Title of Invention	A METHOD, A USER TERMINAL AND SERVER FOR OBTAINING ACCESS LOCATION INFORMATION OF AN ACCESS NETWORK
Abstract	A method of a user terminal obtaining its access location information in next generation network, and a user terminal, and a server having function of Dynamic Host Configuration Protocol (DHCP) function are disclosed. DHCP is extended by adding a new DHCP option to carry the user terminal access location information; when the user terminal accesses to network, DHCP server puts the DHCP option into DHCP response message; receiving the DHCP response message, the user terminal obtains the access location information from the DHCP option. The present invention overcomes the shortcoming of the prior art that when a terminal nomadizes or roams from one access network to another, the access network information configured on the terminal has to be updated manually and thus results in redundant workload and inflexibility, the user terminal is allowed to obtain its access location information automatically, hence nomadicity or roaming of the user terminal is supported.

Title of Invention

A METHOD, A USER TERMINAL AND SERVER FOR OBTAINING ACCESS LOCATION INFORMATION OF AN ACCESS NETWORK

Abstract

A method of a user terminal obtaining its access location information in next generation network, and a user terminal, and a server having function of Dynamic Host Configuration Protocol (DHCP) function are disclosed. DHCP is extended by adding a new DHCP option to carry the user terminal access location information; when the user terminal accesses to network, DHCP server puts the DHCP option into DHCP response message; receiving the DHCP response message, the user terminal obtains the access location information from the DHCP option. The present invention overcomes the shortcoming of the prior art that when a terminal nomadizes or roams from one access network to another, the access network information configured on the terminal has to be updated manually and thus results in redundant workload and inflexibility, the user terminal is allowed to obtain its access location information automatically, hence nomadicity or roaming of the user terminal is supported.

