Nortel Networks Corporation

Northern Telecom Limited

Mark James Parry

Peter John Dyke

Brian Michael Unitt

Michael Philip Dyer

Philip A Norman

Desmond J Kenny

Optical fibre ducting system

A synchronous telecommunications network comprises a number of rings each incorporating a plurality of multiplexers and each coupled to a switch via a respective master multiplexer. A disaster recovery interface point provides an interface to one or more remote switches. Each ring incorporates a dormant master multiplexer coupled to the disaster recovery point and which is activated in response to a failure of the switch as a replacement master multiplexer so as to re-route traffic on the synchronous ring to the remote switch. This maintains service in the event of a catastrophic failure of the switch.

Disaster recovery in a telecommunications network

A cabinet for outdoor use for enclosing a rack of electronics equipment has a double skin protective outer casing comprising a lower air intake into a cavity between the skins of the double skin and an upper air output from the cavity to the outside, for unforced cooling air to flow, to extract heat from the equipment by convection. The inner of the skins is formed in part at least by a heat sink of the rack. This unites the thermal management of the rack and that of the enclosure to provide an improved thermal path from the cards in the rack to the cold wall. This means the temperature difference between the inner skin and the air in the cavity can be increased for a given card temperature, so more heat can be extracted. The heat sink may share the back wall of the rack with the motherboard.

Cabinet with enhanced convection cooling

In an optical fibre cable, the transmission package comprises a stack (11) of ribbon fibre elements (110) secured within a metal tube (12) by an adhesive (13). The adhesive has a peel strength sufficiently low to permit separation of the individual ribbon from the stack, e.g. to effect jointing operations. Advantageously the adhesive is foamed by injection of a gas during cable manufacture.

Optical fibre cable incorporating a stack of fibre ribbon elements

Growing community of inventors

Ware, United Kingdom

Mark James Parry