Automatic coverage hole detection in computer network environments

• US 7,301,926 B1
• Filed: 04/04/2003
• Issued: 11/27/2007
• 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: Friday, Robert J., O'Hara, Robert B. Jr., Dietrich, Paul F.
• Primary Examiner(s): Milord; Marceau
• Application Number:
  US10/407,357
• Time in Patent Office: 1,698 Days
• Field of Search: 370/338, 370/329, 370/333, 370/310, 370/330, 370/331, 370/332, 455/67.11, 455/67.13
• US Class Current: 370/338
• CPC Class Codes: H04W 16/00 Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic

Abstract

Methods, apparatuses and systems enabling real-time analysis of coverage and other performance attributes of distributed or networked systems, such as wireless computer network environments. In one embodiment, the present invention utilizes information obtained from monitoring wireless communications in a wireless network system from remote client elements to access elements in relation to at least one attribute, such as signal strength and signal-to-noise ratio (SNR). Although the present invention has application to a variety of wireless network architectures, in one embodiment, the present invention is implemented in a wireless Local Area Network (WLAN) system having a hierarchical architecture comprising a central control element associated with at least one access element. The access element encapsulates data packets received from remote client elements including protocol and other information (such as attributes of the detected signal associated with the data packets), and tunnels the encapsulated data packets to the central control element. The central control element maintains and analyzes the information contained in the packets to analyze the coverage of the wireless network environment.

Claims

1. In a wireless computer network environment comprising at least one wireless access element operative to communicate with at least one wireless client device, a method facilitating analysis of coverage in the wireless computer network environment, comprising

monitoring, relative to at least one attribute, the signal associated with wireless traffic between at least one wireless client device and at least one wireless access element, wherein monitoring the signal comprises

receiving, at a wireless access element, data packets from at least one wireless client device;

and

detecting, concurrently with the receiving step, the strength of the signals associated with at least a subset of the data packets;

maintaining values of the at least one attribute of the signal between the at least one wireless access element and the at least one wireless client device;

determining a coverage profile for the at least one wireless access element based on the values of the at least one attribute over an analysis interval.

2. The method of claim 1 further comprising

comparing the coverage profile for the at least one wireless access element to a minimum coverage profile;

and

issuing a notification as to the at least one wireless access element if the coverage profile violates the minimum coverage profile.

3. The method of claim 2 wherein wireless client identifiers are detected in the monitoring step and stored in the maintaining step in association with the corresponding access element, the method further comprising

maintaining a user list including at least one wireless client device identifier;

and wherein the issuing a notification step is further conditioned on if the at least one wireless client identifier associated with the corresponding wireless access element is included in the user list.

4. The method of claim 1 further comprising

comparing the coverage profile to a minimum coverage profile;

and

adjusting the configuration of the at least one wireless access element based on the results of the comparing step.

5. The method of claim 3 wherein the adjusting step comprises

lowering the transmit power of the at least one access element if the coverage profile exceeds the minimum coverage profile.

6. The method of claim 1 wherein the determining step comprises

estimating, for the at least one access element, the received signal strength at a wireless client device associated with the at least one access element based on the signal strength indicators in the maintaining step.

7. The method of claim 1 wherein the maintaining step comprises

maintaining the values of the at least one attribute of the signal in a histogram for the at least one wireless access element.

8. The method of claim 1 wherein the maintaining step comprises

maintaining the values of the at least one attribute of the signal in a histogram for the at least one wireless access element.

9. The method of claim 8 wherein the determining step comprises

filtering the histogram to reduce the impact of one or more wireless client devices associated with a large number of data packets.

10. The method of claim 9 wherein the determining step further comprises

comparing the filtered histogram to the minimum coverage profile.

11. The method of claim 1 wherein the at least one attribute is signal strength.

12. The method of claim 1 wherein the at least one attribute is signal-to-noise ratio.

13. An apparatus facilitating analysis of coverage in a wireless computer network environment, comprising

a wireless network interface operative to:

receive data packets in wireless signals from remote wireless clients;

detect the strength of the wireless signals associated with the packets;

provide indicators of the strength of the detected wireless signals;

a data collector operative to maintain the indicators of the strength of the wireless signals provided by the wireless network interface in a data structure, and identifications of the remote wireless clients associated with the packets; and

a coverage analysis module comprising a user list including identifications of remote wireless clients, and wherein the coverage analysis module is operative to

analyze the indicators of the strength of the wireless signals to determine compliance with a minimum coverage profile; and

issue a notification if the minimum coverage profile is violated and an identification of the remote wireless client maintained by the data collector matches an identification in the user list.

14. The apparatus of claim 13 wherein the data structure is a histogram.

15. The apparatus of claim 13 further comprising a database, and wherein the coverage analysis module is operative to store the indicators maintained by the data collector in the database in association with a time stamp.

16. A system facilitating analysis of coverage in a wireless computer network environment, comprising

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

and

a central control element associated with the plurality of access elements;

wherein said access elements are each operative to

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

detect an attribute associated with the wireless signals,

associate the attributes 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 central control element comprises

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

a coverage analysis module operative to

analyze the signal attributes maintained by the data collector to determine compliance with a minimum coverage profile;

maintain a user list including at least one remote client element identifier;

maintain remote client element identifiers in association with corresponding access elements; and

issue a notification as to an access element if the access element does not comply with the minimum coverage profile and at least one wireless client identifier associated with the access element is included in the user list.

17. The system of claim 16 wherein the signal attribute is signal strength.

18. The system of claim 16 wherein the signal attribute is signal-to-noise ratio.