Patent Application
20070255793
The above and other features and advantages of exemplary embodiments of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:
Throughout the drawings, the same drawing reference numerals will be understood to refer to the same elements, features and structures.
The matters defined in the description, such as construction, elements, etc., are provided to assist in a comprehensive understanding of preferred embodiments of the invention. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. Also, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
The present invention provides a method for providing a service between heterogeneous networks. The heterogeneous networks may be an Internet Protocol (IP) Multimedia Subsystem (IMS) network and a portable Internet network. Although a method for providing a service in interworking between the IMS network and the portable Internet network will be described, the present invention can also be applied to provide a service between the IMS network and any type of network capable of interworking with the IMS network.
The IMS core network 100 may include an IMS server, a Home Subscriber Server (HSS), and a multimedia content providing server, and has a Session Initiation Protocol (SIP) interface with the PSS 130.
The ACR 110 manages connection and mobility of a user and provides interfaces with the RAS 120 and the IMS core network 100. The ACR 110 also exchanges functions related to an IP Convergence Sublayer (CS) with the RAS 120. The interface with the IMS core network 100 may be a Common Open Policy Server (COPS) interface. The ACR 110 may use a diameter interface with the AAA server (not shown). The ACR 110 allocates a unique service flow to each service connection.
The RAS 120 is positioned between the ACR 110 and the PSS 130 in order to provide a communication service to the PSS 130 or perform scheduling based on Medium Access Control (MAC) Quality of Service (QoS) information.
The PSS 130 can be provided with various services such as a VoIP service and supports the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard.
Once the PSS 130 sets up a call through SIP signaling, the policy server 150 is notified of call generation from the IMS server. The policy server 150 then generates an identifier for each flow of a session, i.e., a flow identifier (ID), and QoS profile information. The generated information is transmitted to the ACR 110 and the ACR 110 applies a QoS for each service flow based on the received information.
The PSS 200, the BS 210, the IMS server 220, and the policy server 230 include units that operate in terms of hardware and/or software in order to provide a QoS and the units maintain and manage profile information for application QoS 201, 209, and 211, 16 MAC QoS 203, 207, and 215 and IP QoS 205 and 213.
Profile information for each QoS can be configured as follows.
Connection information
Media format information
Bandwidth information
Packet classification (5 tuples): Source IP address, Destination IP address, Protocol, Source port number, and Destination port number.
QoS service class: DSCP (Diffserv Code Point)
QoS data rate
Service flow scheduling type
Tolerated jitter
Maximum latency
Maximum sustained traffic rate
Maximum traffic burst
Maximum reserved traffic rate
Maximum tolerable traffic rate
The IMS server 330 transmits the SIP_INVITE message to the PSS2340 in step 303. The PSS2340 transmits an SIP 183 message to the IMS server 330 in step 305. The SIP 183 message includes SDP information of the PSS2340.
The IMS server 330 transmits an authorization request message including SDP information including bearer information for a session to a policy server 320 in step 307. The policy server 320 generates an authorization identifier, i.e., an authorization token, and a flow ID and transmits an ACKnowledge (ACK) message including the generated authorization token and flow ID to the IMS server 330 in step 311. The authorization token includes information about a policy server that manages a QoS profile of a session and QoS authorization information.
The IMS server 330 transmits an SIP 183 message including the authorization token to the PSS1300 in step 313. The PSS1300 generates a flow ID in step 315 and encapsulates the QoS information of the PSS1300 and the authorization token received from the IMS server 330 into a Dynamic Service Addition-REQuest (DSA-REQ) message and transmits the DSA-REQ message to a BS 310 in step 317. The DSA-REQ message is a message requesting connection setup for a session.
The BS 310 transmits a Common Open Policy Server-DECision (COPS-DEC) message including binding information to the policy server 320 in step 319. The binding information means combined information of the authorization token and the flow ID.
The policy server 320 transmits the COPS-DEC message to the BS 310. The COPS-DEC message may include information indicating whether or not service connection is successful. Subsequent processes are not associated with the subject matter of the present invention and thus will not be described.
The IMS server 430 transmits the SIP_INVITE message to the PSS2440 in step 403. The PSS2440 transmits an SIP 183 message to the IMS server 430 in step 405. The SIP 183 message includes SDP information of the PSS2440.
