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ITU-T e-FLASH
Telecommunication Standardization Sector |
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| Issue No. 11 |
December 2004 |
Bonded DSL Broadens Broadband
ITU
has developed specifications that will allow DSL service providers
worldwide to offer considerably faster broadband to users.
The standards allow the combining of two or more of the
traditional copper telephone lines used for DSL, to transport data
from the service provider to a single subscriber. This will allow
consumers or businesses with more than one telephone line to
benefit from the combined bandwidth of all lines - a feat not
previously possible.
Many operators see the standards as crucial given the push towards
more and more bandwidth hungry services. Multiple wire solutions -
where the wire is already in place - are often seen as a cheaper
solution than rolling out new fiber. It's a way of leveraging
existing infrastructure, while maximizing customer service.
The concept - known as bonding - has seen much interest in
countries where two or more lines are common. It is seen by many
operators as a way of guaranteeing the triple play of voice, video
and data services over DSL. While video is theoretically possible
over DSL, in practice it has been difficult to provide to all
premises - especially where those premises are far from the
exchange.
G.bond (the G.998
series of Recommendations) simply increases the data rate in
proportion to the number of lines that are bonded. So two bonded
lines will double the data rate for both the upstream and
downstream. Likewise three bonded lines will triple the data
upstream and downstream rate, and so on. This is independent of
the DSL technology (ADSL, VDSL etc.).
Yoichi Maeda, NTT Corporation and Chairman of the Study Group that
authored the specs: "G.bond will allow the aggregation of
bandwidth from more than one telephone line. Bonded DSL lines are
the key to offering consumers bandwidth hungry applications like
video and gaming. It is also an ideal way to offer higher
bandwidth to businesses."
The three different flavours of G.bond offer multiplexing of
various service data streams (Ethernet, ATM, TDM) over multiple
DSL links.
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Video Spec Tools-Up for Higher
Definition
The
increasingly important new video compression codec H.264/AVC
has been enhanced by the development of a new set of coding tools
known as the fidelity range extensions (FRExt).
While supporting a broad range of applications, the
previously-available H.264/AVC tools focused more on
lower-resolution entertainment-quality video, rather than the kind
of high resolutions needed for top-quality entertainment and
studio work. The new FRExt extensions are designed to be used for
applications such as standard-definition and high-definition
television, enhanced DVD video, content contribution, content
distribution, post-production processing, and studio video
editing.
Industry has been quick to embrace the new tools. The new
"high profile" defined in FRExt appears certain to be
incorporated into several important application specifications,
including the BD-ROM specification of the Blu-ray Disc Association
and the DVB (digital video broadcast) standards for European
broadcast television. The high profile is also a strong candidate
for consideration for the HD-DVD specification of the DVD Forum
and in a new broadcast TV specification of the US ATSC (advanced
television systems committee).
Indeed, it appears that the new "high profile" may
rapidly overtake the existing "main profile" as the
primary standard codec candidate for new video applications.
Experts suggest that this is because the high profile adds more
coding efficiency without adding a significant amount of
implementation complexity.
Additionally, and at the same meeting of Study
Group 16, agreement was reached on a conformance testing
specification for H.264/AVC. This will allow potential purchasers
and manufacturers to ensure that all equipment designed to use the
video coding standard will work properly together. To this end
reference software has also been designed by the Study Group to
allow users to establish and test for conformance and
interoperability, and to educate users and demonstrate the
capabilities of the standard.
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Study into Electrical Interference for
Home Networks
The
ITU-T group that looks at protection against electromagnetic
effects – Study
Group 5 – has started work in an area important to the
development of home networking technology.
As more technologies emerge to allow the exchange of data within
the home and small business environment, it has become necessary
to address the electromagnetic compatibility (EMC) of these
devices and networks. Standardization will help to create safe
interworking between the various technologies.
The increased use of broadband services has led to the development
of a number of different wireless (eg WLAN and DECT) and wireline
technologies (eg LAN as well as technologies designed to exploit
existing telephone extension and power distribution wiring) to
interconnect a variety of in-home electronic and electrical
equipment (such as TV, PC and other household devices). And, these
techniques introduce many new EMC issues.
The group aims to create standards that relate to the EMC,
resistibility and safety issues in home networks.
