Cellular radiotelephone system with dropped call protection

Claim 2

A cellular radiotelephone communication system having at least first base site equipment and second base site equipment with associated radiotelephone communication coverage areas and a switch controller for connecting radiotelephone communication with the base site equipment, wherein at least one radiotelephone is initially in an active call within the coverage area of the first base site equipment, comprising: a) means for determining that the radiotelephone requires a handoff from the first base site equipment's coverage area; b) first radiotelephone means for determining that the active call has been lost; c) second radiotelephone means, responsive to the determination that the active call has been lost, for indicating to the second base site equipment that the radiotelephone requests a reconnection of the lost call; and d) second base site equipment means, responsive to data exchanged with the switch controller, for communicating with the radiotelephone in order to continue the radiotelephone's active call as the radiotelephone transits into the second base site equipment's coverage area.

Claim 3

A radiotelephone for use in a cellular radiotelephone communication system having at least first base site equipment and second base site equipment with associated coverage areas and a switch controller for connecting radiotelephone communication with the base site equipment, wherein radiotelephones are capable of communicating while in transition between the aforesaid coverage areas and wherein the radiotelephone is initially in an active call on a channel within the coverage area of the first base site equipment, comprising: a) first means for determining that the active call has been lost; b) second means, responsive to said first means determining that the active call has been lost, for indicating to the system that the radiotelephone is requesting a reconnection of the lost call; c) third means, responsive to the second means requesting a reconnection of the lost call, for receiving a channel assignment from the second base site equipment; and d) fourth means, responsive to the third means receiving the channel assignment, for reestablishing the active call on the channel assigned by the second base site equipment within the coverage area of the second base site equipment.

Claim 4

A radiotelephone for use in a cellular radiotelephone communication system having at least first base site equipment and second base site equipment with associated coverage areas and a switch controller for connecting radiotelephone communication with the base site equipment, wherein radiotelephones are capable of communicating while in transition between the aforesaid coverage areas and wherein the radiotelephone is initially in an active call on a channel within the coverage area of the first base site equipment, comprising: a) first means for determining that the active call has been lost; b) second means, responsive to said first means determining that the active call has been lost, for indicating to the system that the radiotelephone is requesting a reconnection of the lost call; c) third means, responsive to the second means requesting a reconnection of the lost call, for receiving a channel assignment from the second base site equipment; and d) fourth means, responsive to the third means receiving the channel assignment, for reestablishing the active call on the channel assigned by the second base site equipment within the coverage area of the second base site equipment.

Claim 5

A radiotelephone according to claim 2, wherein the first means includes means for detecting the absense of a supervisory audio tone provided by the first base site equipment.

Claim 6

A switch controller for connecting radiotelephones with communication equipment in a cellular radiotelephone communication system having at least first base site equipment and second base site equipment with associated communication coverage areas, wherein a radiotelephone is initially in an active call on a channel within the coverage area of the first base site equipment, comprising: a) first means, responsive to a message generated by the radiotelephone received via the second base site equipment, for determining that the radiotelephone has requested that the active call be reconnected; b) second means for effecting a channel assignment for the radiotelephone at the second base site equipment; and c) third means for reestablishing the communication that was initialized in the first base site equipment's coverage area on the channel assigned at the second base site equipment's coverage area in order to reconnect the radiotelephone's call as the radiotelephone transits into the second base site equipment's coverage area.

Claim 7

A switch controller for connecting radiotelephones with communication equipment in a cellular radiotelephone communication system having at least first base site equipment and second base site equipment with associated communication coverage areas, wherein a radiotelephone is initially in an active call on a channel within the coverage area of the first base site equipment, comprising: a) first means, responsive to a message generated by the radiotelephone received via the second base site equipment, for determining that the radiotelephone has requested that the active call be reconnected; b) second means for effecting a channel assignment for the radiotelephone at the second base site equipment; and c) third means for reestablishing the communication that was initialized in the first base site equipment's coverage area on the channel assigned at the second base site equipment's coverage area in order to reconnect the radiotelephone's call as the radiotelephone transits into the second base site equipment's coverage area.

Claim 8

A base site controller for use in a cellular radiotelephone communication system having at least first base site equipment and second base site equipment with associated coverage areas and a switch controller for connecting radiotelephone communication with the base site equipment, wherein a radiotelephone is initially in an active call and the switch controller has determined that a handoff of the call is required from the coverage area of the first base site equipment to the coverage area of the second base site equipment, comprising: a) first means, responsive to the switch controller, for receiving and storing a handoff message for the radiotelephone; b) second means for receiving and interpretting a transmission from the radio telephone that indicates a reconnect request at the second base site equipment's coverage area; and c) third means for reconnecting the call at the second base site equipment's coverage area by transmitting a channel assignment derived from the stored handoff message to the radiotelephone in order to reconnect the radiotelephone's call in the second base site equipment's coverage area.

