Handover technique for wireless communications enabled devices

Patent metadata

Field	Value
Publication number	US-9369936-B2
Application number	US-59450008-A
Country	US
Kind code	B2
Filing date	Mar 19, 2008
Priority date	Apr 2, 2007
Publication date	Jun 14, 2016
Grant date	Jun 14, 2016

Abstract

A method of triggering a network handover controlled by a communications device in a communications system comprising a plurality of networks with which the communications device can perform a handover operation to, the method comprising the steps of: determining a signal characteristic of each available candidate network in said communications system; forecasting a future value of said signal characteristic; determining a future handover margin for said signal characteristic of the network connection established by said communications device; determining if another available candidate network signal characteristic exceeds said handover margin at a future time, and if so, performing a handover operation to said other available candidate network, wherein said future handover margin for said signal characteristic is varied dynamically in dependence on said forecasted signal characteristic.

First claim

What is claimed is:

1. A method of triggering a network handover in a communications system comprising a mobile communications device and a plurality of network access points, wherein a plurality of said network access points provide at least one signal to said mobile communications device, the method comprising:
determining one or more signal characteristics of each communications channel available to the mobile communications device to establish communications with a network access in said communications system;
forecasting a future value of each said signal characteristic;
forecasting a future handover margin for each said signal characteristic; and
determining if, at a predetermined future point in time, another communications channel is available to another network access point for the mobile communications device to handover to from the current communications channel established with the current network access point by determining if the future value of a signal characteristic of said other communications channel is predicted at that time to exceed the value of the equivalent signal characteristic of the current communications channel at that time by at least the value of the handover margin predicted at that time,
wherein the future handover margin is dynamically dependent on the predicted probability of a trigger error occurring.

2. A method as claimed in claim 1 , wherein the method further comprises:
the mobile communications device controlling the handover operation to said other network access point via said other communications channel.

3. A method as claimed in claim 1 , wherein the forecasted value of said handover margin for each said signal characteristic is varied dynamically in dependence on the forecasted value of the respective signal characteristic.

4. A method as claimed in claim 1 , wherein at least one said signal characteristic is determined at a network access point.

5. A method as claimed in claim 1 , wherein at least one said signal characteristic is determined at the mobile communications device.

6. A method as claimed in claim 1 , wherein at least one said signal characteristic comprises a received signal strength index (RSSI) of a signal between a network access point and the mobile communications device.

7. A method of triggering a network handover controlled by a communications device in a communications system comprising a plurality of networks with which the communications device can perform a handover operation to, the method comprising the steps of:
determining a signal characteristic of each available candidate network in said communications system;
forecasting a future value of said signal characteristic;
determining a future handover margin for said signal characteristic of the network connection established by said communications device;
determining if another available candidate network signal characteristic exceeds said handover margin at a future time, and if so, performing a handover operation to said other available candidate network, wherein said future handover margin for said signal characteristic is dynamically varied in response to said forecast signal characteristic, and
wherein the future handover margin is dynamically dependent on the predicted probability of a trigger error occurring.

8. A method as claimed in claim 7 , wherein the margin varies with the location of the communications device.

9. A method as claimed in claim 8 , wherein the margin varies with the number of candidate networks.

10. A method as claimed in claim 8 , wherein a trigger error comprises a false trigger error.

11. A method as claimed in claim 8 , wherein the trigger error comprises a false non-trigger.

12. Apparatus arranged to perform a method of triggering a network handover in a communications system comprising a mobile communications device and a plurality of network access points, wherein a plurality of said network access points provide at least one signal to said mobile communications device, the apparatus comprising:
one or more signal processors arranged to determine one or more signal characteristics of each communications channel available to the mobile communications device to establish communications with a network access point in said communications system;
one or more forecasters arranged to forecast a future value of each said signal characteristic;
one or more forecasters arranged to a future handover margin for each said signal characteristic; and
one or more processors arranged to determine if, at a predetermined future point in time, another communications channel is available to another network access point for the mobile communications device to handover to from the current communications channel established with the current network access point by:
determining if the future value of a signal characteristic of said other communications channel is predicted at that time to exceed the value of the equivalent signal characteristic of the current communications channel at that time by at least the value of the handover margin predicted at that time,
wherein the future handover margin is dynamically dependent on the predicted probability of a trigger error occurring.

13. A communications system arranged to implement a method of triggering a network handover controlled by a communications device in said communications system, the system comprising:
a plurality of candidate networks with which the communications device can perform a handover operation to;
one or more signal processors to determine one or more signal characteristics of each signal detected for an available candidate network in said communications system;
one or more data stores arranged to store data on said signal characteristics as time-series data;
one or more processor components arranged to:
forecast a future value of one or more of said detected signal characteristics from time-series data;
determine a future handover margin for said signal characteristic of the network connection established by said communications device;
determine if another available candidate network signal characteristic exceeds said handover margin at a future time, and if so,
control the performance of a handover operation to said other available candidate network, wherein said future handover margin for said signal characteristic is dynamically varied in response to said forecasted signal characteristic, and
wherein the future handover margin is dynamically dependent on the predicted probability of a trigger error occurring.

14. A communications system as claimed in claim 13 , wherein the trigger error comprises a false trigger.

15. A communications system as claimed in claim 13 , wherein the trigger error comprises a false non-trigger.

Assignees

• Chin Choong M
• Low Andy Ly
• Chien Su Fong
• British Telecomm

Inventors

• Chin Choong M
• Low Andy Ly
• Chien Su Fong

Classifications

• H04W36/30 Primary

  by measured or perceived connection quality data · CPC title

• H04W36/14

  Reselecting a network or an air interface · CPC title

• H04W36/36

  by user or terminal equipment · CPC title

• H04W36/362

  Conditional handover · CPC title

• H04W36/304 Primary

  due to measured or perceived resources with higher communication quality · CPC title