KR20030071400A - Method for hand-off using session initiation protocol in all internet protocol network - Google Patents

Abstract

The present invention, by connecting the connection between the existing control station equipment with the addition of the Internet protocol, using the Session Control Manager (SCM), to facilitate the future evolution and handoff to the integrated Internet protocol network The present invention relates to a handoff method using a connection establishment protocol in an integrated Internet protocol network. The present invention replaces a part connected to an existing ATM by connecting an existing connection between equipment of an existing control station by charging an IP, and performs a session control manager (SCM). By eliminating the use of the mobile communication exchange, In addition, as a part for interworking with the existing network, a mobile station that is not registered in the AAA can immediately go to the mobile switching center and interwork with another network or PSTN network, thereby gradually evolving from the existing network to the integrated IP network. To help.

Description

Method for hand-off using session initiation protocol in all internet protocol network}

The present invention relates to a handoff method using a Session Initiation Protocol (SIP) in an integrated internet protocol network (ALL-IP Network). In particular, the connection between the existing control station equipment by adding the Internet protocol, the session By using a control manager (SCM: Session Control Manager), the present invention relates to a handoff method using a connection establishment protocol in an integrated internet protocol network that facilitates the future evolution and handoff to an integrated internet protocol network.

Currently, the 3rd Generation Partnership Projects (3GPP) and 3GPP2, two organizations of the International Standardization Conference, discuss specifications for replacing the entire network of IMT-2000 systems with an integrated IP (ALL-IP) network based on Internet Protocol (IP). It is becoming.

The ALL-IP network has many differences compared with the network configuration of the conventional next-generation mobile communication system. Preferably, the subscriber server has a home location register (HLR), which is an existing circuit management server, and an authorization / authentication / packet management server. AAA (Authentication Authentication Accounting) server integration and new function definition are needed. In particular, the voice security processing function of the Internet that introduces the authentication procedure currently used in the IP network is required for the voice authentication process, and the security mechanism used in the same IP packet network is applicable. In addition, the addition of the mobility processing part as one function to the same equipment will be very helpful in constructing an effective call scenario, and it is expected that the service management function should be separated into the service characteristic providing area of the operator.

In the ALL-IP network, the subscriber processing server has been proposed to enable effective ALL-IP services including mobility management, service quality management, authentication and authorization management, and billing.

On the other hand, for the evolution to the ALL-IP network, the application of IP of the wireless network continues to be presented, and the well-known 3GPP2 proposes the ALL-IP NAM Rev 1.1.1 DRAFT [1] (see reference below). . Currently, detailed specifications are not proposed, and various plans are being proposed. Currently, the most emerging for voice IP is the wireless IP (WIP) network configuration using the connection establishment protocol (SIP) proposed by the IETF, and mobile IP is applied here. The proposed scheme consists of placing SIP on the PDSN, integrating bearers, and batching them at the PDSN [3] (see references below). (4) (see references below) and the like have been proposed, but the practical implementation is very weak.

SIP configuration is a technology for configuring a signal control unit, but related technologies such as SDP, MGCP, and RTP have already been implemented in software, but a configuration on a specific wireless network has not been presented.

If this is actually applied to the base station (BS) equipment, a partial redesign of the control station (BSC) equipment must be made, and additional network components are required.

In addition, the specification of the proposed standard [2] (see references below) requires some changes.

<References>

[1] "IP Network Architecture Model for cdma 2000 Spread Spectrum Systems", ALL-IP NAM Rev 1.1.1 DRAFT, 3GPP2 SC.POOOX August 06. 2001 Revision 1.1.1 DRAFT.

[2] 3GPP2 Access Network Interfaces Interoperability Specification (IOS) 4.0, 4.1

[3] Mun Gi Choi; Yingchun Xu "A New Multimedia Network Architecture Using 3G CDMA 2000" VTC 2000 Proceedings, p2937 ~ p2944.

[4] Moh M; Berguim g; Yanjun chen "Mobile IP Telephony: Mobility Support of SIP", Computer Communication Networks, 1999. Proceedings. Eight International Conference on, 1999.

Accordingly, the present invention provides a problem that a partial redesign of the control station equipment should be made when the SIP configuration is applied to the conventional control station equipment as described above, a problem requiring additional network components, and a problem that requires a specification change. As proposed to solve,

This object of the present invention, by connecting the connection between the existing control station equipment with the addition of the Internet protocol, and using the Session Control Manager (SCM :), the evolution and handoff to the future integrated Internet protocol network smoothly The present invention provides a handoff method using a connection establishment protocol in an integrated Internet protocol network.

