System and method of completing calls to busy mobile subscribers in a radio telecommunications network

Claim 1

A system in a radio telecommunications network for completing a call from a calling party to a called mobile station (MS) which is busy when said call is first attempted, said system comprising: an originating mobile switching center (O-MSC) where said call enters said radio telecommunications network, said O-MSC including a service switching function (SSF); a visiting mobile switching center (V-MSC) where said called MS is operating, said V-MSC including means for determining whether said called (MS) is busy; means for notifying said O-MSC whether said called MS is busy; a service control function (SCF) associated with said O-MSC, said SCF including service logic for periodically initiating a call attempt to said called MS via said SSF without utilizing a trunk between said O-MSC and said V-MSC; means within said O-MSC for informing said SCF whether said MS is busy; and means for completing said call upon determining that said called MS is idle.

Claim 2

A system in a radio telecommunications network for completing a call from a calling party to a called mobile station (MS) which is busy when said call is first attempted, said system comprising: an originating mobile switching center (O-MSC) where said call enters said radio telecommunications network, said O-MSC including a service switching function (SSF); a visiting mobile switching center (V-MSC) where said called MS is operating, said V-MSC including means for determining whether said called (MS) is busy; means for notifying said O-MSC whether said called MS is busy; a service control function (SCF) associated with said O-MSC, said SCF including service logic for periodically initiating a call attempt to said called MS via said SSF without utilizing a trunk between said O-MSC and said V-MSC; means within said O-MSC for informing said SCF whether said MS is busy; and means for completing said call upon determining that said called MS is idle.

Claim 9

A system in a radio telecommunications network for completing a call from a calling party to a called mobile station (MS) which is busy when said call is first attempted, said system comprising: a mobile switching center (MSC) that performs switching and call connecting functions for said calling party and said called MS, said MSC including means for determining whether said called MS is busy; means within the MSC for releasing all trunks between the calling party and the called MS upon determining that the called MS is busy; a service control point (SCP) associated with said MSC, said SCP including service logic for periodically initiating a call attempt to said called MS via said MSC; means within said MSC for informing said SCP whether said called MS is busy; signaling means for sending a request for call completion by the calling part to the SCP upon determining that the called MS is busy; means within the MSC for establishing a first trunk from the MSC to the calling party upon determining that the called MS is idle; means within the MSC for informing the calling party to wait for call completion; and means within the MSC for completing said call upon determining that said called MS is idle.

Claim 10

A system in a radio telecommunications network for completing a call from a calling party to a called mobile station (MS) which is busy when said call is first attempted, said system comprising: a mobile switching center (MSC) that performs switching and call connecting functions for said calling party and said called MS, said MSC including means for determining whether said called MS is busy; means within the MSC for releasing all trunks between the calling party and the called MS upon determining that the called MS is busy; a service control point (SCP) associated with said MSC, said SCP including service logic for periodically initiating a call attempt to said called MS via said MSC; means within said MSC for informing said SCP whether said called MS is busy; signaling means for sending a request for call completion by the calling part to the SCP upon determining that the called MS is busy; means within the MSC for establishing a first trunk from the MSC to the calling party upon determining that the called MS is idle; means within the MSC for informing the calling party to wait for call completion; and means within the MSC for completing said call upon determining that said called MS is idle.

Claim 12

A method in a radio telecommunications network of completing a call from a calling party to a called mobile station (MS) which is busy when said call is first attempted, said MS operating in a service area of a visiting mobile switching center (V-MSC), said method comprising the steps of: attempting a call by said calling party to said MS; determining a busy status of said MS by a gateway mobile switching center (G-MSC), said G-MSC having a home service area from which said call enters said radio telecommunications network; sending a request for call completion by said calling party to a service control point (SCP) associated with said G-MSC, upon determining that said MS is busy; releasing, by said G-MSC, of all trunks between said calling party and said MS; periodically initiating, by said SCP, a call attempt to said MS via said G-MSC to determine said busy status of said MS; determining whether said MS is in said busy status; establishing a first trunk from said G-MSC to said V-MSC where said MS is operating, upon determining said MS is idle; sending an alerting signal to said MS; detecting that said MS answered said alerting signal; informing said MS to wait for call completion; establishing a second trunk from said G-MSC to said calling party; informing said calling party to wait for call completion; and joining said first trunk to said second trunk to establish a call delivery from said calling party to said MS.

Claim 13

A method in a radio telecommunications network of completing a call from a calling party to a called mobile station (MS) which is busy when said call is first attempted, said MS operating in a service area of a visiting mobile switching center (V-MSC), said method comprising the steps of: attempting a call by said calling party to said MS; determining a busy status of said MS by a gateway mobile switching center (G-MSC), said G-MSC having a home service area from which said call enters said radio telecommunications network; sending a request for call completion by said calling party to a service control point (SCP) associated with said G-MSC, upon determining that said MS is busy; releasing, by said G-MSC, of all trunks between said calling party and said MS; periodically initiating, by said SCP, a call attempt to said MS via said G-MSC to determine said busy status of said MS; determining whether said MS is in said busy status; establishing a first trunk from said G-MSC to said V-MSC where said MS is operating, upon determining said MS is idle; sending an alerting signal to said MS; detecting that said MS answered said alerting signal; informing said MS to wait for call completion; establishing a second trunk from said G-MSC to said calling party; informing said calling party to wait for call completion; and joining said first trunk to said second trunk to establish a call delivery from said calling party to said MS.

Claim 21

A method in a radio telecommunications network of completing a call from a calling party to a called mobile station (MS) which is busy when said call is first attempted, said MS operating in a home service area of a mobile switching center (MSC), said method comprising the steps of: attempting a call by said calling party to said MS; determining a busy status of said MS by said MSC; sending a request for call completion by said calling party to a service control point (SCP) associated with said MSC, upon determining that said MS is busy; releasing, by said MSC, of all trunks between said calling party and said MS; periodically initiating, by said SCP, a call attempt to said MS via said MSC to determine a busy status of said MS; determining whether said MS is in said busy status; sending an alerting signal to said MS; detecting that said MS answered said alerting signal; informing said MS to wait for call completion; establishing a first trunk from said MSC to said calling party; informing said calling party to wait for call completion; and establishing a call delivery from said calling party to said MS.

Claim 22

A method in a radio telecommunications network of completing a call from a calling party to a called mobile station (MS) which is busy when said call is first attempted, said MS operating in a home service area of a mobile switching center (MSC), said method comprising the steps of: attempting a call by said calling party to said MS; determining a busy status of said MS by said MSC; sending a request for call completion by said calling party to a service control point (SCP) associated with said MSC, upon determining that said MS is busy; releasing, by said MSC, of all trunks between said calling party and said MS; periodically initiating, by said SCP, a call attempt to said MS via said MSC to determine a busy status of said MS; determining whether said MS is in said busy status; sending an alerting signal to said MS; detecting that said MS answered said alerting signal; informing said MS to wait for call completion; establishing a first trunk from said MSC to said calling party; informing said calling party to wait for call completion; and establishing a call delivery from said calling party to said MS.