Study group members will seek to characterise the electromagnetic
environment created by the close proximity and use of different
items of household electrical and electronic equipment (such as
TV, VCR, DVD, refrigerator, dishwasher, microwave, CD, Hi-Fi,
satellite set-top box etc.), and technologies designed to re-use
existing infrastructure, including power distribution cabling (in
house-PLC (power line communication) systems), telephony extension
wiring, radio LAN systems, xDSL systems over internal telephony
grade wiring and LAN technologies. With this information
guidelines can be drawn-up that will allow the safe interworking
of all.
Study Group 5 plans to hold a technical session on home networks
at its next meeting, June 2005, Geneva.
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MPLS Recommendation Aids Move to Wider
Network
ITU
has consented a new Recommendation (G.8110/Y.1370)
that aims to progress the development of multiprotocol label
switching (MPLS) in order that it can be used in a wider variety
of network environments.
MPLS emerged as a "packet based network helper" to
manage network layer traffic, but is now being seen as more
general transport infrastructure. Importantly MPLS gives the
ability to provide connectivity across any type of transport
infrastructure. This and other characteristics allow convergence
toward a simplified network structure that reduces network
management and operational complexity.
The standardization work has been driven by network operators keen
to integrate MPLS into their wider transport infrastructure. Many
see this as a way to bring down costs by increasing efficiency.
MPLS for example provides a single framework for managing quality
of service (QoS).
The work undertaken by ITU-T Study
Group 15 describes the architecture of MPLS in a manner that
is consistent with other ITU transport network technologies.
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Action on Standards for the Developing
World
In
view of a mandate given by the World Telecommunication
Standardization Assembly (WTSA)
to all ITU-T study groups, Study
Group 16 has drawn up a draft action plan to support the
involvement of developing countries and countries with economies
in transition in its work. The mandate was given in order that
ITU-T's standardization work continues to address the digital
divide between rich and poor countries. Study Group 16's move will
ensure that developing countries' needs are taken into account in
the development of standards in the field of multimedia,
terminals, systems and applications.
One action identified by the group is to include in its studies,
the specific requirements of these countries. In order to do this,
the group will seek to better engage experts from these areas, and
organize workshops there. Additionally it was agreed that
development work should start on handbooks and guidelines
specifically addressing developing countries' needs.
A concrete example of how developing countries' needs are taken
into account in the development of standards is Study Group 16's
work on modem over IP technology. MoIP essentially helps bridge
the gap between modems and the IP world by allowing the continued
use of dial-up modems in all IP networks. This is important in the
developing world where broadband is not a realistic proposition
for most users. Another example is ITU's H.323
standard for interoperability in audio, video and data
transmissions over IP that has facilitated many applications that
are useful for developing countries. Videoconferencing aided by
H.323 has been essential in the development of e-health
applications. And VoIP, also aided by H.323, is proving to be a
popular way of reducing call costs.
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New Study Group Chairs Meet for the
First Time Since WTSA
November
saw the first meeting of newly elected or re-elected study group
chairmen for the new study period.
Study group chairmen are representatives of the membership of ITU
who head-up the various standardization work areas.
Decisions on the chairs were taken at the World Telecommunication
Standardization Assembly (WTSA-04)
in October. This was the first high-level operational meeting
since then. Discussion centered on the best way to proceed given
decisions made at the event. These include 14 new resolutions,
which can be seen here.
Much
of the focus of the meeting was on ensuring that ITU-T maintains
its quick time to market for standards, in order to meet industry
needs. Topics for discussion included closer coordination between
study groups, particularly where NGN work is concerned,
collocation of meetings to facilitate better participation,
cooperation between standards development organizations (SDOs) and
forums, the creation of tutorial material for newcomers and the
creation of regional groups. Director of ITU's Telecommunication
Standardization Bureau (TSB), Houlin Zhao, encouraged chairmen to
increase regional presence, saying that he would engage ITU
regional offices in support of this aim, which he hopes will also
help to bridge the standardization gap between the developed and
the developing world. The formation of a 'technology watch' was
discussed as well as how best to promote the work of ITU-T.
