Fast call set-up for multi-mode communication

• US 20050239498A1
• Filed: 04/26/2004
• Published: 10/27/2005
• Est. Priority Date: 04/26/2004
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Dorenbosch, Jheroen P., Idnani, Ajaykumar R., Gipson, Jack A.
• Granted Patent: US 7,162,236 B2
• Time in Patent Office: Days
• US Class Current: 455/552.100
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

Fast call set-up for a call to a multi-mode communication unit (102) is facilitated by a method and apparatus for registering and re-registering priorities with a SIP registrar (111). A list of contacts with first priorities associated with a mode of operation in a first enterprise network (106) is established and used. A switch to second priorities is made when a probability of a switch from the first mode of operation to a second mode of operation in a second cellular network (108) satisfies a threshold. The list of contacts includes a contact having an expiration time for the first mode of operation. A quality factor is determined and the list of contacts is re-registered and the expiration time changed if the quality factor does not satisfy a threshold.

Claims

1. A method for reducing a call setup time for a call setup to a multi-mode communication unit, the method comprising:

registering, with a Session Initiation Protocol (SIP) registrar, a list of contacts having first respective priorities associated with a first mode of operation of the multi-mode communication unit;

using the first respective priorities when the multi-mode communication unit is operating in accordance with the first mode of operation; and

modifying the list of contacts at the SIP registrar, with second respective priorities associated with a second mode of operation of the multi-mode communication unit when a probability of a switch from operation in accordance with the first mode of operation to operation in accordance with the second mode of operation satisfies a threshold.

2. A method in accordance with claim 1, wherein the first operational mode includes a LAN mode according to one of a wireless connection and a wired connection, and the second operational mode includes a cellular mode.

3. A method in accordance with claim 1, wherein each of the first operational mode and the second operational mode include one or more of a wireless LAN mode, a wired LAN mode, a cellular mode, and a Publicly Switched Telephone Network PSTN mode.

5. A method in accordance with claim 1, wherein the second respective priorities include a first priority of a first contact associated with the first mode of operation equal to a second priority of a second contact associated with the second mode of operation.

4. (canceled)

6. A method for reducing a call setup time for a call setup to a multi-mode communication unit, the call setup conducted in accordance with a protocol, the method comprising:

registering a list of contacts with a Session Initiation Protocol (SIP) registrar associated with the protocol, the list of contacts including a first contact having a first expiration time associated with operation according to a first mode of operation of the multi-mode communication unit;

determining a quality factor associated with the first mode of operation; and

re-registering the list of contacts with the SIP registrar, the list of contacts including the first contact having a reduced expiration time if the quality factor does not satisfy a first predetermined quality threshold.

7. A method in accordance with claim 6, further comprising:

re-determining the quality factor associated with the first mode of operation before the expiration of the first expiration time to provide a second quality factor; and

re-registering the list of contacts,

wherein the first expiration time is increased if the second quality factor exceeds a second predetermined quality threshold.

8. A method in accordance with claim 6, further comprising preparing for operation in accordance with a second mode of operation if the quality factor does not satisfy the first predetermined quality threshold.

9. A method in accordance with claim 6, further comprising changing to operation in accordance with a second mode of operation if the quality factor does not satisfy a second predetermined quality threshold.

11. A method in accordance with claim 6, wherein:

the first contact further includes a first priority, and

the list of contacts further includes;

a second contact having a second expiration time and a second priority associated with operation according to a second mode of operation of the multi-mode communication unit; and

a third contact having a third expiration time longer than the first expiration time and a third priority associated with the operation according to the first mode of operation of the multi-mode communication unit, where the third priority is lower than the first and the second priority.

10. (canceled)

12. An apparatus for reducing a call setup time associated with a call setup in a multi-mode communication environment, the apparatus capable of operating according to a protocol, the apparatus comprising:

a memory; and

a processor coupled to the memory, the apparatus capable of maintaining at least two contacts in a Session Initiation Protocol (SIP) registrar, the processor configured to;

assign a first priority to a first contact associated with operation according to a first operational mode and a second priority to a second contact associated with operation according to a second operational mode, wherein the assignment results in the registration of the first contact and the second contact with the SIP registrar with the assigned first priority and the second priority respectively;

detect an impending switch between the operation according to the first operational mode and the operation according to the second operational mode; and

modify a relative priority between the first priority and the second priority, the modification resulting from one of modifying the first priority and modifying the second priority, such that the first priority of the first contact is not higher than the second priority of the second contact when the impending switch is detected, wherein the modification results in the modification of the first contact and the second contact at the SIP registrar with the modified relative priority.

13. An apparatus in accordance with claim 12, wherein the first operational mode includes a LAN mode according to one of a wireless connection and a wired connection, and the second operational mode includes a cellular mode.

14. An apparatus in accordance with claim 12, wherein each of the first operational mode and the second operational mode include one of a wireless LAN mode, a wired LAN modes a cellular mode, and a Publicly Switched Telephone Network PSTN mode.

16. An apparatus in accordance with claim 12, wherein the processor is further configured to:

assign a first expiration time to the first contact associated with the operation according to the first operational mode; and

modify the first expiration time when the impending switch is detected such that the modified first expiration time is shorter than the first expiration time.

17. An apparatus in accordance with claim 16, wherein the processor is further configured to:

assign a second expiration time longer than the first expiration time to the second contact associated with operation according to the second operational mode when the impending mode switch is detected.

18. An apparatus in accordance with claim 12, wherein the processor is further configured to:

assign the first priority and the second priority such that the first priority is higher than the second priority.

15. (canceled)

19. An apparatus for reducing a call setup time associated with a call setup in a multi-mode communication environment, the apparatus capable of operating according to a protocol, the apparatus comprising:

a memory; and

a processor coupled to the memory, the processor configured to;

maintain a contact list in a Session Initiation Protocol (SIP) registrar, the contact list containing at least a first contact associated with operation according to a first operational mode, the first contact having a first priority and a first expiration time, and a second contact associated with operation according to a second operational mode, the second contact having a second priority and a second expiration time, wherein maintaining the contact list results in the registration of the first contact and the second contact with the SIP registrar with the assigned first priority and the second priority respectively;

determine a quality factor associated with the first operational mode; and

modify the contact list at the SIP registrar if the quality factor does not meet a predetermined quality level, the modification resulting in at least one of;

a third expiration time for the first contact, the third expiration time being shorter than the first expiration time and shorter than the second expiration time, and

a third priority for the first contact, the third priority being not higher than the second priority.

20. An apparatus in accordance with claim 19, wherein the processor is further configured to:

re-determine the quality factor associated with the first mode of operation to provide a second quality factor; and

re-modify the contact list if the second quality factor meets a second predetermined quality level, the re-modification resulting in at least one of;

an expiration time for the first contact, the expiration time being longer than the third expiration time, and

a priority for the first contact, the priority being not lower than the second priority.

21. An apparatus in accordance with claim 19, wherein the processor, in maintaining the contact list is further configured to one of maintain the first priority, maintain the first expiration time, maintain the second priority, and maintain the second expiration time, wherein the maintained contact list further includes one of

the second expiration time being longer than the first expiration time, and

the second priority being lower than the first priority.