System and method for radius accounting for wireless communication networks

Information

  • Patent Application
  • 20050064845
  • Publication Number
    20050064845
  • Date Filed
    September 23, 2003
    21 years ago
  • Date Published
    March 24, 2005
    19 years ago
Abstract
An authentication server includes a first link connected to an authenticator associated with a Wireless Local Area Network (WLAN) and a second link connected to a gateway associated with a mobile network such as a GPRS network. The authentication server also includes a mapping system having instructions for receiving one or more first messages from the authenticator, the first messages being of a first type associated with the WLAN but not the mobile network, such as a RADIUS message. The mapping system also includes instructions for generating a first group of one or more call detail records from the received first messages, the call detail records being of a second type associated with the mobile network, and sending the first group of call detail records to the gateway.
Description
BACKGROUND OF THE INVENTION

The present invention relates generally to a communications system and, more particularly, to a method and apparatus for billing and/or accounting for users across wireless communication networks using a remote authentication protocol.


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 accounting for Subscriber Identity Module (SIM) users across wireless communication network using a protocol such as the Remote Authentication Dial-In User Service (RADIUS) protocol.


Therefore, what is needed, is a system and method that provides accounting for SIM users across wireless communication network using the RADIUS protocol.


SUMMARY OF THE INVENTION

The present invention describes a system and method that provides accounting for mobile users across wireless communication network using a remote authentication protocol such as the RADIUS protocol. In one embodiment, the system includes an access point connectable to a mobile client and a wireless integrated node connected to the access point and configured for providing and mapping between two different communication protocols. The system also includes a link for connecting the wireless integrated node to a charging gateway and further to an accounting system, such as one associated with a General Packet Radio Service (GPRS) network. The accounting system provides a bill for usage of the wireless network by the mobile client. The first communication protocol is of a format required by the wireless network and the second communication protocol is of a format required by the accounting system.


In another embodiment, a method is provided for generating call detail records in a format used with a mobile network, such as a GPRS network, for a client having an account with the mobile network and using a wireless local area network. The method includes receiving a RADIUS message, such as a start, interim, or stop message, from an access point. A Call Detail Record (CDR) is generated from accounting information contained in the RADIUS message and sent to a charging gateway associated with the mobile network.


In another embodiment, an authentication server is provided. The authentication server includes a first link connected to an authenticator associated with a Wireless Local Area Network (WLAN) and a second link connected to a gateway associated with a mobile network such as a GPRS network. The authentication server also includes a mapping system having instructions for receiving one or more first messages from the authenticator, the first messages being of a first type associated with the WLAN but not the mobile network, such as a RADIUS message. The mapping system also includes instructions for generating a first group of one or more call detail records from the received first messages, the call detail records being of a second type associated with the mobile network, and sending the first group of call detail records to the gateway.


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.




BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1 depicts a message dialog of a wireless unit logging into a RADIUS server.



FIG. 2 depicts an exemplary simplified telecommunications network and system that can benefit from the present invention.



FIG. 3 depicts a message sequence diagram showing the call detail record (CDR) generation triggers and transmission of CDRs.




DETAILED DESCRIPTION

The present invention can be described by the embodiments given below. It is understood, however, that the embodiments below are not necessarily limitations to the present invention, 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 at least two different accounting standards supported by wireless data service providers. The General Packet Radio Service (GPRS) operators currently comply with European Telecommunications Standard Institute (ETSI) standards while the Wireless Internet Service Provider (WISP) operators comply with Internet Engineering Task Force (IETF) standards. In addition, ETSI accounting methods utilize the user's International Mobile Subscriber Identity (IMSI) within a SIM card to identify accounting records while IETF accounting methods use a User ID field to identify accounting records. Moreover, ETSI accounting utilizes Call Detail Records (CDRs) while IETF accounting does not. There are also other differences between each accounting method's parameters. Wireless Local Area Network (WLAN) users can have a GPRS subscription associated with their IMSI or have a WLAN-only subscription associated with an User ID and a password. Currently, the WLAN users with IMSIs utilize ETSI accounting standards while the WLAN users without an IMSI utilize the IETF accounting standards.


However, some situations exist where a combination of the two accounting methods is required. For example, a user with an IMSI (GPRS subscription) may need to use the RADIUS protocol that is usually associated with IETF accounting, but may also desire to use ETSI accounting by the service provider. Nonetheless, no current method exists to create such a combined accounting structure.


The present disclosure solves this dilemma by using the RADIUS accounting records and mapping them to the GPRS CDRs. The present disclosure also creates different triggering events to create the CDRs that do not otherwise exist in traditional GPRS accounting methods.


One example scenario where RADIUS can be used with GPRS CDRs is when IEEE 802.1x and EAP are used in conjunction with RADIUS for a user that has a GPRS subscription. The terms PPP, EAP and IEEE 802.1x are described in further detail below.


