equipment based on the charging related information and the charging derivative information is configured to:

15. The apparatus according to any one of claims 9 to 14, wherein the means for obtaining charging related information sent by a user equipment, about a proximity based service used by the user equipment comprises: - means for obtaining respective charging related information, sent by a plurality of user equipments, about respective proximity based services used by the plurality of user equipments;

wherein the means for obtaining charging derivative information based on the charging related information comprises:

- means for obtaining corresponding charging derivative information based on respective charging related information of the plurality of user equipments; wherein the generating a charging request for the proximity based service used by the user equipment based on the charging related information and the charging derivative information comprises:

- means for obtaining associated charging related information by associating respective charging related information having an identical charging identifier from the plurality of user equipments based on respective charging related information and the charging derivative information;

- means for generating a charging request for the proximity based services used by the plurality of user equipments based on respective charging related information of the plurality of user equipments, the charging derivative information, and the associated charging related information.

16. The apparatus according to any one of claims 9 to 15, wherein the means for obtaining charging related information, sent by a user equipment, about a proximity based service used by the user equipment comprises:

- means for obtaining a plurality of pieces of charging related information, sent by the user equipment within a second threshold time range, about the proximity based service used by the user equipment;

- means for obtaining corresponding charging derivative information based on the plurality of pieces of charging related information;

wherein the means for generating a charging request for the proximity based service used by the user equipment based on the charging related information and the charging derivative information comprises:

- means for determining whether the plurality of pieces of charging related information forming a complete session charging related information based on the plurality of pieces of charging related information and the charging derivative information;

- means for generating a complete session charging request or an incomplete session charging request for the proximity based service used by the user equipment based on the plurality of pieces of charging related information and the charging derivative information and based on a result of determining whether the plurality of pieces of charging related information forming a complete session charging related information.