CN102420807B

CN102420807B - IMS supports the method and system of zone and charging method and system

Info

Publication number: CN102420807B
Application number: CN201010534677.5A
Authority: CN
Inventors: 骆旭剑; 郭文洁; 张玉
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2010-09-26
Filing date: 2010-11-05
Publication date: 2016-03-30
Anticipated expiration: 2030-11-05
Also published as: CN102420807A

Abstract

The invention discloses the method that a kind of IP Multimedia System (IMS) supports zone, Proxy Call Session Control Function (PCSCF) network element is carrying time zone information in conversation initialized protocol (SIP) message sent to the key-course network element except self; After the key-course network element receiving described sip message obtains described time-zone information, in the sip message sent to operation layer network element, carry described time-zone information; Operation layer network element receives the sip message that described key-course network element sends, and obtains the described time-zone information that described sip message carries.The present invention also discloses a kind of IMS and support the system of zone and charging method and system, pass through the solution of the present invention, in ims time-zone information can be delivered to each network element, and realize user's local zone time when charging data record carries call, improve the accuracy of charging.

Description

Method and system for supporting multiple time zones by IMS (IP multimedia subsystem) and charging method and system

Technical Field

The present invention relates to the third generation partnership project (3GPP) technology, and in particular, to a method and system for supporting multiple time zones by an IP Multimedia Subsystem (IMS), and a charging method and system.

Background

In the IMS network architecture described by the third generation partnership project (3GPP), a set of core networks may cover users in multiple time zones in a country, as is the case in the united states. Therefore, User Equipment (UE), access network elements (access network nodes), IMS control layer network elements, and service layer network elements are likely to be distributed in the same or different time zones. The time zone information of the UE is significant for the operator from the aspects of charging, statistics, quality of service (QoS) control, etc. In the existing protocol specification of 3GPP, the information related to the timestamp in the message carrier of the IMS network architecture is standard time information in the Universal Time Coordinated (UTC) format.

From the charging perspective of the operator's profit, different time zones may correspond to different rates that can be allocated, and preferential rate periods may also be set according to the time zones, so that the time zone information where the UE is located is very important information for the operator from the charging and statistics perspectives.

The charging system defined in the existing 3GPP includes two parts, offline and online charging.

Wherein, the offline charging is used to reflect charging and statistical information in near real time, fig. 1 shows the composition of IMS offline charging functional entities and the relationship between them:

a charging trigger function (CTF, charging triggerfunction) is embedded in each network element of the 3gpp ims, and includes an access layer network element, a control layer network element, and a service layer network element, and the main functions of the charging trigger function are that charging information is collected according to the monitored use condition of network resources, and the charging information is sent to a charging data function (CDF, charging data function) through an Rf interface (offecocharingreferencepoint); the main functions of the CDF are to receive a charging request (ACR, accounting request) sent by the CTF, construct a Charging Data Record (CDR), and send it to a Charging Gateway Function (CGF) through a Ga interface; the CGF has a main function of storing and managing the CDR received from the CDF and transmitting the CDR file to a Billing Domain (BD) through a Bi interface.

Online charging is used for online credit control and statistics reporting for UE using network resources in real time. As shown in fig. 2, the Online Charging System (OCS) is connected to the BD and the Serving Call Session Control Function (SCSCF), and interacts credit control request information (CCR, credit control request)/credit control response information (CCA, credit control acknowledge) with the IMS network element through the Ro interface in real time; the IMS network element comprises a Multimedia Resource Function Controller (MRFC) and an Application Server (AS).

3gpp TS32.299 defines the relevant specifications for offline, online Diameter messages ACR/CCR, and TS32.298 defines the relevant specifications for CDRs. The CDR includes fields such as a called number, a call start time (servicedelaystestamp), and a call end time (servicedelaveryentimestamp), and is key information for charging a call of a user. Charging systems (BS) typically calculate the charge based on the user's talk time. These time information are taken from two attribute value pairs (AVP, attributeucollector) of Session Initiation Protocol (SIP) Request time (SIP-Request-Timestamp) and SIP Response time (SIP-Response-Timestamp) in the ACR. They are all of the Time type, representing the number of seconds in UTC Time format since 1 month 1 day 1900.

Through the analysis, it can be known that the time zone information of the UE cannot be obtained from the existing 3GPP specification definition, such a ticket has defects in the aspects of user charging, bill query, account settlement and reconciliation, for example, when preferential time period charging is implemented, preferential calculation needs to be performed according to the local time of the user, and the information about the user communication time point in the statistical information thereof also has errors, which results in the reduction of the customer satisfaction and affects the revenue of the operator.

Disclosure of Invention

In view of the above, the present invention is directed to a method and a system for supporting multiple time zones in an IMS, which can transmit time zone information to each network element in the IMS, so that each network element obtains the time zone information.

Another objective of the present invention is to provide an IMS charging method and system, which can implement the local time of the user when the CDR carries a call, improve the charging accuracy, reduce the possibility of complaints of the user, and reduce the revenue loss of the operator.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

the invention provides a method for supporting multiple time zones by an IMS (IP multimedia subsystem), which comprises the following steps:

a Proxy Call Session Control Function (PCSCF) network element carries time zone information in an SIP message sent to a control layer network element except the network element itself;

after the control layer network element receiving the SIP message obtains the time zone information, the SIP message sent to the service layer network element carries the time zone information;

and the service layer network element receives the SIP message sent by the control layer network element and acquires the time zone information carried by the SIP message.

In the above scheme, the pcsccf network element carries time zone information in an SIP message sent to a control layer network element other than the pcsc network element, and the time zone information is:

under the condition that the PCCF network element trusts the information reported by the UE, when the UE reports the time zone information, the PCCF network element carries the time zone information reported by the UE in an SIP message sent to a control layer network element except the PCCF network element; when UE does not report time zone information, if the access layer network element provides time zone information, the PCSCF network element carries the time zone information provided by the access layer network element in the SIP message sent to the control layer network element except the PCSCF network element; if the access layer network element does not provide time zone information, the PCSCF determines the time zone information of the UE and carries the time zone information in the SIP message sent to the control layer network element except the PCSCF;

under the condition that the PCSCF does not trust the information reported by the UE, when the access layer network element provides time zone information, the PCSCF network element carries the time zone information provided by the access layer network element in an SIP message sent to the control layer network element except the PCSCF network element; when the access layer network element does not provide time zone information, the PCSCF determines the time zone information of the UE and carries the time zone information in the SIP message sent to the control layer network element except the PCSCF.

In the above scheme, the carrying of the time zone information includes: adding the time zone information in a P Access Network Information (PANI) header of the sent SIP message.