Point-to-Point Protocol (PPP) is most commonly used for dial-up Internet access. PPP is also used by some ISPs for DSL and cable modem authentication, in the form of PPP over Ethernet. PPP is part of a Layer 2 Tunneling Protocol of the Open System Interconnect (OSI) 7 layer protocol model.


PPP evolved beyond its original use as a dial-up access method and is now used all over the Internet. One aspect of PPP defines an authentication mechanism, such as a username and password with dial-up Internet access. PPP authentication can be used to identify the user for purposes of granting access.


Some enterprises want to do more for security than simply employing usernames and passwords for access, so a new authentication protocol, called the Extensible Authentication Protocol (EAP), was designed. EAP resides inside of PPP's authentication protocol and provides a generalized framework for several different authentication methods. EAP was designed to let authentication methods such as passwords to challenge-response tokens and public-key infrastructure certificates to work smoothly.


With a standardized EAP, interoperability and compatibility of authentication methods become simpler. For example, when a user dial a remote-access server and uses EAP as part of the PPP connection, the Remote Access Server (RAS) does not need to know any of the details about the authentication system. Only the user and the authentication server have to be coordinated. By supporting EAP authentication, a RAS gets out of the business of acting as middle man, and just packages and repackages EAP packets to hand off to a RADIUS server that will do the actual authentication.


The IEEE 802.1x standard is often used for passing EAP over a wired or wireless LAN. With 802.1x, the EAP messages are packaged in Ethernet frames and do not use PPP. 802.1x is authentication and nothing more. This may be desirable in situations in which the rest of PPP is not needed, where protocols other than TCP/IP are being used, or where the overhead and complexity of using PPP is undesirable.


In 802.1x, the user or client that wants to be authenticated is often called a supplicant. The actual server doing the authentication, typically a RADIUS server, is often called the authentication server. The device in between, such as a wireless access point, is often called the authenticator. One of the key points of 802.1x is that the authenticator can be simple and dumb, i.e., it has limited, if any, processing software. Instead, the brains are in the supplicant and the authentication server. This makes 802.1x ideal for wireless access points, which are typically small and have little memory and processing power.


The protocol in 802.1x is called EAP encapsulation over LANs (EAPOL). It is currently defined for Ethernet-like LANs including 802.11 wireless, as well as token ring LANs such as FDDI. There are a number of modes of operation. An exemplary mode of operation is described in the next few paragraphs.


Referring to FIG. 1, in one embodiment, an authenticator 100, a supplicant 102, and an authentication server 104 are connectable via appropriate links. The authenticator 100 sends an “EAP-Request/Identity” message 106 to the supplicant 102 as soon as it detects that a link is active (e.g., the supplicant system has associated with the access point). The supplicant 102 then sends the authenticator 100 an “EAP-Response/Identity” message 108, which is then passed on to an authentication (RADIUS) server 104 as a “EAP-Response/Identity” message 110.


The authentication server 104 sends the authenticator 100 a challenge message 112, which may employ a token password system. The authenticator 100 unpacks the challenge message 112 from IP, repackages the challenge message into EAPOL, and sends a challenge message 114 to the supplicant 102. However, different authentication methods will vary this message and the total number of messages. EAP supports client-only authentication and strong mutual authentication. Strong mutual authentication is usually considered appropriate for the wireless case.


The supplicant 100 responds to the challenge message 114 received from the authenticator 102 with a challenge response message 116. The authenticator 102 passes the challenge response message 116 on to the authentication server 104 in a challenge response message 118. If the supplicant 100 provides proper identity, the authentication server 104 responds by sending a success message 120 to the authenticator 102. The authenticator 102 forwards this message on to the supplicant 100 as an authentication success message 122. The authenticator 100 now allows access to the LAN—possibly restricted based on attributes that came back from the authentication server 104. For example, the authenticator 102 might switch the supplicant 100 to a particular virtual LAN or install a set of firewall rules.


Referring to FIG. 2, in an exemplary simplified telecommunications network, the intelligent mobile device client (supplicant) 100 is in wireless communication with the authenticator/wireless access point (AP) 102. The AP 102 is in wireline communication with an authentication server or Wireless Services Platform (WSP) 104. One example of a WSP is the WAIN server provided by Transat Technologies, Inc. of Southlake, Tex. The WSP 104 includes one or more memory devices for storing instructions and data files, and one or more processing devices for acting on the instructions and data file, as described in greater detail below. The WSP 104 also includes various interfaces to communicate with other nodes through wired and wireless links. It is understood that the diagram of FIG. 2 is simplified, and many additional and/or different nodes are likely to exist and many additional and/or different links may be used between the various nodes.


The WSP 104 is in communication with a Signaling Gateway 206 which is in communication with a Home Location Register 208. The WSP 104 is in communication with a Charging Gateway 210 which is in communication with a Billing System 212. The WSP 104 is in communication with a public network 214 which may be the Internet and provides access to the intelligent mobile device client 100 to the public network 214. In the present invention, the WSP 104 provides RADIUS Server services among its other services.


