Estimating the location of inexpensive wireless terminals by using signal strength measurements
First Claim
Patent Images
1. An apparatus comprising:
- a first signal monitor for measuring;
(i) the signal strength at said first signal monitor of a first packet transmitted by an emitter; and
(ii) the signal strength at said first signal monitor of a second packet transmitted by a wireless terminal; and
a processor for;
(a) receiving the location of said emitter; and
(b) determining the location of said wireless terminal based on (i), (ii), and the location of said emitter.
24 Assignments
0 Petitions
Accused Products
Abstract
A system is disclosed that enables the estimation of the location of a wireless terminal in a wireless network. The illustrative embodiment works without requiring modifications to be made to the wireless terminal. Furthermore, the hardware of some embodiments of the present invention can be inexpensively deployed indoors. Some embodiments of the present invention are, therefore, ideally suited for use with legacy indoor systems. The system of the illustrative embodiment of the present invention, in some embodiments, uses an offline process and an online process for location estimation. The described system, however, can be used with other techniques for location estimation.
-
Citations
30 Claims
-
1. An apparatus comprising:
-
a first signal monitor for measuring; (i) the signal strength at said first signal monitor of a first packet transmitted by an emitter; and (ii) the signal strength at said first signal monitor of a second packet transmitted by a wireless terminal; and a processor for; (a) receiving the location of said emitter; and (b) determining the location of said wireless terminal based on (i), (ii), and the location of said emitter. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. An apparatus comprising:
-
a first signal monitor for measuring; (i) the signal strength at said first signal monitor of a first packet transmitted by an emitter; (ii) the signal strength at said first signal monitor of a second packet transmitted by a wireless terminal; a second signal monitor for measuring; (i) the signal strength at said second signal monitor of said first packet transmitted by said emitter; and (ii) the signal strength at said second signal monitor of said second packet transmitted by said wireless terminal; and a processor for; (a) receiving the location of said emitter; and (b) determining the location of said wireless terminal based on (i) the signal strength at said first signal monitor of the first packet transmitted by the emitter, (ii) the signal strength at said first signal monitor of the second packet transmitted by the wireless terminal, and the location of said emitter, wherein said processor is also for; acquiring (i) a first plurality of signal strength measurements made by said first signal monitor and (ii) a second plurality of signal strength measurements made by said second signal monitor, wherein said first plurality and said second plurality each are associated with a plurality of signal sources that comprise said emitter; interpolating (i) said first plurality across two dimensions to form a first scalar array of signal samples and (ii) said second plurality across two dimensions to form a second scalar array of signal samples; and generating a vector array of synthetic signal strength vectors based on said first scalar array of signal samples and said second scalar array of signal samples. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15)
-
-
16. An apparatus comprising:
-
an emitter for transmitting a signal and an identifier; a first signal monitor for making; (i) a first plurality of signal strength measurements of said signal, wherein said first plurality is associated with a plurality of signal sources that comprise said emitter; and (ii) a measurement of at least one packet from a wireless terminal; and a second signal monitor for making a second plurality of signal measurements, wherein said second plurality is associated with a plurality of signal sources that comprise said emitter;
wherein said first plurality of signal strength measurements, said second plurality of signal strength measurements, said identifier, and said measurement of said at least one packet are used to determine the location of said wireless terminal. - View Dependent Claims (17, 18, 19, 20)
-
-
21. An apparatus comprising:
-
an emitter for transmitting a signal and an identifier; a first signal monitor for making; (i) a first plurality of signal strength measurements of said signal, wherein said first plurality is associated with a plurality of signal sources that comprise said emitter; and (ii) a measurement of at least one packet from a wireless terminal; a second signal monitor for making a second plurality of signal measurements, wherein said second plurality is associated with a plurality of signal sources that comprise said emitter;
wherein said first plurality of signal strength measurements, said second plurality of signal strength measurements, said identifier, and said measurement of said at least one packet are used to determine the location of said wireless terminal; anda location estimation server for; smoothing (i) said first plurality to form a first set of smoothed measurements and (ii) said second plurality to form a second set of smoothed measurements; interpolating (i) said first set of smoothed measurements across two dimensions to form a first scalar array of signal samples and (ii) said second set of smoothed measurements across two dimensions to form a second scalar array of signal samples; and generating a vector array of synthetic signal strength vectors based on said first scalar array of signal samples and said second scalar array of signal samples. - View Dependent Claims (22, 23, 24, 25, 26)
-
-
27. An apparatus comprising:
-
an emitter for transmitting a signal and an identifier; a first signal monitor for making; (i) a first plurality of signal strength measurements of said signal, wherein said first plurality is associated with a plurality of signal sources that comprise said emitter; and (ii) a measurement of at least one packet from a wireless terminal; a second signal monitor for making a second plurality of signal measurements, wherein said second plurality is associated with a plurality of signal sources that comprise said emitter;
wherein said first plurality of signal strength measurements, said second plurality of signal strength measurements, said identifier, and said measurement of said at least one packet are used to determine the location of said wireless terminal;wherein the signal strength measurement that represents a signal source is one of (i) the median of and (ii) the mean of more than one signal strength measurement made over time of said signal source.
-
-
28. An apparatus comprising:
- a network interface for acquiring a first plurality of signal strength measurements that are received by a first signal monitor, wherein said first plurality represents a plurality of signal sources; and
a processor for;(i) smoothing said first plurality to form a first set; (ii) interpolating said first set to form a first scalar array of signal samples across two dimensions; and (iii) generating a vector array of synthetic signal strength vectors based on said first scalar array of signal samples and a second scalar array of signal samples. - View Dependent Claims (29, 30)
- a network interface for acquiring a first plurality of signal strength measurements that are received by a first signal monitor, wherein said first plurality represents a plurality of signal sources; and
Specification