METHOD AND DEVICE FOR ESTABLISHING AN INTER-RADIO FREQUENCY SUBSYSTEM INTERFACE (ISSI) UNIT-TO-UNIT CALL

• US 20110250923A1
• Filed: 04/08/2010
• Published: 10/13/2011
• Est. Priority Date: 04/08/2010
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Averbuch, Rod N., Fidai, Sikendar, Leigh, Todd A., Drobka, Gerald R., Miller, Trent J., Drozt, Peter M., Pappas, Scott J., Vanswol, Steven E., Poe, Brian R., Newberg, Donald G., Korus, Michael F.
• Granted Patent: US 8,406,800 B2
• Time in Patent Office: Days
• US Class Current: 455/518
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04W 76/10 Connection setup

Abstract

A method and device enable establishing an inter-radio frequency subsystem interface (ISSI) unit-to-unit call between a calling unit of a calling home radio frequency subsystem (RFSS), and a called unit of a called home RFSS, through a hosted ISSI function (HIF). The method includes processing, at the HIF, a first invite message received from the calling home RFSS, wherein the first invite message includes a first request uniform resource identifier (URI) that designates an alias system unit identification (SU-ID). In response to the first invite message, transmitting, from the HIF to the called home RFSS, a second invite message, including a second request URI that designates a real SU-ID, wherein the HIF acts as the calling home RFSS. The unit-to-unit call is thus established between the calling unit and the called unit through the calling home RFSS, the HIF, and the called home RFSS.

Claims

1. A method for establishing an inter-radio frequency subsystem interface (ISSI) unit-to-unit call between a calling unit of a calling home radio frequency subsystem (RFSS) and a called unit of a called home RFSS through a hosted ISSI function (HIF), the method comprising:

processing, at the HIF, a first invite message received from the calling home RFSS, wherein the first invite message includes a first request uniform resource identifier (URI) that designates an alias system unit identification (SU-ID); and

in response to the first invite message, transmitting, from the HIF to the called home RFSS, a second invite message, including a second request URI that designates a real SU-ID, wherein the HIF acts as the calling home RFSS;

whereby the unit-to-unit call is established between the calling unit and the called unit through the calling home RFSS, the HIF, and the called home RFSS.

2. The method of claim 1, further comprising associating, at the HIF, the alias SU-ID with the real SU-ID designating the called unit.

3. The method of claim 2, wherein the called unit is roaming and is associated with a called serving RFSS, and wherein the calling unit is roaming and is associated with a calling serving RFSS.

4. The method of claim 1, wherein the called unit is not roaming, and wherein the calling unit is roaming and is associated with a calling serving RFSS.

5. The method of claim 1, wherein the called unit is roaming and is associated with a called serving RFSS, and wherein the calling unit is not roaming.

6. The method of claim 1, wherein the alias SU-ID and the real SU-ID are identical.

7. The method of claim 1, wherein the first and second invite messages are session initiation protocol (SIP) INVITE messages.

8. The method of claim 1, wherein the HIF stores called unit registration information selected from the following:

home RFSS transport information of the called unit;

an identification of the called home RFSS;

system identification;

a wide area communications network (WACN) identification; and

a subscriber unit identity.

9. The method of claim 1, wherein the HIF functions as a session initiation protocol (SIP) back to back user agent.

10. The method of claim 1, wherein the HIF processes push to talk (PTT) messaging between the calling unit and the called unit.

11. The method of claim 1, wherein voice data packets of the unit to unit call are routed through the HIF.

12. A hosted inter-radio frequency subsystem interface function (HIF) device comprising:

a processor; and

a memory coupled to the processor, the memory including;

computer readable program code components for processing, at the HIF, a first invite message, received from a calling home radio frequency subsystem (RFSS), including a first request uniform resource identifier (URI) that designates an alias system unit identification (SU-ID); and

computer readable program code components for, in response to the first invite message, transmitting from the HIF to a called home RFSS, a second invite message, including a second request URI that designates a real SU-ID, wherein the HIF acts as the calling home RFSS;

whereby a unit-to-unit call can be established between a calling unit and a called unit through the calling home RFSS, the HIF, and the called home RFSS.

13. The device of claim 12, further comprising computer readable program code components for associating, at the HIF, the alias SU-ID with the real SU-ID designating the called unit.

14. The device of claim 13, wherein the called unit is roaming and is associated with a called serving RFSS, and wherein the calling unit is roaming and is associated with a calling serving RFSS.

15. The device of claim 12, wherein the called unit is not roaming, and wherein the calling unit is roaming and is associated with a calling serving RFSS.

16. The device of claim 12, wherein the called unit is roaming and is associated with a called serving RFSS, and wherein the calling unit is not roaming.

17. The device of claim 12, wherein the alias SU-ID and the real SU-ID are identical.

18. The device of claim 12, wherein the first and second invite messages are session initiation protocol (SIP) INVITE messages.

19. The device of claim 12, wherein the HIF stores called unit registration information selected from the following:

home RFSS transport information of the called unit;

an identification of the called home RFSS;

system identification;

a wide area communications network (WACN) identification; and

a subscriber unit identity.

20. The device of claim 12, wherein the HIF processes push to talk (PTT) messaging between the calling unit and the called unit.