Network of hierarchical communication systems and method therefor

• US 5,452,471 A
• Filed: 05/02/1994
• Issued: 09/19/1995
• Est. Priority Date: 11/12/1992
• Status: Expired due to Term

• Current Assignee: Intellectual Ventures I LLC (Intellectual Ventures LLC)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Zancho, William F., Vatt, Gregory B., Leopold, Raymond J.
• Primary Examiner(s): Pham, Chi H.
• Assistant Examiner(s): WISLER, MARK
• Application Number:
  US08/237,422
• Time in Patent Office: 505 Days
• Field of Search: 455/12.1, 455/13.2, 455/13.4, 455/33.1, 455/33.2, 455/33.3, 455/62, 455/63, 455/54.1, 455/67.1, 455/34.1, 455/34.2, 455/33.4, 455/89, 455/56.1, 379/59
• US Class Current: 455/429
• CPC Class Codes: H04B 7/18563 Arrangements for interconnecting multiple systems data switching networks H04L12/00

Abstract

A hierarchical communication network includes primary, secondary, and tertiary communication systems. The primary system uses orbiting satellites as communication nodes and forms a pattern of cells that may cover the entire earth and that move over the earth. A given spectrum is divided among the cells in accordance with a reuse plan. Any number of secondary, terrestrial-based systems have secondary region areas of coverage that are substantially smaller than the distance to the orbits of the satellites used by the primary system. Secondary systems monitor the primary system to determine which channels of the spectrum are available for use in their secondary regions. Any number of tertiary, terrestrial-based systems reside within a secondary region and have tertiary region areas of coverage that are substantially confined within buildings. Tertiary systems use channels concurrently used by the primary system in the same area where their tertiary regions are located.

Claims

1. A subordinate communication system which cooperates with a primary communication system, wherein said primary communications system projects a plurality of cells over Earth, allocates orthogonal channels of a spectrum in adjacent ones of said cells, and reuses channels in geographically spaced apart cells, said subordinate communication system comprising:

an antenna for projecting a secondary region over Earth, said antenna being located so that said secondary region and a local one of said cells occupy a common area;

receiving means for receiving allocation data from said primary communication system, said allocation data identifying channels allocated by said primary communication system for use in said local cell; and

selecting means, coupled to said receiving means and said antenna, for selecting channels of said spectrum that are available for use in said secondary region, said selecting means being responsive to said allocation data, wherein;

said primary communication system is configured so that identities of said local cell and of said channels allocated for use therein change; and

said subordinate communication system additionally comprises means, coupled to said receiving means, for tracking identities of channels allocated by said primary communication system for use in said local cell as said local cell changes.

2. A subordinate communication system as claimed in claim 1 wherein said selecting means is configured so that said channels of said spectrum that are selected as being available for use in said secondary region are not used in said local cell by said primary communication system.

3. A subordinate communication system as claimed in claim 1 additionally comprising:

a second antenna for projecting a second-secondary region over Earth, said second-secondary region and said secondary region occupying different areas, and said second-secondary region and any one cell occupying a second common area;

second means for receiving second allocation data from said primary communication system, said second allocation data identifying channels allocated by said primary communication system for use in said any one cell; and

second means, coupled to said second receiving means and said second antenna, for selecting channels of said spectrum that are available for use in said second-secondary region, said second selecting means being responsive to said second allocation data.

4. A subordinate communication system as claimed in claim 3 wherein said secondary region and said second-secondary region reside adjacent each other, and said subordinate communication system additionally comprises means for sending messages from said secondary region to said second-secondary region to identify claimed channels, said claimed channels being used for communications in said secondary region, so that said claimed channels may be avoided in said second-secondary region.

5. A subordinate communication system as claimed in claim 1 additionally comprising:

means, coupled to said receiving means, for identifying unavailable channels of said spectrum, said unavailable channels being those which, if used within said secondary region, would have a higher likelihood of interfering with primary communication system communications than channels other than said unavailable channels of said spectrum;

a tertiary system controller having a tertiary communication system antenna located within said secondary region; and

means, coupled to said identifying means, for communicating unavailable channel identities to said tertiary system controller.

