# Patent

## Title
Method for accounting information handling in an interworking

## Abstract

A method for accounting information handling in an interworking is provided. A method for processing accounting information by a gateway device includes sending an accounting request message to a first electronic device, and receiving a response message from a first electronic device, the response message responsive to the accounting request message. The accounting request message is related to a communications device attached to the first network. The method also includes processing accounting information. The processing is based on the response message, the gateway device and the first electronic device are part of the first network, the communications device is accessing a second network through the first network, and the communications device has a subscription only with the second network.

## Background
This application is a continuation of U.S. application Ser. No. 12/690,734, filed on Jan. 20, 2010, entitled, “Method for Accounting Information Handling in an Interworking,” which application is hereby incorporated herein by reference.


TECHNICAL FIELD
The present invention relates generally to wireless communications, and more particularly to a method for accounting information handling in an interworking.
BACKGROUND
As wireless communications systems continue to evolve and improve, it may be common for a service area to be served by multiple wireless communications systems as service providers upgrade equipment while keeping older equipment operational for compatibility purposes. When two (or more) wireless communications systems serve a common service area and allow a communications device to access both wireless communications systems, the result may be referred to as an interworking.
An accounting problem may arise when a WiMAX network is interworking with a non-WiMAX network, such as the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE), with the WiMAX network providing access to the non-WiMAX network since the WiMAX network may not specify or support all of the accounting methods supported in the non-WiMAX network. Additionally, a format of accounting messages from the WiMAX network may not be the same as those supported in the non-WiMAX network. In general, a first network providing access to a second network may be referred to as an access network.
Furthermore, the non-WiMAX network may generate accounting information of its own and may choose to ignore accounting information from the WiMAX network. Therefore, accounting information generated by the WiMAX network and injected into both the WiMAX network and the non-WiMAX network may increase the amount of network traffic, thereby potentially reducing overall network performance by increasing network overhead.
SUMMARY
These and other problems are generally solved or circumvented, and technical advantages are generally achieved, by embodiments of a method for accounting information handling in an interworking.
In accordance with an embodiment, a method for processing accounting information by a gateway device is provided. The method includes sending an accounting request message to a first electronic device, receiving a response message from the first electronic device, and processing accounting information. The accounting request message is related to a communications device attached to a first network, the response message is responsive to the accounting request message, and the processing is based on the response message. The gateway device and the first electronic device are part of the first network, the communications device is accessing a second network through the first network, and the communications device has a subscription only with the second network.
In accordance with another embodiment, a method for processing accounting information by an authentication device is provided. The method includes receiving an accounting request message from a first electronic device, and sending a response message responsive to the accounting request message to the first electronic device. The accounting request message is related to a communications device attached to a first network, and the authentication device and the first electronic device are part of the first network. The communications device is accessing a second network through the first network, and the communications device has a service subscription only with the second network.
In accordance with another embodiment, a method for processing accounting information by a gateway device is provided. The method includes determining if a communications device is participating in an interworking with a first network and a second network, stopping generation of accounting information for the communications device if the communications device is participating in an interworking with the first network and the second network, and continuing to generate accounting information for the communications device if the communications device is not participating in an interworking with the first network and the second network. The communications device is accessing a second network through the first network, and the communications device has a subscription only with the second network.
An advantage of an embodiment is that accounting information and accounting messages from a WiMAX network, wherein the WiMAX network is providing access, are handled without impacting a 3GPP network and minimally impacting WiMAX performance.
A further advantage of an embodiment is that an existing parameter in an existing message is used to control the handling of accounting information and accounting messages. Therefore, additions and/or modifications to existing message formats and protocols are not needed.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the embodiments that follow may be better understood. Additional features and advantages of the embodiments will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures or processes for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.



BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the embodiments, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a diagram of a WiMAX-3GPP enhanced packet core (EPC) interworking;
FIG. 2 is a diagram of a detailed view of a WiMAX-3GPP EPC interworking;
FIG. 3a is a flow diagram of high level ASN-GW operations in generating accounting reports;
FIG. 3b is a flow diagram of first ASN-GW operations in generating accounting reports for a mobile participating in a WiMAX-3GPP EPC interworking;
FIG. 3c is a flow diagram of second ASN-GW operations in generating accounting reports for a mobile participating in a WiMAX-3GPP EPC interworking;
FIG. 3d is a flow diagram of third ASN-GW operations in generating accounting reports for a mobile participating in a WiMAX-3GPP EPC interworking;
FIG. 4a is a flow diagram of first WiMAX AAA proxy operations in handling accounting reports from a ASN-GW for a mobile participating in a WiMAX-3GPP EPC interworking; and
FIG. 4b is a flow diagram of second WiMAX AAA proxy operations in handling accounting reports from a ASN-GW for a mobile participating in a WiMAX-3GPP EPC interworking.



DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
The making and using of the embodiments are discussed in detail below. It should be appreciated, however, that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative of specific ways to make and use the invention, and do not limit the scope of the invention.
The embodiments will be described in a specific context, namely an interworking with a WiMAX compliant network serving as an access network and a 3GPP LTE compliant network, where a mobile is using the WiMAX network to access the 3GPP network. The invention may also be applied, however, to other interworkings, such as CDMA-LTE-A, HRPD-LTE, HRPD-LTE-A, CDMA2000-LTE, CDMA2000-LTE-A, CDMA-WiMAX, CDMA2000-WiMAX, CDMA-UMTS, CDMA2000-UMTS, WiMAX-LTE, WiMAX-LTE-A, UMTS-LTE, UMTS-LTE-A, and so on.
FIG. 1 illustrates a WiMAX-3GPP enhanced packet core (EPC) interworking 100. As shown in FIG. 1, a mobile 105 may use a WiMAX compliant network 110 to access a 3GPP compliant network 115. Through 3GPP compliant network 115, mobile 105 may access information source 120, multimedia service 121, content provider 122, and so forth. Mobile 105 may access 3GPP compliant network 115 by first attaching to WiMAX compliant network 110 and then passing authentication/authorization with 3GPP compliant network 115.
Using WiMAX compliant network 110 to access 3GPP compliant network 115 may mean that mobile 105 incurs access charges from both 3GPP compliant network 115 and WiMAX compliant network 110. However, in a WiMAX-3GPP interworking, mobile 105 may be assumed to have a service subscription only with 3GPP compliant network 115.
Both 3GPP compliant network 115 and WiMAX compliant network 110 will generate accounting information for mobile 105. Accounting information may include information such as identity of mobile 105, access start/stop time, duration, service type, amount of data transferred, and so forth. The accounting information may be continuously generated while mobile 105 is in an active session. Furthermore, depending on service agreements, WiMAX compliant network 110 may transmit accounting information to 3GPP compliant network 115 so that 3GPP compliant network 115 may accurately charge mobile 105.
Since mobile 105 is operating through both 3GPP compliant network 115 and WiMAX compliant network 110, the accounting information generated by WiMAX compliant network 110 may be redundant. Because the accounting information generated by WiMAX compliant network 110 may be redundant, the transmission of the accounting information to 3GPP compliant network 115 may negatively impact performance of 3GPP compliant network 115 by increasing network traffic, for example. Additionally, the generation of redundant accounting information by WiMAX compliant network 110 may also impact the performance of WiMAX compliant network 110.
FIG. 2 illustrates a detailed view of a WiMAX-3GPP EPC interworking 200. As discussed previously, in a WiMAX-3GPP EPC interworking scenario, a mobile, such as mobile 205, is assumed to have a subscription to the 3GPP compliant network, such as 3GPP compliant network 215, only. In the 3GPP compliant network, a packet data network gateway (PDN-GW) 220 may generate accounting records along with user data records (UDR) for any access technology, such as WiMAX, interworking with the 3GPP compliant network.
