Note: Descriptions are shown in the official language in which they were submitted.
r~ 4 97 14:11 FRO~I: CA 02225901 l997-l2-24 TLI:613 2~Z 8440 PP~E:~33
p43~6 . IlemDt~Jy Comrol~ Ci~in Con~rol C~ Tr~ v~r r)z~d T~ In~ CannoA W~l~s Tcl--ph~Pff l o A Br~R~d ?~
~MOTEIJY CONTROLLED GAlN CO~TROI
0:~ T~ANSCE~VER USED TO INTER-CO~NEC~T WIRFl F!CS
TELEP~lONES TO ~ BRO~PB~ NI~TWOR~
5 Field ~fthe Invention
~ he present invention relates to wireless telephones and more particularly to appuatus
tor centrally controllin~ the operation and settings of gain control circuitry in remote
transceiYers that carly tolepl~ y signals bet~een wireles~ telephones and a broad~and
10 distribulion network that carrie~ telcpho~ signals to a telephone network
Back~round of the lnvention
The prior art leaches the use of existin~ cable îelevision networl; cables to carr~
5 teleph~ny si~nals between a telephone network and remote transceiver sites in defined cells or
sectors 'rhe transGeivers are used to establish wireless telephony communication link~ with
wirclcss telephones that ale operating withiin ~n ~rea cowred by each remote transceiver. To
increase the number of wireless ~t~le~h~ne subscnbers that c~n use the wireless teleph~-ne
sys~em it has been suggested to decreasc the size and operational ran~,e of each cell or sector~
20 and to incre~se the num~er of ~ells or sectors required to provide wireless telephone serYic~ to
a given uea Havin~ or ~ectors of decreased size penn~ts ~sreater reuse Df the limited
number of fiequ~ncy chdnneli ~llocated for wireless selephone service because other ~ells or
se~tors l~cated ~t ~ clDser r~n~e can reu~e the s~lme f;equency cl~nr -I for additional calls
~thout ~ignal interference. The advanta~es of reducin~ oell or sector ~ize to increase the call
2S canyin~ capacity of the wireless leleFh~ne network is ofl~et by the requirement for additional
remnte transceivers for the additional cells. This offset is n~inimized by 11-ili7il~5 an existin~
broadband distri~ution network to pra~ide the cormnunicationc path ~etween remote
transceivers in each of ~he cells or s~ctors and a centr~l tr~scei~vel Th~ b~e transceiver
CIE{-2~ 97 14:11 FROM: CA 022i590l l99'7-l2-24 T~ t'~ 32 8~0 PRGE:04
~326 ~ R~m~el~ Cohlroll~d ~n C~l OJ T~w~i~a U~cd To Ir~ Wu~lc~ Teleph~.ne:~ To A ~d~J ~ch~or~:
station acts as the in~er~ace b~tween the telephone network and the wireless telephone system,
~nd the central transeeiver acts as the wireless telephone system interface with the bro~dband
distribl~ion network
To carry wireles~ telephony si~nals over ~ broadband distri~ution network, as described
above, ~ predetermin~d b4ndwi~th ~n ttle networ~; is typically a~ ca~ed fDr this purpose.
owever, as required7 more bandw~dth m3y be aJlocatcd to c~lry wir~less t~l~rh~ y si~nals.
Tc~ most efficiently use a given bandwidth to c~y ~4~reles~ telephony Sigllal~ bet~een wireless
telephones ~ld thc ~ phl~ne network, a ~mbin~tion of ~e~uency and time divis;~n
10 muhiple~in~ is utilized This req~i~es base transc~iver st~tion eq~lipment that acts as the
int~ ce with the lelep~ne network and the wireless telephone ~ystem With the base
transceiver station equipment is a central trsnsceiver ~RASP), als~ called a Jleadend Interface
Clo~verter ~H~C)~ ti-al interfaces ~vith the brordb~ distributiun network ~nd it must fimction
with telcphony si~nals in the wide ~equency spectrum of r~di~ freql~ency si~nals on the
15 t~lephone network. ~Ind up lo 1000 ~z over the broetlh~n~ ~istribution network This systom
also requires a plurality ol'remote transcei~ers, also called cable micr~ell inl¢grators (CM~s~
or Remote Anterula I~ri~ers (RADs~, in each of the cells or s~ctori that can c~rry m~ny
channels of tel~phony sign~ls betw~n the w~rel~s telephone~ and the eentral lranscciYor via
the ~r.~h~nd distribution n~twork, ~ithout creatin~s si~snal in~ ren~e with ;he teleph~ny
u sign~ls in adjacent cells ~r sectors In addition. ~he remote transceivers (RAD j~ must ~nction
with and translate lelephony si~n~l~ in the ~ide i~equency ~pectrums of up to 1000 Mh~ on the
broa~ nd dislribution n~twork and between 18SO - l~gO ~Hz for the radio link be~ween
~emote transceiver~ and w~reiess t.,l~hl-l,es
2 5 In a~dition. the relnotely lo~ated transçeiYers ~nd the bros~band distribution network
are exposed tO mJmerous a~verse Cf ,1'~ r~ suçh as te~ e~ah~re extremes, whiGh adversely
~ffect the power levels output ifrom the tnnsceivers, ~nd a~ec 105se5 and gains along the
br~ad~anll distnibution network. The po~4er levels output ~m the remote transceiv~r~ must
DEC-Z~ 97 14:1~ FRO~ CA 02225901 1997-12 24 TO:~13 232 8:1~0 P~(~E:E15
1~43~ - Ren~ely C4n~ C~ol Of T~Dci~ wJ To Inl4r~cnn~ W~b~ I elcph~r~ T4 A ~adb~l~ N~lwark
be constantly moni~ored and ~ sted to cnmpensate f~r these adverse conditions ln addition~
~ueh remote transceivers need to con",~ e not only for network variations between each
rem~te tr~ns~ei~er and lhe ~ traJ trulsceiver, but al~ for the temporat variati~ns in the
v~rious network links between Ihe remole ~nd central tr~nsceivers
Summary s~f the In~/enti~n
Thus, there is a need in the an for tr~nsceivers or RAD~ for use in such a wireless
telephony system to carry telephony sign~ls between a telephone network and w~reless
10 tel~phol~es ~ia a broadb~nd distributiotl net~o~k alon~ which are ren~otely distributed a
plurality o~the transcei~ers The gain ofthese remote trhJ~ ers will be adjust~d ~y the
central transceiver which is mon;itonn~ the pow~r levcl of signa]s recei~ed firom euch remote
transceiver so that sicnals reeeived from the wireless telephones ure at ~ consistent level, that is
wi~hin a relatively narrow lccepta~ility raulge, when inpllt to the central lransceiver
lS
The abo~/e described need in the wireless teleph~ne system prior art is s~ti6fied by the
present inventiun. A ~mal~ transceiver is provided which is u~d in a wirelsss tel~phone system
of the t~e briefly described above These remotely located tran~ceivers ue used to cany
telephony si~nal~ between wireless telephones and central transceivers via a broadband
2 ~ di~tribution network, such as ~C~ fiber OptlC c~blel or co~xial cable, on which the remote
transceivers are hun~ ~nd t~ which they are connected Thus, these remote transceivers are
remotcly l.~cat~d and ~linullate tlle n~l for prior r~ an~enna to~Yers ~o carry telephony signals
between wi~eless telephones and central transceivers Each remote transceiver has ~ain ~ontrol
citcuitry by which the ~ n ~ Ihe remote transceivers can be adjusted by the centr~l tr~nsceiver
2 5 which is monitoring the power level of a gain tone signal received from each relnote
u~.3~iver. This is dnne sO that the signal level oft~ ny si~n~ls from the wireless
telephones and appeanng at the input of Ihe cent¢al l~.,scL;~er are at a ~onsistent level th~t is
~thin a relatively narrow r4nge a~ceptable to the central transceiYer.
OEC-24 97 14.12 FR~. b~3-885-~1~7 10:ol3 2~ 8~40 P~GE:06
CA 0222590l l997-l2-24
~3~ - Q~w~l~ C~olled G~r ~1 ~Tn~iva U~ T~ ~n~ Wi~k~ Tcl~ ToA~d~d~o~
Descnption of the Dr~wing
The invention will be better understood upon readinl3 the fo]lowin~ Petailed
l:)e~cr.~tion in conj~lnetior ~4ith the drawing in which:
S
~ igure 1 is a bl~k diagr~n of a wireless telephony sy~teln integrated ~ith an
eY~ lpl~ybrosdbu~ddistnbu~ionnetwork.
Figure 2 is a simplified blo~k dia~ram of a ren~ote tr~nseeiver u~e~ w,ith the wireless
10 lelephony system,
Figure 3 is a det~iled block diagranl of the portion ~f a remote tr~nsceiver that
transmits telephony si~nals received ~on~ wireless teleph- n~ and sent Yia a bro~dh~nd
dlstribution network to a central transceiver~ and the remote transceiver has gain control
15 circuitry that i~ rernotely controlled by the central transceiver; and
Figure 4 i~ a block ~ia~lram of a portion of ~ central transceiver that is used to monitor
Ihe si~nal g~in of ~ gain tone recei~ed from each of ~ plurality of remote transceivers ~ong
with telephony signals, and send control sign~ls to each remote tr~nscei~er to adjust its signal
2 0 g8in
Det~iled ~ riptinn
In the dra~in~ and the folio~ det~iled description, all ~lements are ~c~i~ned three
2 5 digit reference numbers rhe first digit ~f each reference number indicates in which fi~ure of
the drawin~ an element is loeated The second and third digits of each, efe ce number
indicate s~ecific elements If the same element appeus in more than one figure of the drawin~.
the second and t~urd digits rema~n the ~ame ~nd only the first digit chanyes to iE~diçate the
~r~ '~ - ~1~7 ~ bl3 2i~ 8~4~ P~I~E:07
DEl~-24 g~l' 14:l2 FRO1'1: CA Oi225901 1997-12-24
D4326 ~ eiy l~ollcd ~;b~n C~rol Of T~iva Ibd To I~ W~rcleb~ pho~ T~ db~nd ~i ~tW4~A
figure of the drawing in which th~ element is located As used herein the terrn "~elephony
~i~n~ls" incl~de~ voice, d4ta, f~x and any oth~r types of si~r~als that are sent over a telepholle
net~ork now or in the fi~ re. Throughout the ~i~res and lhe followin~ descripti~nl refe~ence
is m~de f~r one exs~le, [o a combined band pass filler ~nd ~snplifier 3~5a. There ~re a
S nu~nber of other such c~mbined band p~ss fiJterD and ~mplifiers. They are ~hown and
refereTl~d this way for e~se of pre~entation only. In reality they are eacb a discrete, separate
filter the out~ut of which is input to a n ~"~rlifi~t
ln Fi~ure 1 is sho~n ~ simple block dia~raJn of an ~ mF!A~ broadband distnbution10 network 112 integrated with ~ wireless tcle~honc system whicb includes a plurality of remotely
1nc~ted trans~eivers known aS Remote Antenn~ Drivers ~RADs~ . Ther~ are differ~nt types
of broadb~nd distri~ution networks in use that m~y be utilized ~4ith the pre~ent invention
Such networks may utili~e coa~i~t c~ble ~nd fib~r optic ~able rn thc embodiment of the
invention diselos~d herein a conventional hybrid fiber ~oax~sl (~FC~ cable distribution s~slem
15 is utilized o~the type u~ed for cable ~elevision distri~ution nel~orlcs~ but other types or
combin~tions of broadband distribution network~ may also be utilked Electrical power is
distributed ~lon~ ~road~and di~tribution network 112 to power line amplifiers (not shown) of
the btoadband distribution network This electri~al power source ar alternate power sources,
are used to provide power to RA~s 11~ a-i
~o
In~e~rated with ~roadband distribution network 112 i~ a wireless telephony system in
which the presen~ invelltion is ~Itili~ed. One j-lch wireless telephony sy5tem is taught in U S
Pat~nt application 081~5,175, filed Au~ 1, 1996, and entitled "Appara~us And l~,~ethod For
Distnbuting Wir~le~s (~ommumcati~ns Si~nalj To ~omote Cellular Antelulas". The tclcphon~
5 system di~closed herein and shown in Fi~ure 1, in~ s a base l~an~ceiver station (HTS) I 1 S
which is wnnected tC) ~I telephone system I 16 Base transceiver xtation 1 15 i~ also c~nne~t~d
to a Remote ~ntenna Signal Proces~or (R~SP) I ~ 7 ~bhich is the interface to a bro~dband
distribution network 1 12 Telephony si~nals to be sent between telephone sy~ern 1 16 and
Z4 g7 1~: 13 FROI~I: CA 0 2 2 2 5 9 0 1 19 9 7 - 12 - 2 4 Pi~GE: 08
~431~ - p.crnolcl y Cor~l loA4 ~un C~l ~ Us~d T~ W irt l~ l tlcph~ l o A E~ro~ ctwDr.~
wirel~ss tel~Fhon~s I 1~ ~re carried via t~ro~d~on~1 network 1 12 using RASP I 17 an~ Remote
Antenn~ Drivers (RAD) 118.
A~ is l;nown in the prior art, in~ n~s the l~bo~/e ~ited pnor art patent applic~ior~ one
5 or more ~equency bands or ch~ ls ofthe braadhand distrlbutic~n network 112 ~re aeci6ned
to c~m telephony corn~ n ~h~iOrlc and control signals between telephone system 116 and
~ireless telephones I 1~ Telephony sign~ls originating ~om telephone system I ]6 are
,.utted ~y RASP 117, in *eq~ency division mu~ d~e furmat, via bro~d~nd network
112 to ~ plur~lity of remote antenna dnvers (~ADs~ i which are connected to broad~and
10 distribution network 1 1~ Te~ephony signal~ ori~in~ti~ ~t wireless tPleph~n~s I 1~ are
~equency mul~iplexed to~t~th~r by RADs 118 ~-i and ~re transmitted alon~ with contrvl and
~in tone signals via ~roadband net~ork 11~ to ItASP 1 17, al1d Iher~e to base trans~ er
station 1 I S and telephone syssem 3
In ba~ ans~.~er station 115 there are a plurality oftranscei~er modules (not shown~
as is known in the wirele~ telephony an, e~ch of ~hich opcrates ~t a single channel frequen~y
~t a timc, and which can handle ~ predel~fu~."ed m~Y~ m number of telephone calls ~om
wireless telephones In the wireless telephone system described and cl~imed her~in, ~he
frequen~y ~h~t the RADs I 18 are as~igned to operate at must c~rrespond to the operating
2 0 fre4uency of the assigned BTS transceiwr mod~le If ~ particul~r R~D 1 18 is re-assigned tO
fiunction with a di~erent transceiver module ~ithin ~ase transceiver station 11~, ~ir~uit se~tings
wilhin ~he particular RA~ must ~e ~ ng~d to fi~nclion wil~ the dit~rent transceiver
module. