METHOD, SYSTEM AND DEVICE FOR REALIZING GROUP TALK QoE

0001This application claims benefit to Chinese patent application no. <patcit id="pcit0001" dnum="CN200610081659X"><text>200610081659,X</text></patcit>, entitled "Method and System for Implementing Quality of Experience of Group Session" and filed with the Chinese Patent Office on May 19, 2006, which is hereby incorporated by reference in its entirety.

Field of the Invention

0002The present invention relates to the field of communication technologies and in particular to a method, system and device for implementing Quality of Experience of a group session.

Background of the Invention

0003With the development of media compression and wireless network technologies, stream media technologies have been more and more widely used. Although bandwidth in wireless networks are increasing, unlike a fixed network, inherent factors in wireless networks, such as a package loss ratio, jitter, time delay, may have an influence upon user's application experience. Consequently, for various media services, it is an important requirement to improve user's Quality of Experience (QoE). The Quality of experience refers to a degree to which a service satisfies the expectation of a user, and it primarily evaluates service performance from the point of view of a user. User's Quality of Experience of a service involves various aspects, such as Quality of Service (QoS) and priorities.

0004The Quality of Experience may be a single user's Quality of Experience, or may be a group's Quality of Experience, in which a group is consisted of a plurality of users. A group's QoE may be understood as requirements for quality of group service that are related to respective user members in the group, and different QoEs of the group represent different requirements of the group for service experience.

0005For example, the Push to Talk over Cellular (PoC) introduces point-to-point and point-to-multipoint voice communication services in a cellular network. It enables a user to enjoy popular bidirectional wireless talk-back services with the use of a mobile phone, and thereby facilitates mobile services and provides a new business opportunity in the voice communication field.

0006Typical flow of a PoC group session in the prior art is as illustrated in <figref idref="f0001">Fig.1</figref>.

00071. A PoC client A initiates a group session request;

00082. A PoC server A sends the group session request to a PoC server X;

00093. The PoC server X requests a shared group server for a group document of the group;

00104. The shared group XML Document Management (XDM) server returns the group document in a response message;

00115. The PoC server X sends session invitation messages to respective members;

00126. The PoC server X, upon receipt of a first ALERTING response, returns a response message ALERTING to the PoC server A;

00137. The PoC server A sends the response message ALERTING to the PoC client A;

00148. The PoC server X, upon receipt of a first invitation acceptance response message, returns an invitation acceptance response message to the PoC server A;

00159. The PoC server A returns an invitation acceptance response message to the PoC client A.

0016In the PoC, different groups have different requirements for Quality of Experience, so it is required that the system can differentially process QoEs of different groups, however, the existing PoC system provides no corresponding processing mechanism.

Summary of the Invention

0017A primary object of the invention is to provide a method and system for implementing Quality of Experience of a group session, to achieve differentiated services for different groups.

0018Another object of the invention is to provide a group session control server to implement differentiated group session services.

0019Therefore, embodiments of the invention provide the following solutions.

0020A method for implementing Quality of Experience of a group session includes the steps of:

0021determining, by a group session control server, a QoE type of the group session in accordance with preset QoE type information corresponding to the group, when establishing a group session; and

0022configuring, by the group session control server, properties of the established session in accordance with the QoE type corresponding to the group.

0023A system for implementing Quality of Experience of a group session includes,

0024a user device adapted to initiate a group session;

0025a shared group server adapted to store group information including lists of group members and group Quality of Experience QoE types; and

0026a group session control server connected respectively wit the user device and the shared group server, adapted to control the group session requested by the user device in accordance with the group information stored in the shared group server and to configure properties of the established group session in accordance with the QoE type corresponding to the group.

0027A group session control server includes:

0028a group information obtainment module, adapted to obtain QoE types of a group and users in accordance with a group session request message received from a user device;

0029a QoE mapping module, adapted to store QoE mapping information composing a QoE type and corresponding session property parameters; and

0030a session control module, adapted to obtain the QoE mapping information from the QoE mapping module in accordance with the QoE type of the group and to configure properties of the group session to be established in accordance with the QoE mapping information.

0031As can be seen from the above solutions provided according to the embodiments of the invention, the invention sets a group QoE type in group information and thus can configure properties of an established group session in accordance with the QoE type corresponding to the group when the session is established. The group session service property is controlled in accordance with the QoE property so as to implement differentiated group session services effectively.