Full Text	Field of The Invention This invention relates to communication technology, particularly to a method, a user terminal and a server for obtaining access location information. Background of The Related Art Currently, ITU-T and ETSI, respectively as international and European telecommunication standards organizations, are developing network architecture of NGN (Next Generation Network). The ETSI TISPAN NGN architecture is shown in Fig. 1. Based on this NGN architecture, NGN can be divided into three main parts: service control and applications part, the network bearing part, and terminal part, and the functions of the three main parts are respectively described as follows. Service control and applications system, including IP multimedia subsystem (IMS), PSTN/ISDN emulation subsystem, stream media subsystem, completes service control function of various applications and provides various services. Network bearing system, includes the following subsystems: (1) Network Attachment Subsystem (NASS): completes authentication and authorization, address allocation, user location information management and terminal configuration in the network access layer; (2) Resources and Admission Control Subsystem (RACS): completes functions of transport network resources control, distribution, and management based on service requirement, and guarantees quality of service; (3) Transport Subsystem: under control of the above subsystems, completes transportation of various kinds of network datagram; includes the Access Transport Network and Core Transport Network shown in the figure. User terminal: includes various NGN terminals and user family network equipments, comprising family gateway, IAD (Integrated Access Equipment), STB (Set Top Box), Video-Phone, PC, WiFi (Wireless Fidelity) handset etc. Network Attachment Subsystem (NASS) is shown in Fig. 2, including the following functional entities: (1) AMF-- Access Management Function. (2) NACF—Network Access Configuration Function, is generally implemented as a DHCP server (Dynamic Host Configuration Protocol server) for DHCP access. (3) CLF—Connectivity Session Location and Repository Function, provides interface from CLF to service system. (4) UAAF—User Access Authorized Function. (5) PDBF—Profile Data Base Function. (6) CDCF—Client Devices Configuration Function. In the NGN architecture, by introducing NASS and RACS, the difference between the transport subsystems in the underlayer is covered, and a uniform standard interface is provided upwardly. Based on this architecture, service can be separated from access, that is, NGN service providers do not need to pay attention to the detailed differences between underlayer transport subsystems, but only need to provide a standard interface for connecting to access network operator; and access network operators do not need to concern how to provide detailed NGN service either, but only need to provide a standard interface through NASS and RACS, and then NGN service providers can provide NGN service with QOS guarantee using resources of transport networks. Thus, a service system can serve a number of different broadband access networks (a service system can be a service control and application subsystems, or a specific network application, such as IMS(IP Multimedia System), IPTV (IP Television system), or a network game), that is, a user can access a network through different access network operators, and nomadizes or roams among multiple access networks (nomadicity means that a network user switches from a network to another network and the service is interrupted during switching; while in roaming, service is uninterrupted during switching; roaming is usually applied in mobile networks while nomadicity is applied in fixed or semi-mobile networks such as WiFi, DSL applications). The architecture for terminals accessing a service system through different access networks is shown in Fig. 3, wherein a user can obtain corresponding service no matter through which access network. Thus it requires that, when the user registers to service system or submits service request, service system can obtain relevant information of the user from NASS of the user's access network, apply and reserve network bandwidth/QOS resource through RACS of the access network, so as to ensure effective services. Because users can roam across a number of access networks, service operators need to know the location information (visiting location information) of their users. Through obtaining the information, the service system can control QOS precisely, and provide different fee charge strategies (local, long-distance and roaming) and location information services etc. However, the problem is that, a terminal usually does not know its own access location information when it accesses a network. Because the terminal directly registers to or requests service from a service system, the process is transparent to the access network, when the terminal registers to a service system, the service system does not know what network the user is accessing if the access location information cannot be carried by the user terminal, the service system of course does not know from which network to get the user's relevant information and consequently cannot implement the corresponding QOS control. The solution in prior art is that the access network information is configured on the terminal in advance, and the terminal registers the information to a service system at the time of accessing to the service system, then based on the information, the service system can retrieve the user's information from corresponding access network and implement QOS control. However, the prior art does not support terminal nomadizing or roaming, so that the access network configured on the terminal has to be updated manually when the terminal nomadizes or roams from one access network to another, which results in redundant workload and inflexibility. Summary of The Invention It is an object of the present invention to provide a method of obtaining access location information and the corresponding user terminal and server, so that the user terminal can automatically obtain its access location information. The invention may overcome the shortcoming of the prior art that the access network information configured on the terminal cannot be updated automatically when the terminal nomadizes or roams from one access network to another. A method of obtaining access location information according to the present invention comprises the following steps: extends Dynamic Host Configuration Protocol (DHCP) by adding a new DHCP option or redefine an existing option, the DHCP option being utilized to carry the access location information of the user terminal; when the user terminal accesses a network and sends a request, the server puts the DHCP option into a response message; and the user terminal receives the DHCP option and obtains the access location information from the DHCP option. The user terminal first requests the server to provide the access location information of the user terminal through a DHCP Discover message, a DHCP Request message or a DHCP Inform message, and then the server returns the user terminal the DHCP response message carrying the DHCP option. The DHCP response message may be a DHCP offer message or DHCP Ack message. the access location information carried by the DHCP option comprises one or more items of the following: the access operator identifier, the user access network identifier, identifier or address of the Network Attachment Subsystems in the user access network, identifier or address of the Connectivity Session Location and Repository Function of the user access network, identifier or address of broadband remote access server to which the user accesses, identifier or addresses of access equipments to which the user access, identifiers of the physical line and logical link to which the user access. The DHCP option comprises at least a type field and a content field, the type filed indicating it is the location information that is carried in the DHCP option, and the content field carrying the user terminal access location information. The user terminal can request its access location information through a DHCP Discover message, the server answers the request from the user terminal with a DHCP Offer message in which the DHCP option is carried; Alternatively, the user terminal may request the access location information through a DHCP Request message or a DHCP Inform message, the server answers the request from the terminal with a DHCP Ack message in which the DHCP option is carried. A user terminal according to the invention comprises: an access location information acquiring module, and an access location information processing module, the access location information acquiring module receiving the DHCP datagram carrying the access location information sent from the server, obtaining the access location information from the option in the DHCP datagram, and sending the information to the access location information processing module; the access location information processing module preserving the access location information for using the information at the time of registering to service system or requesting service. A server for providing access location information of user terminal, the server comprising: An access location information processing module for preserving the user access location information for configuring the access location information on the user terminal; A DHCP access location information transmitting module for putting the access location information, which is preserved by access location information processing module, into the access location information option in the DHCP datagram sent to the user terminal, and transmitting the information to the corresponding user terminal. In the prior art, when a terminal nomadizes or roams from one access network to another, the access network information configured on the terminal has to be updated manually which results in redundant workload and inflexibility. In the solution of the present invention, DHCP is extended by adding a new DHCP option carrying user access location information. Without change to the network topology and configuration on the user terminal, the user terminal can automatically obtain its access location information by requesting message when it accesses the network. Alternatively, the-request may not be needed, for the DHCP server can directly put the new added DHCP option in a DHCP response message and sent it to the user terminal. The user terminal can register the information to the service system, and thus ensure that the service system can obtain access location information of the terminal. This invention allows user terminal to obtain the current access location information when it accesses to different networks or different locations in the same network, hence nomadicity or roaming of user terminals is supported. Brief Description of The Drawings Fig. 1 is a schema view of NGN network architecture; Fig. 2 is a schema view of the Network Attachment Subsystem; Fig. 3 is a schema view of user terminals accessing a service system through different access networks; Fig. 4 is a flow chart of standard DHCP interaction; Fig. 5 is a flow chart of the user terminal obtaining the location information and submitting to service system according to an embodiment of the present invention; Fig. 6 is a schema view of the modules of the user terminal for implementation of the method according to an embodiment of the present invention; Fig. 7 is a schema view of modules of the equipment implementing function of DHCP server for implementation of the method according to an embodiment of the present invention. Detailed Description of The Preferred Embodiment Hereafter, preferred embodiments according to the present invention will be described in detail with reference to the drawings. DHCP (Dynamic Host Configuration Protocol) is a network protocol to configure relevant network parameters dynamically for users by adopting a mechanism which automates the assignment of related information to client. When a client accesses the system, the server can provide the client with the network configuration information including IP address, gateway, DNS server, etc. Client retrieves the information from the DHCP server. In a large integrated network, DHCP is a protocol frequently used for users to access the network, by which the server can automatically configure network parameters such as IP address, etc. The following example in which a user communicates with a server using DHCP, describes the method of obtaining access information and the corresponding equipments according to an embodiment of the invention. The standard DHCP interaction flow chart is shown in Fig. 4, when a terminal accesses a network, it obtains information such as IP address, subnet mask, DNS etc. through DHCP, and this process is performed upon a request from the terminal to the DHCP server (NASS component). The user terminal requests the DHCP server through DHCP Discover message, DHCP Request message or DHCP Inform message, the DHCP server returns DHCP Offer message and DHCP Ack message to the user terminal. DHCP datagram can carry various DHCP options, and these options can carry various information, such as DNS server, SIP server, etc. According to an embodiment of the present invention, DHCP is extended by adding a new DHCP option to carry access location information of the user terminal (or reuse an existing option, which means not define a new option but redefine an existing DHCP option), and the user terminal and network equipment having function of DHCP server can support the DHCP option. The option contains a dedicated code field, i.e., a type field, through which the user terminal can obtain the location information/visiting location information from network. The format of the DHCP option is shown as following: The CODE field defines the type, indicating the option is for carrying the user terminal access location; Length defines the length of the option; the access location information of the user terminal is carried in the Content field of the option. The user access location information that can be carried in the DHCP option can be all or some of the following sub-options: 1. The access network operator identifier, for example "China telecom". 2. The user access network identifier, which can include the operator's information, and physical region information etc, for example "China Telecom Beijing DSLR101". 3. The identifier or address of the user access network's Network Attachment Subsystem (NASS), for example "China Telecom NASS 001" or "212.100.010.001". 4. The identifier or address of Connectivity Session Location and Repository Function (CLF) in the user access network, for example "China Telecom CLF 001" or "212.100.011.001". 5. The identifier or address of Broadband Remote Access Server (BRAS) to which the user access, for example "Beijing BRAS001" or "212.100.100.001". 6. The identifier or address of the access equipment to which the user access, for example "Beijing DSLAM1001" or "212.100.101.001". 7. The identifier of the physical line and logical link to which the user access, for example "Beijing DSLAM1001 eth 0/1/0/1:100" or "Beijing BRAS001 atm 0/1/0/1:0.35". According to the standard DHCP interaction process described previously, only by transmitting DHCP Offer and/or DHCP Ack message carrying the option to the user terminal, the DHCP server can send the terminal's access location information/visiting location information to the user terminal. Fig. 5 shows the flow chart of the user terminal obtaining location information and submitting it to service system according to an embodiment of the present invention. The DHCP option is handled as following: 1) The DHCP Server issues DHCP Offer and DHCP Ack messages carrying the new added DHCP option according to an embodiment of the present invention, the DHCP option carrying the user access location information which may include the user access location information sub-options as previously described. 2) The user terminal receives the DHCP Offer or DHCP Ack message carrying the DHCP option, and obtains the access location information. Since the access location information may contain a plurality of sub-options, the terminal can obtain all or some of these sub-options as desired. 3) The user terminal can register the information to service system; therefore ensure the service system can obtain the user terminal access location information. The user terminal can request the option defined in the invention through a DHCP Discover message, the DHCP server answers the terminal's request with a DHCP Offer message carrying the user access location information in the DHCP option defined in the invention. The terminal can also request the option defined in the invention through a DHCP Request or a DHCP Inform message, the DHCP server answers the terminal's request with a DHCP Ack message carrying the user access location information in the DHCP option defined in the invention. During the DHCP interaction process, the network equipment implementing DHCP Relay function (for example, Broadband Remote Access Server (BRAS) or Digital Subscriber Line Access Multiplexer (DSLAM)) handles the DHCP datagram with the DCHP option in the same way as handling DHCP datagram without the DHCP option. The network equipment does not alter the DHCP option when handling the datagram. According to an embodiment of the present invention, DHCP is extended by adding a new DHCP option to carry user terminal access location information. Without change to the network topology and configuration on the user terminal, the user terminal can automatically obtain its access location information by requesting message when it accesses the network. Alternatively, the request may not be needed, for the DHCP server can directly put the new added DHCP option in a DHCP Offer or a DHCP Ack message and sent it to the user terminal. The user terminal can register the information to the service system, and thus ensure that the service system can obtain access location information of the terminal. This invention allows user terminal to obtain the current access location information when it accesses to different networks or different locations in the same network, hence nomadicity or roaming of user terminals is supported. To implement the method according to the present invention, a user terminal and an equipment implementing function of DHCP server are also provided. Fig. 6 illustrates the modules of the user terminal for implementation of the method according to an embodiment of the present invention, wherein the user terminal comprises: a DHCP access location information acquiring module; and an access location information processing module, the DHCP access location information acquiring module receiving DHCP datagram carrying the access location information from a DHCP server or other equipment implementing function of DHCP server, obtaining the access location information from the option in the DHCP datagram, and then sending the information to the location information processing module; the access location information processing module locally preserving the access information for using the information at the time of registering to server system or requesting service. Fig. 7 illustrates the modules of the equipment having function of DHCP server for implementation of the method