Method and apparatus for hand over of calls

A wireless communication unit arranged and constructed for operation within a communication network comprising a first communication network and a second communication network, the wireless communication unit comprising:

• a tranceiver configured to support an air interface with the first communication network and with the second communication network;
• a controller arranged to control and cooperatively operate with the transceiver;
• to determine that the wireless communication unit is within a coverage area of the first communication network;
• to exchange messages corresponding to call appearance information with a network switch in the first communication network, wherein to exchange the messages corresponding to the call appearance information further comprises:
• querying the network switch using one of a Session Initiation Protocol (SIP) INVITE message and SIP OPTIONS message, each respectively including call appearance information for calls in the second communication network;
• receiving a SIP OK message indicating the decision is affirmative;
• sending a SIP SUBSCRIBE message including a first identity for the wireless communication unit in the first communication network and a second identity for the wireless communication unit in the second communication network;
• and
• receiving a listing of call appearance information for each call in the first communication networks;
• to decide whether a call within the second communication network can be handed in to the first communication network based on the exchange of the messages corresponding to the call appearance information and provide a corresponding decision;
• and
• to initiate a handing of the call to the first communication network only when the decision is affirmative.

A wireless communication unit arranged and constructed for operation within a communication network comprising a first communication network and a second communication network, the wireless communication unit comprising:

• a transceiver configured to support an air interface with the first communication network and with the second communication network;
• a controller arranged to control and cooperatively operate with the transceiver;
• to determine that the wireless communication unit is within a coverage area of the first communication network;
• to exchange messages corresponding to call apperance information with a network switch in the first communication network;
• to decide whether a call within the second communication network can be handed in to the first communication network based on the exchange of the messages corresponding to the call appearance information and provide a corresponding decision;
• and
• to initiate a handing of the call to the first communication network only when the decision is affirmative, wherein to initiate the handing of the call to the first communication network when the decision is affirmative further comprises sending to the network switch a Session Initiation Protocol (SIP) INVITE message comprising a call identifying field, a To field with a first identity for the wireless communication unit corresponding to the first communication network and a From field with a second identity for the wireless communication unit corresponding to the second communication network, wherein to initiate the handing of the call further comprises initiating a handing of a plurality of calls, the initiating the handing of the plurality of calls further comprises sending the network switch a SIP INVITE message corresponding to each of the plurality of calls, the SIP INVITE message corresponding to the each of the plurality of calls comprising call identity information for the each of the plurality of calls, wherein the plurality of calls can be concurrently handed in to the first communication network.

A wireless communication unit arranged and constructed for operation within a communication network comprising a first communication network and a second communication network, the wireless communication unit comprising:

• a transceiver configured to support an air interface with the first communication network and with the second communication network;
• a controller arranged to control and cooperatively operate with the transceiver;
• to determine that the wireless communication unit is within a coverage area of the first communication network;
• to exchange messages corresponding to call appearance information with a network switch in the first communication network;
• to decide whether a call within the second communication network can be handed in to the first communication network based on the exchange of the messages
• corresponding to the call apperance information and provide a corresponding decision;
• and
• to initiate a handing of the call to the first communication network only when the decision is affirmative, wherein to initiate the handing of the call to the first communication network when the decision is affirmative further comprises sending to the network switch a SIP REFER message with a From field with a second identity for the wireless communication unit corresponding to the second communication network, a To field identifying the call, and a Refer to field with a first identity for the wireless communication unit corresponding to the first communication network, and wherein to initiate the handing of the call comprises initiating a handing of a plurality of calls, the initiating the handing of the plurality of calls further comprises sending the network switch a SIP REFER message corresponding to each of the plurality of the calls, wherein the plurality of calls can be concurrently handed in to the first communication network.

A communication network switch operable to route calls for a first communication network, the communication network switch comprising:

• a switching function operable to couple the first communication network to a second communication network, where the first communication network and the second communication network comprise a coupled communication network;
• and
• a controller arranged to control and cooperatively operate with the switching function:
• to exchange messages corresponding to call apperance information with a wireless communication unit, to decide whether a call within the second communication network can be handed in to the first communication network based in the exchange of the messages corresponding to the call apperance information and providing a corresponding decision;
• and
• initiating a handing of the call to the first communication network only when the decision is affirmative, wherein to exchange the messages corresponding to the call appearance information further comprises:
• receiving a query from the wireless communication unit, the query in one of a Session Initiation Protocol (SIP) INVITE message and SIP OPTIONS message, the one of the SIP INVITE and the SIP OPTIONS message respectively including call appearance information for calls in the second communication network;
• comparing the call appearance information to local call appearance information to provide a comparison;
• and
• sending a SIP OK message when the comparison is favorable, thereby indicating the decision is affirmative.

A communication network switch operable to route calls for a first communication network, the communication network switch comprising:

• a switching function operable to couple the first communication network to a second communication network, where the first communication network and the second communication network comprise a coupled communication network;
• and
• a controller arranged to control and cooperatively operate with the switching function;
• to exchange messages corresponding to call appearance information with a wireless communication unit;
• to decide whether a call within the second communication network can be handed in to the first communication network based on the exchange of the messages corresponding to the call appearance information and provide a corresponding decision;
• and
• to initiate a handin of the call to the first communication network only when the decision is affirmative, wherein to initiate the handing of the call to the first communication network when the decision is affirmative further comprises:
• receiving from the wireless communication unit a Session Initiation Protocol (SIP) INVITE message comprising a call identifying field, a To field with a first identity for the wireless communication unit corresponding to the first communication network and a From field with a second identity for the wireless communication unit corresponding to the second communication network;
• and
• when the call is a plurality of calls, receiving a plurality of SIP INVITE messages corresponding, respcctively, to the plurality of calls such that the plurality of calls can be concurrently handed in.

A communication network switch operable to route calls for a first communication network, the communication network switch comprising:

• a switching function operable to couple the first communication network to a second communication network, where the first communication network and the second communication network comprise a coupled communication network;
• and
• a controller arranged to control and cooperatively operate with the switching function;
• to exchange messages corresponding to call appearance information with a wireless communication unit;
• to decide whether a call within the second communication network can be handed in to the first communication network based on the exchange of the messages corresponding to the call apperance information and provide a corresponding decision;
• and
• to initiate a handin of the call to the first communication network only when the decision is affirmative, wherein to initiate the handing of the call to the first communication network when the decision is affirmative further comprises:
• receiving from the wireless communication unit a Session Initiation Protocol (SIP) REFER message with a From field with a second identity for the wireless communication unit corresponding to the second communication network, a To field identifying the call, and a Refer to field with a first identity for the wireless communication unit corresponding to the first communication network;
• and
• when the call is a plurality of calls, receiving a plurality of SIP REFER messages corresponding, respectively, to the plurality of calls such that the plurality of calls can be concurrently handed in.

A method for facilitating handing calls from a second communication network to a first communication network in a coupled communication network, the method comprising:

• exchanging messages in the first communication network corresponding to call appearance information, wherein the exchanging the messages corresponding to the call appearance information further comprises:
• a wireless communication unit querying a network switch using one of a Session Initiation Protocol (SIP) INVITE message and SIP OPTIONS message, each respectively including call appearance information for calls in the second communication network,
• receiving a SIP OK message indicating the network switch recognizes the call appearance information for the calls in the second communication network, and
• deciding that the decision is affrmative based on the receiving the SIP OK message;
• and
• wherein the initiating the handin of the call to the first communication network further comprises sending to the network switch a second SIP INVITE message comprising a call identifying field, a To field with a first identity for the wireless communication unit corresponding to the first communication network and a From field with a second identity for the wireless communication unit corresponding to the second communication network;
• deciding whether a call within the second communication network can be handed in to the first communication network based on the exchange of the messages corresponding to the call appearance information and providing a corresponding decision;
• and
• initiating a handing of the call to the first communication network only when the decision is affirmative.

A method for facilitating handing calls from a second communication network to a first communication network in a coupled communication network, the method comprising:

• exchanging messages in the first communication network corresponding to call appearance information, wherein the exchanging the messages corresponding to the call appearance information further comprises:
• a wireless communication unit querying a network switch using one of a Session Initiation Protocol (SIP) INVITE message and SIP OPTIONS message, each respectively including call appearance information for calls in the second communication network
• receiving a SIP OK message indicating the network switch recognizes the call appearance information for the calls in the second communication network, and
• deciding that the decision is affirmative based on the receiving the SIP OK message;
• and
• wherein the initiating the handing of the call to the first communication network further comprises sending to the network switch a SIP REFER message comprising a From field with a second identity for the wireless communication unit corresponding to the second communication network, a To field identifying the call, and a Refer to field with a first identity for the wireless communication unit corresponding to the first communication network;
• deciding whether a call within the second communication network can be handed in to the first communication network based on the exchange of the messages corresponding to the call appearance information and providing a corresponding decision;
• and
• initiating a handing of the call to the first communication network only when the decision is affirmative.

A method for facilitating handing calls from a second communication network to a first communication network in a coupled communication network, the method comprising:

• exchanging messages in the first communication network corresponding to call appearance information, to decide whether a call within the second communication network can be handed in to the first communication network based on the exchange of the messages corresponding to the call apperance information and providing a corresponding decision;
• and
• initiating a handing of the call to the first communication network only when the decision is affirmative, wherein the exchanging the messages corresponding to the call appearance information further comprising:
• receiving at a network switch a query from a wireless communication unit, the query in one of a Session Initiation Protocol (SIP) INVITE message and SIP OPTIONS message, the one of the SIP INVITE and the SIP OPTIONS message respectively including call appearance information for calls in the second communication network;
• comparing the call appearance information to local call appearance information to provide a comparison;
• and
• sending a SIP OK message when the comparison is favorable, thereby indicating the decision is affirmative;
• and
• the initiating the handing of the call to the first communication network when the decision is affirmative further comprises:
• receiving from the wireless communication unit a second SIP INVITE message comprising a call identifying field, a To field with a first identity for the wireless commnunication unit corresponding to the first communication network and a From field with a second identity for the wireless communication unit corresponding to the second communication network;
• and
• when the call is a plurality of calls, receiving a plurality of second SIP INVITE messages corresponding, respectively, to the plurality of calls such that the plurality of calls can be concurrently handed in.

A method for facilitating handing calls from a second communication network to a first communication network in a coupled communication network, the method comprising:

• exchanging messages in the first communication network corresponding to call appearance information, to decide whether a call within the second communication network can be handed in to the first communication network based on the exchange of the messages corresponding to the call appearance information and providing a corresponding decision;
• and
• initiating a handing of the call to the first communication network only when the decision is affirmative, wherein the exchanging the messages corresponding to the call appearance information further comprising:
• receiving at a network switch a query from a wireless communication unit, the query in one of a Session Initiation Protocol (SIP) INVITE message and SIP OPTIONS message, the one of the SIP INVITE and the SIP OPTIONS message respectively including call appearance information for calls in the second communication network;
• comparing the call appearance information to local call appearance information to provide a comparison;
• sending a SIP OK message when the comparison is favorable, thereby indicating the decision is affirmative;
• and
• the initiating the handin of the call to the first communication network when the decision is affirmative further comprises:
• receiving from the wireless communication unit a Session Initiation Protocol (SIP) REFER message comprising a From field with a second identity for the wireless communication unit corresponding to the second communication network, a To field identifying the call, and a Refer to field with a first identity for the wireless communication unit corresponding to the first communication network;
• and
• when the call is a plurality of calls, receiving a plurality of SIP REFER messages corresponding, respectively, to the plurality of calls such that the plurality of calls can be concurrently handed in.