In the above solution, the access stratum network element provides time zone information, and the time zone information includes: when a session is established or released, the access layer network element reports the acquired UE time zone information to the pcsccf through a Policy and Charging Control (PCC) architecture.

The invention provides a system for supporting multiple time zones by an IMS, which comprises: the system comprises a PCSCF network element, a control layer network element except the PCSCF and a service layer network element; wherein,

the PCSCF network element is used for carrying time zone information in the SIP message sent to the control layer network element;

the control layer network element is used for receiving the SIP message sent by the PCSCF network element, and carrying the time zone information in the SIP message sent to the service layer network element after obtaining the time zone information;

and the service layer network element is used for receiving the SIP message sent by the control layer network element and acquiring the time zone information carried by the SIP message.

In the above solution, the system further includes: the UE is used for reporting the time zone information to the PCSCF network element;

and the access layer network element is used for providing the time zone information or the position information of the UE to the PCSCF network element.

In the above scheme, the pcsccf network element is specifically configured to, when trusting information reported by the UE and reporting time zone information by the UE, carry the time zone information reported by the UE in an SIP message sent to a control layer network element other than the pcsccf network element; when UE does not report time zone information, if the access layer network element provides time zone information, the SIP message sent to the control layer network element except the UE carries the time zone information provided by the access layer network element; if the access layer network element does not provide time zone information, the time zone information of the UE is determined by the access layer network element, and the SIP message sent to the control layer network element except the access layer network element carries the time zone information;

under the condition of not trusting information reported by UE, when an access layer network element provides time zone information, carrying the time zone information provided by the access layer network element in SIP messages sent to control layer network elements except the access layer network element; when the access layer network element does not provide time zone information, the time zone information of the UE is determined by the access layer network element, and the SIP message sent to the control layer network element except the access layer network element carries the time zone information.

The invention provides an IMS charging method, which comprises the following steps: the PCSCF network element carries time zone information in SIP messages sent to control layer network elements except the PCSCF network element;

the service layer network element receives the SIP message sent by the control layer network element and obtains the time zone information carried by the SIP message;

each network element obtaining the time zone information sends a charging request message carrying the time zone information to a charging entity;

and the charging entity carries out charging processing according to the charging request message carrying the time zone information sent by each network element.

in the above scheme, the sending, by each network element that obtains the time zone information, a charging request message carrying the time zone information to a charging entity is: in an offline charging system, a control layer network element and a service layer network element which acquire the time zone information and comprise PCSCF send ACR information carrying time zone information to CDF; in the online charging system, the control layer network element and the service layer network element which obtain the time zone information except PCSCF send CCR message carrying time zone information to OCS.

In the above solution, the charging entity performs charging processing according to the charging request message carrying time zone information sent by each network element, and the charging processing is as follows: in an offline charging system, a charging entity acquires the time zone information from a charging Request message sent by each network element, and sets a time field of a CDR (clock recovery time) corresponding to each network element to contain effective information of local time of UE (user equipment), namely UTC time + time zone information of the UE, by combining SIP-Request-TimestampAVP and SIP-Response-TimestampAVP in UTC time format; in the online charging system, a charging entity obtains effective information of local time of UE according to a charging request message carrying time zone information sent by each network element, and performs online credit control and statistics according to the effective information.

The invention provides an IMS charging system, which comprises: the system comprises a PCSCF network element, a control layer network element except the PCSCF, a service layer network element and a charging entity; wherein,

the PCSCF network element is used for carrying time zone information in the SIP message sent to the control layer network element and sending a charging request message carrying the time zone information to a charging entity in an offline charging system;

the control layer network element is used for receiving the SIP message sent by the PCSCF network element, carrying the time zone information in the SIP message sent to the service layer network element after obtaining the time zone information, and sending a charging request message carrying the time zone information to a charging entity;

the service layer network element is used for receiving the SIP message sent by the control layer network element, acquiring the time zone information carried by the SIP message and sending a charging request message carrying the time zone information to a charging entity;

and the charging entity is used for carrying out charging processing according to the charging request message sent by each network element.

In the above solution, the charging entity includes: CDF in off-line charging system or OCS in on-line charging system;

the charging request message comprises an ACR message in an offline charging system or a CCR message in an online charging system.

The invention provides a method and a system for supporting multiple time zones and a charging method and a system for an IMS.A PCSCF network element carries time zone information in an SIP message sent to a control layer network element except the PCSCF network element; after the control layer network element receiving the SIP message obtains the time zone information, the SIP message sent to the service layer network element carries the time zone information; the service layer network element receives the SIP message sent by the control layer network element and obtains the time zone information carried by the SIP message; therefore, the time zone information can be transmitted to each network element in the IMS, so that each network element can obtain the time zone information, the CDR carries the local time of the user during the call, the charging accuracy is improved, the possibility of complaint of the user is reduced, and the revenue loss of an operator is reduced.

Drawings

Fig. 1 is a schematic structural diagram of an offline charging functional entity in a conventional 3GPP network;

fig. 2 is a schematic diagram of an online charging logic structure in a conventional 3gpp ims network;

FIG. 3 is a flow chart illustrating a method for implementing IMS supporting multiple time zones according to the present invention;

FIG. 4 is a schematic diagram of a system for supporting multiple time zones by IMS according to the present invention;

FIG. 5 is a flowchart illustrating an implementation of an IMS charging method according to the present invention;

FIG. 6 is a schematic structural diagram of an IMS charging system implemented in the present invention;

FIG. 7 is a diagram of network architectures of the first, second and third embodiments of the present invention;

fig. 8 is a flowchart illustrating a method for pcsccf trusting the reported information of UE41 to implement that IMS supports multiple time slots and performs offline charging in the first embodiment of the present invention;

fig. 9 is a flowchart illustrating a method for implementing that the pcsccf distrusts the reported information of the UE41 to support multiple time slots and perform online charging in the IMS in the second embodiment of the present invention;

fig. 10 is a flowchart illustrating a method for implementing that the pcsccf distrusts the reported information of the UE41 to support multiple time slots and perform online charging in the IMS in the third embodiment of the present invention;

fig. 11 is a schematic diagram of a network architecture according to a fourth embodiment of the present invention;

FIG. 12 is a flowchart illustrating a method for PCSCF trusting the UE41 to report information and realize that IMS supports multiple time zones and performs online charging in accordance with a fourth embodiment of the present invention

Fig. 13 is a schematic diagram of PCC architecture defined in 3GPP on which five and six bases are based according to an embodiment;

fig. 14 is a schematic flowchart illustrating a method for implementing an access stratum network element to provide UE time zone information to a pcsc f when a session is established according to a fifth embodiment;

fig. 15 is a flowchart illustrating a method for implementing an access stratum network element to provide UE time zone information to a pcsc cf when a session is released in the sixth embodiment.

