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ITU-T Study Group 16 (Study Period 2005-2008) |
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Question 29/16 - Mobility for Multimedia Systems and Services |
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(Continuation of Question 5/16)
- Motivation
ITU-T Study Group 16 has created in H.320, H.321, H.322, H.310, H.324 and H.323 a widely-used set of system specifications regarding Multi Media (MM). Beside the provision of Multi Media services an increased demand for the mobility management in a Multi Media environment can be identified. Regarding mobility, several aspects can be identified:
- Terminal mobility: The ability of a terminal to change location (i.e. network point of attachment and H.323 point of attachment) and still be able to communicate
- User mobility (personal mobility): The ability of a user to maintain the same user identity irrespective of the terminal used and its network point of attachment. Terminals used may be of different types
- Service mobility: The ability of a user to use the particular (subscribed) service irrespective of the location of the user and the terminal that is used for that purpose.
Beside these aspects there is a further differentiation between:
- Seamless mobility: The user/terminal is able to change the network access point, as he/it moves, without interrupting the current service session, i.e. handovers are possible.
- Nomadic mobility (roaming): The ability of a user/terminal to change the network access point as he/it moves while the service session is completely stopped and started again i.e. discrete changes of location are done.
Substantial work has been done to create H.510, which deals with nomadic mobility aspects for H.323 systems above the transport layer. H.510 applies new functions defined in support of mobility management to H.323 compliant systems, focusing mainly on the support of terminal mobility as well as the support of user mobility in the context of H.323. The associated security procedures for an H.323 multimedia mobility environment have been defined in H.530. Furthermore H.501 defines in the context of H.323 the appropriate messages and procedures for mobility management and for communication within and between domains of a mobile or non-mobile multimedia environment for the purpose of address resolution, user authentication, service data exchange, access authorisation, call validation and usage reporting.
In this study period the mobility for H.323 and H.324 has to be further developed as needed. Special focus has to be given on:
- Elaboration of service mobility with respect to roaming of user profiles, mobile Multi Media collaboration applications and services. In this context the functionality and protocols at the E reference point (VLF, HLF) and the F reference point (HLF, AuF) have to be defined. Furthermore the Inter-working and Interoperability between Mobile Presence and Instant Messaging systems and current Presence and Instant Messaging systems have to be specified;
- Definition of seamless Handover procedures where active sessions can be maintained during location changes. Specific technologies used in the access part of a network (for instance WLAN) should be kept transparent for the considered procedures;
- Adaptation of H.501 according to the newly introduced procedures;
- Interworking between H.323 environments and other networks, namely GPRS/IMT2000 and NGN to support generalised combined mobility handling in a heterogeneous environment. Procedures for handling user mobility as well as terminal mobility have to be defined. Depending on the actual constraints in their current situation user shall get their services in a consistent manner (service mobility).
- Study Items
The goal of this question is to:
- Further develop mobility for H.323 and H.324 as needed.
- Ensure interworking with NGN to support Multi Media mobility across networks of different types. Requirements which are needed from network side and from the mobile terminal side to support User Mobility with different user profiles and Multi Media Service Mobility in a heterogeneous environment shall be elaborated. Furthermore considerations shall be done with regard to the enhancement of Multi Media Mobility towards nested mobility scenarios, where a network by itself is able to change dynamically its point of attachment to a fixed backbone.
- Ensure that a possible future terminal in its initial version supports mobility.
- Consider protocol support for MM mobility for both user, terminal and service mobility if and where needed.
- Standardize interfaces between an MM terminal, keyboard and display when all are connected by some kind of wireless network, and related protocol support.
- Study the requirements for metadata in descriptions of user profile, terminal capability, access network characteristics that relate to service mobility.
It should be noted that it is not a goal of this work to create an alternative wireless system to IMT 2000 or NGN, nor to duplicate IETF IP mobility work.
- Tasks
Tasks include, but are not limited to:
- Specification of mobility handling (terminal, user) between H.323 environments and GPRS/ IMT2000 networks (Q4/2005);
- Specification of service mobility with respect to roaming of user profiles, mobile Multimedia collaboration applications and services (Q3/2006);
- Specification of handover procedures where active sessions can be maintained during location changes (Q2/2007);
- Specification of Interworking with NGN networks to support generalised mobility handling (Q3/2008).
An up-to-date status of work under this Question is contained in the
SG 16 Work Programme.
- Relationships
Recommendations:
- H.323, H.324, H.501, Y.NGN-MOB.
Questions:
- Question 20(A) on Mediacom, 25(G) on security, 14/16 on facsimile terminals, 1 on H.324 mobility, and 2/16 on H.323.
Study Groups:
Other bodies:
- 3GPP and related consortia, IETF for IP mobility.
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