Mobile satellite system/terrestrial wireless system interworking techniques

• US 6,272,315 B1
• Filed: 04/16/1998
• Issued: 08/07/2001
• Est. Priority Date: 12/03/1997
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Northern Telecom Limited (Nortel Networks Corporation)
• Inventors: Chang, Jue, Lo, Wing F., Kim, Won S.
• Primary Examiner(s): CUMMING, WILLIAM D
• Application Number:
  US09/061,420
• Time in Patent Office: 1,209 Days
• Field of Search: 342/357.6, 342/357.1, 370/209, 370/203, 370/316, 455/433, 455/13.2, 455/13.1, 455/428, 455/435, 455/453
• US Class Current: 455/13.1
• CPC Class Codes: H04B 7/18545 Arrangements for managing station mobility, i.e. for station registration or localisation
• CPC Class Codes: H04B 7/18563 Arrangements for interconnecting multiple systems data switching networks H04L12/00
• CPC Class Codes: H04W 36/12 Reselecting a serving backbone network switching or routing node
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: H04W 84/06 Airborne or Satellite Networks space-based or airborne stations H04B7/185
• 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

Methods for switching a mobile between operation in an mobile satellite system mode and a terrestrial wireless mode. When operating in the terrestrial wireless mode, the mobile terminal will initiate an attempt to switch into the MSS mode when it nears the boundary of the coverage area for a terrestrial wireless system to which it is registered. Conversely, a mobile terminal operating in the MSS mode will regularly attempt to switch into the terrestrial wireless mode. For both, a switch between modes is contingent on the mobile terminal identifying a suitable system for registration therewith upon completing the switch between modes. The criteria for identifying a suitable system for selection purposes include the following: (1) the selected system is available, i.e., the mobile terminal is physically located within a coverage area for the selected system; (2) the mobile terminal is compatible with the selected system; and (3) the selected system is willing to accept the mobile terminal. If multiple systems meet these criteria, the mobile terminal will utilize a stored list of preferred systems to select therefrom. When switching into the terrestrial wireless mode, the MSS system provides the mobile terminal with switch-over information for the underlying terrestrial wireless systems and, when switching into the MSS mode, the terrestrial wireless system provides the mobile terminal with switch-over information for the overlying MSS systems.

Claims

1. For a mobile terminal registered to a mobile satellite system (“

MSS”

) and configured for operation in MSS mode and a terrestrial wireless mode, a method of switching from operating in said MSS mode to operating in said terrestrial wireless mode, comprising the steps of;

creating an idle hand-down channel;

said MSS system broadcasting switch-over information for plural terrestrial wireless systems over said idle hand-down channel, said switch-over information including at least one parameter useful in registering with said wireless terrestrial systems;

said mobile terminal selecting, from said plural terrestrial wireless systems for which switch-over information was broadcast over said idle hand-down channel, a preferred terrestrial wireless system;

said mobile terminal using said broadcast information for said preferred terrestrial wireless system to register with said preferred terrestrial wireless system, wherein prior to registration with said terrestrial wireless system, said mobile terminal is registered with a MSS system and in an idle state;

said mobile terminal de-registering with said terrestrial wireless system; and

said mobile terminal switching from said terrestrial wireless mode to said MSS mode.

2. For a mobile terminal configured for operation in a first, mobile satellite system (“

MSS”

) mode and a second, terrestrial wireless, mode, a method of switching from operating in said second mode to operating in said first mode, comprising the steps of;

said mobile terminal selecting a MSS system;

upon selection of said MSS system, said mobile terminal switching from operating in said second mode to operating in said first mode, wherein prior to selection of said MSS system, said mobile terminal is registered with a terrestrial wireless system and in an idle state;

prior to selecting a MSS system, said terrestrial wireless system identifying MSS systems having a coverage area which overlays a coverage area for said terrestrial wireless system, classifying all MSS systems having coverage areas which overlay said coverage area for said terrestrial wireless system as available MSS systems and transmitting, to said mobile terminal switch-over information for all of said available MSS systems; and

prior to selecting a MSS system, said terrestrial wireless system determining if said mobile terminal is leaving said coverage area for said terrestrial wireless system and advising said mobile terminal that it is leaving said coverage area for said terrestrial wireless system.

