Nortel Networks Corporation

Mark W Tait

Simon John Gale

James Mark Naden

Michael F Grant

Ian Paul Llewellyn

Typically it is expensive to add cable within an existing multiple dwelling units (MDUs) such as blocks of flats to provide additional services such as broadband internet access, video on demand and video telephony. The present invention provides a broadband wireless access system especially suited to MDUs. A base station modulates radio frequency carrier signals with data to be transmitted in the system, and these signals are directed along a distribution network to a plurality of antennas which provide WLANs for subscriber equipment within the MDU.

Broadband wireless access system

The present invention seeks to provide a more reliable method for transmitting data packets over a communications link, such as a wireless link. A method of error correction for a cell based transmission protocol is provided wherein the cells are arranged to form multi-cell frames wherein for each frame the header fields are reduced in size and; wherein idle cells provide space for error correction within the payload of the multi-cell frame. Preferably, an algorithm is provided which is operable to evenly distribute these idle cells in time. The separate coding of the headers and payloads can enable at least some payload errors to be removed by reference to the header field. Where idle cells are present in the frame, the presence of ATM idle cell headers in the header field of the frame is used to enhance the effectiveness of the coding applied to the payload field. The present invention can provide a radio link protocol that affords robust communications between a headend and a plurality of mobile substations in a standardised data communications format, such as the ATM data format

Growing community of inventors

Herts, United Kingdom

Mark W Tait