Brief Description of the Drawings

0032<figref idref="f0001">Fig.1</figref> is a typical flow chart of a PoC group session in the prior art;

0033<figref idref="f0001">Fig.2</figref> is a flow chart of a method for implementing Quality of Experience of a group session according to one embodiment of the invention;

0034<figref idref="f0002">Fig.3</figref> is a flow chart of a method in which a group QoE type is configured through an XDM client according to one embodiment of the invention;

0035<figref idref="f0002">Fig.4</figref> is a flow chart of a method in which a user is added into a group through an XDM client according to one embodiment of the invention;

0036<figref idref="f0003">Fig. 5</figref> is a flow chart of a user initiating a group session request in a method according to one embodiment of the invention;

0037<figref idref="f0004">Fig.6</figref> is a flow chart of a receiver accepting a group session invitation in a method according to one embodiment of the invention;

0038<figref idref="f0004">Fig.7</figref> is a principle diagram of a system for implementing Quality of Experience of a group session according to one embodiment of the invention;

0039<figref idref="f0005">Fig.8</figref> is a principle diagram of a group session control server according to one embodiment of the invention;

0040<figref idref="f0005">Fig.9</figref> is a flow chart of adding a user into a group during a PoC group session application according to one embodiment of the invention;

0041<figref idref="f0006">Fig. 10</figref> is a flow chart of a user initiating a PoC group session during a PoC group session application according to one embodiment of the invention; and

0042<figref idref="f0007">Fig.11</figref> is a flow chart of a user initiating an IM group session during an IM group session application according to one embodiment of the invention.

Detailed Description of the Invention

0043The invention will be further described in details hereinafter with reference to the drawings and embodiments, for better understanding of the technical solutions of the present invention by those skilled in the art.

0044With reference to <figref idref="f0001">Fig.2</figref>, it illustrates a flow chart of a method for implementing Quality of Experience of a group session according to one embodiment of the invention. The method includes the following steps:

0045Step 201: set QoE types corresponding to groups.

0046QoE type identifiers corresponding to respective groups can be configured directly in a shared group server or by a group administrator through an XML Document Management (XDM) client. In other words, QoE type identification information corresponding to the respective groups is added in the group information stored in a shared group server. According to practical application requirements, the QoE type identification information to be configured for the respective groups may also been stored in a group session control server, and when requesting establishment of a group session, a user may conveniently obtain the QoE type identifier corresponding to the group and thereby determine properties of the group session to be established.

0047For example, an element of <qoe-profile-group> is added into the shared group server to indicate a configured QoE type, the value of which is defined as follows:

0048Basic type , indicating a basic QoE;

0049Professional type, indicating a professional QoE;

0050Crisis type, indicating a critical QoE;

0051Office Government Use type, indicating an official application QoE.

0052The above QoE types are sequenced in an ascending order of level as follows: Basic, Profession, Crisis and Official Government Use.

0053Alike, when the group information is required to be modifies, user information may be added directly into the group information stored in the shared group server, or the user information may be added into the group information stored in the shared group server through the XDM client.

0054A specific procedure will be described in detail below in which a group QoE type identifier is configured in the shared group server through the XDM client and a user is added into a group stored at the shared group server through the XDM client.

0055Step 202: When establishing a group session, the group session control server determines a QoE type of the group session according to configured information.

0056When a group session is established, it may be that a preset group QoE type is directly used as a QoE type of the present session, or that a QoE type that meets requirements is determined for the group session under comprehensive consideration of the group QoE type and QoE types to which respective group members subscribe. Practically, it also may be that an initial group QoE type is designated by a session initiator, and the group session control server determines a QoE type identifier of the group session in accordance with the initial group QoE type, the group configured information and the member subscription information, a specific procedure of which will be detailed below.

0057Step 203: The group session control server configures properties of the established session in accordance with the determined QoE type of the group session.

0058QoE mapping information may be configured on the group session control server in advance, and the QoE mapping information includes QoE type identifier and session property parameters corresponding to the QoE type identifier, and the session property parameters include parameters such as network quality of service and session priorities. Thus, after receiving a group session request message and determining the QoE type of the group session, the group session control server may inquire about the QoE mapping information in accordance with the QoE type identifier of the group and obtain the session property parameters corresponding to the QoE type identifier. Thus, during establishment of the group session, the group session control server may configure property of the session to be established in accordance with corresponding session property parameters such as network quality of service and session priorities.

0059<figref idref="f0002">Fig.3</figref> is a flow chart of a process in which a group QoE type is configured through an XDM client according to an embodiment of the invention.

00603-1. A group administrator sends, through the XDM client, to a shared group server a request message XCAP PUT requesting to set group QoE configuration information, and the XCAP PUT message carries configuration information including a group identifier, a QoE type identifier corresponding to the group identifier, and etc.

00613-2. The shared group server, upon receipt of the XCAP PUT message, extracts an identifier of a message requester from the XCAP PUT message and performs authorization check on the QoE configuration, that is, to check whether the requester is authorized to configure a group QoE type.