6. The method of claim 2 and further comprising the step of:

said mobile terminal selecting one of said available MSS systems as said selected MSS system.

7. The method of claim 6 wherein the step of selecting one of said available MSS systems further comprises the steps of:

determining if any of said available MSS systems are compatible with said mobile terminal;

determining if any of said compatible and available MSS systems will accept said mobile terminal;

selecting, from said compatible and available MSS systems willing to accept said mobile terminal, a preferred MSS system as said selected MSS system.

8. The method of claim 7 and further comprising the step of:

continuing to operate said mobile terminal in said second mode if;

(1) there are no available MSS systems;

(2) none of said available MSS systems are compatible with said mobile terminal;

or

(3) none of said compatible available MSS terminals are willing to accept said mobile terminal.

3. For a mobile terminal configured for operation in a first, mobile satellite system (“

MSS”

) mode and a second, terrestrial wireless, mode, a method of switching said mobile terminal from conducting operations with a MSS system in said first mode to conducting operations in said second mode, comprising the steps of;

while operating in said first mode, said mobile terminal selecting a terrestrial wireless system for further operations;

upon selection of a terrestrial wireless system for further operations, said mobile terminal switching from conducting operations in said first mode to conducting operations in said second mode if said selected terrestrial wireless system is available;

while operating in said first mode, said mobile terminal periodically checking for terrestrial wireless systems for possible further operations; and

prior to said mobile terminal selecting a terrestrial wireless terminal, said MSS system transmitting, for each one of at least one terrestrial wireless system underlying a coverage area for said MSS system, switch-over information for use when switching from conducting operations with said MSS system in said first mode to conducting operations, in said second mode, with a respective one of said at least one terrestrial wireless systems underlying said coverage area for said MSS system.

9. The method of claim 3 wherein the step of selecting said terrestrial wireless system for further operations further comprises the step of said mobile terminal selecting said terrestrial wireless system for further operations from said at least one terrestrial wireless system for which said MSS system transmits switch-over information to said mobile terminal.

10. The method of claim 9 wherein the step of selecting said terrestrial wireless system for continued operations from said at least one terrestrial wireless system for which said MSS system transmits switch-over information to said mobile terminal further comprises the steps of:

said mobile terminal determining if any of said at least one terrestrial wireless system for which said MSS system transmits switch-over information is compatible with said mobile terminal;

said mobile terminal determining if any of said at least one terrestrial wireless system for which said MSS system transmits switch-over information and determined to be compatible with said mobile terminal will accept said mobile terminal; and

selecting, from said at least one terrestrial wireless system for which said MSS system transmits switch-over information, determined to be compatible with said mobile terminal and which will accept said mobile terminal, a preferred terrestrial wireless system as said selected terrestrial wireless system for continued operations.

11. The method according to claim 10 and further comprising the steps of:

said mobile terminal periodically determining if said selected terrestrial wireless system is available; and

said mobile terminal registering with said selected terrestrial wireless system upon determining that said selected terrestrial wireless system is available.

12. The method of claim 11 and further comprising the step of:

continuing to operate said mobile terminal in said first mode if;

(1) there are no terrestrial wireless system which underlie said MSS system;

(2) none of said terrestrial wireless systems which underlie said MSS system are compatible with said mobile terminal;

(3) none of said compatible available terrestrial wireless systems which underlie said MSS system are willing to accept said mobile terminal;

or

(4) none of said compatible available terrestrial wireless systems which underlie said MSS system which are willing to accept said mobile terminal are available.

4. For a mobile terminal configured for operation in a first, mobile satellite system (“

MSS”

) mode and a second, terrestrial wireless, mode, a method of switching said mobile terminal from conducting operations with a MSS system in said first mode to conducting operations in said second mode, comprising the steps of;

while operating in said first mode, said mobile terminal selecting a terrestrial wireless system for further operations;

upon selection of a terrestrial wireless system for further operations, said mobile terminal switching from conducting operations in said first mode to conducting operations in said second mode;

while operating in said first mode, said mobile terminal receiving, from said MSS system, for each one of at least one terrestrial wireless system underlying a coverage area for said MSS system, switch-over information for use when switching from conducting operations with said MSS system in said first mode to conducting operations, in said second mode, with a respective one of said at least one terrestrial wireless systems underlying said coverage area for said MSS system;

said mobile terminal selecting said terrestrial wireless system for further operations from said at least one terrestrial wireless system for which said MSS system transmits switch-over information to said mobile terminal; and

said mobile terminal acquiring positional information for said mobile terminal.

