Direct communication method between slave units and PHS terminal for direct communication between PHS slave units

• US 6,456,613 B1
• Filed: 05/17/1999
• Issued: 09/24/2002
• Est. Priority Date: 05/26/1998
• Status: Expired due to Fees

• Current Assignee: OKI Electric Industry Company Limited
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: Kato, Makibi
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): Ferguson, Keith
• Application Number:
  US09/312,853
• Time in Patent Office: 1,226 Days
• Field of Search: 370/337, 370/347, 370/350, 370/442, 370/503, 370/349, 455/509, 455/517, 455/502, 455/426, 455/550, 455/556, 455/557, 455/526, 455/422, 455/424, 455/425, 455/403
• US Class Current: 370/347
• CPC Class Codes: H04B 7/2656 for structure of frame, burst
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 92/18 between terminal devices

Abstract

A PHS terminal has a PHS slave unit and data processing equipment connected to the PHS slave unit for data communication. The PHS terminal includes a continuous slot forming circuit for continuously forming, at least at the time of direct communication between the PHS slave unit and the other PHS slave unit, a desired number of consecutive slots in a TDMA frame. An identification message forming circuit forms, when the PHS terminal calls the other PHS terminal including the other PHS slave unit, a message for informing the other PHS terminal of whether the PHS terminal to which the circuit belongs is a server or a client. A callback control circuit automatically redials if the message shows that the other PHS terminal originated a call is a client. A reserve message forming circuit forms, based on the quantity of data to send, a reserve message representative of the number of slots to reserve in one frame. A number-of-slot setting circuit compares, on receiving the reserve message, the number of reserve slots represented by the reserve message and the number of reserve slots of the PHS terminal to which the circuit belongs, and sets, based on the result of comparison, the number of slots to be sent from the PHS terminal for a frame in the continuous slot forming circuit.

Claims

1. A method of allowing two PHS (Personal Handy-Phone System) slave units respectively connected to two data processing equipment for data communication to directly communicate with each other via radio channels of TDMA (Time Division Multiple Access) frames, said method comprising the steps of:

connecting one of said data processing equipment functioning as a server for data communication to one of said PHS slave units, and connecting the other data processing equipment functioning as a client to the other PHS slave unit;

causing said PHS slave unit of the server to originate a call addressed to said PHS slave unit of the client via a desired communication channel and thereby setting up synchronization between said PHS slave units with respect to an up-link and a down-link via said communication channel;

setting, among m communication slots of a TDMA frame, n (natural number of 1 to m) consecutive communication slots continuing from a slot of said communication channel used for synchronization on at least the down-link extending from one of said PHS slave units to the other PHS slave unit; and

causing said PHS slave terminals to interchange data at asymmetrical rates with respect to the up-link and the down-link in respective TDMA frames by respectively using some of the n slots and some of (m−

n) slots.

2. A method in accordance with claim 1, wherein when the client calls the server, said PHS slave unit of said server once disconnects the channel and calls back said PHS slave unit of said client, whereby the radio channel extending from said PHS slave unit of said server to said PHS slave unit of said client is used as the down-link.

3. A method in accordance with claim 1, further comprising the steps of:

causing, after synchronization between said PHS slave units, said PHS slave units to interchange numbers of communication slots to set with each other by using a slow associated control channel of a communication channel, and causing, when a total number of communication slots to be set by said PHS slave units exceeds m, said PHS slave units to adjust said total number to at least less than m inclusive.

4. A method in accordance with claim 3, wherein each of said PHS slave units, after receiving each other'"'"'s numbers of reserve slots, compare the number of reserve slot of the other PHS slave unit with a respective number of reserve slots, and sets of greater one of said numbers of reserve slots while causing the other PHS slave unit, smaller in the number of reserve slots, to set a remaining number of slots.

5. A method in accordance with claim 4, wherein when the numbers of reserve slots are equal or when priority degrees are equal, the number of slots of the server is set with a priority given thereto.

