System and method for establishing bluetooth communications

• US 7,161,923 B2
• Filed: 08/31/2001
• Issued: 01/09/2007
• Est. Priority Date: 08/31/2001
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Laboratories of America Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Young, Song-Lin
• Primary Examiner(s): Pezzlo, John
• Assistant Examiner(s): MEHRA, INDER P
• Application Number:
  US09/944,890
• Publication Number:
  US 20030063655A1
• Time in Patent Office: 1,957 Days
• Field of Search: 370441-442, 370/479, 370319-373, 455/78, 455/422.1, 455/440, 455/515, 455/456.1, 455/422, 455/462, 455/418, 455/463
• US Class Current: 370/338
• CPC Class Codes: H04W 48/10 using broadcasted information
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A system and method have been provided for establishing communications with an existing Bluetooth protocol piconet. The master device of the piconet broadcasts a beacon frequency at a predetermined frequency. The beacon frequency includes the BD_addr of the master device, as well as clock information, so that an inquiring device monitoring the beacon can acquire the system timing and transmission hopping frequency sequence. In a contention period following the beacon frequency, the inquiring device transmits its own BD_addr. In response to receiving the inquiring device BD_addr, the master device provides the inquiring device with an AM_addr.

Claims

1. In a network of Bluetooth protocol devices, a method for establishing communications comprising:

prior to broadcasting a piconet beacon frequency, establishing a piconet with a master device;

the master device broadcasting the piconet beacon frequency at a first predetermined frequency f(k_B) from a plurality of spread spectrum transmission frequencies, wherein the piconet beacon frequency includes the master device'"'"'s Bluetooth address (BD_addr) and clock (CLK) information;

an inquiring device monitoring to receive the piconet beacon frequency, including the BD_Addr and CLK information of the master device in a first downlink frequency hop synchronization (FHS) packet, and deriving a master device frequency hopping sequence from the master device BD_addr and master device CLK information; and

following the receiving of the first downlink FHS packet by the inquiring device, transmitting a first uplink FHS packet from the inquiring device to the master device, including the inquiring device BD_addr in the FHS packet payload and an access code (AC) derived from the master device BD_addr.

2. The method of claim 1 wherein establishing communications includes, following the receiving of the first uplink FHS packet by the master device, transmitting a second downlink FHS packet from the master device to the inquiring device.

3. The method of claim 2 wherein the transmitting the second downlink FHS packet from the master device to the inquiring device includes transmitting an active member address (AM_addr) in the FHS packet payload.

4. The method of claim 3 wherein transmitting a second downlink FHS packet from the master device to the inquiring device includes transmitting a FHS packet access code derived from the inquiring device BD_addr.

5. The method of claim 4 wherein establishing communications includes, following a receiving of the second downlink FHS packet by the inquiring device, transmitting an ID packet from the inquiring device to the master device, acknowledging a receipt of the AM_addr.

6. The method of claim 5 wherein establishing communications includes:

following a receiving of the ID packet by the master device, transmitting a POLL packet from the master device to the inquiring device;

in response to receiving the POLL packet, transmitting a NULL packet from the inquiring device to the master device; and

establishing higher level protocols between the master device and the inquiring device.

7. The method of claim 6 wherein establishing higher level protocols between the master device and the inquiring device includes the inquiring device becoming a piconet slave device.

8. The method of claim 7 wherein broadcasting a piconet beacon frequency includes the master device broadcasting the first downlink FHS packet in a slot at frequency f(k_B);

wherein transmitting the first uplink FHS packet includes;

the inquiring device randomly selecting a number m, where m is a number between 1 to 8 for a contention period of 15 slots;

the inquiring device transmitting the first uplink FHS packet in the slot at frequency f(k_B+(2 m−

1));

wherein the master device transmits the second downlink FHS packet in the slot at frequency f(k_B+2 m); and

,

wherein the inquiring device transmits the ID packet in the slot at frequency f(k_B+(2 m+1)).

9. The method of claim 8 wherein the inquiring device randomly selecting a number m includes randomly selecting a number m between 1 to 8;

and,

the method further comprising;

establishing a contention period equal to fifteen slots; and

the master device waiting (2 m−

1) slots from the broadcast of the piconet beacon frequency at frequency f(k_B) to receive a first uplink FHS packet from an inquiring device.

10. The method of claim 8 further comprising:

establishing a contention period equal to fifteen slots; and

the master device waiting a maximum of fifteen slots from the broadcast of the piconet beacon frequency at frequency f(k_B) to receive a first uplink FHS packet from an inquiring device.

11. The method of claim 1 further comprising:

establishing a piconet with a master device; and

wherein broadcasting a piconet beacon frequency includes the master device broadcasting at a first plurality of predetermined piconet beacon frequencies from the plurality of spread spectrum transmission frequencies;

wherein monitoring for the piconet beacon frequency includes monitoring the first plurality of piconet beacon frequencies; and

wherein establishing communications with the piconet includes establishing communications in response to receiving one of the plurality of monitored piconet beacon frequencies.

12. In a network of Bluetooth protocol devices, a method for a master device to permit the establishment of piconet communications comprising:

a master device broadcasting a piconet beacon frequency in a first downlink FHS packet including the master device'"'"'s BD_addr and CLK information, at a first predetermined frequency f(k_B) from a plurality of spread spectrum transmission frequencies;

receiving a first uplink FHS packet from an inquiring device, in response to broadcasting the piconet beacon frequency, wherein the first uplink FHS packet includes the inquiring device BD_addr in the FHS packet payload and a FHS packet access code (AC) derived from the master device BD_addr; and

following the receiving of the first uplink FHS packet by the master device, transmitting a second downlink FHS packet from the master device to the inquiring device with an AM_addr in the FHS packet payload.