When the client (supplicant) 100 has access to the GPRS network, accounting records need to be kept for this client. As stated earlier, one embodiment of the present invention provides a combined accounting method for SIM users that traditionally use GPRS accounting, but are using RADIUS messaging. One method to accomplish a combined accounting method is to map RADIUS accounting parameters to a GPRS call detail record.


GSM Call Detail Records


ETSI accounting complies with Global System for Mobile Communication (GSM) specification 12.15 which utilize Call Detail 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.

TABLE 1GPRS CDR FormatPresenceM = MandatoryC = ConditionalFieldO = OptionalDescriptionRecord TypeM (S-CDR/G-The field identifies the type of the record e.g. S-CDR, G-CDRCDR, M-CDR, S-SMO-CDR and S-SMT-CDR.NetworkC (S-CDR/G-This field indicates that Packet Data Protocol (PDP)Initiated PDPCDR)context is network initiated. The field is missing in case ofContextmobile activated PDP context.AnonymousC (S-CDR/G-Set to true to indicate anonymous access (and that theAccessCDR)Served IMSI is not supplied)IndicatorServed IMSIM (S-CDR/G-This field contains the international mobile subscriberCDR)identity (IMSI) of the served party. The Client “served”party is used to describe the mobile subscriber involved inthe transaction recorded (e.g. the calling subscriber in caseof a mobile initiated PDP context.) The structure of theIMSI is defined in GSM 03.03.Served IMEIC (S-CDR/G-This field contains the international mobile equipmentCDR)identity (IMEI) of the equipment served. The Client“served” equipment is used to describe the ME involved inthe transaction recorded (e.g. the called ME in the case ofa network initiated PDP context.) The structure of theIMEI is defined in GSM 03.03.SGSNM (S-CDR/G-The S-CDR fields contain the single address of currentAddressCDR)Serving GPRS Serving Node (SGSN) and GGSN used.GGSNM (S-CDR/G-The IP address of the Gateway GPRS Support NodeAddressCDR)(GGSN) used.MS NetworkThis MS Network Capability field contains the MSCapabilitynetwork capability value of the MS network capabilityinformation element of the served MS on PDP contextactivation or on GPRS attachment as defined in GSM04.08.Routing AreaRouting Area at the time of the record creation.Local AreaLocation area code at the time of the record creation.CodeCell IdentityCell ID at the time of the record creation.Charging IDM (S-CDR/G-This field is a charging identifier which can be usedCDR)together with the GGSN address to identify all recordsproduced in SGSN(s) and GGSN involved in a single PDPcontext. Charging ID is generated by the GGSN at PDPcontext activation and transferred to the context requestingSGSN. At inter-SGSN routing area update, charging ID istransferred to the new SGSN as part of each active PDPcontext. Different GGSNs allocate the charging IDindependently of each other and may allocate the samenumbers. The Charging Gateway Facility (CGF) and/orBS may check the uniqueness of each charging ID togetherwith the GGSN address and optionally (if stillunambiguous) with the record opening time stamp. TheGGSN function in the WS generates an integer in the rangeof 0 . . . 4294967295 unique to itself for every CDR issued.GGSNM (S-CDR)The IP address of the GGSN currently used. The GGSNAddressaddress is always the same for an activated PDP.UsedAccess PointM (S-CDR/G-This field contains the logical Access Point Name (APN)Name NICDR)used to determine the actual connected access point. TheAPN is comprised of a mandatory network identifier andan optional operator identifier (this field is the networkidentifier). The APN can also be a wildcard, in which casethe SGSN selects the access point address. See GSM09.60 and GSM 03.60 for more information about APNformat and access point decision rules. The APN isinformation from the MS or SGSN, that may be used bythe GGSN to differentiate between accesses to differentexternal packet data networks using the same PDP Type.APNO (S-CDR/G-This field indicates how the SGSN selected the APN to beSelectionCDR)used. The values and their meaning are as specified inModeGSM 09.60 clause 7.9 ‘Information elements’.PDP TypeM (S-CDR/G-This field defines the PDP type (e.g. X.25, IP, PPP, orCDR)IHOSS:OSP) (see GSM 09.60 for exact format).Served PDPM (S-CDR/G-This field contains the PDP address of the served IMSI.AddressCDR)This is a network layer address (e.g. of type IP version 4,IP version 6 or X.121). The address for each PDP type isallocated either temporarily or permanently (see field“Dynamic Address Flag”)Remote PDPO (G-CDR)Remote PDP address may be used if PDP type is X.25.AddressThis parameter is not used if the PDP type is IP, PPP, orIHOSS:OSP. Itemized volume billing is available perAPN. This field contains a list of connected remote PDPaddresses.DynamicC (G-CDR)This field indicates that PDP address has been dynamicallyAddress Flagallocated for that particular PDP context. Field is missingif address is static (e.g. part of PDP context subscription).Dynamic address allocation might be relevant for charging(e.g. the duration of PDP context as one resource offeredand possible owned