The present invention for achieving the above object,

By connecting the connection between the existing control station equipment by imposing an IP, the part connected to the existing ATM was replaced, and by using the session control manager (SCM) unit, the use of the mobile communication exchange is eliminated.

In addition, the mobile station that is not registered in the AAA used in [1] as interworking with the existing network can be gradually integrated in the existing network by allowing the mobile station to go directly to the mobile switching center and interwork to go to another network or PSTN network. Enable to evolve into IP network

1 is a reference model diagram of an integrated Internet protocol network to which the present invention is applied;

FIG. 2 is a functional model diagram of applying a session control manager (SCM) in FIG. 1,

3 is a channel set-up procedure diagram applying SIP in the present invention,

4 is a flowchart illustrating a handoff method using a connection establishment protocol in an integrated Internet protocol network according to the present invention.

<Explanation of symbols for the main parts of the drawings>

201 ..... source mobile station

202 ..... Source WAG

203 ..... Source SCM / MM

204 ..... AAA

205 ..... MSC

206 ..... Target SCM / MM

207 ..... Goal WAG

208 ..... target mobile station

Hereinafter, described in detail with reference to the accompanying drawings, preferred embodiments of the present invention according to the technical spirit as described above.

1 is a reference model diagram of an integrated Internet protocol network to which the present invention is applied.

This is a voice packet routing function (VPRF: Voice Packet Routing Function) that processes bearer data using an SCM client and an IP in a wireless access gateway (WAG: 11 to 13) that extends an existing control station (BSC). It is a structure containing wealth. It is a structure that can implement voice IP by applying SIP proposed by IETF.

This network model proposes a structure that applies voice and packet data separately. In this case, when MS receives service with only voice, port number and session ID can be set to SCM / MM (Mobility number) with only one IP or several IPs in WAG (11 to 13) without having to be assigned IP. Manager) The values given by the servers 21 and 22 can communicate through call setup. The SCM / MMs 21 and 22 perform call setup through session setup, and manage session ID, port number, and WAGs 11 to 13. The WAGs 11 to 13 have a VPRF function for processing substantial bearer data with a client part communicating with the SCM, in addition to the function of the existing BSC.

The mobile station (MS) and the WAG follow the IOS standard applied in the existing network structure. The WAG uses the assigned port number and session ID to repeat the setup process between the existing base stations (BTS) (31 to 31 + n, 41 to 41 + n), the mobile station (MS) and the control station (BSC). It is responsible for setting, maintaining, and releasing.

The AAAs 51 and 52 perform location registration of the mobile station and later perform billing, authentication, and service permission together. The MSC 60 is required for interworking with an existing network, and the SCM / MM servers 21 and 22 replace the functions in the present network structure.

In FIG. 1, reference numerals 71 and 72 denote a database DB, reference numerals 81 and 82 denote PDSN, reference numeral 91 denote an IP network, reference numeral 92 denote a cellular network, and Reference numeral 93 denotes a public telephone network (PSTN).

2 illustrates the functions of network entities in a WIP network.

Here, reference numeral 101 denotes a mobile station performing a mobile terminal function, and reference numeral 102 denotes AAA (Authentication, Authorization and Accounting) that performs location registration, authentication, and charging service permission of the mobile terminal. Reference numeral 103 denotes an MM that performs location management and service maintenance of the mobile terminal, reference numeral 104 denotes a Radio Resource Control (RRC) that performs radio channel setting, maintenance, and release functions of the mobile terminal, and reference numeral 105 An SCM that performs session establishment, maintenance, and release functions of the mobile station is represented, and reference numeral 106 denotes a VPRF that performs packet service reachability state maintenance, and buffering and routing of packets when radio resources are not available.

This structure provides the functional models needed to process voice over an IP network.

3 is a channel set-up procedure diagram applying SIP in the present invention.

As shown here, in step S101, the source MS 201 transmits an outgoing message to the source SCM / MM source 203 via the source WAG source 202 ( origination).

The source SCM / MM 203 received this transmits a message (search_req) requesting registration with the AAA 204 with the calling IMSI and the called IMSI in step S102.

