Integrated estimation of the location of a plurality of reference radios
A location engine uses the empirical measurements made by a scouting wireless terminal (i) to discover the existence of a reference radio within a geographic region; (ii) to generate an estimate of the location of the newly-discovered reference radio, and (iii) to generate an estimate of the transmission power of the downlink control channel radio signal transmitted by the newly-discovered reference radio. The location engine then uses: (i) the estimate of the location of the newly-discovered reference radio, and (ii) the estimate of the transmission power of the downlink control channel radio signal transmitted by the newly-discovered reference radio, and (iii) measurements, made by a user wireless terminal, of the power of each of the downlink control channel radio signals transmitted by each of the reference radios to generate an estimate of the location of the user wireless terminal.
1. A method comprising:
receiving:
(i) a first measurement value MV(1,1) of a first radio signal as received at a first measurement location ML(1), wherein the first radio signal is transmitted by a first radio transmitter and is characterized by a wavelength λ, and
(ii) a second measurement value MV(1,2) of the first radio signal as received at a second measurement location ML(2), wherein second measurement location is different than the first measurement location, and
(iii) a third measurement value MV(2,1) of a second radio signal as received at the first measurement location ML(1), wherein the second radio signal is transmitted by a second radio transmitter and is characterized by the wavelength λ, and
(iv) a fourth measurement value MV(2,2) of the second radio signal as received at the second measurement location ML(2); and
generating:
(i) a first candidate location CL(1) for the first radio transmitter and for the second radio transmitter, and
(ii) a second candidate location CL(2) for the first radio transmitter and for the second radio transmitter;
generating:
(i) a first candidate prediction of the total path loss A(1,1) for a hypothetical radio signal from the first candidate location CL(1) to the first measurement location ML(1), wherein the hypothetical radio signal is characterized by the wavelength λ, and
(ii) a second candidate prediction of the total path loss A(1,2) for the hypothetical radio signal from the first candidate location CL(1) to the second measurement location ML(2), and
(iii) a third candidate prediction of the total path loss A(2,1) for the hypothetical radio signal from the second candidate location CL(2) to the first measurement location ML(1), and
(iv) a fourth candidate prediction of the total path loss A(2,2) for the hypothetical radio signal from the second candidate location CL(2) to the second measurement location ML(2), and
generating an estimate of the location of the first radio transmitter and an estimate of the location of the second radio transmitter based on which pairwise combination of:
(1) the first radio transmitter at the first candidate location CL(1) and the second radio transmitter at the first candidate location CL(1), and
(2) the first radio transmitter at the first candidate location CL(1) and the second radio transmitter at the second candidate location CL(2), and
(3) the first radio transmitter at the second candidate location CL(2) and the second radio transmitter at the first candidate location CL(1), and
(4) the first radio transmitter at the second candidate location CL(2) and the second radio transmitter at the second candidate location CL(2)
is more consistent with the first measurement value MV(1,1), the second measurement value MV(1,2), the third measurement value MV(2,1), the fourth measurement value MV(2,2), the first candidate prediction of the total path loss A(1,1), the second candidate prediction of the total path loss A(1,2), the third candidate prediction of the total path loss A(2,1), and the fourth candidate prediction of the total path loss A(2,2).
2. The method of claim 1 further comprising:
receiving a fifth measurement value that is evidence of the power of the first radio signal at a wireless terminal; and
generating an estimate of the location of the wireless terminal based on:
(i) the fifth measurement value, and
(ii) the estimate of the location of the first radio transmitter.
3. The method of claim 2 further comprising:
transmitting the estimate of the location of the wireless terminal to the wireless terminal for use in a location-based application.
4. The method of claim 2 further comprising:
transmitting the estimate of the location of the wireless terminal to a remote data processing system for use in a location-based application.
5. The method of claim 2 further comprising:
using the estimate of the location of the wireless terminal in a location-based application.
6. The method of claim 1 further comprising:
generating an estimate of the transmission power of the first radio transmitter and an estimate of the transmission power of the second radio transmitter based on which pairwise combination of:
(1) the first radio transmitter at the first candidate location CL(1) and the second radio transmitter at the first candidate location CL(1), and
(2) the first radio transmitter at the first candidate location CL(1) and the second radio transmitter at the second candidate location CL(2), and
(3) the first radio transmitter at the second candidate location CL(2) and the second radio transmitter at the first candidate location CL(1), and
(4) the first radio transmitter at the second candidate location CL(2) and the second radio transmitter at the second candidate location CL(2)
is more consistent with the first measurement value MV(1,1), the second measurement value MV(1,2), the third measurement value MV(2,1), the fourth measurement value MV(2,2), the first candidate prediction of the total path loss A(1,1), the second candidate prediction of the total path loss A(1,2), the third candidate prediction of the total path loss A(2,1), and the fourth candidate prediction of the total path loss A(2,2); and
receiving a fifth measurement value that is evidence of the power of the first radio signal at a wireless terminal; and
generating an estimate of the location of the wireless terminal based on:
(i) the fifth measurement value, and
(ii) the estimate of the location of the first radio transmitter, and
(iii) the estimate of the transmission power of the first radio transmitter.