Claim 9

A base site controller for use in a cellular radiotelephone communication system having at least first base site equipment and second base site equipment with associated coverage areas and a switch controller for connecting radiotelephone communication with the base site equipment, wherein a radiotelephone is initially in an active call and the switch controller has determined that a handoff of the call is required from the coverage area of the first base site equipment to the coverage area of the second base site equipment, comprising: a) first means, responsive to the switch controller, for receiving and storing a handoff message for the radiotelephone; b) second means for receiving and interpretting a transmission from the radio telephone that indicates a reconnect request at the second base site equipment's coverage area; and c) third means for reconnecting the call at the second base site equipment's coverage area by transmitting a channel assignment derived from the stored handoff message to the radiotelephone in order to reconnect the radiotelephone's call in the second base site equipment's coverage area.

Claim 10

A cellular radiotelephone communication system having at least first base site equipment and second base site equipment with associated radiotelephone communication coverage areas and a switch controller for connecting radiotelephone communication with the base site equipment, wherein at least one radiotelephone is in an active call on a channel within the coverage area of the first base site equipment and in transition to the coverage area of the second base site equipment, comprising: a) first means for determining that the radiotelephone requires a handoff from the first base site equipment's coverage area; b) switch controller means for communicating a handoff message to the first base site equipment for the radiotelephone; c) first base site equipment means, responsive to the switch controller means handoff message, for communicating a corresponding handoff message to the radiotelephone; d) first radiotelephone means for determining that the active call has been lost; e) second radiotelephone means, responsive to the determination that the active call has been lost, for siezing a control channel and indicating to the base site equipment providing the control channel that the radiotelephone requests a reconnection; and f) base site equipment means, responsive to data exchanged with the switch controller, for communicating with the radiotelephone in order to continue the radiotelephone's active call.

Claim 11

A cellular radiotelephone communication system having at least first base site equipment and second base site equipment with associated radiotelephone communication coverage areas and a switch controller for connecting radiotelephone communication with the base site equipment, wherein at least one radiotelephone is in an active call on a channel within the coverage area of the first base site equipment and in transition to the coverage area of the second base site equipment, comprising: a) first means for determining that the radiotelephone requires a handoff from the first base site equipment's coverage area; b) switch controller means for communicating a handoff message to the first base site equipment for the radiotelephone; c) first base site equipment means, responsive to the switch controller means handoff message, for communicating a corresponding handoff message to the radiotelephone; d) first radiotelephone means for determining that the active call has been lost; e) second radiotelephone means, responsive to the determination that the active call has been lost, for siezing a control channel and indicating to the base site equipment providing the control channel that the radiotelephone requests a reconnection; and f) base site equipment means, responsive to data exchanged with the switch controller, for communicating with the radiotelephone in order to continue the radiotelephone's active call.

Claim 12

For use by a cellular radiotelephone communication system having at least first base site equipment and second base site equipment with associated radiotelephone communication coverage areas and a switch controller for connecting radiotelephone communication with the base site equipment, wherein at least one radiotelephone is initially in an active call within the coverage area of the first base site equipment, a method of recovering a lost call, comprising the steps of: a) determining that the radiotelephone requires a handoff from the first base site equipment's coverage area; b) determining that the active call has been lost at the radiotelephone; c) responsive to the determination that the active call has been lost, indicating from the radiotelephone to the second base site equipment that the radiotelephone requests a reconnection of the lost call; and d) responsive to data received from the switch controller, communicating between second base site equipment and the radiotelephone in order to continue the radiotelephone's active call as the radiotelephone transits into the second base site equipment's coverage area.

Claim 13

For use by a cellular radiotelephone communication system having at least first base site equipment and second base site equipment with associated radiotelephone communication coverage areas and a switch controller for connecting radiotelephone communication with the base site equipment, wherein at least one radiotelephone is initially in an active call within the coverage area of the first base site equipment, a method of recovering a lost call, comprising the steps of: a) determining that the radiotelephone requires a handoff from the first base site equipment's coverage area; b) determining that the active call has been lost at the radiotelephone; c) responsive to the determination that the active call has been lost, indicating from the radiotelephone to the second base site equipment that the radiotelephone requests a reconnection of the lost call; and d) responsive to data received from the switch controller, communicating between second base site equipment and the radiotelephone in order to continue the radiotelephone's active call as the radiotelephone transits into the second base site equipment's coverage area.

Claim 14

A method of reconnecting the active call in a cellular radiotelephone communication system, according to claim 7, wherein the step of determining is executed by the first base site equipment.

Claim 15

A method of reconnecting the active call in a cellular radiotelephone communication system, according to claim 7, wherein the step of determining is executed by the radiotelephone.

Claim 16

A method of reconnecting the active call in a cellular radiotelephone communication system, according to claim 7, wherein the step of indicating includes the step of siezing a control channel provided by the second base site equipment.