Accounting records for a session using WiMAX access through a WiMAX compliant network, such as WiMAX compliant network 210, may be generated by PDN-GW 220 (located in the 3GPP compliant network). Therefore, there is no need for any accounting information from the WiMAX compliant network, even to keep track of billing information related to mobile 205's use of the WiMAX compliant network.
However, in the WiMAX compliant network, an access service network gateway (ASN-GW) 225 may be required to generate accounting records as part of the WiMAX technical standards. ASN-GW 225 may generate accounting records even if they are not necessary in a WiMAX-3GPP EPC interworking scenario.
Typically, the accounting records generated by ASN-GW 225 may be transmitted to a WiMAX accounting/authentication/authorization (AAA) proxy 230, which may then transmit the accounting records to a 3GPP AAA server 235. Because ASN-GW 225 may generate a significant number of accounting records in a long standing connection with mobile 205, the transmission of the accounting records may consume a noticeable amount of available network resources in both the WiMAX compliant network and the 3GPP compliant network. Furthermore, the generation of the accounting records by ASN-GW 225 may increase the performance requirements of ASN-GW 225, for example, increase memory usage, processing power, etc.
FIG. 3a illustrates a flow diagram of high level ASN-GW operations 300 in generating accounting reports. ASN-GW operations 300 may be indicative of operations occurring in an ASN-GW, such as ASN-GW 225, of a WiMAX compliant network. ASN-GW operations 300 may occur when a mobile, such as mobile 205, uses the WiMAX compliant network to access a 3GPP compliant network. ASN-GW operations 300 may occur while the ASN-GW is in a normal operating mode and while the WiMAX compliant network participates in a WiMAX-3GPP EPC interworking with the 3GPP compliant network.
ASN-GW operations 300 may begin with the ASN-GW sending a message to a WiMAX AAA proxy (block 305). The message sent to the WiMAX AAA proxy may include an indication indicating that the message is an accounting request. The message may also include other indications.
The WiMAX AAA proxy, upon receipt of the message, may send back a response to the ASN-GW. The response message may or may not contain an indicator that is pertinent to the accounting request sent to the WiMAX AAA proxy. The ASN-GW may then receive the response from the WiMAX AAA proxy (block 307) and take action based on the response to the accounting request message (block 309). The ASN-GW may take different actions based on the response to the accounting request that it sent to the WiMAX AAA proxy. Several different actions that the ASN-GW may take are discussed in detail below. ASN-GW operations 300 may then terminate.
FIG. 3b illustrates a flow diagram of first ASN-GW operations 325 in generating accounting reports for a mobile participating in a WiMAX-3GPP EPC interworking. ASN-GW operations 325 may be indicative of operations occurring in an ASN-GW, such as ASN-GW 225, of a WiMAX compliant network. ASN-GW operations 325 may occur when a mobile, such as mobile 205, uses the WiMAX compliant network to access a 3GPP compliant network. ASN-GW operations 325 may occur while the ASN-GW is in a normal operating mode and while the WiMAX compliant network participates in a WiMAX-3GPP EPC interworking with the 3GPP compliant network.
ASN-GW operations 325 may begin with the ASN-GW sending a message to a WiMAX AAA proxy (block 330). The message sent to the WiMAX AAA proxy may include an indication indicating that the message is an accounting request. The message may also include other indications.
The WiMAX AAA proxy, upon receipt of the message may send back a response to the ASN-GW. The response message may contain an indication indicating that accounting should be turned off (e.g., “accounting off”). According to an embodiment, the indication may be set to a specified value, for example, eight (8), to indicate that accounting should be turned off. Although the discussion focuses on a specific value for the indication, e.g., eight, any value for the indication may be used as long as the value has not already been reserved to indicate other indicators. Therefore, the discussion of the value eight should not be construed as being limiting to either the spirit or the scope of the embodiments. Additionally, the response message may contain other indications.