13. The method of claim 12 wherein transmitting a second downlink FHS packet from the master device to the inquiring device includes transmitting a FHS packet access code derived from the inquiring device BD_addr.

14. The method of claim 13 further comprising:

following the transmission of the second downlink FHS packet by the master device, receiving an ID packet from the inquiring device acknowledging the receipt of the AM_addr.

15. In a network of Bluetooth protocol devices, a method for an inquiring device to establish communications with a piconet, the method comprising:

monitoring to receive the piconet beacon frequency at a first predetermined frequency f(k_B) from a plurality of spread spectrum transmission frequencies, wherein the piconet beacon frequency includes a master device Bluetooth address (BD_addr) and clock (CLK) information in a first downlink FHS packet;

in response to receiving the piconet beacon frequency, transmitting a first uplink frequency hop synchronization (FHS) packet to establish communications with the piconet, wherein the first uplink FHS packet includes the inquiring device BD_addr in the uplink FHS packet payload and a FHS packet access code (AC) derived from the master device BD_addr;

following the transmission of the first uplink FHS packet, receiving a second downlink FHS packet from the master device including an active member address (AM_addr) in the second downlink FHS packet payload and a FHS packet access code derived from the inquiring device BD_addr; and

deriving a master device frequency hopping sequence from the master device BD_addr and master device CLK information.

16. The method of claim 15 further comprising:

following the receiving of the second downlink FHS packet by the inquiring device, transmitting an ID packet to the master device, acknowledging the receipt of the AM_addr.

17. A system for establishing communications in a network of Bluetooth protocol devices, the system comprising:

a master device broadcasting a piconet beacon frequency at a first predetermined frequency f(k_B) from among a plurality of spread spectrum broadcast frequencies, including the master device'"'"'s Bluetooth address (BD_addr) and clock (CLK) information;

at least one inquiring device monitoring the master device'"'"'s piconet beacon frequency, receiving the master device'"'"'s BD_addr and CLK information of the master device in a first downlink frequency hop synchronization (FHS) packet broadcast, deriving a master device frequency hopping sequence from the master device'"'"'s BD_addr and CLK information, and transmitting a first unlink FHS packet to the master device following the reception of the first downlink FHS packet, including an inquiring device BD_addr in the first uplink FHS packet payload, and a FHS packet access code (AC) derived from the master device BD_addr.

18. The system of claim 17 wherein the master device broadcasts the piconet beacon frequency at a first plurality of predetermined frequencies from among the plurality of spread spectrum broadcast frequencies;

and,

wherein the inquiring device monitors the first plurality of piconet beacon frequencies and, in response to receiving one of the piconet beacon frequencies, establishes communications with the master device.

19. The system of claim 17 wherein the master device transmits a second downlink FHS packet to the inquiring device following the reception of the first uplink FHS packet.

20. The system of claim 19 wherein the master device transmits the second downlink FHS packet to the inquiring device including an active member address (AM_addr) in the second downlink FHS payload.

21. The system of claim 20 wherein the master device transmits a second downlink FHS packet to the inquiring device including a FHS packet access code derived from the inquiring device BD_addr.

22. The system of claim 21 wherein the inquiring device transmits an ID packet to the master device following a reception of the second downlink FHS packet, acknowledging a receipt of the AM_addr.

23. The system of claim 22 wherein the master device transmits a POLL packet to the inquiring device following a receipt of the ID packet by the master device;

wherein the inquiring device transmits a NULL packet to the master device in response to receiving the POLL packet; and

,

wherein the master device establishes higher level protocols with the inquiring device following the receipt of the NULL packet.

24. The system of claim 23 wherein the inquiring device becomes a piconet slave device following the establishment of higher level protocols with the master device.

25. The system of claim 24 wherein the master device broadcasts the first downlink FHS packet in a slot at frequency f(k_B);

wherein the inquiring device randomly selects a number m, and transmits the first uplink FHS packet in the slot at frequency f(k_B+(2 m−

1));

wherein the master device transmits the second downlink FHS packet in the slot at frequency f(k_B+2 m); and

,

wherein the inquiring device transmits the ID packet in the slot at frequency f(k_B+(2 m+1)).

26. The system of claim 25 in which a contention period equal to fifteen slots is established;

wherein the inquiring device randomly selecting a number m includes randomly selecting a number m between 1 to 8; and

,

wherein the master device waits (2 m−

1) slots from the broadcast of the piconet beacon frequency at frequency f(k_B) to receive a first uplink FHS packet from an inquiring device.

27. The system of claim 26 in which a contention period equal to fifteen slots is established;

wherein the master device waits a maximum of fifteen slots from the broadcast of the piconet beacon frequency at frequency f(k_B) to receive a first uplink FHS packet from an inquiring device.

28. A Bluetooth protocol device inquiring device to establish communications with a piconet, the Bluetooth protocol inquiring device comprising:

a receiver having an input to monitor and receive a piconet beacon frequency at a first predetermined frequency f(k_B) from among a plurality of spread spectrum broadcast frequencies, wherein the piconet beacon frequency includes a first downlink frequency hop synchronization (FHS) packet with the master device Bluetooth address (BD_addr) and clock (CLK) information;

a transmitter having an output to establish communications with a piconet master device in response to receiving the piconet beacon frequency;

wherein the Bluetooth protocol inquiring device derives the master device frequency hopping sequence from the master device BD_addr and CLK information; and

wherein the transmitter transmits a first uplink FHS packet, including BD_addr, to the a Bluetooth protocol inquiring piconet master device following the reception of the first downlink FHS packet.