6. A subordinate communication system as claimed in claim 5 wherein said tertiary system controller is configured to conduct communications through said tertiary communication system antenna within a tertiary region, all points of which reside an intimate distance from said tertiary communication system antenna, using said unavailable channels.

7. A subordinate communication system as claimed in claim 6 wherein said cells are projected by a primary communication system antenna, and said subordinate communication system additionally comprises a barrier that impedes propagation of said unavailable channels, said barrier being positioned substantially between said tertiary communication system antenna and said primary communication system antenna.

8. A subordinate communication system as claimed in claim 6 wherein said barrier is positioned between substantially all points within said tertiary region and said primary communication system antenna.

9. A method of integrating one or more subordinate communication systems with a primary communication system, wherein said primary communication system communicates using a spectrum divided into orthogonal channels allocated to cells projected over Earth, said method comprising steps of:

receiving a signal from said primary communication system, said signal being received at a monitoring location;

determining, in response to said receiving step, an available channel set of said spectrum, said available channel set not including channels allocated by said primary communication system to a local cell within which said monitoring location resides; and

communicating in a secondary region, all points of which reside proximate to said monitoring location, using channels from said available channel set, wherein;

said cells projected over Earth by said primary communication system move with respect to said monitoring location; and

said method additionally comprises a step of repeating said determining step to change said available channel set in response to movement of said cells.

10. A method as claimed in claim 9 wherein said method additionally comprises steps of:

receiving a signal from said primary communication system at a second monitoring location, said second monitoring location being spaced apart from said monitoring location;

determining a second available channel set of said spectrum, said second available channel set not including channels allocated by said primary communication system to the cell within which said second monitoring location resides; and

communicating in a second-secondary region, all points of which reside proximate said second monitoring location, using channels from said second available channel set.

11. A method as claimed in claim 9 wherein said secondary region and said second-secondary region reside adjacent to each other, and said method additionally comprises steps of:

sending a message from said secondary region to said second-secondary region to identify a claimed channel, said claimed channel being used for communications in said secondary region; and

refraining, in response to said sending step, from including said claimed channel in said second available channel set.

12. A method as claimed in claim 11 wherein said communicating in a secondary region step comprises the step of establishing a call that uses a first communication link between a base station located in said secondary region and a subscriber unit also located in said secondary region, and said method additionally comprises steps of:

establishing a second communication link between said subscriber unit and a second base station located in said second-secondary region when said subscriber unit is located proximate a boundary between said secondary region and said second-secondary region; and

handing off said call from said first communication link to said second communication link when said subscriber unit nears said boundary.

13. A method as claimed in claim 9 wherein:

said communicating step comprises a step of establishing a communication link between a base station located in said secondary region and a subscriber unit also located in said secondary region, said communication link using a first channel from said available channel set; and

said method additionally comprises the step of handing off said communication link from said first channel to a second channel when said cell movement causes said first channel to become unavailable in said secondary region.

14. A method as claimed in claim 9 wherein:

said primary communication system uses channels from said available channel set in one or more non-local cells; and

said communicating step comprises a step of adjusting power levels for said communications in said secondary region to prevent interference with primary communication system communication in said one or more non-local cells.

15. A method as claimed in claim 9 additionally comprising steps of:

determining an unavailable channel set of said spectrum, said unavailable channel set comprising channels which, if used proximate to said monitoring location, would have a higher likelihood of interfering with primary communication system communications than channels from said available channel set; and

communicating said unavailable channel set to a tertiary system controller located within said secondary region.

16. A method as claimed in claim 15 wherein said tertiary system controller couples to an antenna and said method additionally comprises a step of communicating in a tertiary region, all points of which reside an intimate distance from said antenna, using channels from said unavailable channel set.

17. A method as claimed in claim 16 additionally comprising a step of confining said tertiary region to a space existing substantially within a barrier that impedes propagation of channels from said unavailable channel set.

18. A method as claimed in claim 16 additionally comprising a step of adjusting power levels for said communications in said tertiary region to prevent interference with said primary communication system communication in said local cell.