by network operator).List ofM (S-CDR/G-This list includes one or more containers, which eachTraffic DataCDR)include the following fields: Data Volume Uplink, DataVolumesVolume Downlink, Change Condition and Time Stamp.Data Volume includes the number of octets transmittedduring the use of packet data services. Change conditiondefines the reason for closing the container (see 5.7.1 and5.7.3), such as tariff time change, Quality of Service (QoS)change or closing the CDR. Change time is a time stampwhich defines the moment when the new volume countsare started or the CDR is closed. All the active PDPcontexts do not need to have exactly the same time stamp(e.g. due to same tariff time change variance of the timestamps is implementation and traffic load dependent and isout of the scope of standardization). The first containercan include the following optional fields: QoS Requested(not in G-CDR) and QoS Negotiated. In the containersthat follow, QoS Negotiated is present if previous changecondition is QoS change. For more information, see 12.15page 28.RecordM (S-CDR/G-This field contains the time stamp of when the record isOpeningCDR)opened (see GSM 12.05 for exact format). Record openingTimereason does not have a separate field. For G-CDR and M-CDR, it can be derived from the field “Sequence number”i.e. missing field or value one means activation of PDPcontext and GPRS attachment. For the S-CDR, the field“SGSN change” also needs to be taken into account.DurationM (S-CDR/G-This field contains the relevant duration in seconds forCDR)PDP contexts (S-CDR, G-CDR, and attachment (M-CDR)). For partial records, this is the duration of theindividual partial record and not the cumulative duration.It should be noted that the internal time measurements maybe expressed in terms of tenths of seconds or evenmilliseconds and, as a result, the calculation of the durationmay result in the rounding or truncation of the measuredduration to a whole number of seconds. Whether or notrounding or truncation is to be used is considered to beoutside the scope of this Specification subject to thefollowing restrictions: A duration of zero seconds shall beaccepted providing that the transferred data volume isgreater than zero. The same method oftruncation/rounding shall be applied to both single andpartial records.SGSNC (S-CDR)This field is present only in the S-CDR to indicate that thisChangeis the first record after an inter-SGSN routing area update.Cause forM (S-CDR/G-This field contains a reason for the release of the CDRRecordCDR)including the following: normal release - PDP contextClosingrelease or GPRS detach; partial record generation - datavolume limit, time (duration) limit, SGSN change ofmaximum number of changes in charging conditions;abnormal termination (PDP or MM context); andmanagement intervention (request due to O&M reasons).A more detailed reason may be found in the diagnosticsfield.DiagnosticsO (S-CDR/G-This field includes a more detailed technical reason for theCDR)release of the connection and may contain one of thefollowing: a MAP error from GSM 09.02; or a Cause fromGSM 04.08. The diagnostics may also be extended toinclude manufacturer and network specific information.098i/8h.RecordC (S-CDR/G-This field contains a running sequence number employedSequenceCDR)to link the partial records generated in the SGSN/GGSNNumberfor a particular PDP context (characterized with same theCharging ID and GGSN address pair). In the S-CDR, thesequence number is always started from one after inter-SGSN routing area update (see field “SGSN change”). TheRecord Sequence Number is missing if the record is theonly one produced in the SGSN/GGSN for the PDPcontext (e.g. inter-SGSN routing area update can result totwo S-CDRs without sequence number and field “SGSNupdate” present in the second record).Node IDO (S-CDR/G-This field contains an optional operator configurableCDR)identifier string for the node which generated the CDR.RecordO (S-CDR/G-The field enables network operators and/or manufacturersExtensionsCDR)to add their own extensions to the standard recorddefinitions. This field contains a set of “managementextensions” as defined in CCITT X.721.Local RecordO (S-CDR/G-This field includes a unique record number created by thisSequenceCDR)node. The number is allocated sequentially including allNumberCDR types. The number is unique within one node, whichis identified either by field Node ID or by record dependentnode address (SGSN address, GGSN address, RecordingEntity). The field can be used to identify missing recordsin post processing system.Access PointM (S-CDR)This field contains the logical APN used to determine theName OIactual connected access point. The APN is comprised of amandatory network identifier and an optional operatoridentifier (this field is the operator identifier). APN canalso be a wildcard, in which case SGSN selects the accesspoint address. (see GSM 09.60 and GSM 03.60 for moreinformation about APN format and access point decisionrules.) The APN is information from the MS or SGSN,that may be used by the GGSN to differentiate betweenaccesses to different external packet data networks usingthe same PDP Type.


