Method for enhancing mobility in a wireless mesh network

• US 7,050,806 B2
• Filed: 12/05/2002
• Issued: 05/23/2006
• Est. Priority Date: 06/27/2001
• Status: Expired due to Term

• Current Assignee: Google LLC (Alphabet Inc.), Metricom, Inc.
• Original Assignee: Ricochet Networks, Inc. (Proxim Wireless Corporation)
• Inventors: San Filippo, III, William, Nguyen, Cuong-Thinh, Garces, Rodrigo
• Primary Examiner(s): Maung, Nay
• Assistant Examiner(s): NGUYEN, TU X
• Application Number:
  US10/313,846
• Publication Number:
  US 20030083085A1
• Time in Patent Office: 1,265 Days
• Field of Search: 455/69, 455/522, 455/404.2, 455/421, 455/422.1, 455/428, 455/429, 455/431.1, 455435-436, 455437-439, 455442-444
• US Class Current: 455/441
• CPC Class Codes: H04W 16/32 Hierarchical cell structures

Abstract

In a wireless communication system having sometimes mobile subscriber units and a plurality of fixed network devices located at cell sites, a multimode acquisition protocol is provided at each subscriber unit which first senses whether the subscriber unit is static or mobile from the nature and quality of the communication links with nearby network devices and then enables an acquisition protocol suited to either static mode or mobile mode. In a specific embodiment, the protocol initiates procedures to change acquisition mode from static to mobile upon failure of the subscriber unit to sense three consecutive scheduled polling packets sent by a linked network device or upon loss of communication with any locally-known network device or upon failure to transmit 25 consecutive data packets. In such case, the procedure is initiated to determine whether it is appropriate to switch to a mobile mode for purposes of acquisition.

Claims

1. In a wireless mesh, microcellular communication system having mobile subscriber units within a single wireless network that may be in either static or mobile modes when operating within the single network and a plurality of fixed network devices located at cell sites for communicating with static and mobile subscriber units within the single network, a method for acquiring and managing a plurality of communication modes at each subscriber unit comprising:

first sensing whether the subscriber unit is static or mobile from the nature and quality of the communication links with nearby network devices;

thereafter

enabling a first acquisition protocol suited to static communication mode and mobile communication mode for said subscriber unit;

enabling a second acquisition protocol suited to mobile communication mode for mobile subscriber units and static communication mode for fixed, non-moving subscriber units; and

initiating procedures to determine whether it is appropriate to change acquisition mode from static mode to mobile mode upon failure to transmit a preselected number of consecutive data packets.

2. The method according to claim 1 further comprising:

upon decision to change to mobile mode, foregoing best node qualification.

3. The method according to claim 1 further comprising:

upon decision to change to mobile mode, foregoing registration of location with a name service.

4. The method according to claim 1 further comprising:

upon decision to change to mobile mode, transmitting sync packets at a higher repetitivity.

5. The method according to claim 1, further comprising:

upon decision to change to mobile mode, foregoing best node qualification;

foregoing registration of location with a name service;

foregoing third party query processes; and

transmitting sync packets at a higher repetitivity.

6. The method according to claim 5, where the sync packets are each either 400 milliseconds or 600 milliseconds in duration.

7. In a wireless mesh, microcellular communication system having mobile subscriber units within a single wireless network that may be in either static or mobile modes when operating within the single network and a plurality of fixed network devices located at cell sites for communicating with static and mobile subscriber units within the single network, a method for acquiring and managing a plurality of communication modes at each subscriber unit comprising:

first sensing whether the subscriber unit is static or mobile from the nature and quality of the communication links with nearby network devices;

thereafter

enabling a first acquisition protocol suited to static communication mode and mobile communication mode for said subscriber unit;

enabling a second acquisition protocol suited to mobile communication mode for mobile subscriber units and static communication mode for fixed, non-moving subscriber units; and

initiating procedures to change acquisition mode from static mode to mobile mode upon failure of the subscriber unit to sense a preselected number of consecutive scheduled polling packets sent by a linked device.