19. A method of operating a subscriber unit in accordance with a hierarchical network of communication systems wherein primary and secondary systems have common areas of coverage, and said primary system has a larger area of coverage than said secondary system, said method comprising steps of;

receiving first and second acquisition signals;

obtaining first and second identity data from said first and second acquisition signals;

respectively, said first and second identity data indicating whether said respective acquisition signal was broadcast from said primary system or said secondary system; and

refraining from communicating with said primary system when said first and second identity data indicate that said first and second acquisition signals were broadcast from said primary and secondary systems respectively, wherein;

said network of communication systems additionally includes a tertiary system that has a common area of coverage with said secondary system and has a smaller area of coverage than said secondary system;

said receiving step additionally receives a third acquisition signal;

said obtaining step additionally obtains third identity data, and said third identity data indicates that said third acquisition signal was broadcast from said tertiary system; and

said method additionally comprises a step of communicating with said tertiary system.

20. A method as claimed in claim 19 additionally comprising steps of:

selecting a communication system with which to communicate; and

adjusting a power level at which said subscriber unit transmits in response to whether said primary or said secondary system is selected in said selecting step.

21. A method as claimed in claim 19, additionally comprising, prior to said obtaining step, a step of determining that communications may be conducted with either of said primary or secondary systems.

22. A method as claimed in claim 19, additionally comprising a step of communicating with said secondary system when said obtaining step obtains only said first and second identity data.

23. A method as claimed in claim 19, wherein said method additionally comprises steps of:

selecting whether to communicate with said primary, secondary, or tertiary communication system; and

adjusting a power level at which said subscriber unit transmits to a relatively low level when said tertiary communication system is selected in said selecting step, to a relatively medium level when said secondary communication system is selected in said selecting step, and to a relatively high level when said primary communication system is selected in said selecting step.

24. A subscriber unit for operating in accordance with a hierarchical network of communication systems wherein primary, secondary and tertiary systems have common areas of coverage, and said primary system having a larger area of coverage than said secondary system, said tertiary system having a smaller area of coverage than said secondary system, each of said communication systems being coupled to a public switched telecommunication network (PSTN), said subscriber unit comprising:

a transceiver; and

a processor coupled to said transceiver,

wherein said transceiver includes means for receiving first, second and third acquisition signals; and

wherein said processor includes means for obtaining first, second and third identity data from said first, second and third acquisition signals, respectively, said first, second and third identity data indicating whether said respective acquisition signal was broadcast from said primary system, said secondary system or said tertiary system; and

wherein said transceiver additionally includes;

means for refraining from communicating with said primary system, said means for refraining operating when said first and second identity data indicate that said first and second acquisition signals were broadcast from said primary and secondary systems, respectively,

means for communicating with said tertiary system, said means for communicating operating when said third identity data indicates that said third acquisition signal was broadcast from said tertiary system, and

means for sending a log-on message to said tertiary system over a communication channel identified by said third acquisition signal.

25. A subscriber unit as claimed in claim 24 wherein said transceiver includes means for communicating with said secondary system, said means for communicating with said secondary system operating when said processor obtains only said first and second identity data.

26. A subscriber unit as claimed in claim 24, wherein said processor includes means for selecting whether to communicate with said primary, secondary, or tertiary communication system, and said transceiver includes means for adjusting a transmit power level of said transceiver, said means for adjusting setting said transmit power level to a relatively low level when said tertiary communication system is selected, to a relatively medium level when said secondary communication system is selected, and to a relatively high level when said primary communication system is selected.

27. A subscriber unit as claimed in claim 24 wherein said processor includes means for selecting one of said communication systems with which to communicate and means for adjusting a power level at which said subscriber unit transmits, said means for selecting and means for adjusting operating in response to whether said primary, said secondary or said tertiary system is selected.

28. A subscriber unit as claimed in claim 24 wherein said processor includes means for determining whether communications are conducted with said primary or secondary system.