Detailed Description

The basic idea of the invention is: the PCSCF network element carries time zone information in SIP messages sent to control layer network elements except the PCSCF network element; and the control layer network element receiving the SIP message carries the time zone information in the SIP message sent to the service layer network element.

The invention is further described in detail below with reference to the figures and the specific embodiments.

The present invention realizes a method for supporting multiple time zones by an IMS, as shown in FIG. 3, the method comprises the following steps:

step 201: the PCSCF network element carries time zone information in SIP messages sent to control layer network elements except the PCSCF network element;

specifically, the pcsccf network element, according to the information reported by the configuration trusted UE:

when UE reports time zone information, the PCSCF network element carries the time zone information reported by the UE in SIP messages sent to control layer network elements except the PCSCF network element;

when UE does not report time zone information, if the access layer network element provides time zone information, the PCSCF network element carries the time zone information provided by the access layer network element in the SIP message sent to the control layer network element except the PCSCF network element; if the access layer network element does not provide time zone information, the PCSCF determines the time zone information of the UE and carries the time zone information in the SIP message sent to the control layer network element except the PCSCF; the pcsch determines time zone information of the UE, where the pcsch may map corresponding time zone information according to UE location information provided by an access stratum network element;

under the condition that the PCCF configures the information reported by the untrusted UE, even if the PCCF receives the time zone information reported by the UE, the PCCF replaces the time zone information reported by the UE with the time zone information provided by an access layer network element or the time zone information of the UE determined by the PCCF, and the method specifically comprises the following steps:

under the condition that the PCSCF configures the information reported by the untrusted UE, when the access layer network element provides time zone information, the PCSCF network element carries the time zone information provided by the access layer network element in an SIP message sent to the control layer network element except the PCSCF network element; when the access layer network element does not provide time zone information, the PCSCF determines the time zone information of the UE and carries the time zone information in the SIP message sent to the control layer network element except the PCSCF; the pcsch determines time zone information of the UE, which may be that the pcsch maps corresponding time zone information according to UE location information provided by an access layer network element;

in the above scheme, the carrying of the time zone information generally includes: adding the time zone information in a P Access Network information (PANI, P-Access-Network-Info) header of the sent SIP message, where the added time zone information generally is: adding a time zone information field in an access information (access-info) part of a PANI header, and adding time zone information to the time zone information field;

here, the access stratum network element includes: a PS domain/EPC network element accessed by 3GPP-UTRAN/EUTRAN, a Session Border Controller (SBC), an Access Gateway Control Function (AGCF), etc.; the Evolved Packet Core (EPC) network element includes a Policy and Charging Rules Function (PCRF), a serving gateway (S-GW), a switching gateway (P-GW), a Mobility Management Entity (MME), and the like;

the control layer network elements other than the control layer network elements themselves may be SCSCF, ICSCF (interworking cscf), Breakout Gateway Control Function (BGCF), Media Gateway Control Function (MGCF), and the like.

Step 202: after the control layer network element receiving the SIP message obtains the time zone information, the SIP message sent to the service layer network element carries the time zone information;

here, the time zone information is carried in the SIP message sent to the service layer network element, and generally, the PANI header to which the time zone information is added is carried in the SIP message sent to the service layer network element, and the service layer network element is generally an AS.

Step 203: the service layer network element receives the SIP message sent by the control layer network element and obtains the time zone information carried in the SIP message;

here, the obtaining time zone information generally obtains time zone information added to a PANI header carried in the SIP message.

Through the steps 201-202, the service layer network element in the IMS obtains the time zone information of the UE, and the purpose of supporting multiple time zones in the IMS can be achieved.

Based on the above method, the present invention further provides a system for supporting multiple time zones by IMS, as shown in fig. 4, the system includes: a pcsccf network element 31, a control layer network element 32 other than the pcsccf, and a service layer network element 33; wherein,

the pcsc f network element 31 is configured to carry time zone information in an SIP message sent to the control layer network element 32;

a control layer network element 32, configured to receive the SIP message sent by the pcsc f network element 31, and after obtaining the time zone information, carry the time zone information in the SIP message sent to the service layer network element 33;

the service layer network element 33 is configured to receive the SIP message sent by the control layer network element, and obtain the time zone information carried in the SIP message;

further, the system includes a UE34, configured to report time zone information to the pcsc f network element 31;

further, the system further comprises an access stratum network element for providing time zone information or location information of the UE34 to the pcsccf network element 31;

the pcsc f network element 31 carries time zone information in the SIP message sent to the control layer network element 32, which specifically includes:

the pcsccf network element 31, according to the information reported by the configuration trusted UE 34:

when the UE34 reports the time zone information, the pcsccf network element 31 carries the time zone information reported by the UE34 in the SIP message sent to the control layer network element 32;

when the UE34 does not report time zone information, if the access layer network element provides time zone information, the pcsccf network element 31 carries the time zone information provided by the access layer network element in an SIP message sent to the control layer network element 32; if the access layer network element does not provide time zone information, the pcsc f network element 31 determines the time zone information of the UE34, and carries the time zone information in the SIP message sent to the control layer network element 32; wherein, the pcsccm element 31 determines time zone information of the UE34, which may be that the pcsccm element 31 maps corresponding time zone information according to UE34 location information provided by an access stratum element;

under the condition that the pcsccm element 31 configures the information reported by the untrusted UE34, even if the pcsccm element 31 receives the time zone information reported by the UE34, the time zone information provided by the access stratum element or the time zone information of the UE34 determined by the pcsccm element will be used to replace the time zone information reported by the UE34, which specifically is as follows:

under the condition that the pcsc f network element 31 is configured with the information reported by the untrusted UE34, when the access stratum network element provides time zone information, the pcsc f network element 31 carries the time zone information provided by the access stratum network element in an SIP message sent to the control stratum network element 32; when the access layer network element does not provide time zone information, the PCSCF network element 31 determines the time zone information of the UE34, and carries the time zone information in an SIP message sent to the control layer network element 32 except itself; the pcsccm element 31 determines time zone information of the UE34, where the pcsccm element 31 may map corresponding time zone information according to UE34 location information provided by an access stratum element;

in the above scheme, the carrying of the time zone information generally includes: adding time zone information in PANI header of the sent SIP message, wherein the added time zone information is generally: adding a time zone information field in an access information part of the PANI head, and adding time zone information to the time zone information field;

the service layer network element 33 obtains the time zone information carried in the SIP message, specifically: the service layer network element 33 obtains the time zone information added in the PANI header carried by the SIP message.

