KR100433581B1 - Call Control Method For Guaranteeing End-to-End QoS On Session Modification - Google Patents

Abstract

The present invention relates to a call control method for guaranteeing end-to-end quality of service according to a change of session information. An authentication procedure step of performing an authentication procedure in a network when the quality (QoS) is changed by the terminal; When the maximum transmission rate of the uplink and downlink of the PDP context drops or recovers to 0 Kbps, the packet gateway device (GGSN) notifies the policy control function (PCF) of the change of this PDP context. By providing a method consisting of the PCF notification step to perform, by providing a procedure for bearer authentication, reservation according to the session information change on the All-IP IMS domain, which is a concept that the SIP / SDP application signaling and GPRS bearer is separated, IMS subscriber Services can be provided flexibly, and the quality of service (QoS) can be guaranteed.

Description

Call control method for guaranteeing end-to-end service quality according to session information change {Call Control Method For Guaranteeing End-to-End QoS On Session Modification}

The present invention relates to a call control method for guaranteeing end-to-end quality of service according to a change of session information. In particular, a subscriber receiving a Universal Mobile Telecommunication System (UMTS) All-IP service changes a session information. The present invention relates to a call control method for resetting and authenticating a General Packet Radio Service (GPRS) bearer to ensure end-to-end quality of service.

In general, Quality of Service (QoS) is a unit of performance that indicates the transmission quality and service utilization of a transmission system, where transmission rates, error rates, and other characteristics can be measured and improved over the Internet and other networks. It is a concept that can be guaranteed in advance.

UMTS All-IP uses the Session Initiation Protocol (SIP) and Session Description Protocol (SDP) in the IP Multimedia Subsystem (IMS) domain to transfer, call setup, and control call-related information. do.

To establish an All-IP session between two terminals, first, at the application level through a negotiation process of exchanging SIP and SDP containing session information and exchanging necessary information for call setup. The call setup process is performed, and based on this information, the resources of the actual bearer are reserved so that the call can be made without delay when the call is made.

The bearer for call establishment uses the Packet Data Protocol (PDP) context of GPRS, so the bearer establishment procedure uses the existing GPRS procedure as it is. The connection between the additional application procedures is required, and this is called a binding mechanism, and is supported in the Policy Control Function (PCF) and the Gateway GPRS System Node (GGSN), respectively.

However, when GPRS bearer is reserved and the call is established according to the SDP information exchanged between two terminals at the time of initial call setup, the codec is changed or the data rate needs to be modified in the application session. The content is performed via SIP / SDP protocol signaling. This changed session information must then be applied to the bearer, which requires a change of authentication to ensure that the quality of service newly requested to the network is acceptable, and at this time, whether the GGSN itself will be processed based on previously performed information. The criteria for raising and handling authentication requests should be established.

However, there was no authentication and standard setting for this, and in some cases, if GGSN should notify the PCF only of the change of the bearer state without requiring authentication (for example, accurate recording such as charging due to abnormal call interruption between terminals). There is a problem that there is no call processing procedure for this case.

Accordingly, the present invention was devised to solve the above-mentioned conventional problems, and session information on an All-IP domain, in which SIP / SDP application signaling and GPRS bearer are separated to guarantee quality of service (QoS), is provided. An object of the present invention is to provide a call control method for bearer authentication, reservation, and resetting according to a change of a.

1 is an exemplary view showing the overall configuration of a UMTS All-IP service system according to an embodiment for applying the present invention.

2 is an exemplary view illustrating an operation flow of an authentication procedure according to a call control method for guaranteeing end-to-end service quality according to the change of session information of the present invention.

3 is an exemplary view showing an operation flow of PCF notification according to a call control method for guaranteeing end-to-end service quality according to the change of session information of the present invention.