7. The method of claim 1 further comprising:
generating an estimate of the location of a footprint of a building based on which pairwise combination of:
(1) the first radio transmitter at the first candidate location CL(1) and the second radio transmitter at the first candidate location CL(1), and
(2) the first radio transmitter at the first candidate location CL(1) and the second radio transmitter at the second candidate location CL(2), and
(3) the first radio transmitter at the second candidate location CL(2) and the second radio transmitter at the first candidate location CL(1), and
(4) the first radio transmitter at the second candidate location CL(2) and the second radio transmitter at the second candidate location CL(2)
is more consistent with the first measurement value MV(1,1), the second measurement value MV(1,2), the third measurement value MV(2,1), the fourth measurement value MV(2,2), the first candidate prediction of the total path loss A(1,1), the second candidate prediction of the total path loss A(1,2), the third candidate prediction of the total path loss A(2,1), and the fourth candidate prediction of the total path loss A(2,2); and
receiving a fifth measurement value that is evidence of the power of the first radio signal at a wireless terminal; and
generating an estimate of the location of the wireless terminal based on:
(i) the fifth measurement value, and
(ii) the estimate of the location of the first radio transmitter, and
(iii) the estimate of the location of the footprint of the building.
8. The method of claim 1 further comprising:
generating an estimate of the location of an architectural feature of a building based on which pairwise combination of:
(1) the first radio transmitter at the first candidate location CL(1) and the second radio transmitter at the first candidate location CL(1), and
(2) the first radio transmitter at the first candidate location CL(1) and the second radio transmitter at the second candidate location CL(2), and
(3) the first radio transmitter at the second candidate location CL(2) and the second radio transmitter at the first candidate location CL(1), and
(4) the first radio transmitter at the second candidate location CL(2) and the second radio transmitter at the second candidate location CL(2)
is more consistent with the first measurement value MV(1,1), the second measurement value MV(1,2), the third measurement value MV(2,1), the fourth measurement value MV(2,2), the first candidate prediction of the total path loss A(1,1), the second candidate prediction of the total path loss A(1,2), the third candidate prediction of the total path loss A(2,1), and the fourth candidate prediction of the total path loss A(2,2); and
receiving a fifth measurement value that is evidence of the power of the first radio signal at a wireless terminal; and
generating an estimate of the location of the wireless terminal based on:
(i) the fifth measurement value, and
(ii) the estimate of the location of the first radio transmitter, and
(iii) the estimate of the location of the architectural feature of the building.
9. A method comprising:
receiving:
(i) a first measurement value MV(1,1) of a first radio signal as received at a first measurement location ML(1), wherein the first radio signal is transmitted by a first radio transmitter and is characterized by a wavelength λ, and
(ii) a second measurement value MV(1,2) of the first radio signal as received at a second measurement location ML(2), wherein second measurement location is different than the first measurement location, and
(iii) a third measurement value MV(2,1) of a second radio signal as received at the first measurement location ML(1), wherein the second radio signal is transmitted by a second radio transmitter and is characterized by the wavelength λ, and
(iv) a fourth measurement value MV(2,2) of the second radio signal as received at the second measurement location ML(2); and
generating:
(i) a first candidate location CL(1) for the first radio transmitter and for the second radio transmitter, and
(ii) a second candidate location CL(2) for the first radio transmitter and for the second radio transmitter;
generating:
(i) a first candidate prediction of the total path loss A(1,1) for a hypothetical radio signal from the first candidate location CL(1) to the first measurement location ML(1), wherein the hypothetical radio signal is characterized by the wavelength λ, and
(ii) a second candidate prediction of the total path loss A(1,2) for the hypothetical radio signal from the first candidate location CL(1) to the second measurement location ML(2), and
(iii) a third candidate prediction of the total path loss A(2,1) for the hypothetical radio signal from the second candidate location CL(2) to the first measurement location ML(1), and
(iv) a fourth candidate prediction of the total path loss A(2,2) for the hypothetical radio signal from the second candidate location CL(2) to the second measurement location ML(2), and
generating an estimate of the excess path loss in a portion of a geographic region based on which pairwise combination of:
(1) the first radio transmitter at the first candidate location CL(1) and the second radio transmitter at the first candidate location CL(1), and
(2) the first radio transmitter at the first candidate location CL(1) and the second radio transmitter at the second candidate location CL(2), and
(3) the first radio transmitter at the second candidate location CL(2) and the second radio transmitter at the first candidate location CL(1), and
(4) the first radio transmitter at the second candidate location CL(2) and the second radio transmitter at the second candidate location CL(2)
is more consistent with the first measurement value MV(1,1), the second measurement value MV(1,2), the third measurement value MV(2,1), the fourth measurement value MV(2,2), the first candidate prediction of the total path loss A(1,1), the second candidate prediction of the total path loss A(1,2), the third candidate prediction of the total path loss A(2,1), and the fourth candidate prediction of the total path loss A(2,2).