In step S103, the AAA 204 responds with the requested location of the called IMSI (target WAG IP) (search_success_rep) (at this time, an interworking problem occurs with the AAA of another network. Only when the answer comes).

In step S104, the source WAG 202 checks the registration status, and as a result, it is regarded as an existing legacy network user when not registered in the AAA 204, and performs a call setup process with the mobile communication switch 205. In this case, follow the call setup procedure defined in the existing IOS (search_fail_req).

In addition, in step S105, the source WAG 202 checks the registration status, and as a result, if it is registered in the AAA 204, the channel WAG 202 performs a channel setup process with the source mobile station 201, in which case the existing IOS standard is followed ( channel assign).

In step S106, the source WAG 202 transmits a message (Create_connect_req) for call setup to the source SCM / MM 203.

Then, in step S107, the source SCM / MM 203 transmits a response message (Create_connect_ack) thereto to the source WAG 202.

In step S108, the source SCM / MM 203 transmits SIP_INVITE to the target SCM / MM 206 with the address and RTP number of the target WAG 207.

In step S109, the target SCM / MM 206 transmits Create_connect_req to the target WAG 207.

In step S110, the target SCM / MM 206 sends a SIP_100_Trying to inform the source SCM / MM 203 that the call is being performed.

In step S111 the target WAG 207 performs the receiver channel setup, which follows the existing IOS standard.

In step S112, the target WAG 207 sends a message (Modify_connect_Ringing_req) requesting the ring to the target mobile station 208.

In step S113 the target mobile station 208 sends Modify_connect_Ring to the target SCM / MM 206 via the target WAG 207.

In step S114, the target SCM / MM 206 sends SIP_180_Ringing to the source SCM / MM 203.

In step S115 the source SCM / MM 203 sends Modify_connect_Ring to the source mobile station 201 via the source WAG 202.

In step S116 the target mobile station 208 sends Modify_connect_complete to the target SCM / MM 206 via the target WAG 207.

In step S117, the target SCM / MM 206 sends the SIP_200_OK to the source SCM / MM 203.

In step S118 the source SCM / MM 203 sends Modify_connect_Complete to the source mobile station 201 via the source WAG 202.

Thereafter, since the call is set up in step S119, voice communication is performed between the WAGs.

When the voice communication ends, in step S120, the source mobile station 201 transmits a Delete_Connect message to the source SCM / MM 203 via the source WAG 202 to make a release request. In step S121, the source SCM / MM 203 ) Sends SIP_BYE to the target SCM / MM 206.

In step S122, the Delete_Connect message is sent by the target SCM / MM 206 to the target mobile station 208 via the target WAG 207 to request the release.

In step S123, the target mobile station 208 releases the channel while sending the Delete_Connect-ack message to the target SCM / MM 206 via the target WAG 207.

In step S124, the target SCM / MM 206 sends a SIP_ACK to the source SCM / MM 203.

In step S125 the source SCM / MM 203 releases the channel by sending the source SCM / MM 203 to the source mobile station 201 via the source WAG 202.

4 is a flowchart illustrating a handoff method using a connection establishment protocol in an integrated Internet protocol network according to the present invention.

As shown here, in step S201, the mobile station 301 processes messages coming from the previous WAG 302 according to the existing IOS standard, and the SAG processes the source IP, the RTP port, and the handoff cell information being performed in the WAG. To / MM 304.

In step S202, the SCM / MM 304 transmits the new WAG 303 with the source IP, the RTP port, and the Session ID information in a handoff request message.

In step S203 the new WAG 303 performs a new channel setup with the mobile station 301.

When the channel setup is completed in step S204, the new WAG 303 transmits the target IP and the target RTP port to the SCM / MM 304 in the handoff request response message (Handoff_request_ack).

In step S205, the SCM / MM 304 notifies the previous WAG 302 that a new channel has been established through a message (New_channel_assign_inform).

In step S206, the previous WAG 302 forwards a handoff direction message (Handoff_direction_message) to the mobile station 301, where the procedure follows the existing IOS standard.

In step S207, the previous WAG 302 transmits a message (New_channel_assign_inform_ack) indicating that a new channel has been allocated to the SCM / MM 304.

In step S208, the mobile station 301 transfers the newly established Transported attach message to the new WAG 303. This case also follows the IOS standard.

