Link method for a bluetooth scatternet

• US 20040223482A1
• Filed: 05/09/2003
• Published: 11/11/2004
• Est. Priority Date: 05/09/2003
• Status: Active Grant

• Current Assignee: Institute For Information Industry
• Original Assignee: Institute For Information Industry
• Inventors: Hong, Alexander T.P.
• Granted Patent: US 7,242,677 B2
• Time in Patent Office: Days
• US Class Current: 370/346
• 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
• CPC Class Codes: H04W 92/02 Inter-networking arrangements

Abstract

A link method for establishing a link between two bluetooth devices is provided to enable a device to transfer data to/from other device located in a bluetooth scatternet. The link method executes a link initialization procedure when resetting or initializing a link to determine whether the role of the bluetooth device at a dedicated link is a slave or master. Then, in the link search establishment procedure, it searches all possible paths for transferring data packet and establishes a link path table. Finally, when the link detection timer expires after a pre-determined period, the link detection procedure is resumed to detect whether the link is existed. If the link is not existed, the link initialization procedure is executed; otherwise, it further determines whether to execute the link initialization procedure again. If yes, the link initialization procedure is executed, otherwise the link detection procedure is executed.

Claims

1. A link method for establishing a link between two bluetooth devices located in a bluetooth scatternet, the bluetooth device including multiple link detection timers, a detection procedure timer, multiple master/slave flags, an initialization procedure executing timer, an initialization procedure trigger timer and a missing timer, the method comprising:

(A) a link initialization procedure for determining whether the role of this bluetooth device in a dedicated link is a slave or a master and initializing the corresponding timers when resetting or initializing a link;

(B) a link search establishment procedure for searching all possible paths to transfer data packets and establishing a link path table; and

(C) a link detection procedure for resuming to detect whether the link is existed or not when the corresponding link detection timer of a link expires after a pre-determined period.

2. The link method for establishing a link between two bluetooth devices as claimed in claim 1, wherein the link initialization procedure further comprises:

(A1) setting up and activating the initialization procedure executing timer when a link is reset or initialized;

(A2) listening to bluetooth channel;

(A3) determining whether the bluetooth device detects an inquiry packet or a paging packet;

(A4) setting the bluetooth device as a slave on the link if step (A3) determines that the bluetooth device detects an inquiry packet or a paging packet;

(A5) determining whether the procedure executing timer is expired or not;

(A6) setting up the multiple link detection timers, the detection procedure timer, the initialization procedure trigger timer and the missing timer if step (A5) determines that the procedure executing timer is expired; and

(A7) activating the initialization procedure trigger timer.

3. The link method for establishing a link between two bluetooth devices as claimed in claim 2, wherein when step (A5) determines that the procedure executing timer is not expired, step (A2) is executed.

4. The link method for establishing a link between two bluetooth devices as claimed in claim 2, wherein when step (A3) determines that the bluetooth device detects no inquiry packet or paging packet, the following steps are executed:

(A8) sending an inquiry packet;

(A9) determining whether response packets of the inquiry are received or not; and

(A10) executing step (A5) when step (A9) determines that there is no response of the inquiry packet.

5. The link method for establishing a link between two bluetooth devices as claimed in claim 4, wherein when step (A9) determines that there is a response of the inquiry packet, the following step are executed:

(A11) sending a paging packet and receiving its response, wherein the device becomes a master bluetooth device on the link and sets the master/slave flag as master state.

6. The link method for establishing a link between two bluetooth devices as claimed in claim 1, wherein the link detection procedure further comprises the following steps:

(C1) enabling a link detection timer corresponding to a link initialization of a bluetooth device;

(C2) determining whether the link detection timer is expired or not;

(C3) determining whether the bluetooth device at this link is a master or slave bluetooth device according to the status of the master/slave flag when step (C2) determines that a link detection timer is expired;

(C4) activating a detection procedure, enabling the detection procedure timer, and sending a link detection request when step (C3) determines that the bluetooth device is a master bluetooth device;

(C5) determining whether the detection procedure timer is expired or not;

(C6) exchanging corresponding data between the master and slave device via the link;

(C7) determining whether the initialization procedure trigger timer is expired or not; and

(C8) resetting and activating the detection procedure timer when step (C7) determines that the initialization procedure trigger timer is not expired.

7. The link method for establishing a link between two bluetooth devices as claimed in claim 6, wherein when step (C7) determines that the initialization procedure trigger timer is expired, a link initialization procedure (A) is executed.

8. The link method for establishing a link between two bluetooth devices as claimed in claim 6, wherein when step (C5) determines that the detection procedure timer is expired, the following step are executed:

(C10) activating the missing timer;

(C11) determining whether the missing timer is expired or not; and

(C12) executing a link initialization procedure when step (C11) determines that the missing timer is expired.

9. The link method for establishing a link between two bluetooth devices as claimed in claim 8, wherein when step (C11) determines that the missing timer is not expired, the step (C6) is executed.

10. The link method for establishing a link between two bluetooth devices as claimed in claim 6, wherein when step (C3) determines that the bluetooth device at that link is a slave, a step (C5) is executed after activating a detection procedure, enabling the detection procedure timer, and detecting a link detection request.

11. The link method for establishing a link between two bluetooth devices as claimed in claim 6, wherein the corresponding data in step (C6) includes queue size of the link, data transmission period, and next detection time.