<Description of Symbols for Main Parts of Drawings>

100: GPRS 110: SGSN

120: GGSN 200: SIP server

210: PCF 220: P-CSCF

In order to achieve the above object, a call control method for guaranteeing end-to-end quality of service according to a change of session information of the present invention includes a packet switching device (SGSN), a packet gateway device (GGSN), and a policy control function unit (PCF). Universal Mobile Telecommunications System (UMTS) All-IP service, the Universal Mobile Telecommunications System (UMTS) Quality of Service (QoS) that was authenticated at the time of initial creation or last modification of the Packet Data Protocol (PDP) context. An authentication procedure step of performing an authentication procedure in a network when the terminal is changed by the terminal; When the maximum transmission rate of the uplink and downlink of the PDP context drops to 0 Kbps or is recovered, the packet gateway device (GGSN) notifies the policy control function unit (PCF) of the change of the PDP context. Characterized in that it comprises a PCF notification step of performing the process.

Hereinafter, an operation process of an embodiment according to the present invention will be described with reference to the accompanying drawings.

1 is a view showing the overall configuration of a UMTS All-IP service system according to an embodiment for applying the present invention.

Referring to FIG. 1, a GPRS 100 including a user terminal, a Serving GPRS Support Node (SGSN, 110), and a packet transporting apparatus (GGSN, 120) and a policy decision function (PCF, 210) are built-in. It consists of a SIP server 200 including a proxy-call state control function (P-CSCF, 220).

The packet carrier (GGSN) 120 is a wireless switching network and a public so that when the wireless terminal is to perform a high-speed packet communication, the wireless terminal to perform data communication with a destination via a wireless switching network including a base station and accessing the general Internet network again. (public) plays a role of a gateway (Gateway) interworking with the Internet network, the packet switching device (SGSN, 110) is responsible for tracking the mobile node. This becomes a tunnel for exchanging packets with the GGSN 120, and the connection of this tunnel is called a bearer.

Hereinafter, an operation process according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is an exemplary view illustrating an operation flow of an authentication procedure according to a call control method for guaranteeing end-to-end service quality according to the change of session information of the present invention.

According to FIG. 2, when an 'Update PDP Context Request' message is received from the packet switch (SGSN) 110 (S10), the packet gateway device (GGSN) 120 receives a Local Policy Decision Point (LPDP). The LPDP function refers to a kind of cash function, and the 'Update PDP Context Request' message includes a request to modify a PDP context related to a media flow and a changed general purpose. It contains the mobile communication system (UMTS) quality of service (QoS) parameters.

As a result of the above determination, if the LPDP function is supported, the common open policy service (COPS) request message is queried before being sent to the policy control function unit (PCF). This is a protocol for obtaining QoS policy information.

If the requested QoS does not exceed the previously authenticated QoS and the binding information has not been changed, the authentication is performed through LPDP, and then the process directly proceeds to step S14 without the need for interworking with the PCF 210.

However, if the determination result does not support the LPDP function, or the inquiry result does not exceed the previously authenticated QoS, and the binding information is changed, a COPS request message is sent to the PCF 210 to request authentication (S11). ).

The PCF 210 receives the COPS request message (COPS REQ), performs a policy decision according to the requested change, and then transmits the same to the GGSN 120 through the COPS decision message (COPS DEC) (S12 ~). S13).

The GGSN 120 receives the COPS determination message and performs a policy decision based on the information in the LPDP or the COPS determination message received from the PCF to authenticate the PDP context in which the media flow is to be loaded. The GPSN includes a GGSN in the COPS determination message. Based on this, policy decision information is included to perform policy-based admission control (S14).

After the authentication is completed, the GGSN reports the policy decision performance result (COPS RPT) to the PCF (S15) and simultaneously transmits an 'update PDP context response' message to the SGSN (S16).

3 is an exemplary diagram illustrating an operation flow of PCF notification according to a call control method for guaranteeing end-to-end service quality according to a change of session information.

According to FIG. 3, the SGSN 110 notifies the GGSN 120 of the change of the PDP context information associated with the media flow when the maximum data rate of the uplink and the downlink of the PDP context drops or recovers to 0 Kbps. The update PDP context request 'message is transmitted to the GGSN 120 (S21).

When the 'Update PDP Context Request' message is received from the SGSN 110, the GGSN 120 transmits a COPS RPT message for notifying the PCF 210 of the PDP context change without requiring authentication (S22).

