Wireless local area network with spatial diagnostics

#1. Field of Invention

#The field of the present invention relates in general to wireless local area networks (WLAN) including wireless access points (WAP) and wireless stations and methods for spatial diagnosis of same.

#2. Description of the Related Art

#These and other features and advantages of the present invention will become more apparent to those skilled in the art from the following detailed description in conjunction with the appended drawings in which:

#FIGS. 1A-B are plan views of prior art WLAN intermittent channel soundings and beamformed communications respectively;

#FIGS. 2A-2D are a representative Prior Art channel graph, a Prior Art WLAN timing diagram including soundings, a Prior Art detailed explicit sounding timing diagram, and a Prior Art packet diagram of a WLAN packets including the sounding field.

#The present invention provides a method and apparatus for spatial diagnosis of a wireless home network for services ranging from: WLAN diagnosis, home security, health care monitoring, smart home utility control, elder care, etc. Instead of the WAP merely serving as a bridge for coupling the stations to the Internet, the WAP and associated stations forming the WLAN take on an additional role as an independent source of content, i.e. spatial data. Examples of this spatial data include: a) Changes in the location of one or more of the WLAN nodes including the identification of the node subject to such displacement and the time of displacement. b) Human activity within the WLAN including the time, location and path of the movement, where the location and path are identified at least relative to the associated WLAN link or link vector. c) Structural impediments occupying the space in and around the WLAN. The provision of this spatial data by the existing WLAN avoids the redundancy and obviates the need for many of the additional wireless devices currently vying for inclusion in the residential and commercial WLAN. In many cases the sensing and monitoring capabilities which these devices proffer, can instead be harvested directly from the existing WLAN nodes during the course of their normal operation. This spatial data obviates the need for dedicated sensors and devices within the home and allows application developers to provide applications servicing the following market segments: WLAN diagnosis, home security, health care monitoring, smart home utility control, elder care, etc. without the need for additional devices or dedicated hardware.

#FIGS. 1A-B are plan views of Prior Art WLAN intermittent channel soundings and beamformed communications respectively. The channel soundings shown in FIG. 1A are intermittent probes sent from the WAP identifying one or more station nodes from which sounding feedback is requested. The response to the probe from the recipient station node contains information which allows the WAP to quantify the characteristics of the channel between it and the station node. The transmitter uses this information to improve the efficiency of subsequent communications of data to the intended recipient. The soundings themselves may be sent from a WAP to one or more stations or from a station to the WAP. The soundings whether sent from a device with a single antenna or multiple antenna exhibit an isotropic radiation footprint, i.e. of equal radio frequency (Rf) signal strength in all directions. Soundings exhibit isotropic Rf signal strengths because: a) they are intended to be received by all devices and b) they are designed to allow the recipient device to identify the link channel characteristics. The sounding itself includes a preamble field with known modulation, number of streams, and bit sequence which the recipient device analyzes upon receipt to determine changes thereto brought about the link channel, e.g. fading, attenuation, and phase shift.

#In FIG. 1A the WAP 102 is shown setting up communication links 120 and 140 with wireless station nodes 108 and 112 respectively within residence 100. Each link pair exchanges capabilities, e.g. 122A-B on link 120 and capabilities exchange, 142A-B on link 140. During this exchange the number of antenna, the number of streams, the coding and beamforming support capabilities of each device are exchanged. Next an initial explicit sounding request and response takes place, 122C-D on link 120 and 142C-D on link 140. The sounding is sent using an isotropic radio frequency (Rf) signal strength 104. The sounding itself identifies the target station(s) from which a response is requested, and includes a preamble field which is modulated at the maximum number of streams supported by the link partners using a bit sequence and modulation and coding scheme (MCS) known to all recipients. Upon receipt the recipient station(s) determine changes in amplitude and phase to the sounding transmission brought about the link channel, e.g. fading, attenuation, and phase shift and passes indicia of these channel characteristics as sounding feedback response packet(s), 122D. 142D, back to the WAP where they are immediately used to set up beamforming of subsequent data communications as shown in FIG. 1B.