In step S209, the new WAG 303 forwards the handoff complete message (Handoff_complete) to the SCM / MM 304.

In step S210, the SCM / MM 304 instructs channel release by sending a target IP and an RTP port to a previous WAG 302 through a channel clear command.

In step S211, the channel is released.

In step S212, the channel release completion message (channel_clear_complete) is notified that.

According to the present invention described above, by imposing IP on all the control station (BSC) equipment, there is an advantage that the voice IP can be realized over the air.

In addition, the use of IP facilitates expansion and installation, and the use of widely used Internet protocols has the advantage of eliminating many existing complex protocol specifications.

In addition, there is an advantage that it can be extended to a structure that can be processed using IP even between the base station and the control station structure as a scalable structure in the future.

Claims (4)

Integrated Internet consisting of mobile station (source / target mobile station), old Wireless Access Gateway (WAG) (source WAG), new WAG (target WAG), and Session Control Manager / Mobility Manager (SCM / MM) (source / target SCM / MM) In the handoff method in the protocol network, If a handoff occurs in a state where communication is performed between the mobile station and the SCM / MM, transmitting first information which is being performed in the previous WAG to the SCM / MM; Transmitting second information in a handoff request message from the SCM / MM to the new WAG; Performing a new channel setup procedure with the mobile station in the new WAG, and when the channel setup is completed, transmitting a target IP and a target RTP port to the SCM / MM in a handoff request response message; If the SCM / MM notifies the old WAG that a new channel has been established, forwarding a handoff direction message to the mobile station in the old WAG; The previous WAG sending a message indicating that a new channel has been allocated to the SCM / MM; Forwarding a newly established transmission message at the mobile station to the new WAG; The new WAG transmits a handoff completion message to the SCM / MM, and the SCM / MM receiving the request sends a target IP and RTP port to the previous WAG through a channel delete command to instruct channel release. ; And a channel release completion message indicating that the channel is released when the channel is released. The handoff method according to claim 1, wherein the first information is a source IP, an RTP port, and cell information to be handed off. The handoff method according to claim 1, wherein the second information is source IP, RTP port, and Session ID information. The method of claim 1, wherein the channel setup procedure, Sending, at the source mobile station, the outgoing message via the source WAG to the source SCM / MM; Transmitting a message in the SCM / MM requesting registration with AAA (Authentication, Authentication and Accounting) with a calling IMSI and a called IMSI; When responding with the location of the called IMSI (target WAG IP) requested by the AAA, the registration status is checked at the source WAG, and as a result, it is regarded as an existing network user if not registered with the AAA, and IOS Performing a call setup process with the mobile switching center according to the standard defined in the following description; Checking a registration status at the source WAG and performing a channel setup procedure with a source mobile station when it is registered with the AAA as a result; Transmitting a message for call setup from the source WAG to the source SCM / MM and transmitting a response message to the source WAG from the source SCM / MM which received it; Transmitting SIP_INVITE in the source SCM / MM to a target SCM / MM with an address and an RTP number of a target WAG; Transmitting Create_connect_req to a target WAG in the target SCM / MM; Transmitting SIP_100_Trying indicating that a call is being performed from the target SCM / MM to a source SCM / MM; Performing a called party channel setup at the target WAG and sending a message requesting a ring to a target mobile station; Transmitting, at the target mobile station, Modify_connect_Ring to a target SCM / MM via a target WAG; Transmitting SIP_180_Ringing from the target SCM / MM to a source SCM / MM; Transmitting, at the source SCM / MM, a Modify_connect_Ring to a source mobile station via a source WAG; Sending Modify_connect_complete to a target SCM / MM at the target mobile station; The target SCM / MM sends the SIP_200_OK to the source SCM / MM; Transmitting Modify_connect_Complete to the source mobile station in the source SCM / MM; Requesting channel release by transmitting a connection release message to the source SCM / MM when the voice communication is terminated while voice communication is performed between WAGs after the call is set up through the above steps; Transmitting SIP_BYE from a source SCM / MM to a target SCM / MM; Sending a disconnection message to the target mobile station in the target SCM / MM to request disconnection; Transmitting, at the target mobile station, a connection release response message to a target SCM / MM and releasing a channel; Transmitting a SIP_ACK from the target SCM / MM to a source SCM / MM; And transmitting a connection release message from the source SCM / MM to a source mobile station to release a channel.