The PCF 210 receives the COPS RPT message to notify the call state control function 220 (P-CSCF) of the contents of the session information change to be reflected in the policy such as billing (S23).

The GGSN 120 sends a response message to the SGSN 110 after transmitting the COPS RPT message to the PCF 210 to notify the processing result of the PDP context information change request (S24).

In addition, the step S24 may be performed simultaneously with or before the step S23 to speed up call processing.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

As described above, the call control method for guaranteeing end-to-end quality of service according to the change of the session information of the present invention is a bearer according to the change of session information on the All-IP IMS domain, which is a concept in which SIP / SDP application signaling and GPRS bearer are separated. By providing procedures for authentication and reservation, it is possible to provide flexible services for IMS subscribers and to guarantee quality of service (QoS).

Claims (6)

In the Universal Mobile Telecommunications System (UMTS) All-IP Service, including a Packet Switching Device (SGSN), Packet Gateway Device (GGSN), and Policy Control Function Unit (PCF), The authentication process in the network when the Universal Mobile Telecommunication System (UMTS) Quality of Service (QoS), which was authenticated when the packet data protocol (PDP) context was first created or last modified, was changed. Performing an authentication procedure; When the maximum transmission rate of the uplink and downlink of the PDP context drops to 0 Kbps or is recovered, the packet gateway device (GGSN) notifies the policy control function unit (PCF) of the change of the PDP context. Call control method for guaranteeing end-to-end quality of service according to the session information change, characterized in that it comprises a PCF notification step of performing a process. The method of claim 1, The authentication process step A first step of determining whether the packet gateway device (GGSN) supports a Local Policy Decision Point (LPDP) function when receiving the 'Update PDP Context Request' message from the packet switching device (SGSN); ; A second step of inquiring a common open policy service (COPS) request message before sending it to the policy control function unit (PCF) if the LPDP function is supported as a result of the determination in the first step; As a result of the inquiry of the second step, if the requested QoS does not exceed the previously authenticated QoS and the binding information has not been changed, after authenticating the COPS request message through the LPDP, the process does not need to interwork with the PCF. Performing a third step; If the determination result of the first step does not support the LPDP function, or the inquiry result of the second step does not exceed the previously authenticated QoS, and the binding information is changed, a COPS request message is sent to the PCF to request authentication. Performing a fourth step; A fifth step of authenticating the PDP context that will carry the media flow by performing a policy decision according to the information in the LPDP after the third step of authentication; Alternatively, after receiving the COPS request message of the fourth step, the policy decision is performed according to the requested change, and then received through the COPS decision message, the policy decision is performed according to the COPS decision message received from the PCF. A sixth step of authenticating the PDP context to be loaded; And a seventh step of reporting the result of the policy decision to the PCF after the authentication of the fifth step or the sixth step is completed, and transmitting an 'update PDP context response' message to the SGSN. Call control method to guarantee end-to-end service quality The method of claim 2, The 'Update PDP Context Request' message includes a request to modify a PDP context regarding a media flow and a modified Universal Mobile Telecommunication System (UMTS) Quality of Service (QoS) parameter. Call control method to guarantee inter-service quality. The method of claim 2, The COPS determination message of the fifth step includes policy decision information so that the GGSN can perform policy-based admission control based on this. The method of claim 1, The PCF notification step A first message for transmitting an 'Update PDP Context Request' message informing the GGSN that the PDP context information associated with the media flow has changed when the maximum data rate of the uplink and downlink of the PDP context drops to 0 Kbps or is recovered. Steps; A second step of transmitting a COPS RPT message informing the PCF of the PDP context change without requiring authentication when an 'Update PDP Context Request' message is received from the SGSN; A third step of receiving a COPS RPT message from the second step and notifying the Call State Control Function (P-CSCF) of the contents of the session information change; Guaranteeing end-to-end quality of service according to the session information change characterized in that it comprises a fourth step of sending a response message to the SGSN after the transmission of the COPS RPT message of the second step to notify the processing result of the PDP context information change request Call control method for the. The method of claim 5, The fourth step is a call control method for guaranteeing end-to-end quality of service according to the change of the session information, characterized in that performed at the same time or before the third step to speed up the call processing.