Method for determining when a communication device should rate shift or roam in a wireless environment

• US 7,400,605 B2
• Filed: 09/13/2004
• Issued: 07/15/2008
• Est. Priority Date: 04/12/1999
• Status: Expired due to Fees

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Palmer, Brian G., Jovanovich, Alan F.
• Primary Examiner(s): Eng; George
• Assistant Examiner(s): Torres; Marcos L
• Application Number:
  US10/940,064
• Publication Number:
  US 20050096045A1
• Time in Patent Office: 1,401 Days
• Field of Search: 370331-333, 370328-329, 370/335, 455423-425, 455/63.1, 455/67.11, 455/67.13, 455/432.1, 4554352-440, 455/455, 455450-4522
• US Class Current: 370/333
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/22 Negotiating communication rate
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• CPC Class Codes: H04W 36/24 Reselection being triggered by specific parameters
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data
• CPC Class Codes: H04W 36/32 by location or mobility data, e.g. speed data

Abstract

Methods for improving communication performance in a wireless communication system where the wireless communication system has at least one mobile wireless communication device and a plurality of transmitter/receiver sites. The transmitter/receiver sites have a geographic area, defined as a cell, within which the mobile wireless communication devices can communicate with at least one of the transmitter/receiver sites. The methods determine when the mobile wireless communication device should rate shift or roam based on connection quality measurement data or position information such as GPS. In one method, the measurement data is subjected to configurable parameters to create a functional relationship value that is recorded. The recorded functional relationship values are trended and extrapolated to determine whether a rate shift or roam should be performed. In a second method, the measurement data taken prior to a communication connection failure is stored in at least one data vector with there being at least one data vector for each rate shift and one for roam. A functional relationship utilizing current measurements, last data rate, and the respective data vectors determines whether a rate shift or roam should be performed. In a third method, the position information for the wireless communication device is compared to at least one transmitter/receiver site and a determination is made as to the optimal transmitter/receiver site for communication.

Claims

1. A method of wireless communication in a communication system, the communication system comprising a mobile wireless communication device and a plurality of transceivers, the method comprising:

(a) receiving, at one of the transceivers, communication signals transmitted by the mobile wireless communication device;

(b) evaluating, over time intervals, a quality of the communication signals received from the mobile wireless communication device to obtain measurement values of a quality of the evaluated communication signals;

(c) creating a functional relationship value based on the measurement values and a configurable parameter associated with the measurement values;

(d) calculating an extrapolated functional relationship value based on one or more functional relationship values; and

(e) selecting one of the transceivers to communicate with the mobile wireless communication device based on the extrapolated functional relationship value.

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

storing the functional relationship value.

3. The method according to claim 1, wherein the measurement values comprise signal-to-noise ratios.

4. The method according to claim 1, wherein the measurement values comprise bit error rates.

5. The method according to claim 1, wherein the measurement values comprise transmission-retry counts.

6. The method according to claim 1, wherein the measurement values comprise at least one of received signal strength indicators and energy-to-noise densities.

7. The method according to claim 1, wherein the measurement values comprise cell congestion measurement values.

8. The method according to claim 1, wherein the plurality of transceivers comprise a plurality of access points.

9. The method according to claim 1, wherein the plurality of transceivers comprise an access point coupled to a wired network or a wireless network.

10. The method according to claim 9, wherein the plurality of transceivers comprise an intermediary access point that (1) wirelessly communicates with the access point and the mobile wireless communication device or (2) wirelessly communicates with the access point and another intermediary access point.

11. The method according to claim 1, wherein (c) comprises determining whether to use the measurement values, applying a weighting factor associated with the measurement values, and applying a threshold factor associated with the measurement values.

12. A method of wireless communication in a communication system, the communication system comprising a mobile wireless communication device and a plurality of transceivers, the method comprising:

(a) receiving, at one of the transceivers, communication signals transmitted by the mobile wireless communication device;

(b) evaluating, over time intervals, a quality of the communication signals received from the mobile wireless communication device to obtain measurement values of a quality of the evaluated communication signals;

(c) detecting a failure of the communication signals;

(d) calculating a function based on current measurement values and latest measurement values before the detected failure; and

(e) determining whether to change transmission or reception of the communication signals based at least in part on the function.

13. The method according to claim 12, further comprising:

storing the latest measurement values before the detected failure.

14. The method according to claim 13, wherein the detected failure comprises at least one of a detected transmission failure and a detected reception failure.

15. The method according to claim 12, wherein the measurement values comprise at least one of signal-to-noise ratios and bit error rates.

16. The method according to claim 12, wherein the measurement values comprise at least one of numbers of transmission retries and cell congestion measurement values.

17. The method according to claim 12, wherein the measurement values comprise received signal strength indicators.

18. The method according to claim 12, wherein the measurement values comprise bit energy-to-noise densities.

19. The method according to claim 12,

wherein the mobile wireless communication device and the plurality of transceivers communicate at a variable data rate,

wherein the mobile wireless communication device roams from one transceiver to another transceiver, and

wherein (e) comprises at least one of determining whether the mobile wireless communication device will roam and determining whether the data rate will be shifted.

20. A method of wireless communication in a communication system, the communication system comprising a roaming wireless device and a plurality of access points, the method comprising:

(a) receiving, at one of the access points, communication signals transmitted by the roaming wireless device;

(b) evaluating, over time intervals, a quality of the communication signals received from the roaming wireless device to obtain measurement values of a quality of the evaluated communication signals;

(c) creating a functional relationship value based on the measurement values and a configurable parameter associated with the measurement values;

(d) storing the functional relationship value;

(e) calculating an extrapolated functional relationship value based on a stored functional relationship value; and

(f) selecting one of the access points to communicate with the roaming wireless device based on the extrapolated functional relationship value.