Logical channel control procedures for handover

A communications network comprising:

• a plurality of gateways which are arranged such that in use, one gateway is a source gateway, a second gateway is a target gateway and a third gateway is a destination gateway, said gateways are connected via a switched packet communication path for conveying call data packets between the gateways, at least one gateway being associated with circuitry for converting RF data from a mobile station to call data packets for transmission via the switched packet communication path, and each gateway having a set of selectable ports for transmitting and receiving call data packets on the switched packet communication path, wherein the destination gateway comprises a source port for receiving call data packets from the mobile station and wherein the switched packet communication path between the source gateway and a source port at the destination gateway is a first bi-directional logical communication channel, the network further comprising:
• a central controller connected to the switched packet communication path and operative responsive to a handover required indication from a mobile station operating in the network to selectively open a target port at the destination gateway for communication with the target gateway, to open a second bi-directional logical communication channel between the target gateway and the target port at the destination gateway, to route call data packets via the target gateway to the target port on the second bi-directional communication channel, to detect receipt of said call data packets at the target port, and then responsive to the detection, to route call data packets from the mobile station via the destination gateway to the target gateway on the second bi-directional logical communication channel in the reverse direction for conveying the call data packets from the mobile station and to close the source port at the destination gateway to implement handover of the mobile station from the source gateway to the target gateway.

A method of effecting handover in a communications network of a first mobile station between a source gateway and a target gateway, the first mobile station being engaged in a call with a second mobile station using a destination gateway, wherein the second mobile station is connected to the destination gateway, and wherein the source gateway;

• wherein the target gateway and the destination gateway are connected by a switched packet communication path for conveying call data packets;
• and wherein the switched packet communication path between the source gateway and a source port at the destination gateway is a first uni-directional logical communication channel for conveying call data packets between the first and second mobile stations, the method comprising:
• i) sending call data packets from the first mobile station to the source port at the destination gateway on the first uni-directional logical communication channel;
• ii) opening a target port at the destination gateway for communication with the target gateway;
• iii) opening a second uni-directional logical communication channel between the target gateway and the target port at the destination gateway;
• iv) routing call data packets from the first mobile station via the target gateway to the target port on the second uni-directional logical communication channel;
• v) detecting receipt of said call data packets at the target port and then, responsive to such detection;
• vi) closing the first uni-directional channel and requesting a third uni-directional logical communication channel in the reverse direction;
• vii) routing call data packets from the second mobile station via the destination gateway to the target gateway on the third uni-directional logical communication channel;
• and
• viii) closing the source port at the destination gateway.

A communications network comprising:

• a plurality of gateways which are arranged such that in use, one gateway is a source gateway, a second gateway is a target gateway and a third gateway is a destination gateway, said gateways connected via a switched packet communication path for conveying call data packets between the gateways, at least one gateway being associated with circuitry for converting RF data from a mobile station to call data packets for transmission via the switched packet communication path, and each gateway having a set of selectable ports for transmitting and receiving call data packets on the switched packet communication path, wherein the destination gateway comprises a source port for receiving call data packets from the mobile station and wherein the switched packet communication path between the source gateway and a source port at the destination gateway is a first uni-directional logical communication channel, the network further comprising:
• a central controller connected to the switched packet communication path and operative responsive to a handover required indication from a mobile station operating in the network to selectively open a target port at the destination gateway for communication with the target gateway, to open a second uni-directional logical communication channel between the target gateway and the target port at the destination gateway, to route call data packets via the target gateway to the target port on the second uni-directional communication channel, to detect receipt of said call data packets at the target port, and then responsive to the detection, to close the first uni-directional channel and requesting a third uni-directional logical communication channel in the recerse direction, to route call data packets from the mobile station via the destination gateway to the target gateway on the third uni-directional logical communication channel and to close the source port at the destination gateway to implement handover of the mobile station from the source gateway to the target gateway.