Based on the above method, the present invention also realizes an IMS charging method, as shown in fig. 5, the method includes the following steps:

step 401: the PCSCF network element carries time zone information in SIP messages sent to control layer network elements except the PCSCF network element;

here, the access stratum network element includes: PS domain/EPC network elements, SBC, AGCF and the like accessed by 3 GPP-UTRAN/EUTRAN;

the control layer network elements except for the control layer network elements can be SCFCF, ICSCF, BGCF, MGCF and the like.

Step 402: after the control layer network element receiving the SIP message obtains the time zone information, the SIP message sent to the service layer network element carries the time zone information;

Step 403: the service layer network element receives the SIP message sent by the control layer network element and obtains the time zone information carried in the SIP message;

Step 404: each network element obtaining the time zone information sends a charging request message carrying the time zone information to a charging entity;

specifically, in the offline charging system, a control layer network element and a service layer network element which obtain the time zone information and include pcsc f send ACR messages carrying time zone information to CDF; in an online charging system, a control layer network element and a service layer network element which obtain the time zone information except PCSCF send a CCR message carrying the time zone information to an OCS; the control layer network elements except the PCSCF comprise SCSCF, MRCF and the like;

wherein, the sending of the ACR message carrying time zone information generally is adding the time zone information to an Access-Network-information avp, the ACR message carrying the Access-Network-information avp, and this mode is referred to as an ANI mode for short; or adding a new time zone AVP, adding the time zone information into the newly added time zone AVP, wherein the ACR message carries the time zone AVP, and the mode is a TZ mode for short;

the sending of the CCR message carrying time zone information generally includes adding time zone information to an Access-Network-information vp, where the CCR message carries the Access-Network-information vp; or adding a new time zone AVP, adding the time zone information into the newly added time zone AVP, and carrying the time zone AVP by the CCR message.

Step 405: the charging entity carries out charging processing according to the charging request message carrying time zone information sent by each network element;

specifically, in the offline charging system, the charging entity acquires the time zone information from the charging Request message sent by each network element, and sets the time field of the CDR corresponding to each network element to contain the valid information of the local time of the UE, that is, the UTC time + time zone information of the UE, in combination with the SIP-Request-timestamp avp and the SIP-Response-timestamp avp in the UTC time format; in the online charging system, a charging entity obtains effective information of local time of UE according to a charging request message carrying time zone information sent by each network element, and performs online credit control and statistics according to the effective information.

In order to implement the above method, the present invention further provides an IMS charging system, as shown in fig. 6, where the system includes: a PCSCF network element 51, a control layer network element 52 except the PCSCF, a service layer network element 53 and a charging entity 54; wherein,

a pcsc f network element 51, configured to carry time zone information in an SIP message sent to the control layer network element 52, and send a charging request message carrying the time zone information to a charging entity 54 in an offline charging system;

a control layer network element 52, configured to receive the SIP message sent by the pcsc f network element 51, and after obtaining the time zone information, carry the time zone information in the SIP message sent to the service layer network element 53, and send a charging request message carrying the time zone information to a charging entity 54;

a service layer network element 53, configured to receive the SIP message sent by the control layer network element, obtain the time zone information carried in the SIP message, and send a charging request message carrying the time zone information to a charging entity 54;

a charging entity 54, configured to perform charging processing according to the charging request message sent by each network element;

specifically, when offline charging is performed, the charging entity 54 acquires the time zone information from the charging Request message sent by each network element, and sets the time field of the CDR corresponding to each network element to contain the valid information of the local time of the UE, in combination with the SIP-Request-timestamp avp and the SIP-Response-timestamp avp in the UTC time format; when online charging, the charging entity 54 obtains the effective information of the local time of the UE according to the charging request message carrying the time zone information sent by each network element, and performs online credit control and statistics according to the effective information.

In the above, the charging entity 54 includes: CDF in off-line charging system or OCS in on-line charging system; the charging request message comprises an ACR message in an offline charging system or a CCR message in an online charging system;

in the above, when the charging request message is an ACR message, the sending of the charging request message carrying time zone information generally includes adding time zone information to an Access-Network-information avp, where the ACR message carries the Access-Network-information avp; or adding a new time zone AVP, adding the time zone information into the newly added time zone AVP, wherein the ACR message carries the time zone AVP;

further, the system comprises a UE55, configured to report time zone information to the pcsccf network element 51;

further, the system further comprises an access stratum network element for providing time zone information or location information of the UE55 to the pcsccf network element 51;

the pcsc f network element 51 carries time zone information in the SIP message sent to the control layer network element 52, which specifically includes:

the pcsccf network element 51, according to the information reported by the configuration trusted UE 55:

when the UE55 reports the time zone information, the pcsccf network element 51 carries the time zone information reported by the UE55 in the SIP message sent to the control layer network element 52;

when the UE55 does not report time zone information, if the access layer network element provides time zone information, the pcsccf network element 51 carries the time zone information provided by the access layer network element in an SIP message sent to the control layer network element 52; if the access layer network element does not provide time zone information, the pcsc f network element 51 determines the time zone information of the UE55, and carries the time zone information in the SIP message sent to the control layer network element 52; wherein, the pcsccm element 51 determines time zone information of the UE55, which may be that the pcsccm element 51 maps corresponding time zone information according to UE55 location information provided by an access stratum element;

under the condition that the pcsccm element 51 configures the information reported by the untrusted UE55, even if the pcsccm element 51 receives the time zone information reported by the UE55, the time zone information provided by the access stratum element or the time zone information of the UE55 determined by the pcsccm element 51 replaces the time zone information reported by the UE55, which is specifically:

under the condition that the pcsccf network element 51 reports information according to the configuration untrusted UE55, when the access stratum network element provides time zone information, the pcsccf network element 51 carries the time zone information provided by the access stratum network element in an SIP message sent to the control stratum network element 52; when the access layer network element does not provide time zone information, the PCSCF network element 51 determines the time zone information of the UE55, and carries the time zone information in an SIP message sent to the control layer network element 52 except itself; the pcsccm element 51 determines time zone information of the UE55, where the pcsccm element 51 may map corresponding time zone information according to UE55 location information provided by an access stratum element;

the service layer network element 53 obtains the time zone information carried in the SIP message, specifically: the service layer network element 53 obtains the time zone information added in the PANI header carried by the SIP message.

The following detailed description of the implementation and principles of the method of the present invention is provided in connection with specific embodiments.

