Method and system for wireless handoffs

• US 8,145,218 B2
• Filed: 09/22/2008
• Issued: 03/27/2012
• Est. Priority Date: 09/22/2008
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola Solutions, Inc.
• Inventors: Hyziak, Janusz, Huang, Peisong
• Primary Examiner(s): Patel, Nimesh
• Application Number:
  US12/235,122
• Publication Number:
  US 20100075676A1
• Time in Patent Office: 1,282 Days
• Field of Search: 455/436, 455/437, 455/429, 455/439, 455/440, 455/441, 455/443
• US Class Current: 455/436
• CPC Class Codes: H04W 36/302 due to low signal strength
• CPC Class Codes: H04W 36/322 by location data
• CPC Class Codes: H04W 36/324 by mobility data, e.g. speed data
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A device includes a first wireless transceiver initiating a communication session; and a second wireless transceiver. The device shifts the communication session to the second wireless transceiver if a signal strength of the first wireless transceiver is below a predetermined level and the signal strength is not expected to increase above the predetermined level.

Claims

1. A method, comprising:

establishing a communication coverage area map of at least a first and a second access point in a first communication network that uses a first communication protocol;

communicating by a communication device with the first access point in a first coverage area via a first communication protocol;

evaluating a position and heading of the communication device and whether the device is approaching a periphery of the first coverage area of the first access point;

if a signal strength is below a handoff signal threshold, delaying handoff to determine whether the device will be heading into a second coverage area of the second access point dependent on the position and heading of the communication device; and

shifting communications to a second communication protocol of a second communication network, if the device will not be heading into the second coverage area of the second access point, and otherwise shifting communications to the second access point of the first communication protocol when the device enters the second coverage area.

2. The method of claim 1, further comprising:

instructing the first access point to increase a power level, if the device is approaching a periphery of the first coverage area, prior to shifting communications; and

instructing the first access point to decrease the power level, after shifting communications to either the second communication network or the second access point.

3. The method of claim 1, further comprising alerting a user of the device if a connection cannot be made with the second communication network.

4. The method of claim 1, wherein evaluating whether the device is approaching the periphery of the first coverage area includes determining a speed of the device.

5. A device, comprising:

a first wireless transceiver initiating a communication session with a first access point within a first coverage area in a first communication network via a first communication protocol, wherein the first communication network has an established communication coverage area map of at least the first and a second access point with respective coverage areas;

wherein the device is subject to a handoff if a position and heading of the communication device indicates whether the device is approaching a periphery of the first coverage area of the first access point, wherein if a signal strength is below a handoff signal threshold, a handoff of the device is delayed to determine whether the device will be heading into a second coverage area of the second access point dependent on the position and heading of the communication device, wherein if the device will be heading into the second coverage area of the second access point the communication session on the first wireless transceiver will be handed off to the second access point in the first communication network; and

a second wireless transceiver, the device shifting the communication session to a second communication network with the second wireless transceiver if the device will not be heading into the second coverage area of the second access point.

6. The device of claim 5, wherein the device instructs the first access point communicating with the first transceiver to increase a power level, if the device is approaching a periphery of the first coverage area, the device instructing the first access point to decrease the power level after shifting the communication session to either the second wireless transceiver in the second communication network or the second access point in the first communication network.

7. The device of claim 5, wherein the device also determines a speed of the device in determining whether the device is approaching the periphery of the first coverage area.

8. A system, comprising:

a plurality of access points each having a respective coverage area in a first communication network using a first communication protocol;

a mobile device operable for conducting a communication session via at least a first one of the plurality of access points within its respective coverage area; and

a wireless switch operable for coordinating the access points, and wherein the wireless switch can establish a communication coverage area map of the plurality of access points,

wherein a position and heading of the mobile device can be monitored to determine whether the device is approaching a periphery of the first coverage area of the first access point, and wherein if a signal strength is below a handoff signal threshold, delaying handoff to determine whether the device will be heading into a second coverage area of another access point dependent on the position and heading of the communication device, and wherein the communication session is shifted to a second communication protocol of a second communication network if the device will not be heading into the second coverage area, and otherwise shifting the communication session to the other access point of the first communication protocol when the device enters the second coverage area.

9. The system of claim 8, wherein the monitoring by the wireless switch includes receiving a speed of the mobile device, which the wireless switch compares the coverage map stored in the wireless switch.

10. The system of claim 8, wherein the wireless switch compares the position of the mobile device and the heading of the mobile device to a coverage map stored in the wireless switch.

11. The system of claim 8, wherein the wireless switch instructs the first access point currently communicating with the mobile device to increase a power level if the device is approaching a periphery of the first coverage area prior to the mobile device shifting the communication session, and further instructs the access point to decrease the power level after the mobile device shifts the communication session to either the second communication network or the other access point in the first communication network.

12. The system of claim 8, wherein the position and heading of the mobile device is monitored by the mobile device.

13. The system of claim 8, wherein the handoff determination is made by the mobile device.