Efficient piconet formation and maintenance in a Bluetooth wireless network

• US 7,496,065 B2
• Filed: 11/19/2002
• Issued: 02/24/2009
• Est. Priority Date: 11/29/2001
• Status: Active Grant

• Current Assignee: Nytell Software LLC (Intellectual Ventures LLC)
• Original Assignee: Telcordia Technologies Incorporated (Telefonaktiebolaget LM Ericsson)
• Inventors: Jain, Ravi, Anjum, Farooq, Adamou, Maria
• Primary Examiner(s): Ly; Nghi H
• Application Number:
  US10/298,506
• Publication Number:
  US 20030099212A1
• Time in Patent Office: 2,289 Days
• Field of Search: 370/328, 370/329, 370/338, 370/331, 445/446, 445/422.1, 455/420, 455/446, 455/422.1, 455/436, 455/442
• US Class Current: 370/328
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 84/20 Master-slave selection or change arrangements
• CPC Class Codes: H04W 92/02 Inter-networking arrangements

Abstract

The invention is addressing the problem of efficient formation and maintenance of piconets with assistance from the master of an already existing piconet. The master of an existing piconet initiates the formation of a new helper piconet by at least two of its slaves. One of the slaves of the existing piconet becomes the master of the newly formed helper piconet and the other slave becomes a slave of the helper piconet. This process can be used to expand the number of Bluetooth devices that can use an Internet access point. It can also be used to permit two slave devices to communicate directly with one another so as not to unnecessarily use bandwidth available through the master. Finally, the method and system could be used to provide a method of efficient hand-off from one piconet to another.

Claims

1. A method for banding off communication from a first slave in a first piconet, capable of communicating with a network through a first access point that acts as a first master device, to a second piconet, comprising the steps of:

receiving at the first master device a request from the first slave to transfer to the second piconet;

selecting a second slave device to be the master device in a sleeper piconet;

requesting a first slave device and a second slave device in communication with the first master device to become inactive in the first piconet at a predetermined time for a specified duration;

receiving an acknowledgement at the first master device from the first and second slave devices to become inactive at the predetermined time for a specified duration;

at the predetermined time, transmitting a command from the first master device to the second slave with connection information for enabling connection to the first slave;

wherein once connected as sleeper piconet the second slave acts a master to the first slave and provides a means for the first slave and second slave to synchronize;

determining at the first master device that the first slave device is beyond the range of the first master device;

communicating from the first master device to the first slave device through the sleeper piconet by way of the second slave device until such time as the first slave device becomes active in the second piconet.

2. The method of claim 1 wherein the connection information is the frequency hop synchronization (FHS) packet of said second slave.

3. The method of claim 1 wherein the step of selecting the second slave device to act as the master device in the sleeper piconet is based on the speed and/or direction of travel of the first slave device.

4. The method of claim 1 wherein the step of selecting the second slave device to act as the master device in the sleeper piconet is based on the signal strength of the first slave device.