Analogue Private Circuits
BT strongly believes that packet-based NGN technology offers new and exciting
solutions for the breadth of our portfolio, including data products that have
traditionally been served by Time Division Multiplexing TDM/SDH technology. BT's 21CN is being built on an
infrastructure that supports both innovative packet-switched NGN products as
well as more traditional SDH products.
However, BT also recognises that some customers have applications that rely on
certain characteristics of current TDM data services. BT respects these
requirements and intends 21CN to meet them as far as is technically and
commercially practicable. At a minimum, BT is committed to continuing to
provide the appropriate set of products that meet all relevant international
standards for TDM data transmission, most particularly ETSI G.703.
For circuits at speeds of 2Mbps and greater, we currently plan to meet this
commitment by providing TDM data services on the SDH infrastructure of 21CN and
our legacy network platforms. However, technology advances and we're actively
researching alternative technologies that offer the potential to deliver
comparable performance at lower cost.
Our plan remains to review the state of progress with our customers in Spring
2008, including the practicalities of migration, before any long-term network
design decisions with respect to these products and services are finalised. In
any event, we'll continue to provide service on our existing network until at
least 2011 for all TDM circuits, including those under 2Mbps.
Feasibility study update
BT are conducting a feasibility study on the strategy to provide Analogue Private
Circuits on their 21st Century Network. This study is due to complete at the end of
June 2007, along with the linked Time Division Multiplexing (TDM) feasibilities.
Analogue service falls into three categories:
- Copper own exchange
- A and B end of circuit are fed from the same exchange.
- Copper different exchange
- The A end of circuit is on one exchange, the B end is on a different exchange and
the connection between them is copper and could be amplified.
- Analogue over digital
- A and B ends are fed from different exchanges and the connection between the exchanges
uses the Digital Private Circuit Network (DPCN).
Each of these products provides different challenges and will require different solutions
on 21CN. The current view is that the “Copper own exchange” service will remain unaffected
but that the “Copper different exchange” and “Analogue over digital” circuits will require
some additional planning to migrate to 21CN.
The Analogue feasibility study is now focused on reviewing the options for replacing the
functionality of the existing platforms, assessing the manpower required for continued
maintenance and the future availability of the necessary hardware.
During July, BT will be running a set of bi-lateral meetings with Communication Providers
and also with Global Services’ customers to share an update on the TDM and Analogue
feasibilities and gain more feedback from customers on their preferred options.
Final recommendations will be made internally during Autumn 2006, taking into consideration
the feedback gained from the bi-lateral meetings, and shared as part of the Industry Consultation
in Spring 2008.