13. The method of claim 4 wherein the step of selecting said terrestrial wireless system for continued operations from said at least one terrestrial wireless system for which said MSS system transmits switch-over information to said mobile terminal further comprises the steps of:

said mobile terminal determining if any of said at least one terrestrial wireless systems for which said MSS transmits switch-over information is available;

said mobile terminal determining if any of said at least one terrestrial wireless system for which said MSS system transmits switch-over information and determined to be available are compatible with said mobile terminal;

said mobile terminal determining if any of said at least one terrestrial wireless system for which said MSS system transmits switch-over information and determined to be available and compatible with said mobile terminal will accept said mobile terminal; and

selecting, from said at least one terrestrial wireless system for which said MSS system transmits switch-over information, determined to be available, compatible with said mobile terminal and which will accept said mobile terminal, a preferred terrestrial wireless system as said selected terrestrial wireless system for continued operations.

14. The method according to claim 13 wherein the step of said mobile terminal determining if any of said at least one terrestrial wireless systems for which said MSS transmits switch-over information is available further comprises the steps of:

said mobile terminal determining, for each of said at least one terrestrial wireless systems for which said MSS transmits switch-over information, if said mobile terminal is located within a corresponding coverage area thereof;

if said mobile terminal is located within said coverage area, said mobile terminal determining that said corresponding terrestrial wireless system is available.

15. The method of claim 14 and further comprising the step of:

continuing to operate said mobile terminal in said first mode if;

(1) there are no available terrestrial wireless systems

(2) none of said available terrestrial wireless systems are compatible with said mobile terminal;

or

(3) none of said compatible available terrestrial wireless systems are willing to accept said mobile terminal.

5. For a mobile terminal configured for operation in a first, mobile satellite system (“

MSS”

) mode and a second, terrestrial wireless, mode, a method of switching said mobile terminal from conducting operations with a MSS system in said first mode to conducting operations in said second mode, comprising the steps of;

while operating in said first mode, said mobile terminal selecting a terrestrial wireless system for further operations;

upon selection of a terrestrial wireless system for further operations, said mobile terminal switching from conducting operations in said first mode to conducting operations in said second mode;

said MSS system acquiring positional information for said mobile terminal;

said MSS system determining if said mobile terminal is positioned within a coverage area of each one of at least one terrestrial wireless system underlying a coverage area for said MSS system;

said mobile terminal receiving from said MSS system, for each one of said at least one terrestrial wireless system underlying said coverage area for said MSS system and having a coverage area within which said mobile terminal is positioned, switch-over information for use when switching from conducting operations with said MSS system in said first mode to conducting operations, in said second mode, with a respective one of said at least one terrestrial wireless systems underlying said coverage area for said MSS system;

said mobile terminal selecting said terrestrial wireless system for further operations from said at least one terrestrial wireless system for which said MSS system transmits switch-over information to said mobile terminal;

said mobile terminal determining if any of said at least one terrestrial wireless system for which said MSS system transmits switch-over information are compatible with said mobile terminal;

said mobile terminal determining if any of said at least one terrestrial wireless system for which said MSS system transmits switch-over information and determined to be compatible with said mobile terminal will accept said mobile terminal; and

selecting, from said at least one terrestrial wireless system for which said MSS system transmits switch-over information, determined to be compatible with said mobile terminal and which will accept said mobile terminal, a preferred terrestrial wireless system as said selected terrestrial wireless system for continued operations.

16. The method of claim 5 and further comprising the step of:

continuing to operate said mobile terminal in said first mode if;

(1) there are no terrestrial wireless systems having coverage areas within which said mobile terminal is positioned

(2) none of said terrestrial wireless systems having coverage areas within which said mobile terminal is positioned are compatible with said mobile terminal;

or

(3) none of said compatible terrestrial wireless systems having coverage areas within which said mobile terminal is positioned are willing to accept said mobile terminal.