Example one

In the network architecture shown in fig. 7, in this embodiment, UE41 reports time zone information, pcsc f42 configures the reporting information trusting UE41, where the time zone 1 is not equal to the time zone 2, and when A calling side (IMS-A) carries the time zone information in an ANI manner, an IMS charging method is implemented, as shown in fig. 8, the method includes the following steps:

step 501: the UE41 carries the PANI header with time zone information added in the INVITE request sent to the pcsccf 42;

specifically, the UE41 extends the PANI header, adds a time zone information field to an access information part thereof, adds time zone information of itself to the time zone information field, and then carries the PANI header in an INVITE request sent to the pcsccf 42.

Step 502: after receiving the INVITE request, the pcsccf 42 carries the PANI header with the time zone information added in the INVITE request sent to the SCSCF 43;

step 503: after receiving the INVITE request carrying the PANI header sent by the pcsscf 42, the SCSCF43 carries the PANI header in the INVITE request sent to the subscribed AS 44;

step 504: after receiving the INVITE request carrying the PANI header from the SCSCF43, the AS44 sends its own INVITE request to the SCSCF43, and carries the PANI header;

step 505: SCSCF43 sends an INVITE request carrying the PANI header to a called side network element;

step 506: the called side network element sends a 200OK response to the SCSCF 43;

step 507: the SCSCF43 sends a 200OK response to the AS 44;

step 508: the AS44 replies a 200OK response to the SCSCF 43;

step 509: the AS44 fills in the Access-Network-information VP according to the time zone information in the PANI header, and sends ACR information carrying the Access-Network-information VP to the CDF 45;

step 510: after receiving the ACR message sent by the AS44, the CDF45 opens an ASCDR, and sets the time field of the ASCDR to contain the valid information of the local time of the UE41, that is, the UTC time + time zone information of the UE41, according to the time zone information in the ACR;

step 511: the SCSCF43 sends a 200OK response to the PCSCF 42;

step 512: the SCSCF43 fills in the Access-Network-information VP according to the time zone information in the PANI header, and sends ACR information carrying the Access-Network-information VP to the CDF 45;

step 513: after receiving the ACR message sent by the SCSCF43, the CDF45 opens an scscfdr, and sets the time field of the scfcdr to contain the effective information of the local time of the UE41 according to the time zone information in the ACR;

step 514: pcsccf 42 sends a 200OK response to UE 41;

step 515: PCSCF42 fills in Access-Network-information VP according to the time zone information in the PANI header, and sends ACR information carrying the Access-Network-information VP to CDF 45;

step 516: after receiving the ACR message sent by the PCSCF42, the CDF45 opens a pccfcdr, and sets the time field of the pccfcdr to contain valid information of the local time of the UE41 according to the time zone information in the ACR.

Example two

In this embodiment, as shown in fig. 7, in a network architecture, a UE41 reports or does not report time zone information, an access layer network element provides time zone information to a pcsccf 42, and the pcsc f42 configures reporting information of an untrusted UE41, so that an IMS charging method is implemented during offline charging, as shown in fig. 9, the method includes the following steps:

step 601: the UE41 carries or does not carry time zone information in the INVITE request for sending SIP to the PCSCF42, and the access layer network element carries the time zone information in the INVITE request for sending SIP to the PCSCF 42;

in this step, the time zone information is carried in the INVITE request sent by the UE41 or the access stratum network element, which specifically includes: the INVITE request sent by the UE41 or the access stratum network element carries the PANI header with the time zone information added.

Step 602: the PCSCF42 carries a PANI header added with time zone information in an INVITE request sent to the SCSCF43 according to the INVITE request of the access layer network element;

in this step, since the PCSCF42 reports information according to the configuration untrusted UE41, when the UE41 sends an INVITE request of an SIP carrying time zone information, the PCSCF42 replaces the PANI header in the INVITE request of the UE41 with the PANI header containing the time zone information carried in the INVITE request of the access stratum network element, and carries the replaced PANI header in the INVITE request sent to the SCSCF 43; when the UE41 sends the INVITE request of the SIP without carrying time zone information, the pcsc f42 carries the PANI header containing the time zone information obtained from the INVITE request of the access stratum network element in the INVITE request sent to the SCSCF 43.

Step 603: after receiving the INVITE request carrying the PANI header sent by the pcsscf 42, the SCSCF43 carries the PANI header in the INVITE request sent to the subscribed AS 44;

step 604: after receiving the INVITE request carrying the PANI header from the SCSCF43, the AS44 sends its own INVITE request to the SCSCF43, and carries the PANI header;

step 605: SCSCF43 sends an INVITE request carrying the PANI header to a called side network element;

step 606: the called side network element sends a 200OK response to the SCSCF 43;

step 607: the SCSCF43 sends a 200OK response to the AS 44;

step 608: the AS44 replies a 200OK response to the SCSCF 43;

step 609: the AS44 fills in the Access-Network-information VP according to the time zone information in the PANI header, and sends ACR information carrying the Access-Network-information VP to the CDF 45;

in this embodiment, the time zone information of the UE41 is carried in an extended PANI header manner, and corresponds to Access-Network-information AVP in the charging message Diameter, and if the time zone information of the UE41 is carried in another manner, the AS44 may add the time zone information of the UE41 AS an individual AVP to the DiameterACR message or extend an existing AVP in another ACR message to the CDF 45.

Step 610: after receiving the ACR message sent by the AS44, the CDF45 opens an ASCDR, and sets the time field of the ASCDR to contain the valid information of the local time of the UE41, that is, the UTC time + time zone information of the UE41, according to the time zone information in the ACR message;

step 611: the SCSCF43 sends a 200OK response to the PCSCF 42;

step 612: the SCSCF43 fills in the Access-Network-information VP according to the time zone information in the PANI header, and sends ACR information carrying the Access-Network-information VP to the CDF 45;

in this embodiment, the time zone information of the user is carried in a mode of extending the PANI header, and if the time zone information of the user is carried in another mode, the SCSCF43 may also add the time zone information of the UE41 as a separate AVP to the DiameterACR message or extend the existing AVP in another ACR message to the CDF 45.

Step 613: after receiving the ACR message sent by the SCSCF43, the CDF45 opens an scscfdr, and sets a time field of the scfcdr to contain effective information of the local time of the UE41 according to the time zone information in the ACR message;

step 614: pcsccf 42 sends a 200OK response to UE 41;

step 615: PCSCF42 fills in Access-Network-information VP according to the time zone information in the PANI header, and sends ACR information carrying the Access-Network-information VP to CDF 45;

in this embodiment, the time zone information of the user is carried in a PANI header extension manner, and if the time zone information of the user is carried in another manner, the pcsc 42 may also add the time zone information of the UE41 as a separate AVP to the DiameterACR message or extend an existing AVP in another ACR message to the CDF 45.