according to an embodiment of the present invention, wherein the equipment comprises: an access location information processing module for preserving the user access location information for configuring the access information on the user terminal; an access location information transmitting module for putting the access location information, which is preserved by the access location information processing module, into the access location information option in the DHCP datagram sent to the user and transmitting the information to the corresponding user terminal. If the network equipment supports embedded DHCP server function, then the equipment can implement the same functions as an independent DHCP server. The invention provides a method of a user terminal obtaining its access location information, the user terminals and the network equipment in next generation network. The above-described is only preferred embodiments of the present invention, and the scope of the present invention is not limited thereto. Modifications and alterations are easily imaged by those skilled in the art within the technical scope disclosed in the present invention, and should come within and protected by the scope of the present invention as set by the appended claims and its equivalents. WE CLAIM: 1. A method of obtaining access location information of an user access network, through which a user terminal accesses a service system, the access network comprising Network Attachment Subsystem, NASS, and Resource and Admission Control Subsystem, RACS, to provide a uniform standard interface to the service system, the method comprising: receiving a Dynamic Host Configuration Protocol, DHCP, response message with access location information of the user access network from NASS at the user terminal when the user terminal accesses a service system through the user access network, wherein the access location information of the user access network is carried in a DHCP option of the DHCP response message and the DHCP option is obtained by adding a new DHCP option or redefining an existing DHCP option; and obtaining, by the user terminal, the access location information of the user access network from the DHCP option, and providing, by the user terminal, the access location information of the user access network to the service system, obtaining, by the service system, relevant information of user from NASS of the user access network based on the access location information, and apply and reserve network bandwidth/QOS resource through RACS of the access network; wherein the access location information comprises one or more of the following: the user access network operator identifier, the user access network identifier, identifier or address of the Network Attachment Subsystem in the user access network, identifier or address of the Connectivity Session Location and Repository Function of the user access network, identifier or address of a broadband remote access server in the user access network to which broadband remote access server the user accesses, identifier or address of the access equipment in the user access network which access equipment the user accesses, identifier of the physical line and logical link of the user access network, which physical line and logical link the user accesses. 2. The method of obtaining access location information according to Claim 1, wherein the DHCP response message is in response to a request from the user terminal, and the request is in the form of a DHCP Discover message (DHCPDISCOVER), a DHCP Request message (DHCP REQUEST) or a DHCP Inform message (DHPINFORM). 3. The method of obtaining access location information according to Claim 1 or 2, wherein the DHCP response message comprises a DHCP Offer message (DHCPOFFER) or a DHCP Acknowledge message (DHCPACK). 4. The method of obtaining access location information according to Claim 3, wherein said DHCP option comprises at least a type field and a content field, the type field indicating the access location information that is carried in said DHCP option, and the content field carrying the user access location information. 5. The method of obtaining access location information according to Claim 3, wherein the user terminal requests its access location information through a DHCP Discover message(DHCPDISCOVER), and the server answers the request from the user terminal with a DHCP Offer (DHCPOFFER) message in which said DHCP option is carried; alternatively, the user terminal requests its access location information through a DHCP Request message (DHCPREQUEST) or a DHCP Inform message (DHCPINFORM), and the server answers the requests from the user terminal with a DHCP Acknowledge message(DHCPACK) in which the DHCP option is carried. 6. A user terminal for accesses a service system through a user access network, the access network comprising Network Attachment Subsystem, NASS, and Resource and Admission Control Subsystem, RACS, to provide a uniform standard interface to the service system, the terminal comprising: an access location information acquiring module, and an access location information processing module, said access location information acquiring module is adapted to receive a DHCP datagram carrying access location information of the user access network for the user terminal from the DHCP server, to obtain the access location information from an option in the DHCP datagram, and to send the access location information to said access location information processing module; and said access location information processing module is adapted to preserve the access location information for using the information at the time of registering to the service system or requesting a service through the user access network or requesting a service, to provide the access location information of the access network by the user terminal to the service system: so that the service system can obtain relevant information of user from NASS of the user's access network based on the access location information, and apply and reserve network bandwidth/QOS resource through RACS of the access network; wherein the access location information comprises one or more of the following: the user access network operator identifier, the user access network identifier, identifier or address of the Network Attachment Subsystem in the user access network, identifier or address of the Connectivity Session Location and Repository Function of the user access network, identifier or address of a broadband remote access server in the user access network, to which broadband remote access server the user accesses, identifier or address of an access equipment in the user access network which access equipment the user accesses, identifier of the physical line and logical link of the user access network, which physical line or logical link the user accesses. 7. A system comprising a user access network and a user terminal, the user access network comprising a server for providing access location information of the user access network for the user terminal, through which user access network the user terminal accesses a service system, a Network Attachment Subsystem, NASS, and a Resource and Admission Control Subsystem, RACS, to provide a uniorm standard interface to the service system, the server being adapted to preserve the user access location information of the access network and configure the access location information on the user terminal; and the server being adapted to put the acces location information into an access location information option in a DHCP datagram sent to the user terminal and transmitting the access location information to the corresponding user terminal, the user terminal being adapted to provide the access location information of the access network by the user terminal to a service system when the user terminal accesses the service system through the access network, so that the service system can obtain relevant information of user from NASS of the user's access network based on the access location information, and apply and reserve network bandwith/QOS resource through RACS of the access network; wherein the access location information comprises one or more of the following: the user access network operator identifier, the user access network identifier, identifier or address of the Network Attachment Subsystem in the user access network, identifier or address of the Connectivity Session Location and Repository Function of the user access network, identifier or address of a broadband remote access server the user accesses, identifier or address of an access equipment the user accesses, identifier of the physical line and logical link the user accesses. ABSTRACT A Method, A User Terminal And A Server For Obtaining Access Location Information A method of a user terminal obtaining its access location information in next generation network, and a user terminal, and a server having function of Dynamic Host Configuration Protocol (DHCP) function are disclosed. DHCP is extended by adding a new DHCP option to carry the user terminal access location information; when the user terminal accesses to network, DHCP server puts the DHCP option into DHCP response message; receiving the DHCP response message, the user terminal obtains the access location information from the DHCP option. The present invention overcomes the shortcoming of the prior art that when a terminal nomadizes or roams from one access network to another, the access network information configured on the terminal has to be updated manually and thus results in redundant workload and inflexibility, the user terminal is allowed to obtain its access location information automatically, hence nomadicity or roaming of the user terminal is supported.

Full Text

Field of The Invention
This invention relates to communication technology, particularly to a method, a
user terminal and a server for obtaining access location information.
Background of The Related Art
Currently, ITU-T and ETSI, respectively as international and European
telecommunication standards organizations, are developing network architecture of NGN
(Next Generation Network). The ETSI TISPAN NGN architecture is shown in Fig. 1.
Based on this NGN architecture, NGN can be divided into three main parts: service
control and applications part, the network bearing part, and terminal part, and the
functions of the three main parts are respectively described as follows.
Service control and applications system, including IP multimedia subsystem
(IMS), PSTN/ISDN emulation subsystem, stream media subsystem, completes service
control function of various applications and provides various services.
Network bearing system, includes the following subsystems:
(1) Network Attachment Subsystem (NASS): completes authentication and
authorization, address allocation, user location information management and terminal
configuration in the network access layer;
(2) Resources and Admission Control Subsystem (RACS): completes functions of
transport network resources control, distribution, and management based on service
requirement, and guarantees quality of service;
(3) Transport Subsystem: under control of the above subsystems, completes
transportation of various kinds of network datagram; includes the Access Transport
Network and Core Transport Network shown in the figure.
User terminal: includes various NGN terminals and user family network
equipments, comprising family gateway, IAD (Integrated Access Equipment), STB (Set
Top Box), Video-Phone, PC, WiFi (Wireless Fidelity) handset etc.

Network Attachment Subsystem (NASS) is shown in Fig. 2, including the
following functional entities:
(1) AMF-- Access Management Function.
(2) NACF—Network Access Configuration Function, is generally implemented as a
DHCP server (Dynamic Host Configuration Protocol server) for DHCP access.
(3) CLF—Connectivity Session Location and Repository Function, provides
interface from CLF to service system.
(4) UAAF—User Access Authorized Function.
(5) PDBF—Profile Data Base Function.
(6) CDCF—Client Devices Configuration Function.
In the NGN architecture, by introducing NASS and RACS, the difference
between the transport subsystems in the underlayer is covered, and a uniform standard
interface is provided upwardly. Based on this architecture, service can be separated from
access, that is, NGN service providers do not need to pay attention to the detailed
differences between underlayer transport subsystems, but only need to provide a standard
interface for connecting to access network operator; and access network operators do not
need to concern how to provide detailed NGN service either, but only need to provide a
standard interface through NASS and RACS, and then NGN service providers can
provide NGN service with QOS guarantee using resources of transport networks.
Thus, a service system can serve a number of different broadband access
networks (a service system can be a service control and application subsystems, or a
specific network application, such as IMS(IP Multimedia System), IPTV (IP Television
system), or a network game), that is, a user can access a network through different access
network operators, and nomadizes or roams among multiple access networks (nomadicity
means that a network user switches from a network to another network and the service is
interrupted during switching; while in roaming, service is uninterrupted during switching;
roaming is usually applied in mobile networks while nomadicity is applied in fixed or
semi-mobile networks such as WiFi, DSL applications). The architecture for terminals
accessing a service system through different access networks is shown in Fig. 3, wherein

a user can obtain corresponding service no matter through which access network. Thus it
requires that, when the user registers to service system or submits service request, service
system can obtain relevant information of the user from NASS of the user's access
network, apply and reserve network bandwidth/QOS resource through RACS of the
access network, so as to ensure effective services.
Because users can roam across a number of access networks, service operators
need to know the location information (visiting location information) of their users.
Through obtaining the information, the service system can control QOS precisely, and
provide different fee charge strategies (local, long-distance and roaming) and location
information services etc. However, the problem is that, a terminal usually does not know
its own access location information when it accesses a network. Because the terminal
directly registers to or requests service from a service system, the process is transparent
to the access network, when the terminal registers to a service system, the service system
does not know what network the user is accessing if the access location information
cannot be carried by the user terminal, the service system of course does not know from
which network to get the user's relevant information and consequently cannot implement
the corresponding QOS control.
The solution in prior art is that the access network information is configured on
the terminal in advance, and the terminal registers the information to a service system at
the time of accessing to the service system, then based on the information, the service
system can retrieve the user's information from corresponding access network and
implement QOS control. However, the prior art does not support terminal nomadizing or
roaming, so that the access network configured on the terminal has to be updated
manually when the terminal nomadizes or roams from one access network to another,
which results in redundant workload and inflexibility.
Summary of The Invention
It is an object of the present invention to provide a method of obtaining access
location information and the corresponding user terminal and server, so that the user
terminal can automatically obtain its access location information. The invention may