The ASN-GW may then receive the response message from the WiMAX AAA proxy (block 332). The ASN-GW may check to determine if there is an indication indicating that it should turn off generating accounting reports (block 334). If the response includes such an indication, then the ASN-GW may stop generating and sending accounting reports (block 336) and ASN-GW operations 325 may then terminate. If the response does not include such an indication, then the ASN-GW may continue generating and sending accounting reports and ASN-GW operations 325 may then terminate.
FIG. 3c illustrates a flow diagram of second ASN-GW operations 350 in generating accounting reports for a mobile participating in a WiMAX-3GPP EPC interworking. ASN-GW operations 350 may be indicative of operations occurring in an ASN-GW, such as ASN-GW 225, of a WiMAX compliant network. ASN-GW operations 350 may occur when a mobile, such as mobile 205, uses the WiMAX compliant network to access a 3GPP compliant network. ASN-GW operations 350 may occur while the ASN-GW is in a normal operating mode and while the WiMAX compliant network participates in a WiMAX-3GPP EPC interworking with the 3GPP compliant network.
ASN-GW operations 350 may begin with the ASN-GW sending a message to a WiMAX AAA proxy (block 355). The message sent to the WiMAX AAA proxy may include an indication indicating that the message is an accounting request. The message may also include other indications.
The WiMAX AAA proxy, upon receipt of the message, may send back a response to the ASN-GW. The response message may not contain an indication indicating that accounting should be turned off “accounting off,” as discussed previously. However, the response message may contain other indications.
The ASN-GW may then receive the response message from the WiMAX AAA proxy (block 357). The ASN-GW may check to determine if there is an indication indicating that it should turn off generating accounting reports (block 359). If the response does include such an indication, then the ASN-GW may stop generating and sending accounting reports (block 361) and ASN-GW operations 350 may then terminate. If the response does not include such an indication, then the ASN-GW may continue generating and sending accounting reports and ASN-GW operations 350 may then terminate.
FIG. 3d illustrates a flow diagram of third ASN-GW operations 375 in generating accounting reports for a mobile participating in a WiMAX-3GPP EPC interworking. ASN-GW operations 375 may be indicative of operations occurring in an ASN-GW, such as ASN-GW 225, of a WiMAX compliant network. ASN-GW operations 375 may occur when a mobile, such as mobile 205, uses the WiMAX compliant network to access a 3GPP compliant network. ASN-GW operations 375 may occur while the ASN-GW is in a normal operating mode and while the WiMAX compliant network participates in a WiMAX-3GPP EPC interworking with the 3GPP compliant network.
ASN-GW operations 375 may begin with the ASN-GW performing a check to determine if it is operating in an interworking with a 3GPP EPC (block 380). According to an embodiment, the ASN-GW may be able to determine that it is operating in an interworking by examining message traffic originating from the mobile, for example, the ASN-GW may examine message type of message traffic from the mobile, connection types requested by message traffic from the mobile, an intended destination of the message traffic from the mobile, and so on.
If the ASN-GW is operating in an interworking with a 3GPP EPC, then the ASN-GW may stop generating accounting records for the mobile (block 382). Additionally, if the ASN-GW has already generated accounting records for the mobile, then the ASN-GW may suppress transmission of the generated accounting records if they have not already been sent. According to an embodiment, the ASN-GW may stop generating accounting records for the mobile only for connections involving the mobile and the 3GPP EPC. For example, if the mobile has several active connections and at least one of them does not involve the 3GPP EPC, then the ASN-GW may still continue to generate accounting records for the connection(s) not involving the 3GPP EPC. ASN-GW operations 375 may then terminate.
