Multimode radio communication system

• US 6,678,341 B1
• Filed: 12/01/1998
• Issued: 01/13/2004
• Est. Priority Date: 07/18/1995
• Status: Expired due to Fees

• Current Assignee: Casio Computer Company Limited
• Original Assignee: Casio Computer Company Limited
• Inventors: Miyake, Masayasu, Dang, Lucian X.
• Primary Examiner(s): Ghayour, Mohammad H.
• Assistant Examiner(s): BURD, KEVIN MICHAEL
• Application Number:
  US09/204,204
• Time in Patent Office: 1,869 Days
• Field of Search: 375/356, 375/354, 375/358, 375/219, 375/220, 375/211, 455/502, 455/403, 455/414, 455/422, 455/11.1, 455/517, 370/321, 370/337, 370/345, 370/347, 370/350, 370/458, 370/338
• US Class Current: 375/356
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

Like a conventional one-way pager system, a two-way pager system is provided in which a message is received by paging from a base station and a message responding to the received message is returned to the base station. In this system, direct communication and peer-to-peer communication between terminals are performed. All the terminals included in the service area of the base station are always synchronized with sync signals paged from the base station. No special infrastructure is therefore required for synchronizing the terminals with the sync signals to perform the peer-to-peer communication. Furthermore, since each of the terminals receives a paging signal during the peer-to-peer communication, it can respond to a paging call.

Claims

1. A radio communication terminal comprising:

means for operating in synchronization with a sync signal transmitted from a base station connected to a wire communication network;

means for communicating with said base station using a first time slot of a plurality of time slots, produced by a first time slot timing signal, said first time slot assigned to its own radio communication terminal for communication with said base station; and

means for communicating to another radio communication terminal a communication originating at the radio communication terminal, said means for communicating including means for transmitting a position information indicating the position of the terminal to said base station to inquire whether or not a direct communication to the other radio communication terminal without using the base station is available to the base station using the first time slot, means for controlling the direct communication to the other radio communication terminal when a first signal indicating that the direct communication is available is received by the communicating means, and means for controlling an indirect communication to the other radio communication terminal via the base station when a second signal indicating that the direct communication is not available is received by the communicating means.

2. A radio communication terminal according to claim 1, further comprising:

means for detecting a position thereof; and

means for transmitting the position thereof to the base station using the first time slot.

3. A radio communication terminal according to claim 1, further comprising:

means for transmitting an end signal to the base station using the first time slot when the direct communication is terminated.

4. A radio communication terminal according to claim 1, wherein said radio communication terminal further comprises means for detecting a position thereof.

5. A radio communication terminal according to claim 1, wherein said first signal includes parameters to set up a radio channel between the radio communication terminals.

6. A radio communication terminal according to claim 1, wherein said direct communication is a peer-to-peer communication and said indirect communication is a two-way pager communication.

7. A radio communication terminal according to claim 1, wherein the direct communication is with a time-division multiple access system.

8. A radio communication terminal according to claim 1, wherein the direct communication is with a frequency-division multiple access system.

9. A radio communication terminal according to claim 1, wherein the direct communication is with a time-division duplex/time division multiple access system.

10. A radio communication terminal according to claim 1, wherein the indirect communication uses system infrastructure equipment.

11. A base station which communicates with radio communication terminals, comprising:

means for receiving signals from the radio communication terminals;

means for detecting positions of the radio communication terminals based on the signals received by said receiving means;

means for receiving a request to inquire whether a direct communication with a first one of the radio communication terminals without using the base station is available or not from a second one of the radio communication terminals;

means for determining whether or not the direct communication between the first radio communication terminal and the second radio communication terminal is available based on the positions of the first radio communication terminal and the second radio communication terminal;

means for transmitting a first signal to start the direct communication between the first radio communication terminal and the second radio communication terminal when it is determined that the direct communication is available; and

means for transmitting a second signal to start an indirect communication between the first radio communication terminal and the second radio communication terminal when it is determined that the direct communication is not available.

12. A base station according to claim 11, wherein said receiving means receives a direct communication request and a position signal indicating the position of the first radio communication terminal from the second radio communication terminal.

13. A base station according to claim 11, wherein said direct communication is a peer-to-peer communication and said indirect communication is a two-way pager communication.

14. A base station according to claim 11, wherein the direct communication is with a time-division multiple access system.

15. A base station according to claim 11, wherein the direct communication is with a frequency-division multiple access system.

16. A base station according to claim 11, wherein the direct communication is with a time-division duplex/time-division multiple access system.

17. A base station according to claim 11, wherein the indirect communication uses system infrastructure equipment.