ITU-T Newslog - Signalling

Protocols outline QoS for NGN

Fri, 04 May 2007 08:06:49 GMT

Study Group 11 meeting in Geneva, end April has consented three important documents charting protocols for quality of service (QoS) in NGN. The protocols will ensure interoperability between network elements and systems as well as giving service providers the ability to specify rules for specific communication types.

The announcement marks a significant step forward for ITU-Ts NGN work. Protocol development is seen as the final stage of standards development following identification of the requirements, architecture, services etc. The Recommendations are a crucial part of the NGN standards package and a concrete realization of the functional architecture defined in ITU-T Rec. Y.2111 - Resource and admission control functions in Next Generation Networks.

The protocols agreed at the April meeting will guarantee that when a service request is made QoS needs are transmitted, ensuring that each network element provisions the correct level of bandwith and resources to ensure the class of QoS for that particular application. So for example more bandwidth can be allocated and guaranteed for IPTV than for voice.

The three ITU-T Recommendations include the specification of the physical entities involved in resource control signalling, the interfaces across which signalling takes place, and the mapping between these entities and interfaces and the corresponding functional entities and reference points in ITU-T Rec. Y.2111. An Appendix provides a further mapping between the interfaces and the protocol specifications which realize those interfaces.

The Recommendations refer to signalling used in different geographical parts of the world: ITU-T Recommendation H.248/Megaco used in for example Japan, COPS used for example in China and Diameter which is used in North America.

Another three protocols in the field of resource control were consented by Study Group 11 earlier in the year.

Video Coding Work Voted Most Influential

Mon, 02 Oct 2006 08:52:49 GMT

Over seven hundred people voted for the most influential standards work from ITU-T in a recent poll to celebrate 50 years of CCITT/ITU-T.

The work area receiving the most votes was video coding. The task of video coding is to establish efficient formats for storing and transmitting video data. The work of ITUT in this field was pioneered in joint projects with the International Organization for Standardization/International Electrotechnical Commission (ISO/IEC).

Gary Sullivan Rapporteur of the group that has led video coding work: It is a great honor to see our video coding work so highly appreciated. Much of the credit should go to my predecessors in leading the ITU-T video coding work, Sakae Okubo, Richard Schaphorst, and Karel Rijkse, and also to my Associate Rapporteur Thomas Wiegand, as well as to all our contributors and our ISO/IEC collaborators. One key technical contributor I would cite in particular is Gisle Bjøntegaard.

Besides the two video standards that were explicitly mentioned in the poll question (H.262/MPEG2-Video and H.264/AVC), there were several others of substantial importance in the standardization of that field. Specifically, that includes H.120, H.261, and H.263.

I think perhaps our edge over SS7 and other such telephony network standards in the voting was really just a matter of our work being more familiar to most people and perhaps fresher in people's minds. The work of the ITU has been at the heart of developing a reliable world-wide telephony network, and that has been hugely important to us all.

Signalling System number 7 (SS7) received the second highest number of votes. SS7 is a common channel signalling system that separates network resource control from the resources being controlled. This fundamental shift enabled the implementation of highly efficient centralized databases for call control, especially valuable for services that may be accessed from any subscriber line (Intelligent Networks, 800/Freephone, credit card, VPN, etc.), and an integral capability on which todays ubiquitous mobile phone systems depend. Among other service supporting capabilities, it enables monitoring the status of a line to see if it is busy or idle, alerts that indicate the arrival of a call, and the addressing system that routes calls.

John Visser, Chairman of ITU-T Study Group 19: "SS7 is felt by many to be a cornerstone technology of modern telecommunications. Visser describes the group which developed the SS7 Recommendations and who were recognized by their peers as Knights of SS7, as a camaraderie who proudly display the certificates awarded to them as part of this recognition of their efforts.

Voting results can be seen here.

Vote for the most influential standards work from ITU-T

Mon, 05 Jun 2006 07:05:08 GMT

As part of celebrations for the 50^th anniversary of ITU-T, you are invited to vote for the most influential standards work from ITU-T.

ITU work is behind many of the worlds most prevalent information and communications technologies. Choose here from our shortlist which you think has best shaped the ICT world of today, or feel free to suggest your own idea.

NGN Global Standards Initiative Event Sees Excellent Progress

Fri, 17 Feb 2006 07:50:50 GMT

January saw a gathering of hundreds of NGN experts in Geneva for the first NGN-GSI (global standards initiative) event. Good progress was reported in several key areas particularly in the important area of functional architecture and requirements for resource and admission control functions (RACF) in NGNs. The Recommendation covering RACF is said to be stable and is expected to be consented at the July GSI event.

The January event comprised three full Study Group meetings (11, 13 and 19). Experts from various other Study Groups were in attendance for this first meeting of the GSI following its launch in November, 2005.

Study Group 13, the lead for NGN work, alone saw over 250 contributions, many a result of the work of the Focus Group on NGN. SG 13 saw three new Recommendations consented, see separate stories (Y.1731, Y.1452, Y.1453).

Study Group 11 reported that 50 contributions were received and launched work on an NGN Protocol Set. According to SG documents ITU-T NGN-Protocol Set 1 will define protocols for the support of:

· Network to Network Interface (NNI) session control;

· User to network Interface (UNI) session control;

· Resource Control Interfaces;

· Network Attachment Interfaces.

Protocol Set 1 is targeted for completion by the end of 2006.

The chair of Study Group 19 reported good progress in the area of FMC (fixed-mobile convergence).

It is expected that many other of the outputs of the Focus Group on NGN will be consented at this July meeting. Among them will be a Recommendation dealing with performance, management and measurement, another key area in NGN. See the work programmes for the various Study Groups involved in NGN for a full list.

Signalling Specs Defined for the IP World

Thu, 12 May 2005 17:28:44 GMT

New specifications ratified by ITU-T Study Group 11 will transfer some of the call control elements of SS7 to the IP world. SS7 is the signalling system used by telecoms operators worldwide to allow the efficient routing of calls, and its worldwide implementation has paved the way for an efficiently operating international telecommunication network.

The new Recommendation - Q.1980.1- defines narrowband signalling syntax (NSS), a flexible text-based syntax that can be used to transfer narrowband signalling information in protocols that cannot inherently transfer such information (eg the session initiation protocol (SIP)).

This NSS solution aims at helping operators reflect the services that they provide in the public switched telephone network (PSTN) in next generation IP based networks. It provides a standardized set of PSTN/ISDN services signalling parameters that can be mapped into the many SS7 ISDN user part (ISUP*) variations, to be transmitted transparently through IP networks. NSS has been designed to enable seamless interworking between the PSTN and IP networks and transition from legacy TDM (time division multiplexing) circuit switched networks to packet-based transport technologies without service degradation or changes.

* ISUP determines the procedures for setting-up, coordinating and taking down calls on an SS7 network. It provides calling party number information, call status checking, and controls tone and announcement delivery.