If the ASN-GW is not operating in an interworking with a 3GPP EPC, then the ASN-GW may continue generating accounting records for the mobile and ASN-GW operations 375 may then terminate.
FIG. 4a illustrates a flow diagram of first WiMAX AAA proxy operations 400 in handling accounting reports from a ASN-GW for a mobile participating in a WiMAX-3GPP EPC interworking. WiMAX AAA proxy operations 400 may be indicative of operations occurring in a WiMAX AAA proxy, such as WiMAX AAA proxy 230, of a WiMAX compliant network. WiMAX AAA proxy operations 400 may occur when a mobile, such as mobile 205, uses the WiMAX compliant network to access a 3GPP compliant network. WiMAX AAA proxy operations 400 may occur while the WiMAX AAA proxy is in a normal operating mode and while the WiMAX compliant network participates in a WiMAX-3GPP EPC interworking with the 3GPP compliant network.
WiMAX AAA proxy operations 400 may begin with the WiMAX AAA proxy receiving a message from an ASN-GW, wherein the message includes an indication indicating that the message is an accounting request (block 405). The message received by the WiMAX AAA proxy may also include other indications.
In response to the received message with the indication indicating that the message is an accounting request, the WiMAX AAA proxy may send back to the ASN-GW a response message that contains an indication indicating that accounting should be turned off (e.g., “accounting off”) (block 410). According to an embodiment, the indication may be set to a specified value, for example, eight (8), to indicate accounting off. Although the discussion focuses on a specific value for the indication, e.g., eight, any value for the indication may be used as long as the value has not already been reserved to indicate other indicators. Therefore, the discussion of the value eight should not be construed as being limiting to either the spirit or the scope of the embodiments. Additionally, the response message may contain other indications. The response message may also contain other indications.
If the WiMAX AAA proxy continues to receive messages from the ASN-GW containing accounting records, the WiMAX AAA proxy may discard the accounting records (block 415). WiMAX AAA proxy operations 400 may then terminate.
FIG. 4b illustrates a flow diagram of second WiMAX AAA proxy operations 450 in handling accounting reports from a ASN-GW for a mobile participating in a WiMAX-3GPP EPC interworking. WiMAX AAA proxy operations 450 may be indicative of operations occurring in a WiMAX AAA proxy, such as WiMAX AAA proxy 230, of a WiMAX compliant network. WiMAX AAA proxy operations 450 may occur when a mobile, such as mobile 205, uses the WiMAX compliant network to access a 3GPP compliant network. WiMAX AAA proxy operations 450 may occur while the WiMAX AAA proxy is in a normal operating mode and while the WiMAX compliant network participates in a WiMAX-3GPP EPC interworking with the 3GPP compliant network.
WiMAX AAA proxy operations 450 may begin with the WiMAX AAA proxy receiving a message from an ASN-GW, wherein the message includes an indication indicating that the message is an accounting request (block 455). The message received by the WiMAX AAA proxy may also include other indications.
In response to the received message with the indication indicating that the message is an accounting request, the WiMAX AAA proxy may send back to the ASN-GW a response message that contains no indication related to accounting (block 460). Although the response message may not contain an indication related to accounting, the response message may contain other indications.
If the WiMAX AAA proxy receives accounting records from the ASN-GW, then the WiMAX AAA proxy may optionally convert the accounting records into a 3GPP format and send the converted accounting records to a 3GPP AAA server (block 465). Conversion of the accounting records from the WiMAX format into the 3GPP format may include placing sufficient information into the 3GPP formatted accounting records for correlation purposes. WiMAX AAA proxy operations 450 may then terminate.
Although the embodiments and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

