SCALABLE, SELF-ORGANIZING PACKET RADIO NETWORK HAVING DECENTRALIZED CHANNEL MANAGEMENT PROVIDING COLLISION-FREE PACKET TRANSFER

摘要

A scalable, self-organizing packet radio network providing decentralized collision-free packet transfer is disclosed having spread-spectrum transmitters and receivers for eliminating contention from background noise, spread-spectrum receivers with multiple tracking and despreading channels for eliminating contention from multiple transmitters contending for the same receiver at the same time, and a processor implemented scheduling technique for eliminating contention arising both from self-contention and from comparatively-high power transmissions of neighboring stations. In the preferred embodiments, the processor implemented scheduling technique randomly provides a unique schedule of transmit and receive opportunities for each station. In accord therewith, each station obliges itself to listen and publishes the unique schedule of each station to every neighboring station. To avoid self-contention, a packet is transmitted to an intended station at a time that corresponds to the first available listening opportunity thereof that is long enough to receive the packet. To avoid contention arising from comparatively-high power transmissions of neighboring stations, a packet is transmitted to an intended station at a time that corresponds to the first available transmit opportunity thereof that does not overlap with the receive windows of any neighboring station. In the preferred embodiments, a processor implemented power control technique is disclosed which so varies transmitter power as to provide a fixed level of power at any intended recipient station. In the preferred embodiments, minimum energy routing is employed for specifying intended stations for multi-hop packet transfer. In the presently preferred embodiments, the random generation at each station of its unique schedule is implemented by a pseudo-random schedule generator common to all stations and by a pseudo-random clock unique to each station. In the presently preferred embodiment, neighboring stations periodically exchange rendezvous packets that include information representative of each station's pseudo-random clock, transmitted power and station identity.