00623-3. After the check is passed, the configuration information is stored and a success response message (200 OK) is returned to the XDM client.

0063In addition to the group identifier and the QoE type identifier corresponding to the group identifier, the configuration information carried in the above XCAP PUT request message requesting to set group QoE configuration information may also carry a member QoE mandatory flag that indicates whether it is required to validate a QoE type of a user, that is, indicating whether there is a minimum requirement for a QoE of a group member, or in other words, whether it is required that the level of QoE type identifier of a group member is not lower than that of the group QoE type identifier. With the member QoE mandatory flag, when a user is added into a group stored in the shared group server through the XML document management client, the shared group server may validate the QoE type of the user to be added into the group in accordance with the member QoE mandatory flag; or when the user initiates a group session, the group session control server may validate the QoE types of respective members in the group in accordance with the member QoE mandatory flag. Certainly, the member QoE mandatory flag may not be included, and the shared group server or the group session control server acquiesces in the validation of the QoE types of respective members in the group.

0064In this regard, detailed descriptions will be presented respectively below.

0065Firstly, with reference to <figref idref="f0002">Fig.4</figref>, it shows a flow chart of a method in which a user is added into a group through the XDM client according to an embodiment of the present invention.

00664-1. The XDM client sends to the shared group server a request message for adding a member into a group.

00674-2. The shared group server, upon receipt of the request message for adding a member into a group, exacts a user identifier and a group identifier in the message and obtains QoE type identifiers of the user and the group in accordance with the user identifier and the group identifier.

0068When the user to be added into the group is in the same domain as the shared group server, the shared group server can obtain the QoE type identifier of the user directly and locally, i.e., a QoE type identifier to which the user subscribes.

0069When the user to be added into the group is not in the same domain as the shared group server, the shared group server can obtain the QoE type identifier of the user through accessing the user QoE configuration information in a domain where the user is located, or can directly set the minimum level identifier as the QoE type identifier of the user.

0070For example, if the shared group server belongs to a domain A and the user to be added belongs to a domain B, the shared group server may obtain QoE type configuration information of the user in the following two methods:

0071First method: If the two domains A and B may share QoE type identifier configuration information of their users, the shared group server may obtain the QoE type identifier of the user to be added through accessing QoE type identifier configuration information of the user in the domain B; or if not, the QoE type identifier of the user is acquiesced to be Basic, and thus the shared group server in the domain A may consider the QoE type identifier of the user that belongs to the domain B as Basic.

0072Second method: The QoE type identifier of the user is stored in an XDM server dedicated for storage of user personal information, and thus when the shared group XDM server needs to obtain the QoE type identifier of the user who does not belong to the present domain, the shared group XDM server may access the XDM server in the domain where the user is located so as to obtain the QoE type identifier of the user, in which the XDM server stores user personal information.

00734-3. While a member QoE mandatory flag is present in the QoE configuration information of the group, the shared group server validates the above QoE configuration type identifier, i.e., compares and determines whether a level of the QoE type of the user is not lower than that of the QoE type of the group.

0074While the level of the QoE type of the user is higher than or equal to that of the QoE type of the group, the user is added into the group; and

0075While the level of the QoE type of the user is lower than that of the QoE type of the group, the user is rejected to be added into the group.

0076The process of validating the QoE types of the group members may also be performed when the group session is initiated, in which the group session control server validates the QoEs of the respective members in the group, a specific procedure of which will be detailed below.

00774-4. The shared group XDM server generates a response message in accordance with a validation result.

0078While the validation is not passed, a failure response message is generated with failure reason included in the message body, and the message includes the QoE configuration type identifier of the group.

0079If the validation is passed, a success response message is generated.

00804-5. The corresponding response message is sent to the XDM client in accordance with the validation result.

0081If the member QoE mandatory flag is present in the QoE configuration information of the group, the group session control server also validates the QoE types of the group members when the group session is initiated, in the following procedure:

00821. After obtaining group information, the group session control server firstly obtains the QoE type identifier of each member in the group (i.e., the QoE type identifier to which the group member user subscribes).

00832. The group session control server checks whether the QoE type identifier of each member satisfies QoE type requirement of the group (that is, the level of the QoE type of the member is not lower than that of the QoE type of the group), the group members who do not satisfy the requirement are deleted from the group, and a notification message is sent to the deleted group members.

00843. Finally, a group session invitation is sent to each group member satisfying the QoE type requirement.

0085As mentioned previously, in order to implement differentiated services for different groups, when a group session is established, the group session control server needs to obtain the QoE type identifier information of the group, and inquire about the QoE mapping information in accordance with the QoE type identifier, to obtain the session property parameters corresponding to the QoE type identifier and configure properties of the session to be established using these parameters.

0086The group session control server may read directly the shared group server, obtain the stored QoE type of the group and use it as the QoE type of the group for which the session is established, or may determine the QoE type of the group session through a QoE negotiation procedure.

0087The QoE negotiation procedure, through which the QoE type identifier information of the group session is determined, is as follows:

008810 The user initiates, through a client, a request message for a group session to the group session control server. The request message carries initial QoE type information and/or session QoE type mandatory information.

00892. The group session control server sends an invitation message respectively to respective members in the group.

00903. The group session control server determines a QoE type of the group session in accordance with QoE type levels in the received response messages from the respective members.

0091If the request message for the group session carries the session QoE type mandatory information, the group session control server may, after determining the QoE type of the group session, check whether the level of the determined QoE type of the group session is lower than that of the initial QoE type in the session request message, and if yes, the establishment of the present session is determined to be failed; or if not, a normal session flow is established.

0092The QoE negotiation procedure will be further described in detail below with reference to <figref idref="f0003">Fig.5</figref> and <figref idref="f0004">Fig.6</figref>.

0093With reference to <figref idref="f0003">Fig.5</figref>, it illustrates a flow of a user initiating a group session request according to an embodiment of the present invention.

00945-1. A user A initiates a request message INVITE for a group session to a group session control server A, and the message may include an initial QoE type code designated by the user A, and a session QoE type mandatory flag indicating whether a QoE type code allocated to the group session should satisfy the initial QoE type code in the message, so that a session receiver can decide whether to accept the invitation in accordance with the flag. The value of this field of the QoE type mandatory flag may indicate whether the condition to be satisfied is Mandatory or Optional.

00955-2. The group session control server A, upon receipt of the request message from the user A, may determine the initial QoE type code as an invitation QoE type code if the request message carries the initial QoE type code, or may send to the shared group server an XCAP GET requesting QoE type information of the group if the request message carries no initial QoE type code.

00965-3. The shared group server returns the QoE type information of the group to the group session control server A in a 200 OK message.

00975-4. The group session control server A extracts the QoE type identifier of the group and determines it as the invitation QoE type code.

00985-5. The group session control server A invites respective members in the group sequentially using an invitation message including the determined invitation QoE type code, and returns an ALERT message to the user A after receiving a first ALERTING request message.

00995-6. The group session control server A, after receiving responses from all of the session receivers, allocates a QOE type code, for example, the lowest one of the QoE type levels included in all responses, to the group, in accordance with the responses from the respective receivers. If the level of the initial QoE type code designated by the user A is lower than the lowest one of the QoE type levels included in all the responses, the initial QoE type code may also be selected as the QoE type code of the group session. If the determined group QoE type level does not satisfy the initial QoE type level designated by the user A, an error message may be returned to the user A.

0100In the above procedure, for a specific type of the invitation QoE type code (e.g., the type of Crisis), the QoE type Crisis may be directly allocated to the group session, regardless of the responses from the respective session receivers.

0101The QoE type code may not be included in the invitation message sent by the group session control server A to the respective members in the group, but be allocated to the group, i.e., the QoE type code of the present session may be determined, in accordance with responses from the respective receivers, upon receipt of the responses from the session receivers.

01025-7. The group session control server A, after receiving the first invitation acceptance response message, returns to the user A a final response message (OK) including the QoE type code allocated to the session by the group session control server A.

01035-8. The group session control server A configures session property, e.g., a priority of the session, QoS parameters of the session, etc., in accordance with the QOE mapping information.

0104With reference to <figref idref="f0004">Fig.6</figref>, it illustrates a flow of a receiver accepting a group session invitation according to an embodiment of the invention.

01056-1. A group session control server B at a receiving side receiver sends to a participating server B at the receiving side a group session invitation message including invitation QoE type information.

01066-2. The participating server B determines a response QoE type code, puts the response QoE type code into an ALERTING message and returns the message to the group session control server B, where the response QoE type code is determined in accordance with QoE subscription information of a user B at the receiving side.

0107The participating server B may also determine whether to accept the present session invitation in accordance with QoE type configuration information of the user B and the invitation QoE type information, and if the present session invitation is accepted, the server returns the QoE type identifier of the user B in an ALERTING request message to the group session control server of the session initiator; or if the present session invitation is not accepted, the server may send an invitation rejection message to the group session control server of the session initiator.

01086-3. After determining responses from all users at the receiving side, the group session control server at the transmitting side determines a final QoE type code to be allocated to the group session and sends it in a PRACK message to respective participating servers including the participating server B.

01096-4. The participating server B sends to the user B a group session INVITE message including the final QoE type code.

01106-5. The user B sends a session acceptance response message OK.

01116-6. The participating server B forwards the response message to the group session control server B.

0112It can be seen that, with the invention, the QoE type of the group session can be determined not only through the shared group server but also through the QoE negotiation procedure, thereby further improving the flexibility of applications of the invention. The invention can be applied to numerous different group session procedures.

0113With reference to <figref idref="f0004">Fig.7</figref>, it illustrates a principle diagram of a system according to a preferred embodiment of the invention.

0114The embodiment of the system includes: a user device 81, a shared group server S2, and a group session control server S3 connected respectively with the user device S1 and the shared group server S2. Particularly, the user device S1 is adapted to initiate a group session; the shared group server S2 is adapted to store group information including lists of group members and group QoE type identifiers; and the group session control server S3 is adapted to control the group session requested by the user device S1 in accordance with the group information stored in the shared group server S2, and to configure properties of the established group session in accordance with the QoE type of the group.

0115The QoE type identifiers corresponding to respective groups can be configured directly in the shared group server S2 and a user is added into a group stored in the shared group server. Alternatively, the QoE type identifiers corresponding to respective groups can be configured in the shared group server by a group administrator through an XML document management client S4 and a user is added into a group stored in the shared group server. When the XML document management client S4 adds a user into a group stored in the shared group server S2, the shared group server may also validate a QoE type of the user to be added into the group. The specific procedure thereof could be obtained with reference to the previous description of the method of the present invention.

0116The user device S1 may initiate a group session request through a group session client and stores the QoE type identifier of the user in the group session client, so as to select the QoE type when the session is initiated.

0117In order to implement differentiated services for different groups, the group session control server S3 according to the embodiment of the invention includes a group information obtainment module S31 and a session control module S32, and also includes a QoE mapping module S33 for storage of QoE mapping information. The QoE mapping information includes QoE type identifiers and session property parameters corresponding to the QoE type identifiers.

0118When the user device S1 requests the group session control server S3 for a group session, the group information obtainment module S31 obtains the QoE type identifiers of the user and the group from the shared group server S2 in accordance with the group session request message received from the user device and sends the obtained QoE type identifiers to the session control module S32. The session control module S32 obtains corresponding QoE mapping information from the QoE mapping module in accordance with the QoE type identifier of the group, and configures properties of the group session to be established in accordance with the corresponding QoE mapping information.

0119A specific procedure in which a user initiates a group session and a receiver receives a group session invitation is the same with that of the present invention as described above, and descriptions thereof will be omitted here.

0120<figref idref="f0005">Fig.8</figref> illustrates a principle diagram of the group session control server according to another embodiment of the invention.

0121In this embodiment, the group session control server includes: a group information obtainment module S31, a session control module S32, a QoE mapping module S33 and a group information storage module S34. Particularly, the group information obtainment module S31 is adapted to obtain QoE types of a group and users in accordance with a group session request message received from a user device; the QoE mapping module S32 is adapted to store QoE mapping information including QoE types and session characteristics parameters corresponding to the QoE types; the session control module S33 is adapted to obtain the QoE mapping information from the QoE mapping module in accordance with the group QoE type, and to configure properties of a group session to be established in accordance with the QoE mapping information; and the group information storage module S34 is adapted to store group information including lists of group members and group QoE types.

0122When the user device requests the group session control server for a group session, the group information obtainment module S31 obtains QoE type identifiers of users and groups from the group information storage module S34 in accordance with the group session request message received from the user device, and sends the obtained QoE type identifiers to the session control module S32. The session control module S32 obtains corresponding QoE mapping information from the QoE mapping module in accordance with the QoE type identifier of the group and configures, in accordance with the information, properties of the group session to be established.

0123The invention may be applied to numerous different group session procedures, and applications of the invention in different contexts will be further described below by way of examples of a PoC group session and an Instant Messaging (IM) group session.

0124Example 1: Taking a PoC group session as an example, it is assumed that PoC client A is an owner of a group G, the QoE type identifier of the group G is Professional and the member QoE mandatory flag is Mandatory". User A firstly adds users U and V into the group G, and calls clients of the users U and V, i.e., PoC client U and PoC client V, through the PoC client A. It is assumed that QoE configuration of the user U is Professional, QoE configuration of the user V is Official Government Use. There is additionally a group H with a QoE type identifier Basic and a member QoE mandatory flag Mandatory.

0125A procedure in which the user A adds the user U into the group G is as illustrated in <figref idref="f0005">Fig.9</figref>.

01268-1. The user A sends through its XDM client A to an aggregation proxy a request for adding the user U into the group G.

01278-2. The aggregation proxy forwards the request for adding the user U into the group G

01288-3. The share group server obtains a QoE type identifier of the user U in the request message and a QoE type identifier in the QoE configuration of the group A

01298-4. Because the member QoE mandatory flag of the group is Mandatory, the shared group server validates the QoEs; and because the QoE type identifier of the user U is Professional and the QoE type identifier of the group is also Professional, the verification is passed.

01308-5. The shared group server generates a success response message in accordance with the validation result.

01318-6. The shared group server returns a success response to the aggregation proxy.

01328-7. The aggregation proxy forwards the response to the XDM client A, and the user A adds the user U into the group G successfully.

0133The procedure in which the user A adds the user V into the group G is similar to the above procedure.

0134A flow in which the user A initiates a PoC group session is as illustrated in <figref idref="f0006">Fig.10</figref>.

01359-1. The PoC client A sends a group session invitation message. The group session invitation message includes an identifier of the group, an initial QoE type identifier and a session QoE mandatory flag, in which the initial QoE type identifier is set as Professional and the session mandatory flag is set as Mandatory.

0136The message mainly includes the following contents:

0137Initiator identifier: a Session-Initiation-Protocol Uniform Resource Identifier (SIP URI) of client A;

0138Group identifier: a service Uniform Resource Identifier (URI) of the group G;

0139QoE type identifier: Professional; and

0140QoE mandatory flag: Mandatory.

01419-2. A PoC participating server A forwards the message to a PoC control server X.

01429-3. The PoC control server X extracts the identifier of the group G in the message and sends to the shared group server a request for obtaining a group document corresponding to the above group.

01439-4. The shared group server returns the requested group document.

01449-5. The PoC control server X extracts the QoE type identifier of the group, obtains its value Professional and determines the QoE type identifier of the session as Professional.

0145According to global configuration, the level of QoE type of a group session that can be initiated by the user may be restricted not to exceed the level of a QoE type designated in the definition of the group, and if the QoE type level in the group session request message is higher than that of the QoE type designated in the group definition, the value of the QoE type identifier of the session should be the QoE type identifier in the definition of the group.

01469-6. The PoC control server X sends to a PoC participating server C a session invitation message, and the QoE type identifier of the session is included in the session invitation message.

01479-7. The PoC participating server B returns to the PoC control server X an ALERTING message, and the QoE type identifier Professional of the user B is included in the ALERTING message.

01489-8. The PoC control server X sends to the PoC participating server C a session invitation message, and the QoE type identifier of the session is in the session invitation message.

01499-9. A PoC participating server C returns to the PoC control server X an ALERTING message, and a QoE type identifier "Official Government Use" of the user C is included in the ALERTING message.

01509-10. The PoC control server X determines a final QoE type identifier allocated to the group session as Professional, in accordance with the QoE type identifiers in the response messages in the previous four steps, and performs QoE configuration of the group session in accordance with the QoE type identifier. Practically, the PoC control server X may also perform QoE configuration of the group session after receiving invitation acceptance response messages from all members.

0151Because the session QoE mandatory flag in the group session request message is Mandatory, that is, it is required that the group session satisfies the designated QoE type identifier; if a QoE type level that is lower than the designated QoE type level is returned in either of the steps 9-7 and 9-9, the session falls.

0152The above steps 9-6 to 9-10 are a procedure of negotiating about the QoE type of the session, In the procedure, the PoC control server X receives QoE type parameters in the group session invitation message and sends the session invitation to respective session members. The participating server of each session member, after receiving the invitation, issues a QoE type response to the PoC control server X in accordance the QoE configuration information of the member, and the PoC control server X designates the QoE type of the entire session in accordance with the QoE type responses of the respective members and thereafter configures the session in accordance with the QoE type of the session.

01539-11. The PoC control server X sends to the PoC participating server B a PRACK message, and the final QoE type identifier is included in the PRACK message.

01549-12. The PoC participating server B sends to the PoC client B a group session invitation message, and the final QoE type identifier is included in the group session invitation message.

01559-13. The PoC client B returns an ALERTING message to the PoC participating server B.

01569-14. The PoC participating server B sends the ALERTING message to the PoC control server X.

01579-15. The PoC control server X sends the ALERTING message to the PoC participating server A.

01589-16. The PoC participating server A sends the ALERTING message to the PoC client A initiating the session.

01599-17. The PoC control server X sends to the PoC participating server C a PRACK message including a final QoE type identifier.

01609-18. The PoC participating server C sends to the PoC client C a group session invitation message INVITE including the final QoE type identifier.

01619-19. The PoC client C returns an ALERTING message to the PoC participating server C.

01629-20. The PoC participating server C returns the ALERTING message to the PoC control server.

01639-21. The PoC client B sends a final response message to the PoC participating server B.

01649-22. The PoC participating server 8 sends the final response message to the PoC control server X.

01659-23. The PoC control server X sends the final response message to the PoC participating server A.

01669-24. The PoC participating server A returns the final response message to the PoC client.