RADIUS Accounting Method


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 a user identifier that links the RADIUS accounting record to a particular user. Listed below is a table with the RADIUS attributes.

TABLE 2RADIUS Accounting RecordRADIUS ElementDescriptionNAS-IP-AddressThis attribute indicates the identifying IP address of the server whichis requesting authentication of the user. This attribute may be presentif NAS-Identifier is not present. This attribute is configurable at theWSP.NAS-Port-TypeThis attribute indicates the type of the physical port of the NAS whichis authenticating the user. It is only used in Access-Request packets.The value of the NAS-Port-Type is 19 to represent 802.11.User-NameThis attribute indicates the name of the user to be authenticated. Thisis the user credential collected from the web login page.Framed-IP-AddressThis attribute indicates the IP address assigned to the user.Acct-Session-IDThis attribute is a unique Accounting ID to make it easy to match startand stop records in a log file. The start, stop, and interim records for agiven session have the same Acct-Session-Id. An Accounting-Request message has an Acct-Session-Id. This attribute is generatedby the WSP when it sends Accounting Request (Acct-Status-Type = Start) message.Acct-Status-TypeThis attribute indicates whether this Accounting Request marks thebeginning of the user service (Start), interim (Interim), or the end(Stop). The WSP supports the following values: Start; Stop; andInterim.Acct-Terminate-This attribute indicates how the session was terminated, and can onlyCausebe present in Accounting-Request records where the Acct-Status-Typeis set to Stop. The WSP supports the following values: SessionTimeout (5); User Request (1); Lost Service (3); Lost Carrier (2); andNAS Reboot (11). ‘Session Timeout’ indicates that the expiry ofSession-Timeout values received in Accounting Request (Acct-Status-Type = Stop). ‘User Request’ indicates the user has logged out. ‘LostService’ indicates there was a problem communicating with theRADIUS server or RADIUS accounting server. ‘Lost Carrier’indicates that the server is no longer able to communicate with thesubscriber. ‘NAS Reboot’ indicates that the server has encountered acommunication problem with internal software modules.Event-TimestampThis attribute is included in an Accounting Request message to recordthe time that this event occurred on the NAS, in seconds since Jan.1, 1970 00:00 UTC.Acct-Input-OctetsThis attribute indicates how many octets have been received from theport over the course of this service being provided, and is sent inAccounting-Request records where the Acct-Status-Type is set to Stopor Interim.Acct-Output-OctetsThis attribute indicates how many octets have been sent to the port inthe course of delivering this service, and is sent in Accounting-Request records where the Acct-Status-Type is set to Stop or Interim.Acct-Input-PacketsThis attribute indicates how many packets have been received fromthe port over the course of this service being provided to a FramedUser, and is sent in Accounting-Request records where the Acct-Status-Type is set to Stop or Interim.Acct-Output-PacketsThis attribute indicates how many packets have been sent to the portin the course of delivering this service to a Framed User, and is sent inAccounting-Request records where the Acct-Status-Type is set to Stopor Interim.Acct-Session-TimeThis attribute indicates how many seconds the user has receivedservice, and can only be present in Accounting-Request records wherethe Acct-Status-Type is set to Stop or Interim.Acct-Delay-TimeThis attribute indicates how many seconds the client has been tryingto send the accounting message, and can be subtracted from the timeof arrival on the server to find the approximate time of the eventgenerating this Accounting Request message. (Network transit time isignored.) It is sent in all Accounting Request message.ClassThis attribute is available to be sent by the server to the client in anAccess Accept message, and is sent unmodified by the client to theaccounting server as part of the Accounting Request message ifaccounting is supported.VSA (VendorThis Attribute is available to allow vendors to support their ownSpecific Attribute)extended Attributes not suitable for general usage. However, thisattribute must not affect the operation of the RADIUS protocol.Servers not equipped to interpret the vendor-specific information sentby a client should ignore it (although it may be reported). Clientswhich do not receive desired vendor-specific information should makean attempt to operate without it, although they may do so (and reportthey are doing so) in a degraded mode.


The system and method of the present embodiments use RADIUS accounting records to trigger GPRS CDR generation for those WLAN users that do have a GPRS account and use RADIUS messaging. The system of the present embodiment maps the parameters generated for a RADIUS Accounting-Request to a CDR. However, the CDR generation triggers are modified.


Referring to FIG. 3, one embodiment of a message dialog is shown which depicts CDR generation triggers and transmission of CDRs. The participants in the message flow are the AP 102, the WSP 104 filling the role of RADIUS Proxy (meaning the WSP is providing the services of a RADIUS Server), and a CG 210. The AP 102 may be any vendor's device which is requesting RADIUS services of the WSP 104. The message dialog begins with the AP 102 sending a RADIUS Access Request message 300 to the WSP 104. The WSP 104 responds by returning a RADIUS Access Accept message 302 to the AP 102. The AP 102 sends a RADIUS Accounting Status (start) message 304 to the WSP 104. The WSP 104 responds to this RADIUS Accounting Status (start) message 304 by generating a GSM accounting record—a Call Detail Record (CDR)—from the RADIUS accounting information contained in the RADIUS Accounting Status (start) message 304. The WSP 104 sends this CDR message 308 to the CG 210. The WSP may be configured to periodically send additional CDRs on to the CG 210 during the course of the association between the AP 102 and the WSP 104. At some later time the AP 102 sends a RADIUS Accounting Status (interim) message 310 to the WSP 104. The WSP 104 responds to this RADIUS Accounting Status (interim) message 310 by generating a CDR from the RADIUS accounting information contained in the RADIUS Accounting Status (interim) message 310 and sends this CDR message 312 on to the CG 210. The AP may periodically send additional RADIUS Accounting Status (interim) messages to the WSP 104, and on these events the WSP 104 will generate a CDR from the accounting information contained in these RADIUS Accounting Status (interim) message and send this CDR on to the CG 210. At the end of the association between the AP 102 and the WSP 104, the AP 102 sends a RADIUS Accounting Status (stop) message 314 to the WSP 104. The WSP 104 responds to this RADIUS Accounting Status (stop) message 314 by generating a CDR from the RADIUS accounting information contained in the RADIUS Accounting Status (stop) message 314 and sends this CDR message 316 on to the CG 210.


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 WSP 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.

TABLE 3Correlation of RADIUS elements to CDRdynamically from RADIUS Messages.RADIUSGPRS CDRElementDescriptionElementDescriptionNetworkThis attribute indicates theN/AN/AAccessidentifying IP address of theServerserver which is requesting(NAS)-IP-authentication of the user.AddressThis attribute must bepresent if NAS-Identifier isnot present. This attribute isconfigurable at the WSP.NAS-Port-This attribute indicates theN/AN/ATypetype of the physical port ofthe NAS which isauthenticating the user. It isonly used in Access-Requestpackets. The value of theNAS-Port-Type is populatedas 19 to represent 802.11.User-NameThis attribute indicates theServed IMSIThis fields contains thename of the user to beIMSI of the served party.authenticated. This is theThe Client “served party”user credential collectedis used to describe thefrom the web login page.mobile subscriberinvolved in the transactionrecorded (e.g. the callingsubscriber in case of amobile initiated PDPcontext).Framed-IP-This attribute indicates theServed PDPThis field contains theAddressIP address assigned to theAddressPDP address of the serveduser.IMSI. This is a networklayer address (e.g. of typeIP version 4, or IP version6).Acct-This attribute is a uniqueCharging IDThis field is a chargingSession-IDAccounting ID to make itidentifier which can beeasy to match start and stopused together with GGSNrecords in a log file. Theaddress to identify allstart, stop, and interimrecords produced in therecords for a given sessionSGSN(s) and the GGSNhave the same Acct-Session-involved in a single PDPId. An Accounting-Requestcontext. Charging ID ismessage has an Acct-generated by the GGSN atSession-Id. This attribute isPDP context activationgenerated by the WSP whenand transferred to ait sends an Accountingcontext requesting SGSN.Request (Acct-Status-At inter-SGSN routingType = Start) message.area updates, the chargingID is transferred to thenew SGSN as part of eachactive PDP context.Acct-This attribute indicatesN/AN/AStatus-Typewhether this AccountingRequest marks the beginningof the user service (Start),interim (Interim), or the end(Stop). The WSP supportsthe following values: Start;Stop; and Interim.Acct-This attribute indicates howCause forThis field contains aTerminate-the session was terminated,Recordreason for the release ofCauseand can only be present inClosing/Diagnosticthe CDR including theAccounting-Request recordsfollowing: normal release —where the Acct-Status-TypePDP context release oris set to Stop. The WSPGPRS detach; partialsupports the followingrecord generation —datavalues: Session Timeout (5);volume limit, timeUser Request (1); Lost(duration) limit, SGSNService (3); Lost Carrier (2);change of maximumand NAS Reboot (11).number of changes in‘Session Timeout’ indicatescharging conditions;that the expiry of Session-abnormal terminationTimeout values received in(PDP or MM context);Accounting Request (Acct-and managementStatus-Type = Stop). ‘Userintervention (request dueRequest’ indicates the userto O&M reasons).has logged out. ‘LostA more detailed reasonService’ indicates there wasmay be found in thea problem communicatingdiagnostics field.with the RADIUS server orRADIUS accounting server.‘Lost Carrier’ indicates thatthe server is no longer ableto communicate with thesubscriber. ‘NAS Reboot’indicates that the server hasencountered acommunication problemwith internal softwaremodules.Event-This attribute is included inRecordThis field contains theTimestampan Accounting RequestOpeningtime stamp when themessage to record the timeTimerecord is opened (seethat this event occurred onGSM 12.05 for exactthe NAS, in seconds sinceformat).Jan. 1, 1970 00:00 UTC.Acct-Input-This attribute indicates howList ofThis list includes one orOctetsmany octets have beenTraffic Datamore containers, whichreceived from the port overVolumes:each include the followingthe course of this serviceData Volumefields: Data Volumebeing provided, and is sentDownlinkUplink, Data Volumein Accounting-RequestDownlink, Changerecords where the Acct-Condition and TimeStatus-Type is set to Stop orStamp. Data VolumeInterim.includes the number ofoctets transmitted duringthe use of packet dataservices.Acct-This attribute indicates howList ofThis list includes one orOutput-many octets have been sentTraffic Datamore containers, whichOctetsto the port in the course ofVolumes:each include the followingdelivering this service, andData Volumefields: Data Volumeis sent in Accounting-UplinkUplink, Data VolumeRequest records where theDownlink, ChangeAcct-Status-Type is set toCondition and TimeStop or Interim.Stamp. Data Volumeincludes the number ofoctets transmitted duringthe use of packet dataservices.Acct-Input-This attribute indicates howN/AN/APacketsmany packets have beenreceived from the port overthe course of this servicebeing provided to a FramedUser, and is sent inAccounting-Request recordswhere the Acct-Status-Typeis set to Stop or Interim.Acct-This attribute indicates howN/AN/AOutput-many packets have been sentPacketsto the port in the course ofdelivering this service to aFramed User, and is sent inAccounting-Request recordswhere the Acct-Status-Typeis set to Stop or Interim.Acct-This attribute indicates howDurationThis field contains theSession-many seconds the user hasrelevant duration inTimereceived service for, and canseconds for PDP contextsonly be present in(S-CDR, G-CDR). ForAccounting-Request recordspartial records, this is thewhere the Acct-Status-Typeduration of the individualis set to Stop or Interim.partial record and not thecumulative duration.Acct-Delay-This attribute indicates howN/AN/ATimemany seconds the client hasbeen trying to send theaccounting message, and canbe subtracted from the timeof arrival on the server tofind the approximate time ofthe event generating thisAccounting Requestmessage. (Network transittime is ignored.) It is sent inall Accounting Requestmessage.VSAThis Attribute is available toN/AN/Aallow vendors to supporttheir own extendedAttributes not suitable forgeneral usage. However,this attribute must not affectthe operation of theRADIUS protocol. Serversnot equipped to interpret thevendor-specific informationsent by a client ignore it(although it may bereported). Clients which donot receive desired vendor-specific information shouldmake an attempt to operatewithout it, although theymay do so (and report theyare doing so) in a degradedmode.ClassThis attribute is available toN/AN/Abe sent by the server to theclient in an Access Acceptmessage, and SHOULD besent unmodified by the clientto the accounting server aspart of the AccountingRequest message ifaccounting is supported.


The parameters that the Access Point generates internally or read from the configuration file are listed below in Table 4 along with the source information.

TABLE 4Source of the CDR elements that cannot bederived from RADIUS messagesPresenceM = MandatoryC = ConditionalFieldO = OptionalDescriptionRecordM (S-CDR/G-CDR)The field identifies the type of the record e.g. S-CDR,TypeG-CDR, M-CDR, S-SMO-CDR and S-SMT-CDR.GGSNM (S-CDR/G-CDR)The IP address of the GGSN used.AddressSGSNM (S-CDR/G-CDR)The IP address of the SGSN.AddressRoutingRouting Area at the time of the record creation.AreaLocal AreaO (S-CDR)Location area code at the time of the record creation.CodeCellO (S-CDR)Cell ID at the time of the record creation.IdentityGGSNM (S-CDR)The IP address of the GGSN currently used. TheAddressGGSN address is always the same for an activatedUsedPDP.AccessM (S-CDR/G-CDR)This field contains the logical APN used to determinePointthe actual connected access point. APN comprises ofNameNImandatory network identifier and optional operatoridentifier (This field is the network identifier). APNcan also be a wildcard, in which case SGSN selectsthe access point address. See GSM 09.60 and GSM03.60 for more information about APN format andaccess point decision rules. The APN is informationfrom the MS or SGSN, that may be used by theGGSN to differentiate between accesses to differentexternal packet data networks using the same PDPType.APNO (S-CDR/G-CDR)This field indicates how the SGSN selected the APNSelectionto be used. The values and their meaning are asModespecified in GSM 09.60 clause 7.9 ‘Informationelements’.PDP TypeM (S-CDR/G-CDR)This field defines the PDP type, e.g. X.25, IP, PPP, orIHOSS:OSP (see GSM 09.60 for exact format).DynamicC (G-CDR)This field indicates that PDP address has beenAddressdynamically allocated for that particular PDP context.FlagField is missing if address is static (e.g. part of PDPcontext subscription). Dynamic address allocationmight be relevant for charging (e.g. the duration ofPDP context as one resource offered and possiblyowned by network operator).Node IDO (S-CDR/G-CDR)This field contains an optional operator configurableidentifier string for the node which generated theCDR.LocalO (S-CDR/G-CDR)This field includes a unique record number created byRecordthis node. The number is allocated sequentiallySequenceincluding all CDR types. The number is uniqueNumberwithin one node, which is identified either by fieldNode ID or by record dependent node address (SGSNaddress, GGSN address, Recording Entity). The fieldcan be used to identify missing records in a postprocessing system.AccessO (S-CDR)This field contains the logical APN used to determinePoint Namethe actual connected access point. APN comprises ofOImandatory network identifier and optional operatoridentifier (this field is the operator identifier). APNcan also be a wildcard, in which case SGSN selectsthe access point address. See GSM 09.60 and GSM03.60 for more information about APN format andaccess point decision rules. The APN is informationfrom the MS or SGSN, that may be used by the GGSNto differentiate between accesses to different externalpacket data networks using the same PDP Type.RecordC (S-CDR/G-CDR)This field contains a running sequence numberSequenceemployed to link the partial records generated in theNumberSGSN/GGSN for a particular PDP context(characterized with same the Charging ID and GGSNaddress pair). In the S-CDR, the sequence number isalways started from one after inter-SGSN routing areaupdate, see field “SGSN change”. The RecordSequence Number is missing if the record is the onlyone produced in the SGSN/GGSN for the PDP context(e.g. inter-SGSN routing area update can result to twoS-CDRs without sequence number and field “SGSNupdate” present in the second record).


