I was inspired to submit content in order to explore the potential for
integration of NOP into current revised standards for transmission of SS7
over IP over satellite.
If this content is deemed too commercial for this readership kindly advise
or direct me towards a more appropriate audience; a brief overview of the
concept is included in the text below related to a joint development
successfully completed with ESA (European Space Agency): The complete
article is covered in the attached link, and a separate .xls file includes
calculation parameters for NOP benefits over SIP and H323.
"WTL has an excellent track record in providing equipment for voice services
using satellite trunking and has over 100 systems deployed around the world.
The company's key strength in this area has always been the superior
bandwidth-saving capability of WTL's patented NOP (Network Optimisation
The Artes 4 contract provided joint funding for a series of developments
designed to make WTL equipment perform an even better job for telecom
operators wishing to use these emerging low cost satellite services. One
aspect of the ESA project was to modify NOP to operate efficiently over
DVB-RCS services. The lower price point of DVB-RCS equipment and space
segment means that this is of great interest to operators, particularly in
the developing world."
International Account Manager
Changing the way the World Communicates ............
World Telecom Labs
Telephone +32 2 722 7200
Fax +32 2 725 6006
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ESA Funded VoIP over Satellite Development helps African
01 Jul 2008
Telecom operators across Africa and the Middle
East can now benefit from new technology developed with the
assistance of the European Space Agency.
World Telecom Labs, a Belgian-based developer of Voice over IP
(VoIP) equipment for telecom operators, developed this technology
through ESA’s Research in Telecommunications Systems (ARTES)
program. The project’s objective was to address the difficulties of
carrying VoIP traffic over shared satellite services, primarily
DVB-RCS, to result in a commercially saleable device allowing
telecom operators to deploy a range of satellite-based commercial
The platform used for this development was WTL's existing IPNx
switch. Modifications needed to be made in order for it to become
suitable for satcom operators by adapting WTL's patented Network
Optimisation Protocol (NOP). Using WTL’s NOP bandwidth-saving
technology will typically cut the cost of satellite bandwidth in
half without sacrificing quality. Simply put, this technique packs
multiple VoIP voice samples into a single IP packet. Because the
samples are not modified, quality is unaffected but, on
multi-call links, significant savings are made on the packet
overhead. Also, since single samples are taken from each active call
rather than queuing multiple samples from the same call, delay is
As the focus of the project was to create commercial benefits, a
live customer network was to be installed and tested. The
client chosen for this pilot was Xplorium, an international
wholesale VoIP carrier with a presence in Europe, the Americas, the
Middle East and Africa. Xplorium's specialities include
carrying the international traffic of Global System for Mobile
Communications (GSM) operators. In a number of locations the traffic
is carried via satellite and this has given rise to concerns about
the voice quality and the efficiency of transmission.
The first operational link used for the pilot was between Gambia
and the client’s NOC in Paris with a capacity for 360 optimised VoIP
calls (equivalent to 12 E1s). The trial was successful by
demonstrating high voice quality and confirming that significant
bandwidth savings were actually achieved. As a result the pilot was
soon followed by deployments in a number of other African locations,
with the traffic again being sent to the Paris hub.
Simon Pearson, WTL’s Business Development Director says; “For
this installation we have been able to draw on the improvements that
we made to NOP in the ESA funded project. This allows us almost to
do the impossible – in some cases we can save bandwidth and improve
the voice quality of VoIP over satellite. We have added features
specifically to counteract the common problems of satellite
transmission of VoIP, namely variable delay or jitter, long delay
and packet loss in busy contended services.”
Frank Zeppenfeldt, Communications Engineer with ESA's
Telecommunications and Integrated Applications department
says; "In this project ESA offered its technical DVB-RCS
assets to support WTL in testing the performance of voice codecs in
a satellite environment. This is a typical example of a development
supported by the ARTES 4 program of ESA Telecommunications, in which
a new product is developed that is close to the market and allows
the enhancement of voice services over satellite."
ESA supports a wide range of projects, which encourage adoption
of the DVB-RCS standard, providing positive benefits for all.
DVB-RCS is an open standard for bi-directional or two-way
transmission of digital data. It employs satellite
transmission using combinations of C, Ku and Ka bands with
return bandwidth up to 2 Mbit/s. Such projects stimulate growth and
keep Europe on the forefront of the telecommunications industry.
For more information, see the links located in the top right
corner of this page.