29. A subscriber unit for communicating with a primary and a subordinate communication system, said subordinate communication system cooperating with said primary communication system, said primary communication system projecting a plurality of cells on Earth, allocating orthogonal channels of a spectrum in adjacent ones of said cells, and reusing channels in geographically spaced apart cells, said primary communication system broadcasting a primary system acquisition channel that carries acquisition data that identifies said primary communication system and identifies a primary system communication channel with which to communicate, said subordinate communication system broadcasting a subordinate system acquisition channel that carries acquisition data that identifies said subordinate communication system and identifies a subordinate system communication channel with which to communicate, said subscriber unit comprising:

a transceiver for synchronizing to said primary system acquisition channel and said subordinate system acquisition channel;

a memory for saving data carried by said primary system acquisition channel and said subordinate system acquisition channel; and

a processor for selecting either said primary or said subordinate communication system, said subordinate communication system being selected when said acquisition data from both said primary and subordinate communication systems is received, said primary communication system being selected when said acquisition data from only said primary communication system is received,

wherein said transceiver has means for sending a log-on message to either said primary communication system over said primary system communication channel, or said subordinate communication system over said subordinate system communication channel specified by said acquisition data.

30. A subscriber unit as claimed in claim 29 wherein said processor includes means for selecting a second acquisition channel of either said primary or said subordinate communication system, said means for selecting operating when said transceiver unsuccessfully synchronizes to either said primary system or said subordinate system acquisition channel.

31. A subscriber unit as claimed in claim 29 wherein said data identifies channels for sending a message to said primary, said subordinate communication system and a tertiary communication system, said transceiver includes means for identifying all possible acquisition channels for said primary, subordinate and tertiary communication systems.

32. A subscriber unit as claimed in claim 31 wherein, said processor includes means for determining if one of said possible acquisition channels was broadcast from said tertiary system, and for selecting said tertiary system for communicating, and

wherein said processor includes means for adjusting a power level of said transceiver to communicate with said tertiary system, said power level being adjusted to a low setting to minimize interference with said primary or subordinate communication systems.

33. A subscriber unit as claimed in claim 32 wherein said processor includes means for determining, when one of said possible acquisition channels was not broadcast from said tertiary system, if one of said possible acquisition channels was broadcast from said subordinate communication system, and for selecting said subordinate communication system for communication.

34. A subscriber unit as claimed in claim 29 wherein said processor includes means for selecting another one of said communication systems when said log-on message is unsuccessful, for adjusting a power level for said another one of said communication systems, and for tuning said transceiver to a channel specified by said another communication system.

35. A subscriber unit as claimed in claim 29 wherein said subscriber unit includes means for communicating on said subordinate communication system, and

wherein said transceiver includes means for monitoring broadcast channels of said primary and subordinate communication systems and for switching from said subordinate communication system to said primary communication system when said subscriber unit moves out of range of said subordinate communication system.

36. A subscriber unit as claimed in claim 31 wherein said subscriber unit includes means for communicating on said tertiary communication system, and wherein said transceiver includes means for monitoring broadcast channels of said primary, said subordinate and said tertiary communication systems and means for switching from said tertiary communication system to said subordinate communication system when said subscriber unit moves out of range of said tertiary communication system.

37. A subscriber unit for communicating with a primary and a subordinate communication system, said subordinate communication system cooperating with said primary communication system, said primary communication system projecting a plurality of cells on Earth, allocating orthogonal channels of a spectrum in adjacent ones of said cells, and reusing channels in geographically spaced apart cells, either said primary or said subordinate communication system broadcasting an acquisition channel, said acquisition channel carrying acquisition data that identifies either said primary or said subordinate communication systems and identifies a communication channel to communicate with said primary or said subordinate communication systems, said subscriber unit comprising:

a transceiver for synchronizing to said acquisition channel;

a memory for saving said acquisition data carried by said acquisition channel; and

a processor for selecting either said primary or said subordinate communication system,

said transceiver sending a log-on message to either said primary or said subordinate communication system over said communication channel specified by said acquisition data, and wherein said subordinate communication system comprises;

an antenna for projecting a secondary region over said Earth, wherein said secondary region and a local one of said cells occupy a common area;

receiving means for receiving allocation data from said primary communication system, said allocation data identifying channels allocated by said primary communication system for use in said local cell;

selecting means, coupled to said receiving means and said antenna, for selecting channels of said spectrum that are available for use in said secondary region; and

means coupled to said receiving means, for tracking identities of said channels allocated by said primary communication system for use in said local cell as said local cell changes.