A narrowband/wideband packet radio system
Robert K. Morrow · 2002
By transmitting packet headers on a narrowband channel, followed by packet data on a wideband channel, one can gain several advantages over using either narrowband or wideband techniques exclusively. All network nodes can easily obtain channel traffic loading and destination information by examining only the narrowband headers. Wideband synchronization is facilitated by using the end of the header transmission as a time index for wideband signal acquisition. Long signature sequences minimize the probability that two or more wideband packets will be transmitted with their sequences aligned, while avoiding the requirement that each receiver search for several different sequences as in a transmitter-oriented protocol. A common signature sequence facilitates packet broadcasting. Finally, flow control can be implemented by monitoring the CSMA narrowband channel and insuring that the network offered rate remains below the saturation point.