6. A method in accordance with claim 3, wherein information representative of a priority degree with respect to data transmission is added to the slow associated control channel, whereby the number of slots with a higher priority degree is set.

7. A method in accordance with claim 1, wherein the one PHS slave unit first sends one slot in an initial frame for data communication and then performs data communication by sequentially increasing the number of slots by one for each frame up to n slots.

8. A method in accordance with claim 7, wherein the other PHS slave unit sets at least one slot for a single frame and informs, when received data includes an error, the one PHS slave unit of said error by using said one slot, while said one PHS slave unit sends, until said error disappears, the slots by sequentially reducing the number of said slots by one for each frame and again increases, on disappearance of said error, the number of slots by one for each frame.

9. A method in accordance with claim 8, wherein the error or the disappearance of said error is represented by information added to a slow associated control channel of the communication slots.

10. A method as claimed in claim 8, wherein the other PHS slave unit sends the at least one slot as one of communication slots appearing at least half a frame later than the initial slot of the TDMA frame and after receipt of the n consecutive slots from the one PHS slave unit.

11. A method in accordance with claim 10, wherein the communication slot sent from the other PHS slave unit is a last communication slot of the TDMA frame.

12. A PHS terminal including a PHS slave unit and data processing equipment connected to said PHS slave unit for data communication, said PHS terminal comprising:

a continuous slot forming circuit for continuously forming, at least at a time of direct communication between said PHS slave unit and another PHS slave unit, a desired number of consecutive slots in a TDMA frame;

an identification message forming circuit for forming, when said PHS terminal calls another PHS terminal including said another PHS slave unit, a message for informing said another PHS terminal of whether said PHS terminal is a server or a client;

a callback control circuit for automatically redialing if said message shows that said another PHS terminal originated a call is a client;

a reserve message forming circuit for forming, based on a quantity of data to send, a reserve message representative of a number of slots to reserve in one frame; and

a number-of-slot setting circuit for comparing, on receiving the reserve message from said another PHS terminal, the number of reserve slots represented by said reserve message and a number of reserve slots of said PHS terminal and setting, based on a result of comparison, a number of slots to be sent from said PHS terminal for a frame in said continuous slot forming circuit.

13. A PHS terminal in accordance with claim 12, wherein said reserve message forming circuit includes a priority degree setting circuit for setting in a slow associated control channel of a priority degree of data transmission together with the number of reserve slots.

14. A PHS terminal in accordance with claim 13, wherein said number-of-slot setting circuit sets the number of slots in said continuous slot forming circuit on the basis of the number of reserve slots of said another PHS terminal and the number of reserve slots of said PHS terminal and priority degrees.

15. A PHS terminal in accordance with claim 12, wherein said number-of-slot setting circuit gives priority to the number of slots of the server when the numbers of reserve slots are equal or when the priority degrees are equal.

16. A PHS terminal in accordance with claim 12, wherein said number-of-slot setting circuit includes a counter for setting one slot in an initial frame for data transmission and then sequentially increasing the number of slots for each frame up to n reserved slots while setting said number of slots in said continuous slot forming circuit.

17. A PHS terminal in accordance with claim 16, wherein said counter sequentially reduces the number of slots by one slot for each frame in response to an error message representative of an error included in transmitted data and received from said another PHS terminal, and again sequentially increasing the number of slots in response to a recovery message representative of disappearance of said error and also received from said another PHS terminal.

18. A PHS terminal in accordance with claim 12, wherein said PHS terminal belongs to a client and further comprises an error message reporting circuit for setting at least one slot in a frame and forming a message for reporting an error included in received data by using said at least one slot.

19. A PHS terminal in accordance with 18, further comprising a slot forming circuit for forming said at least one slot as one of communication slots appearing at least half a frame later than the initial slot of the TDMA frame and after a receipt of n consecutive slots from the server.