## Claims

1. A method for operating a gateway device in a first network, the method comprising:
transmitting accounting information for a communications device attached to the first network to a proxy device, wherein the communications device accesses a second network through the first network;
transmitting an accounting request message related to the communications device to the proxy device in the first network;
receiving a response message responsive to the accounting request message from the proxy device; and
ceasing transmission of the accounting information if an indicator in the response message indicates a turning off of the accounting information, wherein the communication device remains attached to the first network after ceasing transmission of the accounting information, and
wherein the communications device continues to access the second network through the first network after ceasing transmission of the accounting information to the proxy device.

2. The method of claim 1, wherein the indicator is an Acct-Status-Type indicator.

3. The method of claim 1, wherein the indicator indicates the turning off of the accounting information with an Accounting-Off value.

4. The method of claim 3, wherein the Accounting-Off value is an integer value of eight.

5. The method of claim 1, wherein the accounting information is related to an internetwork connection of the communications device with the second network through the first network.

6. The method of claim 1, wherein the proxy device comprises an accounting, authentication, and authorization device.

7. The method of claim 1, wherein the first network is a WiMAX compliant network, and wherein the second network is a Third Generation Partnership Project Evolved Packet Core compliant network.

8. The method of claim 7, wherein the gateway device is an access service network gateway.

9. A gateway of an access service network connected to a first network, the gateway comprising:
a processor; and
a computer readable storage medium storing programming for execution by the processor, the programming including instructions to:

transmit accounting information for a communications device attached to the first network to a proxy device, wherein the communications device is accessing a second network through the first network;
transmit an accounting request message related to the communications device to the proxy device in the first network;
receive a response message responsive to the accounting request message from the proxy device; and
stop transmitting the accounting information if an indicator in the response message indicates a turning off of the accounting information, wherein the communications device continues to access the second network through the first network after the processor executes the instructions to stop transmitting the accounting information.

10. The gateway of claim 9, wherein the indicator indicates the turning off of the accounting information with an Accounting-Off value.

11. The gateway of claim 10, wherein the Accounting-Off value is an integer value of eight.

12. The gateway of claim 9, wherein the gateway is configured to stop transmitting of accounting information related to an internetwork connection of the communications device with the second network through the first network.

13. The gateway of claim 9, wherein the first network is a WiMAX compliant network, and wherein the second network is a Third Generation Partnership Project Evolved Packet Core compliant network.

14. The gateway of claim 9, wherein the proxy device comprises an accounting, authentication, and authorization device.

15. The method of claim 1, wherein the communications device has a service subscription with the second network but not with the first network.

16. The method of claim 1 further comprising continuing the transmitting of the accounting information unchanged if the indicator does not indicate turning off of the accounting information.

17. The gateway of claim 9, and wherein the communications device has a service subscription with the second network but not with the first network.

18. The gateway of claim 9, wherein the programming further includes instructions to transmit the accounting information if the indicator does not indicate the turning off of the accounting information.

19. The gateway of claim 9, wherein the communications device remains attached to the first network after the processor executes the instructions to stop transmitting the accounting information.

20. An apparatus for communicating accounting information in a WiMAX compliant network that is interworking with a non-WiMAX compliant network, the apparatus comprising:
a processor; and
a computer readable storage medium storing programming for execution by the processor, the programming including instructions to:
communicate accounting information related to a communications session of a mobile station in the WiMAX network, and wherein the communications session allows the mobile station to access the non-WiMAX network through the WiMAX network;
receive an accounting off instruction from a proxy server; and
discontinue communication of the accounting information in response to receiving the accounting off instruction, wherein the communications session of the mobile station continues in the WiMAX network after discontinuing communication of the accounting information.

21. A method for operating an access service network gateway (ASN-GW) in a WiMAX-third generation partnership (3GGP) enhanced packet core (EPC) interworking scenario, the method comprising:
generating accounting records for a session of a subscriber device in a WiMAX network, wherein the session allows the subscriber device to access a 3GGP network via the WiMAX network;
sending an Accounting Request message to a WiMAX proxy;
receiving an Accounting Response message from the WiMAX proxy, the Accounting Response message including an Acct-Status-Type indicator that indicates an Accounting-off instruction; and
stopping generation of the accounting records pursuant to the Accounting-off instruction, wherein the session continues in the WiMAX network after generation of the accounting records is stopped.

22. The method of claim 21, wherein the subscriber device only has a subscription to the 3GGP network.

23. The method of claim 21, wherein the subscriber device continues to access the 3GGP network via the WiMAX network after generation of the accounting records is stopped.