Granted Patent B1

US 9,078,153 · App. 14/530,657 · Granted Jul 7, 2015

Abstract

Claims (31)

1. A diagnostic system for spatial diagnosis of a wireless local area network (WLAN), and the diagnostic system comprising:

a sounding aggregator configured to aggregate multiple-input multiple-output (MIMO) channel state information (CSI) from channel soundings of each communication link on the WLAN between a wireless access point (WAP) node thereof and associated station nodes and to retain a history of the CSI on each link after normal use in WLAN communications, whereby the history includes CSI from prior channel soundings of each communication link; and

a spatial correlator coupled to the sounding aggregator and configured to correlate the CSI history from each link's prior channel soundings with spatial characteristics of the WLAN including an identification of a displacement and a change in throughput before and after displacement of an identified one of the WLAN station nodes based on perturbations over time in the CSI history of an associated communication link with the WAP node.

2. The diagnostic system of claim 1 , further comprising:

a sounding generator configured to generate heterogeneous MIMO channel soundings which exhibit a mix of isotropic and anisotropic signal strengths among orthogonal frequency division multiplexed (OFDM) sub-channels of a wireless communication channel; whereby an identifiable directionality of the anisotropically sounded sub-channels improves an accuracy of the correlation performed by the spatial correlator.

3. The diagnostic system of claim 1 , further comprising:

the sounding aggregator further configured to aggregate from uplink channel soundings between a first station node and the WAP node CSI for communication cross-links between the first station node and at least one other station node; thereby increasing an amount of available CSI for the special correlator.

4. The diagnostic system of claim 1 , integral with at least one of: the WAP and a computer server coupled to the WAP.

5. The diagnostic system of claim 1 , further comprising:

the spatial correlator further configured to correlate perturbations over time in the CSI history of each link between the WAP node and an associated station node with human activity among the WLAN nodes and to identify a time of such human activity.

6. A method for spatial diagnosis of a wireless local area network (WLAN), and the method comprising:

aggregating multiple-input multiple-output (MIMO) channel state information (CSI) from channel soundings of each communication link between a wireless access point (WAP) node and associated station nodes on the WLAN;

retaining a history of the CSI on each link aggregated in the aggregating act after normal use in WLAN communications, whereby the history includes CSI from prior channel soundings of each communication link; and

correlating the CSI history from each link's prior channel soundings with spatial characteristics of the WLAN including an identification of a displacement and a change in throughput before and after displacement of an identified one of the WLAN station nodes based on perturbations over time in the CSI history of an associated communication link with the WAP node.

7. The method for spatial diagnosis of a WLAN of claim 6 , further comprising:

generating heterogeneous MIMO channel soundings which exhibit a mix of isotropic and anisotropic signal strengths among orthogonal frequency division multiplexed (OFDM) sub-channels of a wireless communication channel; and

identifying a directionality of the anisotropically sounded ones of the sub-channels to increase an accuracy of the correlating act.

8. The method for spatial diagnosis of a WLAN of claim 6 , wherein the aggregating act further comprises:

aggregating from uplink channel soundings between a first station node and the WAP node cross-link CSI between the first station node and at least one other station node; thereby increasing an amount of available CSI for the WLAN.

9. The method for spatial diagnosis of a WLAN of claim 6 , further comprising:

performing the aggregating and correlating acts on at least one of: the WAP node, and a computer server accessible over the Internet.

10. The method of claim 6 , wherein the correlating act further comprises:

correlating perturbations over time in the CSI history of at least one link between the WAP node and an associated station node with human activity across the at least one link; and

identifying a time of such human activity responsive to the second correlating act.

11. A non-transient computer readable medium containing program instructions for causing a computer to perform the method of:

aggregating multiple-input multiple-output (MIMO) channel state information (CSI) from channel soundings of each communication link between a wireless access point (WAP) node and associated station nodes of the WLAN;

retaining a history of the CSI on each link aggregated in the aggregating act after normal use in WLAN communications, whereby the history includes CSI from prior channel soundings of each communication link; and

correlating the CSI history from each link's prior channel soundings with spatial characteristics of the WLAN including an identification of a displacement and a change in throughput before and after displacement of an identified one of the WLAN station nodes based on perturbations over time in the CSI history of an associated communication link with the WAP node.

12. The non-transient computer readable medium containing program instructions of claim 11 for causing a computer to perform the method of:

correlating perturbations over time in the CSI history of at least one link between the WAP node and an associated station node with human activity across the at least one link; and

identifying a time of such human activity responsive to the second correlating act.

Assignments (7)