9 IMS user group

29.3643GPPIP Multimedia Subsystem (IMS) Application Server (AS) service data descriptions for AS interoperabilityRelease 17TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

9.1 General

An IMS user group comprises a list of IMS users which are members of the group and for which a certain service is offered specific to the group. Some generic data with the same meaning may appear for any IMS user group, especially the ones related to the relations between the IMS user group and its members, e.g. the list of the users that are members of the group. This specification only addresses the case when this generic data is stored in the HSS and transferred to the HSS though Sh as transparent data.

This specification standardizes the coding of a set of generic IMS user group data over the Sh interface within the repository data and the associated service indications.

The generic IMS user group data is defined in clause 9.3

Data describing service or feature content supported by an IMS user group is not considered as generic data associated to this IMS user group or to a member of this IMS user group. Such data is outside the scope of this specification.

9.2 Group identification and service indications

An IMS user group may be identified by

a Public Service Identity of which the form is described in 3GPP TS 23.003 [24] or

a Public User Identity when the group is identified by one of its user (e.g. the group controller).

The group identifier is handled as part of an IMS subscription but is used solely for Sh transparent data handling. The only intention of the IMS user group identifier is to identify a data container into HSS. IMS subscription management or traffic procedures of an IMS user group identifier do not apply to the group as such or any of its members. E.g. if IMPU1 is used to identify an IMS user group that consists of two users, identified by IMPU1 and IMPU2, if IMPU1 is registered, it does not have any effect in the group as such, i.e. IMPU2 registration status is not modified. The only intention of the usage of IMPU1 as the group identifier is to identify IMPU1 as the subscriber in HSS where the group transparent information (see 9.3.1) is stored.

The generic IMS user group data associated to an IMS user group shall be contained in the Service Data of the Repository data with the Service Indication having the value "IMS-GROUP".

The generic IMS group member data associated to an IMS user, identified by its public user identity, that is member of one or more IMS user groups shall be contained in the Service data of the Repository Data of this user with a Service Indication having the value "IMS-GROUP-MEMBER".

When a user belongs to different IMS groups, the Service Data comprises different subsets of IMS group member data, each associated to an IMS user group.

9.3 Information elements

9.3.1 Information elements associated to a IMS user group

The generic IMS user group data associated to an IMS user group comprises:

– the list of members of the IMS user group that comprises the public user identity of each member

Specific IMS user group data in particular parameters depending of the service content and attached to the group or to a member of the group is not standardised in this specification. It is implementation dependent to describe this data in repository data with specific AS dependent service indications.

9.3.2 Information elements associated to a IMS group member

The generic IMS user group member data of a user that is member of one or more IMS user groups associated comprises:

– the identities of the IMS groups to which the user belongs to

Specific group member data in particular parameters depending of the service content of the group for this member is not standardised in this specification. It is implementation dependent to describe this data in repository data with specific AS dependent service indications.

9.4 XML schemas

9.4.1 XML schema of the IMS group data

The hereafter XML schema describes the structure and content of the IMS group data. It will allow future extensions for adding new generic IMS group data.

<?xml version="1.0" encoding="utf-8" ?>

<xs:schema attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">

<xs:element name="Group" type="tGroup" />

<xs:complexType name="tGroup">

<xs:sequence>

<xs:element minOccurs="0" maxOccurs="unbounded" name="GroupMember" type="tGroupMember" />

<xs:any minOccurs="0" maxOccurs="unbounded" namespace="##other" processContents="lax" />

</xs:sequence>

</xs:complexType>

<xs:complexType name="tGroupMember">

<xs:sequence>

<xs:element name="GroupMemberIdentity" type="tGroupMemberIdentity" />

<xs:any minOccurs="0" maxOccurs="unbounded" namespace="##other" processContents="lax" />

</xs:sequence>

</xs:complexType>

<xs:simpleType name="tGroupMemberIdentity" final="restriction list">

<xs:union memberTypes="tSIP_URL tTEL_URL" />

</xs:simpleType>

<xs:simpleType name="tSIP_URL" final="restriction list">

<xs:restriction base="xs:anyURI" />

</xs:simpleType>

<xs:simpleType name="tTEL_URL" final="restriction list">

<xs:restriction base="xs:anyURI" />

</xs:simpleType>

</xs:schema>

9.4.2 XML schema of the IMS group member data

The hereafter XML schema describes the structure and content of the IMS group data. It will allow future extensions for adding new generic IMS group data.

<?xml version="1.0" encoding="utf-8" ?>

<xs:schema attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">

<xs:element name="GroupsMembership" type="tGroupsMembership" />

<xs:complexType name="tGroupsMembership">

<xs:sequence>

<xs:element minOccurs="0" maxOccurs="unbounded" name="GroupMembership" type="tGroupMembership" />

<xs:any minOccurs="0" maxOccurs="unbounded" namespace="##other" processContents="lax" />

</xs:sequence>

</xs:complexType>

<xs:complexType name="tGroupMembership">

<xs:sequence>

<xs:element name="GroupIdentity" type="tGroupIdentity" />

<xs:any minOccurs="0" maxOccurs="unbounded" namespace="##other" processContents="lax" />

</xs:sequence>

</xs:complexType>

<xs:simpleType name="tGroupIdentity" final="restriction list">

<xs:union memberTypes="tSIP_URL tTEL_URL" />

</xs:simpleType>

<xs:simpleType name="tSIP_URL" final="restriction list">

<xs:restriction base="xs:anyURI" />

</xs:simpleType>

<xs:simpleType name="tTEL_URL" final="restriction list">

<xs:restriction base="xs:anyURI" />

</xs:simpleType>

</xs:schema>