Step 616: after receiving the ACR message sent by the PCSCF42, the CDF45 opens a pccfcdr, and sets the time field of the pccfcdr to contain the valid information of the local time of the UE41 according to the time zone information in the ACR message.

EXAMPLE III

In this embodiment, as shown in fig. 6, in a network architecture, a UE41 and an access stratum network element do not provide time zone information, and a pcsccf 42 determines time zone information of a UE41 according to location information, so as to implement an IMS charging method during offline charging, as shown in fig. 10, the method includes the following steps:

step 701: the UE41 sends an INVITE request of SIP to the pcsccf 42;

step 702: after receiving the INVITE request, the pcsccf 42 carries the PANI header with the time zone information added in the INVITE request sent to the SCSCF 43;

in this step, the pcsccf, according to the location information of the UE41 provided by the UE41 or the access stratum network element, for example: a tracking area (TA, TrackingArea) or a cell identity CellID, etc., maps time zone information where the UE41 is located in a configuration table of the tracking area (TA, TrackingArea) or cell identity CellID, and adds the time zone information to a PANI header of an INVITE request sent to the SCSCF 43; the configuration table on the PCSCF refers to a table which allows an operator to configure the mapping relationship between the location information of the UE and the time zone information of the corresponding UE.

Step 703: after receiving the INVITE request carrying the PANI header sent by the pcsscf 42, the SCSCF43 carries the PANI header in the INVITE request sent to the subscribed AS 44;

step 704: after receiving the INVITE request carrying the PANI header from the SCSCF43, the AS44 sends its own INVITE request to the SCSCF43, and carries the PANI header;

step 705: SCSCF43 sends an INVITE request carrying the PANI header to a called side network element;

step 706: the called side network element sends a 200OK response to the SCSCF 43;

step 707: the SCSCF43 sends a 200OK response to the AS 44;

step 708: the AS44 replies a 200OK response to the SCSCF 43;

step 709: the AS44 fills in the Access-Network-information VP according to the time zone information in the PANI header, and sends ACR information carrying the Access-Network-information VP to the CDF 45;

in this embodiment, the time zone information of the UE41 is carried in a PANI header extension manner, and corresponds to Access-Network-information vp in the charging message Diameter, and if the time zone information is carried in another extension manner, the AS44 may add the time zone information of the UE41 AS an individual AVP to the Diameter ACR message or extend an existing AVP in another ACR message to the CDF 45.

Step 710: after receiving the ACR message sent by the AS44, the CDF45 opens an ASCDR, and sets the time field of the ASCDR to contain the valid information of the local time of the UE41, that is, the UTC time + time zone information of the UE41, according to the time zone information in the ACR message;

step 711: the SCSCF43 sends a 200OK response to the PCSCF 42;

step 712: the SCSCF43 fills in the Access-Network-information VP according to the time zone information in the PANI header, and sends ACR information carrying the Access-Network-information VP to the CDF 45;

in this embodiment, the time zone information of the UE41 is carried in the extended PANI header manner, and if the time zone information is carried in another manner, the SCSCF43 may also add the time zone information of the UE41 as a separate AVP to the DiameterACR message or extend the existing AVP in another ACR message to the CDF 45.

Step 713: after receiving the ACR message sent by the SCSCF43, the CDF45 opens an scscfdr, and sets a time field of the scfcdr to contain effective information of the local time of the UE41 according to the time zone information in the ACR message;

step 714: pcsccf 42 sends a 200OK response to UE 41;

step 715: PCSCF42 fills in Access-Network-information VP according to the time zone information in the PANI header, and sends ACR information carrying the Access-Network-information VP to CDF 45;

in this embodiment, the time zone information of the UE41 is carried in an extended PANI header manner, and if the time zone information is carried in another manner, the pcsc f42 may also add the time zone information of the UE41 as a separate AVP to the DiameterACR message or extend the existing AVP in another ACR message to the CDF 45.

Step 716: after receiving the ACR message sent by the PCSCF42, the CDF45 opens a pccfcdr, and sets the time field of the pccfcdr to contain the valid information of the local time of the UE41 according to the time zone information in the ACR message.

Example four

In this embodiment, UE41 reports time zone information, and pcsccf trusts the report information of UE according to configuration, in the network architecture shown in fig. 11, time zone 1 ≠ time zone 2 ≠ time zone 3, and the time zone information is carried by UE41(IMS-A) on the calling side in an ANI manner, and when online charging, the IMS charging method is implemented, as shown in fig. 12, the method includes the following steps:

step 801: the UE41 sends an INVITE request of the SIP to the PCSCF42, and carries a PANI header containing UE41 time zone information;

step 802: after receiving the INVITE request, the pcsccf 42 carries the PANI header with the time zone information added in the INVITE request sent to the SCSCF 43;

specifically, after the pcsc 42 receives the INVITE request, the pcsc 42 transparently transmits the PANI header to which time zone information has been added according to the time zone information reported by the configuration trusted UE41, that is, the PANI header to which time zone information has been added is carried in the INVITE request sent to the SCSCF 43.

Step 803: after receiving the INVITE request carrying the PANI header sent by the pcsscf 42, the SCSCF43 carries the PANI header in the INVITE request sent to the subscribed AS 44;

step 804: after receiving the INVITE request carrying the PANI header from the SCSCF43, the AS44 sends its own INVITE request to the SCSCF43, and carries the PANI header;

step 805: SCSCF43 sends an INVITE request carrying the PANI header to a called side network element;

step 806: the called side network element sends a 200OK response to the SCSCF 43;

step 807: the SCSCF43 sends a 200OK response to the AS 44;

step 808: the AS44 replies a 200OK response to the SCSCF 43;

step 809: AS44 fills in Access-Network-information VP according to the time zone information in the PANI header, and sends CCR message carrying the Access-Network-information VP to OCS 45;

in this embodiment, the time zone information of the UE41 is carried in a PANI header extension manner, and corresponds to Access-Network-information vp in the charging message Diameter, and if the time zone information is carried in another manner, the AS44 may add the time zone information of the UE41 AS an individual AVP to the Diameter CCR message or extend an existing AVP in another CCR message to send to the OCS 45.

Step 810: the OCS45 obtains effective information of local time of the UE41 according to the time zone information in the CCR message, and performs online credit control and statistics according to the effective information;

step 811: the SCSCF43 sends a 200OK response to the PCSCF 42;

step 812: the SCSCF43 sends an INVITE request carrying a PANI header to an IMS gateway function (IMS-GWF), the IMS-GWF fills Access-Network-information VP according to time zone information in the PANI header, and sends a CCR message carrying the Access-Network-information VP to an OCS 45;

in this embodiment, the time zone information of the UE41 is carried in a PANI header extension manner, and corresponds to Access-Network-information vp in the charging message Diameter, and if the time zone information is carried in another extension manner, the SCSCF43 may also add the time zone information of the UE41 as an individual AVP to the Diameter CCR message or extend an existing AVP in another CCR message to send to the OCS 45.

Step 813: the OCS45 obtains effective information of local time of the UE41 according to the time zone information in the CCR message, and performs online credit control and statistics according to the effective information;

step 814: pcsccf 42 sends a 200OK response to UE 41.

The above embodiments are embodiments in which the calling party initiates a session, and the processing of the time zone information in which the UE is located in the terminating flow of other mobile stations is similar to the above embodiments and will not be described again.

In the above embodiments, the time zone information is transferred by using the PANI header extension method, and other time zone information transfer methods further include: one information field alone or extending other fields is used to convey time zone information.

Since some countries may have only one time zone, namely: there is no problem of deploying core networks across time zones, such as: the inter-network transmission of the time zone information of the UE in this case is optional according to the requirements of local operators in each country of the european union.

The process of providing time zone information to the pcsc cf by the access layer network element in the second embodiment is specifically described below through fifth and sixth embodiments, both of which are based on the PCC architecture defined in 3GPP shown in fig. 13, where the PCRF issues a new policy for policy and charging control according to subscription information of a subscriber subscription database (SPR), service information issued by the AF, and event information triggering charging policy and QoS change reported by a Bearer Binding and Event Reporting Function (BBERF), and the PCEF performs online and offline message transfer through Gy and Gz interfaces, respectively.

EXAMPLE five

In this embodiment, when a session is established, a method for providing UE time zone information to a pcsc cf through a PCC architecture is implemented, as shown in fig. 14, the method includes the following steps:

step 901: when an IMS session is established, the PCSCF authorizes resources required by the session, provides service information to the PCRF, and informs the PCRF to report UE time zone information;

step 902: when a PMIP-S5/S8 protocol is established between a P-GW and an S-GW, a PCRF initiates a gating and QoS rule providing process and triggers the S-GW to distribute a special bearer, and the S-GW carries UE time zone information provided by an MME in gating and QoS rule response; when a GTP-S5/S8 protocol is used between the P-GW and the S-GW, the PCRF initiates a charging and QoS rule providing process and triggers the P-GW to distribute a special bearer, and the P-GW carries UE time zone information provided by an MME in a charging and QoS rule response;

specifically, when the PMIP-S5/S8 protocol is used between the P-GW and the S-GW, the step includes the following steps:

step 902-a: the PCRF provides gating and QoS rules to the S-GW;

step 902-b: S-GW sends a request for creating a bearer to MME;

step 902-c: the MME reserves media bearer and acquires UE time zone information;

step 902-d: the MME returns a bearer establishing response to the S-GW and carries the UE time zone information in the bearer establishing response;

step 902-e: and the S-GW returns gating and QoS rule response to the PCRF, and the gating and QoS rule response carries the UE time zone information.

When GTP-S5/S8 protocol is adopted between the P-GW and the S-GW, the step comprises the following steps:

step 902-A: PCRF provides charging and QoS rules to P-GW;

step 902-B: P-GW sends a load establishing request to S-GW;

step 902-C: S-GW transmits a load establishing request to MME;

step 902-D: the MME reserves media bearer and acquires UE time zone information;

step 902-E: the MME returns a bearer establishing response to the S-GW and carries the UE time zone information in the bearer establishing response;

step 902-F: S-GW transmits a creating load response to P-GW, wherein the creating load response carries UE time zone information;

step 902-G: and the P-GW returns a charging and QoS rule response to the PCRF, and the charging and QoS rule response carries the UE time zone information.

Step 903: after detecting UE time zone information serving as a bearer level event, the PCRF sends the UE time zone information to the PCSCF;

step 904: the pcsccf responds to the PCRF.

EXAMPLE six

In this embodiment, when a session is released, a method for providing UE time zone information to a pcsc cf through a PCC architecture is implemented, as shown in fig. 15, the method includes the following steps:

step 1001: after detecting that a session release event initiates an IMS session release process, the PCCF removes and releases resources related to the bearer and informs the PCRF to report UE time zone information;

in this step, the detection of the session release event may be the reception of a sip bye message or the like.

Step 1002: when a PMIP-S5/S8 protocol is established between a P-GW and an S-GW, a PCRF initiates gating and QoS rule providing processes and triggers the S-GW to deactivate a special bearer, and the S-GW carries UE time zone information provided by an MME in gating and QoS rule responses; when a GTP-S5/S8 protocol is used between the P-GW and the S-GW, the PCRF initiates a charging and QoS rule providing process and triggers the P-GW to deactivate the special bearer, and the P-GW carries the UE time zone information provided by the MME in the charging and QoS rule response;

step 1002-a: the PCRF provides gating and QoS rules to the S-GW;

step 1002-b: S-GW sends a request for deleting load to MME;

step 1002-c: the MME deletes the media bearer and acquires the UE time zone information;

step 1002-d: the MME returns a bearer deletion response to the S-GW, and carries the UE time zone information in the bearer deletion response;

step 1002-e: and the S-GW returns gating and QoS rule response to the PCRF, and the gating and QoS rule response carries the UE time zone information.

step 1002-A: PCRF provides charging and QoS rules to P-GW;

step 1002-B: P-GW sends a request for deleting load to S-GW;

step 1002-C: S-GW forwards the request for deleting the load to MME;

step 1002-D: the MME deletes the media bearer and acquires the UE time zone information;

step 1002-E: the MME returns a bearer deletion response to the S-GW, and carries the UE time zone information in the bearer deletion response;

step 1002-F: S-GW forwards a bearer deletion response to P-GW, wherein the bearer deletion response carries UE time zone information;

step 1002-G: and the P-GW returns a charging and QoS rule response to the PCRF, and the charging and QoS rule response carries the UE time zone information.

Step 1003: after detecting UE time zone information serving as a bearer level event, the PCRF sends the UE time zone information to the PCSCF;

step 1004: the pcsccf responds to the PCRF.

It should be noted that, the UE time zone information may change during the session, and the operator may set whether the change of the time zone information is used as a bearer level event or not according to the needs of the operator, and notify the pcsccf by the PCRF; if necessary, when the PCRF detects that the time zone information is changed, the PCCFUE is informed of the change of the time zone information, the PCCF sends the INFO message of the SIP to a control layer network element and a service layer network element except the network element, and triggers a charging request message to be sent to a charging entity, and the charging entity can record the changed time zone information in a part of call tickets (partial CDR). However, this also causes a high network signaling load, and the time zone information change in the session occurs with a very small probability, and most operators will not choose to increase the network load for this small probability.

The method of the invention can transmit the time zone information to each network element in the IMS, and realize that the CDR carries the local time of the user when in communication, thereby improving the accuracy of charging, reducing the possibility of complaint of the user and reducing the revenue loss of operators.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, and any modifications, equivalents, improvements, etc. that are within the spirit and principle of the present invention should be included in the present invention.

Claims

1. A method for supporting multiple time zones for an IP Multimedia Subsystem (IMS), the method comprising:

a Proxy Call Session Control Function (PCSCF) network element carries time zone information in a Session Initiation Protocol (SIP) message sent to a control layer network element except the network element; the time zone information is: time zone information reported by UE, or time zone information provided for an access layer network element, or time zone information of the UE determined for the PCSCF; wherein the time zone information of the UE determined by the pcsccf itself is: the PCSCF obtains corresponding time zone information according to the UE position information mapping provided by the access layer network element;

2. The method of claim 1, wherein the pcsccf network element carries time zone information in an SIP message sent to a control layer network element other than itself, and the time zone information is:

under the condition that the PCCF network element trusts information reported by User Equipment (UE), when the UE reports time zone information, the PCCF network element carries the time zone information reported by the UE in an SIP message sent to a control layer network element except the PCCF network element; when UE does not report time zone information, if the access layer network element provides time zone information, the PCSCF network element carries the time zone information provided by the access layer network element in the SIP message sent to the control layer network element except the PCSCF network element; if the access layer network element does not provide time zone information, the PCSCF determines the time zone information of the UE and carries the time zone information in the SIP message sent to the control layer network element except the PCSCF;

3. The method of claim 2, wherein the time zone information is carried by: adding the time zone information in a P Access Network Information (PANI) header of the sent SIP message.

4. The method of claim 2, wherein the access stratum network element provides time zone information as: when the session is established or released, the access layer network element reports the acquired UE time zone information to the PCSCF through a Policy and Charging Control (PCC) architecture.

5. A system for supporting multiple time zones by IMS, the system comprising: the system comprises a PCSCF network element, a control layer network element except the PCSCF and a service layer network element; wherein,

the PCSCF network element is used for carrying time zone information in the SIP message sent to the control layer network element; the time zone information is: time zone information reported by UE, or time zone information provided for an access layer network element, or time zone information of the UE determined for the PCSCF; wherein the time zone information of the UE determined by the pcsccf itself is: the PCSCF obtains corresponding time zone information according to the UE position information mapping provided by the access layer network element;

6. The system of claim 5, further comprising: the UE is used for reporting the time zone information to the PCSCF network element;

7. The system according to claim 6, wherein the pcsccf network element is specifically configured to, in a case where the information reported by the UE is trusted, carry, in an SIP message sent to the control layer network element other than the pcsccf network element, the time zone information reported by the UE when the UE reports the time zone information; when UE does not report time zone information, if the access layer network element provides time zone information, the SIP message sent to the control layer network element except the UE carries the time zone information provided by the access layer network element; if the access layer network element does not provide time zone information, the time zone information of the UE is determined by the access layer network element, and the SIP message sent to the control layer network element except the access layer network element carries the time zone information;

8. An IMS charging method, comprising: the PCSCF network element carries time zone information in SIP messages sent to control layer network elements except the PCSCF network element; the time zone information is: time zone information reported by UE, or time zone information provided for an access layer network element, or time zone information of the UE determined for the PCSCF; wherein the time zone information of the UE determined by the pcsccf itself is: the PCSCF obtains corresponding time zone information according to the UE position information mapping provided by the access layer network element;

9. The method of claim 8, wherein the pcsccf network element carries time zone information in an SIP message sent to a control layer network element other than itself, and the time zone information is:

10. The method of claim 8, wherein the step of sending a charging request message carrying time zone information to a charging entity by each network element that obtains the time zone information comprises: in an offline charging system, a control layer network element and a service layer network element which obtain the time zone information and comprise PCSCF send A Charging Request (ACR) message carrying the time zone information to a Charging Data Function (CDF); in the online charging system, the control layer network element and the service layer network element except the PCSCF, which obtain the time zone information, send a Credit Control Request (CCR) message carrying the time zone information to an Online Charging System (OCS).

11. The method of claim 8, wherein the charging entity performs the charging process according to the charging request message carrying the time zone information sent by each network element, and the charging process is as follows: in an offline charging system, a charging entity acquires the time zone information from a charging Request message sent by each network element, and sets a time field of a Charging Data Record (CDR) corresponding to each network element to contain effective information of local time of UE (user equipment), namely UTC time + time zone information of the UE, by combining an SIP Request time attribute value pair (SIP-Request-TimestampAVP) and an SIP Response time attribute value pair (SIP-Response-TimestampAVP) in UTC time format; in the online charging system, a charging entity obtains effective information of local time of UE according to a charging request message carrying time zone information sent by each network element, and performs online credit control and statistics according to the effective information.

12. An IMS charging system, comprising: the system comprises a PCSCF network element, a control layer network element except the PCSCF, a service layer network element and a charging entity; wherein,

the PCSCF network element is used for carrying time zone information in the SIP message sent to the control layer network element and sending a charging request message carrying the time zone information to a charging entity in an offline charging system; the time zone information is: time zone information reported by UE, or time zone information provided for an access layer network element, or time zone information of the UE determined for the PCSCF; wherein the time zone information of the UE determined by the pcsccf itself is: the PCSCF obtains corresponding time zone information according to the UE position information mapping provided by the access layer network element;

13. The system according to claim 12, wherein the pcsccf network element is specifically configured to, in a case where information reported by the UE is trusted, carry, in an SIP message sent to a control layer network element other than the pcsccf network element, time zone information reported by the UE when the UE reports the time zone information; when UE does not report time zone information, if the access layer network element provides time zone information, the SIP message sent to the control layer network element except the UE carries the time zone information provided by the access layer network element; if the access layer network element does not provide time zone information, the time zone information of the UE is determined by the access layer network element, and the SIP message sent to the control layer network element except the access layer network element carries the time zone information;

14. The system of claim 12, wherein the charging entity comprises: CDF in off-line charging system or OCS in on-line charging system;