Abstract: A network with wireless links is a dynamic learning system which allows a mobile (wireless) unit to determine which access point (wired) unit provides the mobile unit with the best communications as the mobile unit roams within an area and from area to area. As a mobile unit enters a new area, it scans the area to find an access point unit. After the mobile unit is verified by the access point unit, the mobile unit receives updated information about other access points in the area, including information indicating which access point units are within wireless transmission 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 information is updated as the system gathers new information through the mobile units and access point units within the system area.

Abstract: A wireless local area network includes a radio transmitter/receiver for transmitting and receiving in accordance with the FCC rules for the ISM band. The receiver/transmitter supports spread spectrum frequency hopping in the 2.4 GHz ISM band and can be tuned to one of e.g. 82 different frequencies spaced at 1 MHz intervals. The radio transmitter/receiver is a low cost, low power, small size unit located on a printed circuit board in a PCMCIA form factor. Third order mixers are used in combination with a switched prescaler for a low cost and compact frequency control system capable of rapid switching of the radio between transmitting and receiving functions. No special shielding is needed between the frequency control circuitry and the receiver IF circuitry.

Abstract: A wireless network is initialized by communications between mobile units forming an ad hoc network or by communications between a mobile unit and an access point unit. Mobile units transmit announcements in order to establish a communication link. To ensure the announcements are received, the mobile units scan different frequencies at various times using various hop sequences. Once communication is established, one mobile unit adopts the hop frequency of the other mobile unit according to a comparison between the hop frequencies of the two units. Multiple mobile units initialize to form ad hoc networks in similar manner.

Abstract: 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.