Device discovery and connection establishment for ad hoc networks

• US 7,809,835 B2
• Filed: 02/06/2004
• Issued: 10/05/2010
• Est. Priority Date: 02/06/2004
• Status: Active Grant

• Current Assignee: ThinkLogix, LLC (Ascend Innovation Management, LLC)
• Original Assignee: Spyder Navigations LLC (Intellectual Ventures LLC)
• Inventors: Reunamaki, Jukka, Kaaja, Harald, Kasslin, Mika, Palin, Arto, Salokannel, Juha, Jokela, Jari
• Primary Examiner(s): BARQADLE, YASIN M
• Application Number:
  US10/772,255
• Publication Number:
  US 20050177639A1
• Time in Patent Office: 2,433 Days
• Field of Search: 709203-205, 709217-219, 709227-229, 709236-237, 370328-330, 370/338, 455/453, 455464-466
• US Class Current: 709/227
• CPC Class Codes: H04W 40/246 Connectivity information discovery
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A wireless device transmits beacon packets at periodically occurring time intervals across a wireless channel. When the wireless communications device has not formed a piconet with one or more remote devices, the device scans the wireless channel for a predetermined amount of time immediately following each of the periodically occurring time intervals. During this time a remote device may respond to the beacon packet.

Claims

1. A method of forming a piconet in a wireless communications device, the method comprising:

transmitting a beacon packet from the wireless communications device across a wireless channel during a first predetermined time interval;

scanning the wireless channel from the wireless communications device for a second predetermined time interval, the second predetermined time interval immediately following the first predetermined time interval;

receiving a request for additional information from a remote wireless communications device during the second predetermined time interval without associating with the remote wireless communications device;

transmitting a second beacon packet from the wireless communications device during a third time interval;

transmitting a beacon extension from the wireless communications device during an extension interval immediately following the third time interval, wherein the beacon extension includes the additional information;

receiving a piconet joining request packet from the remote wireless communications device during a fourth predetermined time interval; and

transmitting a confirmation packet to the remote wireless communications device during a fifth predetermined time interval, the fifth predetermined time interval immediately following the fourth predetermined time interval.

2. The method of claim 1, wherein the piconet joining request includes a request for a role switch.

3. The method of claim 2, further comprising receiving a beacon packet from the remote wireless communications device.

4. The method of claim 1, wherein the beacon packet, the piconet joining request packet, and the confirmation packet each include one or more OFDM symbols.

5. The method of claim 1, wherein the wireless channel employs a frequency hopping pattern.

6. The method of claim 1, wherein the additional information includes available services from the wireless communications device.

7. The method of claim 1, wherein the additional information includes identifiers of devices that are in a piconet with the wireless communications device.

8. A wireless communications device, comprising:

means for transmitting a beacon packet across a wireless channel during a first predetermined time interval;

means for scanning the wireless channel for a second predetermined time interval, the second predetermined time interval immediately following the first predetermined time interval;

means for receiving a request for additional information from a remote wireless communications device during the second predetermined time interval without associating with the remote wireless communications device;

means for transmitting a second beacon packet from the wireless communications device during a third time interval;

means for transmitting a beacon extension from the wireless communications device during an extension interval immediately following said third time interval, wherein the beacon extension includes the additional information;

means for receiving a piconet joining request packet from the remote wireless communications device during a fourth predetermined time interval; and

means for transmitting a confirmation packet to the remote wireless communications device during a fifth predetermined time interval, the fifth predetermined time interval immediately following the fourth predetermined time interval.

9. A system for forming a piconet of a plurality of wireless communications devices, the system comprising:

a beacon-transmitting device configured to transmit a beacon packet across a wireless channel during a first predetermined time interval and scan the wireless channel for a second predetermined time interval, the second predetermined time interval immediately following the first predetermined time interval; and

a remote wireless communication device configured to receive the beacon packet and transmit a request for additional information to the beacon-transmitting device during a second predetermined interval without associating with the beacon-transmitting device,

wherein the beacon-transmitting device is further configured to receive the request for additional information from the remote wireless communication device during the second predetermined interval without associating with the remote wireless communications device, transmit a second beacon packet during a third time interval, and transmit a beacon extension following the third time interval, wherein the beacon extension includes the additional information,

wherein the remote wireless communication device is configured to receive the additional information and transmit a piconet joining request, and

wherein the beacon-transmitting device is configured to receive the piconet joining request packet during a fourth predetermined time interval and transmit a confirmation packet to the remote wireless communications device during a fifth predetermined time interval, the fifth predetermined time interval immediately following the fourth predetermined time interval.

10. The system of claim 9, wherein the piconet joining request includes a request for a role switch.

11. The system of claim 10, wherein the remote wireless communications device transmits the beacon packet and the beacon-transmitting device receives the beacon packet.

12. The system of claim 9, wherein the beacon packet, the piconet joining request packet, and the confirmation packet each include one or more OFDM symbols.

13. The system of claim 9, wherein the wireless channel employs a frequency hopping pattern.