The IMS server 430 transmits an authorization request message including SDP information including bearer information for a session to a policy server 420 in step 407. The policy server 420 generates an authorization identifier, i.e., an authorization token, and a flow ID and transmits an ACKnowledge (ACK) message including the generated authorization token and flow ID to the IMS server 430 in step 411.
The IMS server 430 transmits the SIP 183 message including the authorization token to the PSS1400 in step 413. The PSS1400 generates a flow ID for identifying a flow for each medium using its own SDP information in step 415 and transmits a DSA-REQ message including the authorization token received from the IMS server 430 and the generated flow ID in step 417.
The BS 410 transmits a COPS-REQ message including binding information, i.e., combined information of the authorization token and the flow ID, to the policy server 420 in step 419. The BS 410 then maps the flow ID and a Service Flow IDentifier (SFID) to each other in step 412. The SFID is generated by the BS 410 and the BS 410 logically maps the flow ID and the SFID to each other. The flow ID is used to identify a flow for each medium based on SDP information and the SFID means an identifier for unidirectional connection having a particular QoS.
The flow ID is flow information of an application layer, whereas the SFID is flow information of an MAC layer. The flow ID included in the DSA-REQ message received from a PSS is identical in a downlink and an uplink, whereas the SFID has to have a value for distinguishing between a downlink and an uplink. For this reason, the flow ID that is identical in the uplink and the downlink has to be mapped to the SFID that is different in the uplink and the downlink in step 421. Step 421 will be described in more detail with reference to
The mapped information will serve as binding information for mapping the SFID using QoS profile information provided from the policy server 420 using the flow ID.
The policy server 420 transmits a COPS-DEC message including QoS information and classifier information to the BS 410 in step 423. The policy server 420 maps SDP information for a session to IP QoS information and encapsulates the mapped information into the COPS-DEC message.
The BS 410 having received the COPS-DEC message allocates a bearer resource to a session, maps the received IP QoS information to MAC QoS information, and compares the received IP QoS information with MAC QoS information requested by the PSS1400 in order to determine a MAC QoS suitable for the PSS1400. The BS 410 encapsulates the determined MAC QoS information into a Dynamic Service Addition-Response (DSA-RSP) message and transmits the DSA-RSP message to the PSS1400 in step 427.
The PSS1400 transmits a DSA-ACK message to the BS 410 in response to the DSA-RSP message in step 427. The BS 410 transmits a COPSRPT message including information indicating that bearer resource allocation and MAC QoS determination are successful to the policy server 420 in step 429.
In step 439, the PSS1400 can perform traffic exchange to which a QoS provided from the IMS network is applied with the PSS2440 through SIP message transmission/reception (steps 423 through 437) between the PSS1400, the IMS server 430, and the PSS2440.
A PSS generates a flow ID for each medium using SDP information. Table 1 illustrates an example in which a PSS allocates a flow ID for each medium (m) and each uplink (UL)/downlink (DL). In Table 1, “RTP” indicates a Real Time Protocol and “RTCP” indicates a Real Time Control Protocol.
As mentioned above, the PSS has to encapsulate the flow ID into a DSA-REQ message and transmit the DSA-REQ message to a BS. The BS can apply a QoS profile for each flow using the received flow ID. Table 2 illustrates a DSA-REQ message format that is newly suggested in the present invention.
Although the flow ID generated by the PSS is transmitted through the DSA-REQ message herein, the flow ID can also be generated by a policy server. Thus, the PSS may receive the flow ID generated by the policy server and encapsulate the received flow ID into the DSA-REQ message for transmission to the BS. When the BS transmits the DSA-RSP message without receiving the DSA-REQ message from the PSS, it may encapsulate the flow ID into the DSA-RSP message for transmission.
The BS may acquire QoS information for each uplink and/or downlink traffic using the read 5-tuple information 706 and other information. The BS maps a flow ID and a newly generated SFID to each other based on the acquired QoS information. For example, the SFID #1 for UL audio may be mapped to a flow ID<1,1> transmitted from the PSS.
As described above, according to the present invention, when an IMS network and another type of network interwork with each other, a PSS can be provided with an optimized QoS. In particular, in a system where a portable Internet network and the IMS network interwork with each other, the PSS can be provided with an optimized QoS.
While the invention has been shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-37690 | Apr 2006 | KR | national |
| 2006-63871 | Jul 2006 | KR | national |