overcome the shortcoming of the prior art that the access network information configured
on the terminal cannot be updated automatically when the terminal nomadizes or roams
from one access network to another.
A method of obtaining access location information according to the present
invention comprises the following steps:
extends Dynamic Host Configuration Protocol (DHCP) by adding a new DHCP
option or redefine an existing option, the DHCP option being utilized to carry the access
location information of the user terminal;
when the user terminal accesses a network and sends a request, the server puts the
DHCP option into a response message; and
the user terminal receives the DHCP option and obtains the access location
information from the DHCP option.
The user terminal first requests the server to provide the access location
information of the user terminal through a DHCP Discover message, a DHCP Request
message or a DHCP Inform message, and then the server returns the user terminal the
DHCP response message carrying the DHCP option.
The DHCP response message may be a DHCP offer message or DHCP Ack
message.
the access location information carried by the DHCP option comprises one or
more items of the following: the access operator identifier, the user access network
identifier, identifier or address of the Network Attachment Subsystems in the user access
network, identifier or address of the Connectivity Session Location and Repository
Function of the user access network, identifier or address of broadband remote access
server to which the user accesses, identifier or addresses of access equipments to which
the user access, identifiers of the physical line and logical link to which the user access.
The DHCP option comprises at least a type field and a content field, the type filed

indicating it is the location information that is carried in the DHCP option, and the
content field carrying the user terminal access location information.
The user terminal can request its access location information through a DHCP
Discover message, the server answers the request from the user terminal with a DHCP
Offer message in which the DHCP option is carried;
Alternatively, the user terminal may request the access location information
through a DHCP Request message or a DHCP Inform message, the server answers the
request from the terminal with a DHCP Ack message in which the DHCP option is
carried.
A user terminal according to the invention comprises:
an access location information acquiring module, and
an access location information processing module,
the access location information acquiring module receiving the DHCP datagram
carrying the access location information sent from the server, obtaining the access
location information from the option in the DHCP datagram, and sending the information
to the access location information processing module;
the access location information processing module preserving the access location
information for using the information at the time of registering to service system or
requesting service.
A server for providing access location information of user terminal, the server
comprising:
An access location information processing module for preserving the user access
location information for configuring the access location information on the user terminal;
A DHCP access location information transmitting module for putting the access
location information, which is preserved by access location information processing
module, into the access location information option in the DHCP datagram sent to the
user terminal, and transmitting the information to the corresponding user terminal.

In the prior art, when a terminal nomadizes or roams from one access network to
another, the access network information configured on the terminal has to be updated
manually which results in redundant workload and inflexibility. In the solution of the
present invention, DHCP is extended by adding a new DHCP option carrying user access
location information. Without change to the network topology and configuration on the
user terminal, the user terminal can automatically obtain its access location information
by requesting message when it accesses the network. Alternatively, the-request may not
be needed, for the DHCP server can directly put the new added DHCP option in a DHCP
response message and sent it to the user terminal. The user terminal can register the
information to the service system, and thus ensure that the service system can obtain
access location information of the terminal. This invention allows user terminal to obtain
the current access location information when it accesses to different networks or different
locations in the same network, hence nomadicity or roaming of user terminals is
supported.
Brief Description of The Drawings
Fig. 1 is a schema view of NGN network architecture;
Fig. 2 is a schema view of the Network Attachment Subsystem;
Fig. 3 is a schema view of user terminals accessing a service system through
different access networks;
Fig. 4 is a flow chart of standard DHCP interaction;
Fig. 5 is a flow chart of the user terminal obtaining the location information and
submitting to service system according to an embodiment of the present invention;
Fig. 6 is a schema view of the modules of the user terminal for implementation of
the method according to an embodiment of the present invention;
Fig. 7 is a schema view of modules of the equipment implementing function of
DHCP server for implementation of the method according to an embodiment of the
present invention.
Detailed Description of The Preferred Embodiment

Hereafter, preferred embodiments according to the present invention will be
described in detail with reference to the drawings.
DHCP (Dynamic Host Configuration Protocol) is a network protocol to configure
relevant network parameters dynamically for users by adopting a mechanism which
automates the assignment of related information to client. When a client accesses the
system, the server can provide the client with the network configuration information
including IP address, gateway, DNS server, etc. Client retrieves the information from the
DHCP server. In a large integrated network, DHCP is a protocol frequently used for users
to access the network, by which the server can automatically configure network
parameters such as IP address, etc. The following example in which a user communicates
with a server using DHCP, describes the method of obtaining access information and the
corresponding equipments according to an embodiment of the invention.
The standard DHCP interaction flow chart is shown in Fig. 4, when a terminal
accesses a network, it obtains information such as IP address, subnet mask, DNS etc.
through DHCP, and this process is performed upon a request from the terminal to the
DHCP server (NASS component). The user terminal requests the DHCP server through
DHCP Discover message, DHCP Request message or DHCP Inform message, the DHCP
server returns DHCP Offer message and DHCP Ack message to the user terminal. DHCP
datagram can carry various DHCP options, and these options can carry various
information, such as DNS server, SIP server, etc.
According to an embodiment of the present invention, DHCP is extended by
adding a new DHCP option to carry access location information of the user terminal (or
reuse an existing option, which means not define a new option but redefine an existing
DHCP option), and the user terminal and network equipment having function of DHCP
server can support the DHCP option. The option contains a dedicated code field, i.e., a
type field, through which the user terminal can obtain the location information/visiting
location information from network. The format of the DHCP option is shown as
following:

The CODE field defines the type, indicating the option is for carrying the user
terminal access location; Length defines the length of the option; the access location
information of the user terminal is carried in the Content field of the option. The user
access location information that can be carried in the DHCP option can be all or some of
the following sub-options:
1. The access network operator identifier, for example "China telecom".
2. The user access network identifier, which can include the operator's
information, and physical region information etc, for example "China Telecom Beijing
DSLR101".
3. The identifier or address of the user access network's Network Attachment
Subsystem (NASS), for example "China Telecom NASS 001" or "212.100.010.001".
4. The identifier or address of Connectivity Session Location and Repository
Function (CLF) in the user access network, for example "China Telecom CLF 001" or
"212.100.011.001".
5. The identifier or address of Broadband Remote Access Server (BRAS) to
which the user access, for example "Beijing BRAS001" or "212.100.100.001".
6. The identifier or address of the access equipment to which the user access, for
example "Beijing DSLAM1001" or "212.100.101.001".
7. The identifier of the physical line and logical link to which the user access, for
example "Beijing DSLAM1001 eth 0/1/0/1:100" or "Beijing BRAS001 atm 0/1/0/1:0.35".
According to the standard DHCP interaction process described previously, only
by transmitting DHCP Offer and/or DHCP Ack message carrying the option to the user
terminal, the DHCP server can send the terminal's access location information/visiting
location information to the user terminal.
Fig. 5 shows the flow chart of the user terminal obtaining location information
and submitting it to service system according to an embodiment of the present invention.
The DHCP option is handled as following:

1) The DHCP Server issues DHCP Offer and DHCP Ack messages carrying the
new added DHCP option according to an embodiment of the present invention, the DHCP
option carrying the user access location information which may include the user access
location information sub-options as previously described.
2) The user terminal receives the DHCP Offer or DHCP Ack message carrying the
DHCP option, and obtains the access location information. Since the access location
information may contain a plurality of sub-options, the terminal can obtain all or some of
these sub-options as desired.
3) The user terminal can register the information to service system; therefore
ensure the service system can obtain the user terminal access location information.
The user terminal can request the option defined in the invention through a DHCP
Discover message, the DHCP server answers the terminal's request with a DHCP Offer
message carrying the user access location information in the DHCP option defined in the
invention. The terminal can also request the option defined in the invention through a
DHCP Request or a DHCP Inform message, the DHCP server answers the terminal's
request with a DHCP Ack message carrying the user access location information in the
DHCP option defined in the invention.
During the DHCP interaction process, the network equipment implementing
DHCP Relay function (for example, Broadband Remote Access Server (BRAS) or
Digital Subscriber Line Access Multiplexer (DSLAM)) handles the DHCP datagram with
the DCHP option in the same way as handling DHCP datagram without the DHCP option.
The network equipment does not alter the DHCP option when handling the datagram.
According to an embodiment of the present invention, DHCP is extended by
adding a new DHCP option to carry user terminal access location information. Without
change to the network topology and configuration on the user terminal, the user terminal
can automatically obtain its access location information by requesting message when it
accesses the network. Alternatively, the request may not be needed, for the DHCP server
can directly put the new added DHCP option in a DHCP Offer or a DHCP Ack message

and sent it to the user terminal. The user terminal can register the information to the
service system, and thus ensure that the service system can obtain access location
information of the terminal. This invention allows user terminal to obtain the current
access location information when it accesses to different networks or different locations
in the same network, hence nomadicity or roaming of user terminals is supported.
To implement the method according to the present invention, a user terminal and
an equipment implementing function of DHCP server are also provided.
Fig. 6 illustrates the modules of the user terminal for implementation of the
method according to an embodiment of the present invention, wherein the user terminal
comprises:
a DHCP access location information acquiring module; and
an access location information processing module,
the DHCP access location information acquiring module receiving DHCP
datagram carrying the access location information from a DHCP server or other
equipment implementing function of DHCP server, obtaining the access location
information from the option in the DHCP datagram, and then sending the information to
the location information processing module;
the access location information processing module locally preserving the access
information for using the information at the time of registering to server system or
requesting service.
Fig. 7 illustrates the modules of the equipment having function of DHCP server
for implementation of the method according to an embodiment of the present invention,
wherein the equipment comprises:
an access location information processing module for preserving the user access
location information for configuring the access information on the user terminal;
an access location information transmitting module for putting the access location
information, which is preserved by the access location information processing module,
into the access location information option in the DHCP datagram sent to the user and

transmitting the information to the corresponding user terminal.
If the network equipment supports embedded DHCP server function, then the
equipment can implement the same functions as an independent DHCP server.
The invention provides a method of a user terminal obtaining its access location
information, the user terminals and the network equipment in next generation network.
The above-described is only preferred embodiments of the present invention, and
the scope of the present invention is not limited thereto. Modifications and alterations are
easily imaged by those skilled in the art within the technical scope disclosed in the
present invention, and should come within and protected by the scope of the present
invention as set by the appended claims and its equivalents.

