Wireless local area network with roaming indicating multiple communication ranges

摘要

A wireless network transmits information to mobile units which indicate communication ranges of particular access point units. Each mobile unit scans traffic on the network communications channel (typically frequency hopping radio transmissions using spread spectrum). As a mobile unit leaves one area and enters another area of the network, access point units in the new area transmit information, which the mobile unit receives. The transmission includes information indicating which access point units are within radio range of the mobile unit as well as multiple values indicating a communication range for a particular access point unit to the mobile unit. The mobile unit uses this information to establish communication with desired access point units.