The make-up of the group reflects the diversity of membership of
ITU-T and especially its global reach. It consists of: Study
Group 2, Ms. Marie-Thérèse Alajouanine, Autorité de Régulation
des Télécommunications, France; Study
Group 3, Mr. Ki-Shik Park, Centre Electronics and
Telecommunications Research Institute (ETRI), Korea; Study
Group 4, Mr. David J. Sidor, Nortel Networks, USA; Study
Group 5, Mr. Roberto Pomponi, Telecom Italia Lab (TILAB),
Italy; Study
Group 6, Mr. Francesco Montalti, Telecom Italia, Italy; Study
Group 9, Mr. Richard Green, Cable Television Laboratories,
Inc., USA; Study
Group 11, Mr. Yukio Hiramatsu, Nippon Telegraph and Telephone
Corporation (NTT), Japan; Study
Group 12, Mr. Jean-Yves Monfort, France Telecom, France; Study
Group 13, Mr. B.W. Moore, Lucent Technologies, UK; Study
Group 15, Mr. Yoichi Maeda, NTT Corporation, Japan; Study
Group 16, Mr. Pierre-André Probst, Swisscom SA, Switzerland; Study
Group 17, Mr. Herbert Bertine, Lucent Technologies Inc., USA; Study
Group 19, Mr. John Visser, Nortel Networks, Canada; TSAG,
Mr. Gary Fishman, Lucent Technologies Inc., USA.
Marie-Thérèse
Alajouanine is the first female chair of an ITU-T Study Group
(there are three female vice-chairs). In light of the new
resolution 'mainstreaming gender in ITU-T activities', TSB
Director, Mr Zhao encouraged all chairs to try and increase the
participation of women in ITU-T activities.
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Management Tools Designed for ASON
At
a busy Study
Group 15 meeting, experts agreed a new Recommendation (G.7718)
to provide management support for automatically switched optical
network (ASON) installations.
The specifications have become necessary as ASON moves from the
lab to installations in the real world. As one expert put it, ‘a
condition of the deployment of a new technology is the ability to
manage it’. The same expert says that he believes ASON to be on
the radar of most operators.
The aim of ASON is to provide quick and reliable service
activation to service platforms like switches and routers. ASONs
give operators a way to dynamically manage network traffic away
from points of failure, for example. Operators see ASON as a more
efficient way of provisioning services, so providing a better
quality of service to their customers.
ASON management standards will allow the development of software
to manage this architecture.
The Recommendation follows the principles laid out in ITU’s
telecommunication management network (TMN) specifications (ITU-T
Recommendation M.3010) and the ASON architecture specification
(G.8080).
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Products and Services - ASN.1 Database
The
ASN.1
database is an invaluable, but free, source of machine-processable
ASN.1 modules for developers. It lists all modules in ITU-T
Recommendations and related ISO, IEC and IETF texts.
ASN.1 is an extremely important part of today's network topology.
The database is designed to assist those that use the formal
language for protocol specification or systems design. Ratified as
a standard in 1984, ASN.1 is used, for example, in the signalling
system (SS7) for most telephone calls, package tracking, credit
card verification and digital certificates and in many of the most
used software programs. It is also widely deployed by electrical
utilities to remotely control substations. Every time that you
place an 800-number call, messages that are described by ASN.1 are
exchanged between the switching machine and the network database
to route the call to the correct common carrier and local phone
number to which the 800-number maps. And when supplementary
services are used, such as reverse charging, closed user groups,
and international calling card verification, the messages are
encoded using ASN.1. Latest uses of the industry shaping
specification language include incorporation in biometrics
specifications, the practice of verifying identity based on a
physiological or behavioural characteristic, such as fingerprints,
handwriting or retinal scans.
The frequently updated database is searchable using module name,
object identifier (OID) or ITU-T, ISO, IEC or IETF catalogue
number. One feature of the database tracks errors in modules
contained within these documents to ensure trouble free
implementation. A hyperlinked index of ASN.1 module assignments as
well as a dependence tree of modules for each document is also
available.
A recent addition to the family of ITU-T's ASN.1 tools is a UUID
(universally unique identifier) generator donated by France
Telecom. This allows users to generate UUIDs that can be used for
a variety of tasks including tagging objects with an extremely
short lifetime and reliably identifying very persistent objects
across a network. This feature is a direct application of ITU-T
Rec. X.667 | ISO/IEC 9834-8.
Similar databases are available for other formal languages
including MIB
and XML.
ITU-T also plans to develop databases for other formal languages
used in ITU-T Recommendations. |
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