WE CLAIM:
1. A method of obtaining access location information of an user access network, through
which a user terminal accesses a service system, the access network comprising Network
Attachment Subsystem, NASS, and Resource and Admission Control Subsystem, RACS, to
provide a uniform standard interface to the service system, the method comprising:
receiving a Dynamic Host Configuration Protocol, DHCP, response message with access
location information of the user access network from NASS at the user terminal when the
user terminal accesses a service system through the user access network, wherein the access
location information of the user access network is carried in a DHCP option of the DHCP
response message and the DHCP option is obtained by adding a new DHCP option or
redefining an existing DHCP option; and
obtaining, by the user terminal, the access location information of the user access network
from the DHCP option, and
providing, by the user terminal, the access location information of the user access network to
the service system,
obtaining, by the service system, relevant information of user from NASS of the user access
network based on the access location information, and apply and reserve network
bandwidth/QOS resource through RACS of the access network;
wherein the access location information comprises one or more of the following: the user
access network operator identifier, the user access network identifier, identifier or address of
the Network Attachment Subsystem in the user access network, identifier or address of the
Connectivity Session Location and Repository Function of the user access network, identifier
or address of a broadband remote access server in the user access network to which
broadband remote access server the user accesses, identifier or address of the access
equipment in the user access network which access equipment the user accesses, identifier of
the physical line and logical link of the user access network, which physical line and logical
link the user accesses.
2. The method of obtaining access location information according to Claim 1, wherein the
DHCP response message is in response to a request from the user terminal, and the request is
in the form of a DHCP Discover message (DHCPDISCOVER), a DHCP Request message
(DHCP REQUEST) or a DHCP Inform message (DHPINFORM).
3. The method of obtaining access location information according to Claim 1 or 2, wherein
the DHCP response message comprises a DHCP Offer message (DHCPOFFER) or a DHCP
Acknowledge message (DHCPACK).
4. The method of obtaining access location information according to Claim 3, wherein said
DHCP option comprises at least a type field and a content field, the type field indicating the
access location information that is carried in said DHCP option, and the content field carrying
the user access location information.
5. The method of obtaining access location information according to Claim 3, wherein the
user terminal requests its access location information through a DHCP Discover

message(DHCPDISCOVER), and the server answers the request from the user terminal with
a DHCP Offer (DHCPOFFER) message in which said DHCP option is carried;
alternatively, the user terminal requests its access location information through a DHCP
Request message (DHCPREQUEST) or a DHCP Inform message (DHCPINFORM), and the
server answers the requests from the user terminal with a DHCP Acknowledge
message(DHCPACK) in which the DHCP option is carried.
6. A user terminal for accesses a service system through a user access network, the access
network comprising Network Attachment Subsystem, NASS, and Resource and Admission
Control Subsystem, RACS, to provide a uniform standard interface to the service system, the
terminal comprising:
an access location information acquiring module, and
an access location information processing module,
said access location information acquiring module is adapted to receive a DHCP datagram
carrying access location information of the user access network for the user terminal from the
DHCP server, to obtain the access location information from an option in the DHCP
datagram, and to send the access location information to said access location information
processing module; and
said access location information processing module is adapted to preserve the access location
information for using the information at the time of registering to the service system or
requesting a service through the user access network or requesting a service, to provide the
access location information of the access network by the user terminal to the service system:
so that the service system can obtain relevant information of user from NASS of the user's
access network based on the access location information, and apply and reserve network
bandwidth/QOS resource through RACS of the access network; wherein the access location
information comprises one or more of the following: the user access network operator
identifier, the user access network identifier, identifier or address of the Network Attachment
Subsystem in the user access network, identifier or address of the Connectivity Session
Location and Repository Function of the user access network, identifier or address of a
broadband remote access server in the user access network, to which broadband remote
access server the user accesses, identifier or address of an access equipment in the user access
network which access equipment the user accesses, identifier of the physical line and logical
link of the user access network, which physical line or logical link the user accesses.
7. A system comprising a user access network and a user terminal, the user access network
comprising a server for providing access location information of the user access network for
the user terminal, through which user access network the user terminal accesses a service
system, a Network Attachment Subsystem, NASS, and a Resource and Admission Control
Subsystem, RACS, to provide a uniorm standard interface to the service system,
the server being adapted to preserve the user access location information of the access
network and configure the access location information on the user terminal; and
the server being adapted to put the acces location information into an access location
information option in a DHCP datagram sent to the user terminal and transmitting the access
location information to the corresponding user terminal, the user terminal being adapted to
provide the access location information of the access network by the user terminal to a
service system when the user terminal accesses the service system through the access

network, so that the service system can obtain relevant information of user from NASS of the
user's access network based on the access location information, and apply and reserve
network bandwith/QOS resource through RACS of the access network;
wherein the access location information comprises one or more of the following: the user
access network operator identifier, the user access network identifier, identifier or address of
the Network Attachment Subsystem in the user access network, identifier or address of the
Connectivity Session Location and Repository Function of the user access network, identifier
or address of a broadband remote access server the user accesses, identifier or address of an
access equipment the user accesses, identifier of the physical line and logical link the user
accesses.

ABSTRACT

A Method, A User Terminal And A Server For
Obtaining Access Location Information
A method of a user terminal obtaining its access location information in next
generation network, and a user terminal, and a server having function of Dynamic Host
Configuration Protocol (DHCP) function are disclosed. DHCP is extended by adding a
new DHCP option to carry the user terminal access location information; when the user
terminal accesses to network, DHCP server puts the DHCP option into DHCP response
message; receiving the DHCP response message, the user terminal obtains the access
location information from the DHCP option. The present invention overcomes the
shortcoming of the prior art that when a terminal nomadizes or roams from one access
network to another, the access network information configured on the terminal has to be
updated manually and thus results in redundant workload and inflexibility, the user
terminal is allowed to obtain its access location information automatically, hence
nomadicity or roaming of the user terminal is supported.

A METHOD, A USER TERMINAL AND SERVER FOR OBTAINING ACCESS LOCATION INFORMATION OF AN ACCESS NETWORK

Documents:

Inventors:

PCT Conventions: