`
`
`PATENI NUMDcn » -
`
`.‘~PTO
`
`
`
`[Is/7108635 970U
`
`T(Hi:
`
`
`
`
` ISSUING CLASSIFICATION
`
`
`
`cnoss HEFERENCEIS)
`—-
`“MMI_ :i:
`
`
`|----—
`
`
`
`_‘—I—----m
`
`
`
`
`
`
`
`
`DTEI‘IMINAL '
`.
`CLAIMS ALLOWED
`DRAWINGS
`-
`nIspLAIIIIEnI
`
`
`Sheets DIVIg.
`Hg. 0M9
`PM!5:19.
`TmlClaims
`PuntClaImforO.(3.
`
`
`£5
`47
`75
`
`
`:I The Iarm 01 ml: paIenI.
`
`
`NOTICE OF ALLOWANCEM—ILED
`nubssquéht to
`5
`
`
`
`" has baan dlsdalmed.
`
`
` 3 Thojliéhn.otfl1lshatefi
`.
`not axIand beyond the axp‘
`
`.’
`of U5 Patent. No]
`
`
`
`
`Ii
`
`I] The Iermlnal ______monI
`
`Ihls patent have been dlspll’
`
`
`The Inlomieuoh'dIsclom hmln may bi rosm‘bfidUrIumhIJrIzIaddlsclosure may be pInthIIed by Ina Unllad Suva! Code Thla 35. Sealona 122.t51and 365."
`
`
`
`.
`1
`Possession omslde m U.S. Faun:a. Tradqmam Ofllcc I! resumed to aulhorIzud empiayaea and contmciara only.’
`.
`y
`‘\-
`
`
`FILED WITH: [Z]DISK (CFIF) [j FICHE El CDROM '1
`'
`
`/
`(Au-ma In pmhl on IdemImIigivIIép)
`.5- m V“
`
`FUII'MAL BRAWINSS
`
`
`
`,
`
` W
`
`Cisco V. TracBeam / CSCO-1002
`
`Page 1 of 2386
`
`Cisco v. TracBeam / CSCO-1002
`Page 1 of 2386
`
`

`

`SEARCHED
`
` SEARCH NOTES
`
`(INCLUDING SEARCH STRATEGY)
`
`
`
`BESTAVAILABLE COPY
`
`
`
`
`
`IE’NTERFERENCE SEARCHED
`
`{Ciass --?
`
`Wig—flaw
`" W?(§3E 77' Wm“WWWm3)
`
`Cisco V. TracBeam / CSCO-1002
`
`Page 2 of 2386
`
`Cisco v. TracBeam / CSCO-1002
`Page 2 of 2386
`
`

`

`SSI
`
`.LS
`
`fluma.m
`...(dWEmTS
`INITIALS
`
`.cdHa
`
`.r
`
`S0
`
`s.
`
`rkw
`,6.
`
`In
`,C,
`
`).S.
`.e.
`
`POSITION;
`
`FEE DETERMINATION
`O.I.P.E. CLASSIFIER
`.
`5PONSE FORMALITY REVIEW
`
`I n_|.. nun-u I .
`
`INDEX OF CLAIMS
`
`
`
`
`
`
`
`
`
`
`
`
`
`FORMALITY REVIEW
`
`
`
`.1..by
`
`...1,42.....JIHJ]
`
`31.I
`
`‘\,‘m__._.....mmummmnmmmmmw--!
`
`
`,uuaamammmgmmfiamamnmam..,,
`
`m "".
`
`“III'I
`9-3 V!-
`E'IL'IIII
`
`5-9
`
`»
`
`,-
`
`stiapl
`
`9‘3
`
`dditlopal sheenher.e._ C. :
`(LEI-“I" INSIDE)
`
`Cisco V. TracBeam / CSCO-1002
`
`Page 3 of 2386
`
`Cisco v. TracBeam / CSCO-1002
`Page 3 of 2386
`
`

`

`‘ DRAFnNG
`
`rl/\\
`
`INDEX OF CLAIMS
`
`C
`
`
`mfi
`,H
`
`wruu
`
`.1.5....1
`
`~...pn:.|
`ll'lll'_|
`
`Ennlnuummmmmmmmmfi
`
`.3.
`
`. Inledeum
`
`
`
`
`
`.:.Ihuu:.rlu..“|u.l.7....|...,.,1:nun.1.)Irlr.it.nHI}..Iu|i\|.1.“.lui.,.7l.u.“n..-l.|4‘.h
`
`'I:1.1ll.,.1.ul.[inuwwuuHfl—HFLuPMIIHA'],.,..:nH.1:-.4,1‘13VLEII'~I\nI.l||l.|fl|l|uu.|\...A
`
`Ila-llIIIi.l.-IllliiflBailillaiflflflflmliflfli
`
`
`
`
`
`
`
`:lf.1!MN!.Ithr.11!,........tA...41:-iufluul.JUlI...1...}.tA}4...A:..\
`.in!“».v.I...
`
`SYMBOLS
`., ..
`
`.. Heiecled
`Allnwed
`Reslriaed
`. Non-etccled
`
`innit,
`
`M
`
`n
`an
`
`my...”
`
`flmflmm
`
`I.-
`
`\xxs.
`...,flfiwwmwgqmrm
`m.mca:...2.9.“-..1......)m_.VO£}.;P..!.EI.iIu.1qu
`
`
`Iaflfimnflnflmflm
`
`
`
`.u.r...nz....u.,.,«La,uaufiwwfi..7hwt.....p...v;.ux..:muh1.?In...»
`
`illnmmmmmmmmmmmmwmmmwmHafimmmmmmmmmmmmmmmmmmmmWI-III.-
`m“.finmmmnmnmmnflmmnflmmmflnmflnun“nnnlnnnunnnuflmmmailill-
`
`nannyzwampp..i.-I--a
`
`
`nag..tawyw‘vYV‘JH:.
`
`1MMllmMEIlull!flflImmfluflunnlnnnnuflflflnllmE-Ill-
`IIIIIIIIIIIIIIIIIJHHII‘fillI.‘EMEI-II.IIIEMIIIIIIIIIIIIIIIIIIIIIIJIHII\Ml
`mmgmmgnummmuwmnmmnawmmamwmz
`
`.uf.”...l...r.r!fuli.m“IWinn-byfir‘v-fimqrfifimfirufnu-In..n.wn%.
`IIIJIIIIAJflJ.Jmiaanlaaiaafiamflnan.
`mmmgnfiumfifidfiawmm“any...“a$33--gamma”mfimfiwmwaflflwmfifimmmmmamwwwwmmanniI
`.-II.-.-Emmmnnnunnuuuunmmmnunnnnnnunmme
`II.-..,.-...
`....ill..-
`
`
`
`
`
`u....u...3........<....«h.-..u...r.upanama;($23....‘z...u.......II.|
`
`Cisco V. TracBeam / CSCO-1002
`
`Page 4 of 2386
`
`Cisco v. TracBeam / CSCO-1002
`Page 4 of 2386
`
`
`
`
`
`
`
`
`
`
`

`

`
`
`01'24'.
`
`.
`NUATHON PATENT APPLICANT
`for new nonprovisional applications under 37 CF ,
`a(b))
`
`‘
`
`__—|_L
`
`.
`
`i.-
`
`UTiLiTY CC
`
`1003-1
`
`Ea
`E5 g
`”=1; c
`GE .
`BE Morney Docket No:
`D—‘=
`Inventors: Dennis J. Dupray of 1801 Belvedere Street, Golden,Colorado 80401
`:23
`Charles L. Karr of 400 Sandbrook Lane, Tuscaloosa, Alabama 35405
`E 0
`Express Mail Label No.1 EL545144476US
`
`0 7;
`:- 2-
`flaw ga
`113:; go
`:32 ii
`F 3;:
`3R2:
`m= 2°
`.2, 5
`
`Title:
`
`“LOCATION OF A MOBILE STATION"
`
`Prior Group Art Unit:
`
`3662
`
`Prior Examiner: Dao Phan
`
`Assistant Commissioner for Patents
`Box Patent Application
`Washington, DC
`20231
`
`This is a Continuation application of pending prior application No. 09/194,367 filed November 24, 1998. The entire
`disclosure of the prior application, from which a copy of the oath or declaration is supplied, is considered to be part of the
`,‘disclosure of the accompanying application and is hereby incorporated by reference.
`
`Ergclpsed for filing with the above-identified utility patent application, please find the following:
`
` 1.
`
`,
`
`f—
`[2
`13.3
`LE
`
`2.
`3.
`4.
`5.
`
`[X]
`
`[X]
`[x1
`[X]
`[]
`
`Copy of Oath/Declaration from the above-referenced pending prior application (37 CFR
`1.63(d))
`Preliminary Amendment
`Return Postcard (MPEP 503) (should be specifically itemized)
`A check in the amount of $1.1 19.00 is enclosed.
`Other:
`
`FEECALCULATION:
`
`Cancel in this application original Claims 1 - 124 of the prior application before calculating the filing fee.
`
`_RGEENTITY
`_MALLENTITY
`(COL. 2*)
`(COL. 1)
`NO- EXTR)A —— RATE
`N0 FILED
`BASIC FEE:_- $355.00 m_ $71000
`mmwms.
`$684.00 [5--
`map cows
`$8000 [5 x$ao= _
`$0.00 IE +$27o= _
`$1,119.00
`
`ZERO, ENTER "0" IN COL. 2.
`
`'IF THE DIFFERENCE IN COL. 2 IS LESS THAN
`
`+$135=
`TOTAL:
`
`Cisco V. TracBeam / CSCO-1002
`
`Page 5 of 2386
`
`Cisco v. TracBeam / CSCO-1002
`Page 5 of 2386
`
`

`

`OTHER INFORMATION:
`
`
`
`9 oner is hereby authorized to debit any un
`’Jpayments or credit any overpayment to
`The Co .
`,‘I
`Deposit Account No. 19-1970.
`
`The Commissioner is hereby authorized to charge all required fees for extensions of time under
`§1.17 to Deposit Account No. 19-1970.
`
`Foreign Priority benefits are claimed under 35 USC §119 of Patent Application Serial No. filed
`
`The Small Entity Statementwas filed in the above-referenced prior application. Small Entity status
`is still proper and desired.
`
`[]
`
`[]
`
`[]
`
`[X]
`
`1.
`
`2.
`
`3.
`
`4.
`
`5.
`
`6.
`
`[X]
`
`The prior application is assigned to TracBeam LLC.
`
`Correspondence Address:
`
`Dennis J. Dupray, Ph.D.
`1801 Belvedere Street
`Golden,Colorado 80401
`Telephone: (303) 863-2975
`Facsimile: (303) 863-0223
`
`W
`
`
`Cisco V. TracBeam / CSCO-1002
`
`Page 6 of 2386
`
`Cisco v. TracBeam / CSCO-1002
`Page 6 of 2386
`
`

`

`O
`
`'
`
`or
`
`WIRELESS IL©<CATH©INI USING MULTIPLE SIMULFAINIEOJUS IL©CAFII®|NI ESTIMATOJIRS
`
`FIELD OF THE INVENTION
`
`The present invention is directed generally to a system and method for locating people or objects, and in particular, to a
`
`system and method for locating a wireless mobile station using a plurality of simultaneously activated mobile station location
`estimators.
`
`BACKGROUND OF THE INVENTION
`
`Introduction
`
`
`
`10
`
`15
`
`-20
`
`25
`
`30
`
`Mreless communications systems are becoming increasingly important worldwide. Wireless cellular telecommunications
`
`systems are rapidly replacing conventional wire-based telecommunications systems in many applications. Cellular radio telephone
`
`networks (“CRT"), and specialized mobile radio and mobile data radio networks are examples. The general principles of wireless
`
`cellular telephony have been described variously, for example in U. S. Patent 5,295,| 80 to Vendetti, et al, which is incorporated herein
`
`by reference.
`
`There is great interest in using existing infrastructures for wireless communication systems for locating people and/or
`
`objects in a cost effective manner. Such a capability would be invaluable in a variety of situations, especially in emergency or crime
`
`situations. Due to the substantial benefits of such a location system, several attempts have been made to design and implement such
`a system.
`I
`
`Systems have been pmposed that rely upon signal strength and trilateralization techniques to permit location include those
`
`disclosed in us. Patents 4,8l8,998 and 4,908,629 to Apsell etal. (“the Apsell patents”) and 4,89l,650to Sheffer (“the Sheffer
`
`patent"). However, these systems have drawbacks that include high expense in that special purpose electronics are required.
`
`Furthermore, the systems are generally only effective in Iine-of-sight conditions, such as rural settings. Radio wave surface
`
`reflections, refractions and ground clutter cause significant distortion, in determining the location of a signal source in most
`geographical areas that are more than sparsely populated. Moreover, these drawbacks are particularly exacerbated in dense urban
`
`canyon (city) areas, where errors and/or conflicts in location measurements can result in substantial inaccuracies.
`
`Another example of a location system using time of arrival and triangulation for location are satellite-based systems, such
`
`as the military and commercial versions of the Global Positioning Satellite system (“GPS”). GPS can provide accurate position
`
`determination (i.e., about IOO meters error for the commercial version of GPS) from a time-based signal received simultaneously
`
`from at least three satellites. A ground-based GPS receiver at or near the object to belocated determines the difference between the
`
`time at which each satellite transmits a time signal and the time at which the signal is received and, based on the time differentials,
`
`determines the object's location. However, the GPS is impractical in many applications. The signal power levels from the satellites
`1
`
`Cisco V. TracBeam / CSCO-1002
`
`Page 7 of 2386
`
`Cisco v. TracBeam / CSCO-1002
`Page 7 of 2386
`
`

`

`are low and the GPS receiver re.a clear, line-of-sight path to at least three satellites.a horizon of about 60 degrees for
`
`effective operation. Accordingly, inclement weather conditions, such as clouds, terrain features, such as hills and trees, and buildings
`
`restrict the ability of the GPS receiver to determine its position. Furthermore, the initial GPS signal detection process fora GPS
`
`receiver is relatively long (i.e., several minutes) for determining the receiver's position. Such delays are unacceptable in many
`
`applications such as, for example, emergency response and vehicle tracking.
`
`Differential GPS, or DGPS systems offer correction schemes to account for time synchronizationdrift. Such correction
`schemes include the transmission of correction signals over a two-wayradio link or broadcast via FM radio station subcarriers. These
`
`systems have been found to be awkward and have met with limited success.
`
`7
`
`10
`
`Additionally, GPS-based location systems have been attempted in which the received GPS signals are transmitted to a
`central data center for performing location calculations. Such systems have also met with limited success.
`In brief, each of the
`
`various GPS embodiments have the same fundamental problems of limited reception of the satellite signals and added expense and
`
`complexity of the electronics required for an inexpensive location mo bile station or handset for detecting and receiving the GPS
`
`
`
`15
`
`20
`
`25
`
`30
`
`signals from the satellites.
`
`Radio Propagation Background
`
`The behavior of a mobile radio signal in the general environment is unique and complicated. Efforts to perform
`
`correlations between radio signals and distance between a base station and a mobile station are similarly complex. Repeated attempts
`
`to solve this problem in the past have been met with only marginal success. Factors include terrain undulations, fixed and variable
`
`clutter, atmospheric conditions, internal radio characteristics of cellular and PCS systems, such as frequencies, antenna
`
`configurations, modulation schemes, diversity methods, and the physical geometries of direct, refracted and reflected waves between
`
`the base stations and the mobile. Noise. such as man-made externally sources (e.g., auto ignitions) and radio system co-channel and
`
`adjacent channel interference also affect radio reception and related performance measurements, such as the analog carrier-to-
`interference ratio (C/l), or digital energy-per-bit/Noise density ratio (EW) and are particular to various points in time and space
`domains.
`
`RF Propagation in Free Space
`
`Before discussing real world correlations between signals and distance, it is useful to review thetheoretical premise, that of
`
`radio energy path loss across a pure isotropic vacuum propagation channel, and its dependencies within and among various
`
`communications channel types. Fig. l illustrates a definition of channel types arising in communications:
`
`Over the last forty years various mathematical expressions have been developed to assist the radio mobile cell designer in establishing
`
`the proper balance between base station capital investment and the quality of the radio link, typically using radio energy field-
`
`strength, usually measured in microvolts/meter, or decibels.
`
`V
`
`First consider Hata‘s single ray model. A simplified radio channel can be described as:
`
`Cisco V. TracBeam / CSCO-1002
`
`Page 8 of 2386
`
`Cisco v. TracBeam / CSCO-1002
`Page 8 of 2386
`
`

`

`.i=LP+F+ L,+ L,V,,+l.,,-G‘+Gr . '
`
`(Equationl)
`
`where (ii = system gain in decibels
`
`LP: free space path loss in dB,
`
`f = fade margin in dB,
`
`LI = transmission line loss from coaxials used to connect radio to antenna, in dB,
`
`L,,.= miscellaneous losses such as minor antenna misalignment. coaxial corrosion, increase in the receiver noise figure due
`
`to aging, in dB,
`
`10'
`
`Lb: branching loss due to filter and circulator used to combine or split transmitter and receiver signals in a single
`antenna
`
`6‘: gain of transmitting antenna
`
`6,: gain of receiving antenna
`
`15
`
`
`
`20
`
`25
`
`free space path lossI LP as discussed in Mobile Communications Design Fundamentals, William C. Y. Lee, 2nd, Ed across the propagation channel
`
`is a function of distance d, frequency
`
`f(forf values < l GHz, such as the 890-950 mHz cellular band):
`
`
`P07 _
`1
`R —(4Izdfc)2
`
`e
`(equation 2)
`
`where
`
`I’or = received power in free space
`
`Pt = transmitting power
`
`_ c = speed of light,
`
`The difference between two received signal powers in free space,
`
`
`
`AP = (10)log(;°’2] = (20)log[%](d3)
`
`or]
`
`(equatinn3)
`
`Cisco V. TracBeam / CSCO-1002
`
`Page 9 of 2386
`
`Cisco v. TracBeam / CSCO-1002
`Page 9 of 2386
`
`

`

`indicates that the free propaga.h loss is 20 dB per decade. frequencies between I (.1 ZGHz experience increased values in
`the exponent. ranging from 2 to 4. or 20 to 40 dB/decade, which would be predicted for the new PCS |_.8 - L9 GHz band.
`
`5
`
`This suggests that the free propagation path loss is 20 dB per decade. However, frequencies between I GHz and 2 GHz experience
`
`increased values in the exponent. ranging from 2 to 4, or 20 to 40 dB/decade. which would be predicted for the new PCS 1.8 - |.9 GHz
`
`band. One consequence from a location perspective is that the effective range of values for higherexponents is an increased at higher
`
`frequencies, thus pmviding improved granularity of ranging correlation.
`
`Environmental Clutter and RF Propagation Effects
`
`10
`
`Actual data collected in real-world envimnments uncovered huge variations with respect to the free space path loss
`
`equation. giving rise to the creation of many empirical formulas for radio signal coverage prediction. Clutter, either fixed or
`
`stationary in geometric relation to the propagation of the radio signals, causes a shadow effect of blocking that perturbs the free
`space loss effectePerhaps the best known model set that characterizes the average path loss is Hata's, “Empirical formula for
`Pmpagation Loss in Land Mobile Radio”. M. Hata, lEEE Transactions VT-29, pp. 3|7-325, August I980, three pathloss models, based
`on Okumura’s measurements in and around Tokyo, “Field Strength and its Variability in VHF and UHF land Mobile Service”, Y.
`0kumura, et al. Review ofthe Electrical Communications laboratory, Vol l6, pp 825-873, Sept. - Oct. I968.
`
`15
`
`:E:
`:1
`E2
`2:;
`
` 20
`
`The typical urban Hata model for LP was defined as LP 2 th:
`
`L,“ = 69.55 + 26.16log(f) — 13.8210g(has ) — a(hMS )+ ((44.9 — 6.5510g(HBS) log(d)[dB])
`
`'
`
`'
`
`(Equation 4)
`
`where LHu = path loss, Hata urban
`
`25
`
`hBS = base station antenna height
`
`hMS= mobile station antenna height
`d = distance BS-MS in km
`
`30
`
`“(MW is a correction factorfor small and medium sized cities, found to be:
`
`Cisco V. TracBeam / CSCO-1002
`
`Page 10 of 2386
`
`Cisco v. TracBeam / CSCO-1002
`Page 10 of 2386
`
`

`

`5
`
`10
`
`' 15
`
`
`
`
`110g(f .)hMS'—1.56log(f — 0.8) = a(hMS) .
`
`For large cities the correction factor was found to be:
`
`a (th) = 3.2 [log 11.75th] 2 — 4.97
`
`assuming f is equal to or greater than 400 mHz.
`
`Ihe typical suburban model correction was found to be:
`
`(Equation 5)
`
`(Equation 6)
`
`Lam = LH“ —2[log('2—8)
`
`f 2
`
`]—5.4[dB]
`
`»
`
`,
`
`(Equation7)
`
`Ihe typical rural model modified the urban formula differently. as seen below:
`
`LHruml = LHu — 4.78 (log f) 2 +18.33logf- 40.94 [dB]
`20
`
`(Equation 3)
`
`Although the Hata model was found to be useful for generalized RF wave prediction in frequencies under l GHz in certain
`
`suburban and rural settings, as either the frequency and/or clutter increased, predictability decreased. In current practice, however,
`
`field technicians often have to make a guess for dense urban an suburban areas (applying whatever model seems best), then
`
`installing a base stations and begin taking manual measurements. Coverage problems can take up to ayear to resolve.
`
`25
`
`Relating Received Signal Strength to Location
`
`Having previously established a relationship between d and P0,, reference equation 2 above: d represents the distance
`
`between the mobile station (MS) and the base station (BS); P,r represents the received power in free space) for a given set of
`
`unchanging envimnmental conditions, it may be possible to dynamically measure P,r and then determine d.
`
`In l99l, US. Patent 5,055,85l to Sheffer taught that if three or more relationships have been established in a triangular
`
`30
`
`space of three or more base stations (85s) with a location database constructed having data related to possible mobile station (MS)
`
`locations. then arculation calculations may be performed, which use three distinct P,r measurements to determine an X,Y, two
`
`5
`
`Cisco V. TracBeam / CSCO-1002
`
`Page 11 0f2386
`
`Cisco v. TracBeam / CSCO-1002
`Page 11 of 2386
`
`

`

`dimensional location, which ca
`
` “ on is based on the fact that the
`
`-- projected onto an area map. The triangulation ca A
`
`approximate distance of the mobile station (MS) from any base station (BS) cell can be calculated based on the received signal
`
`strength. Sheffer acknowledges that terrain variations affect accuracy, although as noted above, Sheffer’s disclosure does not account
`for a sufficient number of variables, such as fixed and variable location shadow fading, which are typical in dense urban areas with
`
`5
`
`moving traffic.
`
`Most field research before about I988 has focused on characterizing (with the objective of RF coverage prediction) the RF
`
`propagation channel (i.e., electromagnetic radio waves) using a single-ray model, although standard fit errors in regressions proved
`
`dismal (e.g., 40-80 dB). Later. multi-ray models were proposed, and much later, certain behaviors were studied with radio and
`
`digital channels. In |98|, Vogler proposed thatradio waves at higher frequencies could be modeled using optics principles. In I988
`
`10
`
`Walfisch and Bertoni applied optical methods to develop a two-ray model, which when compared to certain highly specific, controlled
`
`field data, provided extremely good regression fit standard errors of within |.2 dB.
`
`In the Bertoni two ray model it was assumed that most cities would consist of a core of high-rise buildings surrounded by a
`
`much larger area having buildings of uniform height spread over regions comprising many square blocks, with street grids organizing
`buildings into mws that are nearly parallel. liays penetrating buildings then emanating outside a building were neglected. fig. 2
`
`15
`
`provides a basis for the variables.
`
`After a lengthy analysis it was concluded that path loss was a function of three factors: (l)_the path loss between antennas
`
`in free space; (2) the reduction of rooftop wave fields due to settling; and (3) the effect of diffraction of the rooftop fields down to
`
`ground level. The last two factors were summarily termed Léx, given by:
`
`20
`
`25
`
`L“ = 57.1 + A + log(f) + R — ((18log(H))— 1810g|:1— 11371?](Equation9)
`
`V
`
`2
`
`
`The influence of building geometry is contained in A:
`
`= Slog [(9)2] -9logd + 2010g {tan [2(h —H )]_1}
`
`MS
`
`2
`
`'
`
`(Equation IO)
`
`However. a substantial difficulty with the two-ray model in practice is that it requires a substantial amount of data
`
`regarding building dimensions, geometries, street widths, antenna gain characteristics for every possible ray path. etc. Additionally,
`
`it requires an inordinate amount of computational resources and such a model is not easily updated or maintained.
`
`Unfortunately, in practice clutter geometries and building heights are random. Moreover, data of sufficient detail has been
`
`
`
`
`30
`
`extremely difficult to acquire. and regression standard fit errors are poor; i.e., in the general case, these errors were found to be 40-
`
`60 dB. Thus the two-ray model approach. although sometimes providing an improvement over single ray techniques, still did not
`
`predict Rf signal characteristics in the general case to level of accuracy desired (< |0d B).
`
`6
`
`Cisco V. TracBeam / CSCO-1002
`
`Page 12 0f2386
`
`Cisco v. TracBeam / CSCO-1002
`Page 12 of 2386
`
`

`

`Work by Greenstein .ce developed from the perspective of measurement-.egression models,as opposed to the
`previous approach of predicting-first, then performing measurement comparisons. Apparently yielding to the fact that low-power,
`
`low antenna (e.g., l2-25 feet above ground) height PCS microcell coverage was insufficient in urban buildings, Greenstein, et al,
`
`authored “Performance Evaluations for Urban Line-of-sight Microcells Usinga Multi-ray Propagation Model”, in IEEE Globecom
`
`5
`
`Proceedings, |2/9l. This paper proposed the idea of formulating regressions based on field measurements using small PCS microcells
`
`in a lineal microcell geometry (i.e., geometries in which there is always a line-of-sight (LOS) path betweena subscriber’s mo bile and
`
`its current microsite).
`
`Additionally, Greenstein studied the communication channels variable Bit-Error-liate (BER) in a spatial domain, which was
`
`a departure from previous research that limited field measurements to the RF propagation channel signal strength alone. However,
`Greenstein based his finding on two suspicious assumptions: l) he assumed that distance correlation estimates were identical for
`
`10
`
`uplink and downlinktransmission paths; and 2) modulation techniques would be transparent in terms of improved distance
`
`correlation conclusions. Although some data held very correlations. other data and environments produced poor results. Accordingly,
`
`his results appear unreliable for use in general location context. -
`In I999 Greenstein, et al, authored “A Measurement-Based Model for Predicting Coverage Areas of Urban Microcells”, in
`
`15
`
`the IEEE Journal 0n Selected Areas in Communications, Vol. II, No. 7, 9/93. Greenstein reported a generic measurement-based model
`
`of RF attenuation in terms of constant-value contours surroimding a given low-power, low antenna microcell environment in a dense,
`
`rectilinear neighborhood, such as New York City. However, these contours were for the cellular frequency band. In this case, L08 and
`
`non-LOS clutter were considered for a given microcell site. A result of this analysis was that RF propagation losses (or attenuations),
`
`when cell antenna heights were relatively low, provided attenuation contours resembling a spline plane curve depicted as an asteroid,
`
`20
`
`aligned with major street grid patterns. Further, Greenstein found that convex diamond-shaped llF propagation loss contours were a
`
`common occurrence in field measurements in a rectilinear urban area. The special plane curve asteroid is represented by the formula
`
`x2” + y”3 = rm. However, these results alone have not been sufficiently robust and general to accurately locate an MS, due to the
`
`variable nature of urban clutter spatial arrangements..
`
`At Telesis Technology in I994 Howard Xia, et al, authored “Microcellular Propagation Characteristics for Personal
`
`25
`
`Communications in Urban and Suburban Environments", in IEEE Transactions of Vehicular Technology, Vol. 43, No.3, 8/94,which
`
`performed measurements specifically in the PCS |.8 to L9 GHz frequency band. Xia found corresponding but more variable outcome
`
`results in San Francisco, Oakland (urban) and the Sunset and Mission Districts (suburban).
`
`Summary of factors Affecting Rf Propagation
`
`The physical radio propagation channel perturbs signal strength,frequency (causing rate changes, phase delay, signal to
`
`30
`
`noise ratios (e.g., C/I for the analog case, or [W , RF energy per hit, over average noise density ratio for the digital case) and
`
`Doppler-shift. Signal strength is usually characterized by:
`
`- Free Space Path Loss (Lg)
`
`
`
`;I’==
`
`Cisco V. TracBeam / CSCO-1002
`
`Page 13 of 2386
`
`Cisco v. TracBeam / CSCO-1002
`Page 13 of 2386
`
`

`

`- Slow fading loss or. (Lb)
`- Fast fading loss or margin (Lhn)
`
`.
`
`loss due to slow fading includes shadowing due to clutter blockage (sometimes included in Lp). Fast fading is composed of
`
`multipath reflections which cause: I) delay spread; 2) random phase shift or Rayleigh fading; and 3) random frequency modulation
`
`5
`
`.
`due to different Doppler shifts on different paths.
`Summing the path loss and the two fading margin loss components from the above yields a total path loss of:
`
`lw=lp+Lh+lim
`
`Referring to Fig. 3, the figure illustrates key components of a typical cellular and PCS power budget design process. The cell designer
`increases the transmitted power P“ by the shadow fading margin L." which is usually chosen to be within the l-Z percentile of the
`
`10
`
`slow fading probability density function (PDF) to minimize the probability of unsatisfactorily low received power level P,“ at the
`
`receiver. The Pu level must have enough signal to noise energy level (e.g., l0 dB) to overcome the receiver’s internal noise level (e.g.,
`
`-l l8dBm in the use of cellular 0.9 GHz), for a minimum voice quality standard. Thus in the example Pu must never be below -l08
`
`dBm, in order to maintain the quality standard.
`
`.
`
`15
`
`Additionally the short term fast signal fading due to multipath propagation is taken into account by deploying fast fading
`
`margin hm, which is typically also chosen to be a few percentiles of the fast fading distribution. The l to 2 percentiles compliment
`
`other network blockage guidelines. For example the cell base station traffic loading capacity and network transport facilities are
`
`usually designed for a l-2 percentile blockage factoras well. However, in the worst-case scenario both fading margins are
`
`simultaneously exceeded, thus causing a fading margin overload.
`
`20
`
`In Roy , Steele’s, text, Mobile Radio Communications, lEEE Press, I992, estimates for a GSM system operating in the LB
`
`GHz band with a transmitter antenna height of 6.4m and an MS receiver antenna height of 2m, and assumptions regarding total
`
`path loss, transmitter power would be calculated as follows:
`
`if:
`"a'm:5
`
`"mi~=
`“=3ms
`‘5‘='—_-
`«i:3:
`as
`
`
`M2"
`“lill'iiii
`
`Cisco V. TracBeam / CSCO-1002
`
`Page 14 of 2386
`
`Cisco v. TracBeam / CSCO-1002
`Page 14 of 2386
`
`

`

`Table I: GSM Power Budget Example
`
`_n—
`
`—-—
`
`Mm RX pwr required
`
`
`
`
`
`
` TXpwr = 27 dBm
`
`
`
`Steele's sample size in a specific urban London area of 80,000 LOS measurements and data reduction found a slow fading variance of
`
`c = 7dB
`
`assuming lognormal slow fading PDF and allowing for a l.4% slow fading margin overload. thus
`
`slow = 25 = l4dB
`
`The fast fading margin was determined to be:
`
`Lfast = 7dB
`
` 10
`
`15
`
`In contrast, Xia’s measurements in urban and suburban California at La GHz uncovered flat-land shadow fades
`
`on the order of 25-30 dB when the mobile station (MS) receiver was traveling from LOS to non-LOS geometries. ln hilly terrain fades
`
`of +5 to -50 dB were experienced. Thus it is evident that attempts to correlate signal strength with MS ranging distance suggest that
`
`error ranges could not be expected to improve below l4 dB, with a high side of 25 to 50 dB. Based on 20 to 40 dB per decade,
`
`20
`
`Corresponding error ranges for the distance variable would then be on the order of 900 feet to several thousand feet, depending upon
`
`the particular environmental topology and the transmitter and receiver geometries.
`
`Cisco V. TracBeam / CSCO-1002
`
`Page 15 of 2386
`
`Cisco v. TracBeam / CSCO-1002
`Page 15 of 2386
`
`

`

`SUMMARY OF THE INVENTION
`
`OBJECTS OF THE INVENTION
`
`It is an objective of the present invention to provide a system and method for to wireless telecommunication systems for
`
`accurately locating people and/or objects in a cost effective manner. Additionally, it is an objective of the present invention to provide
`
`such location capabilities using the measurements from wireless signals communicated between mobile stations and a network of base
`
`stations, wherein the same communication standard or protocol is utilized for location as is used by the network of base stations for
`
`providing wireless communications with mobile stations for other purposes such as voice communication and/or visual
`
`communication (such as text paging, graphical or video communications). Related objectives for the present invention include
`
`providing a system and method that:
`
`q
`
`(LI)
`can be readily incorporated into existing commercial wireless telephony systems with few, if any,'modifications ol a typical
`telephony wireless infrastructure;
`7
`
`(II)
`can use the native electronics of typical commercially available telephony wireless mobile stations (e.g., handsets) as
`location devices;
`‘
`
`(l3)
`
`can be used for effectively locating people and/or objects wherein there are few (if any) line-of—sight wireless receivers for
`
`receiving location signals from a mobile station (herein also denoted MS);
`
`can be used not only lordecreasing location determining difficulties due to multipath phenomena but in fact uses such
`(L4)
`multipath for providing more accurate location estimates;
`
`(LS)
`
`(L6)
`
`can be used for integrating a wide variety of location techniques in a straight-forward manner; and
`
`can substantially automatically adapt and/or (re)train and/or (re)calibrate itself according to changes in the environment
`
`and/or terrain of a geographical area where the present invention is utilized.
`
`Yet another objective is to provide a low cost location system and method, adaptable to wireless telephony systems, for
`
`In
`using simultaneously a plurality of location techniques for synergistically increasing MS location accuracy and consistency.
`particular, at least some of the following NS location techniques can be utilized by various embodiments of the present invention:
`
`10
`
`15
`
`20
`
`
`
`25
`
`(2.I)
`
`(2.2)
`
`time-of-arrival wireless signal processing techniques;
`
`time-difference-of—arrival wireless signal processing techniques;
`
`adaptive wireless signal processing techniques having, for example, learning capabilities and including, for instance,
`(23)
`artificial neural net and genetic algorithm processing;
`I
`
`(2.4)
`
`(2.5)
`
`(2.6)
`
`30
`
`signal processing techniques for matching MS location signals with wireless signal characteristics of known areas;
`
`conflict resolution techniques for resolving conflicts in hypotheses for MS location estimates;
`
`enhancement of MS location estimates through the use of both heuristics and historical data associating MS wireless signal
`
`characteristics with known locations and/or environmental conditions.
`
`10
`
`Cisco V. TracBeam / CSCO-1002
`
`Page 16 of 2386
`
`Cisco v. TracBeam / CSCO-1002
`Page 16 of 2386
`
`

`

`
`
`speed, and an extrapolated next location in cases where the MS signal subsequently becomes unavailable.
`
`in be used to establish motion,
`
`Yet another objectiv I
`
`rovide location estimates in terms of time vectors, .
`
`,,=_t a
`
`1:!
`«F“:91
`
`‘v. a'u
`
`
`
`DEFINITIONS
`
`5
`
`Ihe following definitions are provided for convenience. In general, the definitions here are also defined elsewhere in this
`document as well.
`
`(3.|)
`
`Ihe term “wireless" herein is, in general, an abbreviation for “digital wireless”, and in particular, “wireless" refers to
`
`digital radio signaling using one of standard digital protocols such as CDMA, NAMPS, AMPS, TDMA and GSM, as one skilled in the art
`will understand.
`
`10
`
`(3.2)
`
`As used herein, the term “mobile station” (equivalently, MS) refers to a wireless device that is at least a transmitting
`
`device, and in most cases is also a wireless receiving device, such as a portable radio telephony handset. Note that in some contexts
`
`herein instead or in addition to MS, the following terms are also used: “personal station” (PS), and “location unit” (N). In general,
`
`these terms may be considered synonymous. However, the later two terms may be used when referring to reduced functionality
`
`communication devices in comparison to a typical digital wireless mobile telephone.
`
`15
`
`(33)
`
`The te