Patent Grant
7336941
The present invention relates generally to a communications system and, more particularly, to a method and apparatus for unified accounting across wireless communication network.
There exists several different accounting methods that users may utilize to access a wireless communications networks However, no efficient method or system exists that provides unified accounting for a variety of accounting methods.
Therefore, what is needed, is a system and method that provides unified accounting for more than one accounting method utilized for more than one access method.
The present disclosure provides a system and method that provide unified accounting across wireless communication networks.
Therefore, in accordance with the previous summary, objects, features and advantages of the present disclosure will become apparent to one skilled in the art from the subsequent description and the appended claims taken in conjunction with the accompanying drawings.
The present disclosure can be described by the embodiments given below. It is understood, however, that the embodiments below are not necessarily limitations to the present disclosure, but are used to describe a typical implementation of the invention. In addition, details of a Wireless Access Integrated Node (WAIN) server and architecture can be found in the patent application Ser. No. 09/851,681, incorporated by reference above.
There are currently two different accounting standards supported by wireless data service providers. The General Packet Radio Service (GPRS) operators comply with European Telecommunications Standard Institute (ETSI) standards while the Wireless Internet Service Provider (WISP) operators comply with Internet Engineering Task Force (IETF) standards.
However, these two standards differ from each other. Some Wireless Local Area Network (WLAN) users may not have a GPRS subscription associated with an International Mobile Subscriber Identity (IMSI) within a Security Identity Module (SIM) card. Thus, those WLAN users utilize the IETF accounting standards. Therefore, it is desirable if those users could use the same GPRS charging and billing system as specified by ETSI standards.
ETSI accounting complies with Global System for Mobile Communication (GSM) specification 12.15 which utilize Call Data Records (CDRs). These CDRs are generated upon reaching certain trigger conditions specified by the GSM 12.15. Moreover, the IMSI is a user identifier that links the CDR to a particular user. Two types of CDRs are generated, an S-CDR and a G-CDR. The CDR contents are shown in Table 1.
On the other hand, the accounting standard specified by the IETF is a Remote Authentication Dial-In User Server/Service (RADIUS) accounting standard defined by Request for Comment (RFC) 2866. RADIUS accounting records, like the CDR counterparts, are generated upon reaching certain triggers. In addition, a field named “User-Name” is an user identifier that links the RADIUS accounting record to a particular user. Listed below is a table with the RADIUS attributes.
The system and method of the present invention uses RADIUS accounting records to trigger GPRS CDR generation for those WLAN users that do not have GPRS account. The system of the present invention maps the parameters generated for a RADIUS Accounting-Request to a CDR. However, the CDR generation triggers remain the same. This new accounting system identifies the CDRs for the WLAN users by an IMSI which does not currently exist in the IETF domain. The accounting system of the present invention establishes a method by which a virtual IMSI is generated for the WLAN users based on certain rules. The virtual IMSI is then transferred to a WAIN Server and used in the CDR generation.
Now referring to
The new accounting system of the present invention maps the User-Name field in the RADIUS Account Record to the IMSI field in the CDR. However, the MSIN field in the IMSI, unlike the MNC and MCC fields, is assigned by the operator and is unique within its network. For each RADIUS user, a Virtual IMSI (V-IMSI) is defined to provide a one-to-one mapping to its User-Name. Although the V-IMSI is of the same format as the IMSI, it is used internally in the operator's network for identifying accounting records for WLAN users who do not have the GPRS subscription and IMSI assignment.
To identify the WLAN accounting and to avoid any conflict with a standard IMSI used in the accounting system, a special MSIN (V-MSIN) encoding is used for the V-IMSI. For example, the first 3 digits of the MSIN may be set to zero and the remaining digits used to identity individual WLAN users: V-MSIN=000XXXXXXX. Whatever mapping is used is known to both the RADIUS authentication server and the accounting system. However, other methods can also be used to generate a V-IMSI.
First referring to
On the other hand, WLAN-only users do not have an IMSI and therefore can not use conventional GPRS CDRs. However, the present invention uses the RADIUS server to create a V-IMSI. The system then uses RADIUS messages to transport the V-IMSI from the RADIUS server to the WAIN server 204.
In the present embodiments, the WAIN Server 200 is used in two different configurations. One method uses the WAIN server as an Access Controller (AC) and the other method use the WAIN server as merely a RADIUS proxy and not an AC.
Now turning to
As the user 200 logs out or the session is discontinued, the new RADIUS and GPRS ASN.1 formatted (GSM 12.15) combined accounting records are created into a CDR. In addition, the V-IMSI is inserted into every one of these CDRs. These CDRs are then collected by the existing GPRS Charging Gateway 210 and forwarded to the Billing System 212. The user information is then recovered from the V-IMSI in the CDRs and used for accounting purposes.
In addition, if the V-MSIN is chosen carefully, the V-IMSI can be later converted to a valid IMSI if the WLAN-only user subscribes to an integrated GPRS+WLAN service. The same IMSI can then be used for both GPRS and WLAN authentication and accounting.
In the present embodiment, the use of the Class attribute or the VSA for the V-IMSI is optional. However, the CDR generation based on the V-IMSI is dependent upon its presence in the Access Accept message from the RADIUS server 300. The WAIN Server 204 first checks for the presence of the VSA in the proper IMSI format. If the VSA is present in the proper format, then it is used; otherwise, the Class attribute is checked for the V-IMSI. If the V-IMSI is not present in the Access Accept message, the CDR is not generated. In this embodiment, if the coding of the V-IMSI received is in any other format besides the one specified below, the user will not be logged in.
Now turning to
A summary of the VSA format is shown below. The fields are transmitted from left to right.
Type: 26 for Vendor-Specific.
Length: =21 (6 fixed bytes+15 ASCII Characters)
Vendor-Id: The high-order octet is 0 and the low-order 3 octets are the SMI Network Management Private Enterprise Code of the Vendor in network byte order, as defined in the Assigned Numbers 13448.
String: The String field is one or more octets. The actual format of the information is site or application specific, and a robust implementation should support the field as undistinguished octets. It should be encoded as a sequence of vendor type/vendor length/value fields, as follows:
Vendor Type: 0
Vendor Length: 15 (the length of the “Attribute-Specific” field)
Attribute-Specific: The Attribute-Specific field is coded as an ASCII string of maximum size 15 representing the V-IMSI as following:
The message exchange detailing a client logging into the GPRS network is now described. First, the Client 400 sends a Login-Request to the RC 406 as depicted by 410. The RC 406 then sends an Access-Request to the RS 408 as depicted by 412. The RS 408 responds with an Access-Accept with the Class or VSA attribute containing the V-IMSI value in ASCII format as depicted by 414. The Client 400 then Deactivates or Logs out as depicted by 420.
Although the WCM 402, the WSM 404 and the RC 406 are shown as separate modules in this embodiment, they can combined within a single entity. For example, the WAIN server, can implement each of the modules within the server itself.
Now details of the second method wherein the WAIN Server 500 acts as a RADIUS proxy 500 and not as an AC is described in relation to
Once the RADIUS user 200 is successfully authenticated, the RADIUS Server 300 passes the V-IMSI to the AP 202 in a Class or a VSA attribute of the RADIUS Access Accept message. The AP 202 conveys the received V-IMSI to the WAIN Server 500 in the Class attribute or the VSA of accounting messages (e.g. Accounting Start, Accounting Stop and Interim Update). The choice of the Class attribute or the VSA to be used for V-IMSI is determined dynamically by the WAIN Server 500 in this embodiment also.
As the user logs out or the session is discontinued, the RADIUS and GPRS ASN.1 formatted (GSM 12.15) accounting records are created in CDRs for the RADIUS user 200. As in the previous embodiment, the V-IMSI for the RADIUS user 200 is inserted in every CDR. These CDRs are then collected by the existing GPRS Charging Gateway 210 and forwarded to the Billing System 212. The user information is then recovered from the V-IMSI in the CDRs and used for accounting purposes. Moreover, partial CDRs in this embodiment are tied to the Interim Update message. When the WAIN Server 500 receives an Interim Update message, it generates a partial CDR. This method also depends upon the support of the Class attribute or the VSA by the AC 202 and its ability to generate RADIUS accounting records for the WAIN server 500.
Moreover, although only single entities of the CG 210, HLR 208, and RADIUS Server 300, are shown in this embodiment, multiple entities for each node can be implemented and handled with the architecture of the present invention.
In addition, in order to convert the RADIUS messages into the GPRS CDR format to form a combined RADIUS/GPRS CDR, a parameter mapping is used by the present invention. In this embodiment, the CDR is generated by getting required parameters in real time and then writing them in the CDR. Some of the parameters are gathered from the RADIUS messages while others are generated internally by the WAIN Server or read from a configuration file. The RADIUS accounting record is also generated and exists for V-IMSI users. Table 3 below shows the RADIUS elements correlation with the CDR elements.
The parameters that the WAIN Server generates internally or read from the configuration file are listed below in Table 4 along with the source information.
Using both tables 3 and 4, the system of the present invention creates the new combined RADIUS/GPRS CDRs for the WLAN-only users that conform with the GPRS accounting format. Thus, the present invention creates a unified accounting system for both WLAN-only users as well as GPRS users. In addition, the system of the present invention provides a method for WLAN-only users to later convert their V-IMSI into a permanent IMSI for GPRS use.
It is understood that several modifications, changes and substitutions are intended in the foregoing disclosure and in some instances some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.
This application claims benefit of U.S. Provisional Application No. 60/430,510, filed Dec. 2, 2002. Furthermore, this application relates to U.S. application Ser. No. 09/851,681, filed on May 8, 2001, which is commonly assigned and incorporated herein by reference in its entirety.
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| 5483575 | Zdanowski et al. | Jan 1996 | A |
| 6608832 | Forslow | Aug 2003 | B2 |
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| 20030050041 | Wu | Mar 2003 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 60430510 | Dec 2002 | US |