01679-25. The PoC client C returns the final response message to the PoC participating server C.

01689-26. The PoC participating server C returns the final response message to the PoC control server X.

0169A procedure of establishing a group session of group H is similar to that of establishing a group session of group G and is particularly as follows.

0170The initiator initiates a session request including an initial group session QoE type identifier Basic and a member QoE mandatory flag Mandatory; the group server sends to respective members a session invitation message carrying the QoE type identifier Basic; the participating server corresponding to each member returns an ALERTING response message carrying the QoE type identifier "Basic", the group server sends to the respective participating servers a PRACK message carrying a final QoE type identifier Basic; the respective participating servers send to the respective members a session invitation message carrying the QoE type identifier Basic; and finally, a group session is established, with a corresponding QoE type identifier Basic.

0171A procedure in which the group session server configures properties of a group session in accordance with different QoE types will be further described in detail below.

0172Some IP network performance parameters are defined as follows:

0173IPTD: IP Packet Transmission Delay, It defines a time period for an IP packet to pass a basic segment or a set of network segments, regardless whether the packet is transmitted successfully.

0174IPDV: IP Packet Delay Variation. An end-to-end IP packet delay variation between two points (vk) indicates a difference between an actual delay from the time at which an IP packet k (xk) passes a source node SRC (MP1) to the time at which the IP packet k (xk) passes a destination node DST (MP2) and a transmission delay (d1, 2) for a reference IP packet to transmit through the same path, that is, vk=xk-d1, 2.

0175IPER: IP Packet Error Ratio. It refers to a ratio of the number of error IP packets to a sum of the number of successful IP packets and the number of error IP packets.

0176IPLR: IP packet loss ratio. An IP packet throughout in bytes at an egress node is equal to the number of all bytes in successful IP packets that are observed at this node during a specific interval of time divided by this interval of time.

0177Session service QoS levels and corresponding network performance parameter indexes are defined in Table 1 below: <tables id="tabl0001" num="0001"><table frame="all"><title>Table 1:</title><tgroup cols="5"><colspec colnum="1" colname="col1" colwidth="20mm" /><colspec colnum="2" colname="col2" colwidth="16mm" /><colspec colnum="3" colname="col3" colwidth="15mm" /><colspec colnum="4" colname="col4" colwidth="16mm" /><colspec colnum="5" colname="col5" colwidth="16mm" /><thead><row><entry align="center" valign="top">Qos Class</entry><entry align="center" valign="top">IPTD</entry><entry align="center" valign="top">IPDV</entry><entry align="center" valign="top">IPLR</entry><entry align="center" valign="top">IPER</entry></row></thead><tbody><row><entry align="center">Class 0</entry><entry align="center">100 ms</entry><entry align="center">50 ms</entry><entry align="center">5 x 10-4</entry><entry align="center">5 x 10-5</entry></row><row><entry align="center">Class 1</entry><entry align="center">180 ms</entry><entry align="center">55 ms</entry><entry align="center">5 x 10-4</entry><entry align="center">5 x 10-5</entry></row><row><entry align="center">Class 2</entry><entry align="center">240 ms</entry><entry align="center">60 ms</entry><entry align="center">5 x 10-4</entry><entry align="center">5 x 10-5</entry></row><row><entry align="center">Class 3</entry><entry align="center">300 ms</entry><entry align="center">70 ms</entry><entry align="center">5 x 10-4</entry><entry align="center">5 x 10-5</entry></row></tbody></tgroup></table></tables>

0178A QoE type identifier may be mapped to a session priority parameter and the above QoS level, as shown in Table 2 below: <tables id="tabl0002" num="0002"><table frame="all"><title>Table 2:</title><tgroup cols="3"><colspec colnum="1" colname="col1" colwidth="39mm" /><colspec colnum="2" colname="col2" colwidth="20mm" /><colspec colnum="3" colname="col3" colwidth="27mm" /><thead><row><entry align="center" valign="top">QoE Type Identifier</entry><entry align="center" valign="top">QoS Level</entry><entry align="center" valign="top">Session Priority</entry></row></thead><tbody><row><entry align="center">Basic</entry><entry align="center">Class 3</entry><entry align="center">0.1</entry></row><row><entry align="center">Professional</entry><entry align="center">Class 2</entry><entry align="center">0.2</entry></row><row><entry align="center">Crisis</entry><entry align="center">Class 1</entry><entry align="center">0.3</entry></row><row><entry align="center">Official Government Use</entry><entry align="center">Class 0</entry><entry align="center">0.4</entry></row></tbody></tgroup></table></tables>

0179In accordance with the above information, the QoE type identifier "Basic" is mapped to the QoS level "Class 3" and the session priority "0.1"; and the QoE type identifier "Professional" is mapped to the QoS level "Class 2" and the session priority "0.2".

