Disclosed herein is a redundant network and communication protocol at least including host computers, RF base stations, and roaming terminals. The network may utilize a polling communication protocol such that under heavy traffic conditions, a roaming terminal wishing to initiate communication may be...http://www.google.co.uk/patents/US7548553?utm_source=gb-gplus-sharePatent US7548553 - Redundant radio frequency network having a roaming terminal communication protocol
