Provision of Partial Baseband Private Circuits - Change-over Considerations Mike Ainger Transmission Design & Planning Manager Racal Telecom The contents of this document are for discussion only, and do not represent or imply a commitment by any company to implement of supply any of the technology, processes or products described

Background The order process is likely to result in one of two different implementation scenarios: –New PBPC over previously spare copper pair –New PBLC over copper pair in use for Telephony In the first scenario there is no requirement for a live service change-over In the second a live service change-over must be executed This will in most cases be combined with a number port

Streamlining the Change-over It is in all parties interest that this change-over should be as efficient and interruption-less as possible: –Customer wants minimum service disruption –BT and OLO want to minimise skilled resources, in particular wasted resources co-ordinating timed activities –Public safety consideration - minimum interruption to emergency access

Possible Methods (1) BT installs NT 2000 and test access x-connect as a preparatory step –Also gives opportunity to label any BT owned CPE to avoid accidental recovery by OLO / customer BT Switch Test Access Cross-Connect 1 2 MDF 2w Circuit NT 2000 CPE Property of BT

Number Transfer to the incoming operator to be implemented in advance of the PBPC implementation –Timed visit to port number could be done when OLO installs (but does not bring into service) DSL equipment Possible Methods (2) BT Switch Test Access Cross-Connect 1 2 MDF 2w Circuit Property of BT Property of OLO DSL

If BT could now use the Test Access Cross-connect to remotely transfer the line to the incoming OLO: –Timed visit would be eliminated –If trouble experienced on change-over then reversion is simple - avoids risk of long periods without emergency access First the OLO Equipment would be connected to the Test Access Cross-Connect Possible Methods (3) BT Switch Test Access Cross-Connect 1 2 MDF 2w Circuit Property of BT Property of OLO DSL AM OLO Equipment

BT would then remotely switch-over, on request from the OLO, when the OLO technician is at the customer premises The OLO then commission the new service, ensuring continuity of emergency access (by mobile if necessary) –Reversion can be invoked as a last resort Possible Methods (4) BT Switch Test Access Cross-Connect 1 2 MDF 2w Circuit Property of BT Property of OLO DSL AM OLO Equipment

BT then complete the implementation - at their leisure –Recover BT Owned CPE –Connect remote line test equipment to test access cross - connect in place of BT switching equipment Possible Methods (5) Line Test Equipment Test Access Cross-Connect 1 2 MDF 2w Circuit Property of OLO DSL AM OLO Equipment

Conclusions The live service change-over arrangements, combined with number portability, create a complex change-over arrangement Specific measures need to be adopted to reduce the dependence on (multiple) timed visits for change- over These measures could either be available on day one, or introduced in a roll-out plan as the systems and processes become available (which should align with the volumes rising).