A Self‐Routing Packet Network Via Optical Processing of the Header

Abstract

The speed limitations of optoelectronic conversions and electronic signal processing for routing control in a packet network restrict the usable bandwidth of a fiber optic channel to well below its full potential. By keeping the signal in optical form and using optical signal processing, it is possible to remove the electronic bottleneck and utilize the untapped bandwidth of fiber optics. Furthermore, fiber optics facilitates the use of bandwidth expansion techniques, such as wavelength division multiplexing, to simplify network design. To allow multiple users access to a high speed optical channel, a new scheme, given the name code‐division header recognition (CDHR), is devised that uses both frequency ‐ and time‐domain bandwidth expansion as well as optical signal processing. An encoded destination address for a data packet is transmitted on a low speed subchannel at a different wavelength from a high speed main channel and optical delay‐line correlators are used for packet routing. The CDHR receivers are used to form a ring network which is then analyzed at the physical layer and the data link layer, specifically the media access control, of tiie OSI network model.