Using both tables 3 and 4, the system of the present embodiments creates the new combined RADIUS/GPRS CDRs for the SIM users that utilize the RADIUS accounting and that also conform with the GPRS accounting format.


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.

Claims
  • 1. A system for providing accounting for a wireless network, the system including: an access point connectable to a mobile client; a wireless integrated node connected to the access point and configured for providing and mapping between two different communication protocols; and a link for connecting the wireless integrated node to a charging gateway and further to an accounting system, wherein the accounting system provides a bill for usage of the wireless network by the mobile client; wherein the first communication protocol is of a format required by the wireless network and the second communication protocol is of a format required by the accounting system.
  • 2. The system of claim 1 wherein the wireless integrated node includes means for generating a call detail record for use with the second communication protocol.
  • 3. The system of claim 2 wherein the generating means maps RADIUS elements to the call detail record.
  • 4. The system of claim 3 wherein the generation means is triggered by receiving a RADIUS Accounting Status (start) message at the wireless integrated node.
  • 5. The system of claim 3 wherein the generation means is triggered by receiving a RADIUS Accounting Status (interim) message at the wireless integrated node.
  • 6. The system of claim 3 wherein the generation means is triggered by receiving a RADIUS Accounting Status (stop) message at the wireless integrated node.
  • 7. A method for generating call detail records in a format used with a mobile network for a client having an account with the mobile network and using a wireless local area network, the method comprising: receiving a RADIUS start message from an access point; generating a first Call Detail Record (CDR) from accounting information contained in the RADIUS start message; and sending the first CDR message to a charging gateway associated with the mobile network.
  • 8. The method of claim 7 wherein the mobile network is a GPRS network and the charging gateway is capable of forwarding the first CDR to an accounting system of the GPRS network.
  • 9. The method of claim 7 further comprising: periodically sending additional CDRs to the charging gateway during the course of the association with the access point.
  • 10. The method of claim 7 further comprising: receiving a RADIUS interim message from the access point; generating a second CDR from accounting information contained in the RADIUS interim message; sending the second CDR to the charging gateway.
  • 11. The method of claim 10 further comprising: continually receiving additional RADIUS interim messages; generating additional CDRs from accounting information contained in the additional RADIUS interim messages; and sending the additional CDRs to the charging gateway.
  • 12. The method of claim 7 further comprising: receiving a RADIUS stop message from the access point; generating a stop CDR from accounting information contained in the RADIUS stop message; and sending the stop CDR message to the charging gateway.
  • 13. The method of claim 7 wherein the step of generating the first CDR includes: obtaining some parameters for the first CDR from the account information contained in the RADIUS start message in real time; and internally generating other parameters for the first CDR from a configuration file.
  • 14. An authentication server comprising: a first link connected to an authenticator associated with a Wireless Local Area Network (WLAN); a second link connected to a gateway associated with a mobile network; and a mapping system including instruction for receiving one or more first messages from the authenticator, the first messages being of a first type associated with the WLAN but not the mobile network; generating a first group of one or more call detail records from the received first messages, the call detail records being of a second type associated with the mobile network; and sending the first group of call detail records to the gateway.
  • 15. The authentication server of claim 14 wherein the one or more first messages are associated with a client of the WLAN and the mapping system further comprises instructions for periodically sending additional call detail records to the charging gateway while the client is using the WLAN.
  • 16. The authentication server of claim 14 wherein the mapping system further comprises instructions for receiving one or more second messages of the first type from the access point; generating a second group of one or more CDRs from accounting information contained in the one or more second messages; and sending the second group of one or more CDRs to the charging gateway.
  • 17. The authentication server of claim 16 wherein the mapping system further comprises instructions for receiving one or more third messages of the first type from the access point; generating a third group of one or more CDRs from accounting information contained in the one or more third messages; and sending the third group of one or more CDRs to the charging gateway.
  • 18. The authentication server of claim 14 whereby the charging gateway is configured for forwarding the first group of one or more of the CDRs to an accounting system of the mobile network.
  • 19. The authentication server of claim 14 further comprising a configuration file and wherein the instructions for generating a first group of one or more call detail records includes instructions for obtaining some parameters from the account information contained in the one or more first messages in real time and instruction for internally generating other parameters from the configuration file.
  • 20. The authentication server of claim 14 wherein the mobile network is a packet data network.
RELATED APPLICATION

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.