Dynamic transmit power configuration system for wireless network environments

• US 7,313,113 B1
• Filed: 04/04/2003
• Issued: 12/25/2007
• Est. Priority Date: 04/04/2003
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Airespace, Inc. (Cisco Systems, Inc.)
• Inventors: Hills, Alexander H., Dietrich, Paul F., Friday, Robert J.
• Primary Examiner(s): Milord, Marceau
• Application Number:
  US10/407,372
• Time in Patent Office: 1,726 Days
• Field of Search: 370/332, 370/330, 370/337, 370/346, 370/347, 370/329, 455/426.1, 455/464, 455/67.11, 455/67.14, 455/423, 375/134
• US Class Current: 370/332
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 52/245 taking into account received signal strength
• CPC Class Codes: H04W 52/34 TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

Methods, apparatuses and systems facilitating the configuration of transmit power and coverage areas corresponding to access points in a wireless network environment. The present invention in one embodiment facilitates the dynamic configuration of coverage boundaries across a plurality of access points, improving the performance of the wireless network environment.

Claims

1. A system facilitating the dynamic configuration of transmit power in a wireless network environment including a plurality of access points, comprising

a plurality of access elements for wireless communication with at least one remote client element and for communication with a coverage analyzer,

wherein the access elements are each operative, in a coverage scanning mode, to:

receive radio frequency (RF) signals carrying respective wireless frames transmitted by one or more neighboring wireless access elements;

detect the strength of the received RF signals relative to the wireless frames;

gather coverage scan data characterizing the detected strength of the RF signals transmitted by the neighboring access elements, and

transmit the coverage scan data to a coverage analyzer;

a coverage analyzer operative to;

process coverage scan data received from the access elements; and

compute a set of transmit power levels for the access elements based on the detected strength of the RF signals transmitted by the access elements.

2. The system of claim 1 wherein the access elements are each further operative to

establish and maintain, in an access point mode, wireless connections with remote client elements;

switch to a scanning mode for a scanning period at a scanning interval to detect wireless traffic associated with other access elements, and

record coverage scan data characterizing the detected wireless traffic.

3. The system of claim 2 wherein the scanning period is a configurable parameter.

4. The system of claim 2 wherein the scanning interval is a configurable parameter.

5. The system of claim 2 wherein the access element is operative to scan for wireless traffic on a plurality of frequency channels.

6. The system of claim 2 wherein the wireless traffic comprises a plurality of packets;

and wherein the access elements are each operative to parse the information in the packets, detect the strength of the signals associated with the packets, and transmit the packet information and associated signal strengths to the coverage analyzer.

7. The system of claim 1 wherein the access elements are each further operative to:

broadcast wireless management packets for detection by other access elements.

8. The system of claim 7 wherein the access elements are further operative to:

detect wireless management packets transmitted by other access elements;

detect the strength of the signal associated with the wireless management packets;

parse information in the wireless management packets; and

transmit the packet information and the associated signal strength to the coverage analyzer.

9. The system of claim 1 wherein the access elements are each operative to

detect the strength of the wireless signals associated with packets transmitted by remote wireless clients;

provide indicators of the strength of the detected wireless signals;

wherein the coverage analyzer is further operative to;

maintain the indicators of the strength of the wireless signals provide by the access elements; and

analyze the indicators of the strength of the wireless signals associated with each access element to determine compliance with a minimum coverage profile,

compute a set of transmit power levels for the access elements based on the coverage scan data and the compliance as to each access element with the minimum coverage profile.

10. A system facilitating the dynamic configuration of transmit power in a wireless network environment including a plurality of access points, comprising

a plurality of access elements for wireless communication with at least one remote client element and for communication with a central control element;

a central control element for supervising said access elements, wherein the central control element is operative to manage wireless connections between the access elements and corresponding remote client elements,

wherein the access elements are each operative to

receive radio frequency (RF) signals carrying respective wireless frames transmitted by one or more neighboring wireless access elements;

detect the strength of the received RF signals relative to the wireless frames;

gather coverage scan data characterizing the detected strength of the RF signals transmitted by the neighboring access elements, and

transmit the coverage scan data to the central control element;

wherein the central control element comprises a coverage analyzer operative to;

process coverage scan data received from the access elements;

compute a set of transmit power levels for the access elements based on the detected strength of the RF signals transmitted by the access elements.

11. The system of claim 10 wherein the central control element is operative to adjust the transmit power of the access elements to implement the computed set of transmit power levels.

12. The system of claim 10 wherein

wherein said access elements are each operative to

receive wireless signals transmitting wireless data packets from the at least one remote client element;

detect strength of the wireless signals,

associate the detected signal strengths with the corresponding data packets,

transmit the packet information and associated signal strengths to the coverage analyzer.

13. The system of claim 10 wherein

wherein said access elements are each operative to

receive wireless signals transmitting wireless data packets from the at least one remote client element;

detect the strength of the wireless signals,

associate the detected signal strengths with the corresponding data packets,

encapsulate the wireless data packets in an encapsulating packet, wherein the encapsulating packet includes the corresponding signal attribute, and

transmit the encapsulating packet to the central control element;

wherein the central control element is operative to decapsulate the encapsulating packets and bridge the wireless data packets to appropriate destination nodes, and

wherein the coverage analyzer comprises

a data collector operative to maintain the signal strengths contained in encapsulating packets in a data structure; and

wherein the coverage analyzer is further operative to

analyze the signal strengths maintained by the data collector to determine compliance of each access element with a minimum coverage profile, and

compute a set of transmit power levels for the access elements based on the coverage scan data and the compliance as to each access element with the minimum coverage profile.

14. A coverage analyzer comprising a coverage analysis module operative to gather coverage scan data from a plurality of access elements characterizing the strength of the signals transmitted by neighboring access elements;

receive, from the access elements, indicators of the strength of the wireless signals associated with packets transmitted by remote wireless clients;

analyze the indicators of the strength of the wireless signals associated with each access elements to determine compliance with a minimum coverage profile;

process coverage scan data received from the access elements; and

compute a set of transmit power levels for the plurality of access elements based on the coverage scan data and the compliance as to each access element with the minimum coverage profile;

process coverage scan data received from the access elements; and

compute a set of transmit power levels for the plurality of access elements based on the coverage scan data.