Communications handoff using an adaptive antenna

The communication device of 1 wherein the control circuit is further configured to

• establish a second communication link with the second base station, and
• terminate the first communication link with the first base station.

The communication device of 1 wherein searching for the second base station includes

• periodically, continuously, or sporadically scanning for pilot signals from base stations, and
• storing the directional and signal strength information of the base stations found during the search.

The communication device of 1 wherein searching for the second base station includes configuring the first antenna to

• generate a plurality of directional search beams, and
• scan each directional search beam for pilot signals from base stations.

The communication device of 4 wherein the plurality of directional search beams corresponds to predefined discrete sectors of the first antenna and the search beams are scanned one beam at a time to obtain the relative direction of the base stations, and.

The communication device of 1 wherein searching for the second base station includes

• obtaining known locations of one or more base stations, and
• configuring the first antenna to search for at least one of the one or more base stations based on the known locations.

The communication device of 1 further comprising:

• a second antenna communicatively coupled to the control circuit and configured to search for the second base station,
• wherein during the communications handoff, a second communication link is established with the second base station via the second antenna.

The communication device of 7, wherein, if a signal is received indicating that the second base station is ready to communicate over the second communication link, the control circuit is further configured to

• switch the second communication link to a directional beam on the first antenna directed to the second base station.

The communication device of 1 wherein determining if a communication handoff should be performed from the first base station to the second base station includes

• determining the signal strength of the first base station,
• determining the signal strength of the second base station, and
• initiating the communications handoff from the first base station to the second base station if the signal strength of the second base station is greater than the signal strength of the first base station.

The communication device of 9 wherein the communications handoff from the first base station to the second base station is initiated if the signal strength of the first base station is below a threshold value.

The communication device of 1 further comprising:

• simultaneously transmitting to both the first base station and the second base station using different directional beams.

The communication device of 1 wherein the control circuit is further configured to

• reconfigure the first antenna to operate as an omni-directional antenna during the communications handoff, and
• reconfigure the first antenna to operate as a directional antenna once a second communication link is established with the second base station.

The communication device of 1 wherein the first base station and second base stations are part of an aeronautical communications network.

The communication device of 1 wherein initiating the communications handoff from the first base station to the second base station is a hard handoff that includes

• first terminating the first communication link with the first base station, and
• secondly establishing a second communication link with the second base station.

The communication device of 14 wherein establishing the second communication link includes setting up a physical layer call between the communication device and the second base station.

The wireless communication device of 16 further comprising:

• second means for wireless communications communicatively coupled to the control means, wherein the second means for wireless communications is employed to search for the new base station,
• the first communication link is established via the first means for adaptive wireless communications and the second communication link is established via the second means for wireless communications, and
• the control means is further configured to switch the second communication link to the first means for adaptive wireless communications if the signal is received indicating that the second base station is ready to communicate over the second communication link.

The method of 18 further comprising:

• transmitting over the second communication link through the adaptive antenna, and
• terminating the first communication link once the new base stations begins receiving on the second communication link.

The method of 18 further comprising:

• configuring the adaptive antenna to generate a plurality of directional search beams, and
• periodically, continuously, or sporadically scanning each directional search beam for pilot signals from base stations, wherein the search beams are scanned one beam at a time to obtain the relative direction of the base stations detected.

The method of 18 wherein the first communication link is established via a first directional beam of the adaptive antenna and the second communication is established via a second directional beam of a second antenna.

The machine-readable medium of 23 wherein, if a communication handoff should be performed, the processor performs the operations comprising:

• simultaneously transmitting to both the current base station and the new base station using different directional beams,
• establishing a second communication link with the new base station, and
• maintaining the first communication link with the current base station until the new base station is ready to communicate over the second communication link.

The machine-readable medium of 24 wherein the communication handoff is a hard handoff including

• establishing a second communication link with the new base station after terminating the first communication link with the current base station, wherein establishing the second communication link includes setting up a physical layer call between the communication device and the new base station.

The communication system of 27 wherein simultaneously transmitting to the first base station and the second base station includes

• configuring the adaptive antenna to generate a first directional beam to communicate with the first base station,
• configuring a second antenna to generate a second directional beam to communicate with the second base station, and
• reconfiguring the adaptive antenna to operate as a directional antenna with a single directional beam to the second base station once the second communication link is established with the second base station.

The communication system of 27 further comprising:

• a base station controller communicatively coupled to the first and second base stations and configured to transmit a signal to the mobile communication transceiver via the first communication link indicating that the second base station is ready to communicate over the second communication link.

The communication system of 26 wherein the control circuit is further configured to

• determine whether a communication handoff from the first base station to the second base station is warranted, and if such communication handoff is warranted, then performing a hard handoff by
• pointing the adaptive antenna to the second base station, and
• establishing a second communication link with the second base station by setting up a physical layer call between the mobile communication transceiver and the second base station.

The communication system of 30 wherein the control circuit is further configured to

• terminate the first communication link with the first base station before establishing the second communication link with the second base station.

The communication system of 30 further comprising:

• a base station controller communicatively coupled to the first and second base stations and, wherein the base station controller is configured to
• recognize when the mobile communication transceiver has switched from the first base station to the second base station, and
• route unacknowledged packets addressed to the mobile communication transceiver to the to the second base station.

The communication system of 32 wherein the base station controller recognizes when the mobile communication transceiver has switched from the first base station to the second base station by monitoring for unacknowledged packets addressed to the mobile communication transceiver to the to the first base station.

The processor of 34 wherein the circuit is further configured to

• simultaneously transmit to both the current base station and the new base station using different directional beams,
• establish a second communication link with the new base station, and
• maintain the first communication link with the current base station until the new base station is ready to communicate over the second communication link.

The processor of 34 wherein the circuit is further configured to

• determine the signal strength of the first base station,
• determine the signal strength of the second base station, and
• initiate the communications handoff from the first base station to the second base station if the signal strength of the second base station is greater than the signal strength of the first base station.

The processor of 34 wherein the circuit is configured to

• establish a second communication link with the new base station after terminating the first communication link with the current base station,
• wherein establishing the second communication link includes setting up a physical layer call between the communication device and the new base station.