0180In accordance with the above mapping results, respective parameters of a QoS of the group G are set as respective parameter values in Table 3 below: <tables id="tabl0003" num="0003"><table frame="all"><title>Table 3:</title><tgroup cols="6"><colspec colnum="1" colname="col1" colwidth="20mm" /><colspec colnum="2" colname="col2" colwidth="16mm" /><colspec colnum="3" colname="col3" colwidth="15mm" /><colspec colnum="4" colname="col4" colwidth="16mm" /><colspec colnum="5" colname="col5" colwidth="16mm" /><colspec colnum="6" colname="col6" colwidth="15mm" /><thead><row><entry align="center" valign="top">QoS Class</entry><entry align="center" valign="top">IPTD</entry><entry align="center" valign="top">IPDV</entry><entry align="center" valign="top">IPLR</entry><entry align="center" valign="top">IPER</entry><entry align="center" valign="top">IPDR</entry></row></thead><tbody><row><entry align="center">Class 0</entry><entry align="center">100 ms</entry><entry align="center">50 ms</entry><entry align="center">5 x 10-4</entry><entry align="center">5 x 10-5</entry><entry align="center">5x10-4</entry></row></tbody></tgroup></table></tables>

0181Respective parameters of QoS of the group H are set as respective parameter values in Table 4 below: <tables id="tabl0004" num="0004"><table frame="all"><title>Table 4:</title><tgroup cols="6"><colspec colnum="1" colname="col1" colwidth="20mm" /><colspec colnum="2" colname="col2" colwidth="16mm" /><colspec colnum="3" colname="col3" colwidth="15mm" /><colspec colnum="4" colname="col4" colwidth="16mm" /><colspec colnum="5" colname="col5" colwidth="16mm" /><colspec colnum="6" colname="col6" colwidth="17mm" /><thead><row><entry align="center" valign="top">Qos Class</entry><entry align="center" valign="top">IPTD</entry><entry align="center" valign="top">IPDV</entry><entry align="center" valign="top">IPLR</entry><entry align="center" valign="top">IPER</entry><entry align="center" valign="top">IPDR</entry></row></thead><tbody><row><entry align="center">Class 1</entry><entry align="center">180 ms</entry><entry align="center">55 ms</entry><entry align="center">5 x 10-4</entry><entry align="center">5 x 10-5</entry><entry align="center">5 x 10-4</entry></row></tbody></tgroup></table></tables>

0182For management of the session priority, when participants are to be added respectively into the groups G and H, the requirement of the group G is satisfied preferentially and more network bandwidth is allocated to the group G in accordance with the magnitude of priority.

0183Priority processing can be carried out in a multi-queuing method.

0184The group session control server can put request messages in respective active group sessions, which are not processed temporarily, into a plurality of queues. For example, queue A is one with session type Basic, and queues B, C and D are ones respectively with session types Professional, Crisis and Official Government Use. A ratio of processing speeds of the four queues is 1:2:3:4, and a queue with a higher priority is picked up first, so that a request with a higher priority can be processed firstly, and considerations also are given to a session request with a lower priority.

0185Example 2: taking an IM group session as an example, the QoE negotiation principle in an IM group session procedure is consistent with that in the PoC group session procedure and their flows are substantially the same. In this example, an IM client A initiates a group session of the group G, with a configured QoE type code Professional.

0186A message flow is as illustrated in <figref idref="f0007">Fig. 11</figref>.

018710-1. The IM client A sends a group session request to an IM participating server A.

018810-2. The IM participating server A sends a request to an IM control server X.

018910-3. The IM control server X obtains group information from the request message and sends to the shared group server an XCAP GET message requesting a group document.

019010-4. The shared group server returns the group information to the IM control server X.

019110-5. The IM control server X obtains the QoE type identifier Professional of the group from the group information and sends to respective group member a session invitation message including the obtained QoE type identifier information.

019210-6. The IM control server X, after receiving the temporary response messages returned from the group members (the messages including response QoE type identifiers), sends the temporary response messages to the IM participating server A.

019310-7. The IM participating server A sends a temporal response message to the IM client A.

019410-8. The IM control server X determines a final group QoE type in accordance with the respective response messages and configures the QoE of the group session in accordance with the group QoE type.

019510-9. The IM control server X, after receiving the first final response message, sends a final response message with a final QoE to the IM participating server A.

019610-10. The IM participating server sends to the IM client A the final response message including a finally selected group session QoE type identifier Professional.

0197Although the invention has been described with reference to the embodiments, those ordinarily skilled in the art shall appreciate that numerous modifications and variations of the invention are possible and it is intended that these modifications and variations shall fall within the scope of the invention.