10. The method of claim 9 further comprising:
receiving a fifth measurement value that is evidence of the power of the first radio signal at a wireless terminal; and
generating an estimate of the location of the wireless terminal based on:
(i) the fifth measurement value, and
(ii) the estimate of the excess path loss in the portion of the geographic region.
11. The method of claim 10 further comprising:
transmitting the estimate of the location of the wireless terminal to the wireless terminal for use in a location-based application.
12. The method of claim 10 further comprising:
transmitting the estimate of the location of the wireless terminal to a remote data processing system for use in a location-based application.
13. The method of claim 10 further comprising:
using the estimate of the location of the wireless terminal in a location-based application.
14. A method comprising:
receiving:
(i) a first measurement value MV(1,1) of a first radio signal as received at a first measurement location ML(1), wherein the first radio signal is transmitted by a first radio transmitter and is characterized by a wavelength λ, and
(ii) a second measurement value MV(1,2) of the first radio signal as received at a second measurement location ML(2), wherein second measurement location is different than the first measurement location, and
(iii) a third measurement value MV(2,1) of a second radio signal as received at the first measurement location ML(1), wherein the second radio signal is transmitted by a second radio transmitter and is characterized by the wavelength λ, and
(iv) a fourth measurement value MV(2,2) of the second radio signal as received at the second measurement location ML(2); and
generating:
(i) a first candidate location CL(1) for the first radio transmitter and for the second radio transmitter, and
(ii) a second candidate location CL(2) for the first radio transmitter and for the second radio transmitter;
generating:
(i) a first candidate prediction of the total path loss A(1,1) for a hypothetical radio signal from the first candidate location CL(1) to the first measurement location ML(1), wherein the hypothetical radio signal is characterized by the wavelength λ, and
(ii) a second candidate prediction of the total path loss A(1,2) for the hypothetical radio signal from the first candidate location CL(1) to the second measurement location ML(2), and
(iii) a third candidate prediction of the total path loss A(2,1) for the hypothetical radio signal from the second candidate location CL(2) to the first measurement location ML(1), and
(iv) a fourth candidate prediction of the total path loss A(2,2) for the hypothetical radio signal from the second candidate location CL(2) to the second measurement location ML(2), and
generating an estimate of the transmission power of the first radio transmitter and an estimate of the transmission power of the second radio transmitter based on which pairwise combination of:
(1) the first radio transmitter at the first candidate location CL(1) and the second radio transmitter at the first candidate location CL(1), and
(2) the first radio transmitter at the first candidate location CL(1) and the second radio transmitter at the second candidate location CL(2), and
(3) the first radio transmitter at the second candidate location CL(2) and the second radio transmitter at the first candidate location CL(1), and
(4) the first radio transmitter at the second candidate location CL(2) and the second radio transmitter at the second candidate location CL(2)
is more consistent with the first measurement value MV(1,1), the second measurement value MV(1,2), the third measurement value MV(2,1), the fourth measurement value MV(2,2), the first candidate prediction of the total path loss A(1,1), the second candidate prediction of the total path loss A(1,2), the third candidate prediction of the total path loss A(2,1), and the fourth candidate prediction of the total path loss A(2,2).
15. The method of claim 14 further comprising:
receiving a fifth measurement value that is evidence of the power of the first radio signal at a wireless terminal and a fourth measurement value that is evidence of the power of the second radio signal at the wireless terminal; and
generating an estimate of the location of the wireless terminal based on:
(i) the fifth measurement value, and
(ii) the sixth measurement value, and
(iii) the estimate of the transmission power of the first radio transmitter, and
(iv) the estimate of the transmission power of the second radio transmitter.
16. The method of claim 15 further comprising:
transmitting the estimate of the location of the wireless terminal to the wireless terminal for use in a location-based application.
17. The method of claim 15 further comprising:
transmitting the estimate of the location of the wireless terminal to a remote data processing system for use in a location-based application.
18. The method of claim 15 further comprising:
using the estimate of the location of the wireless terminal in a location-based application.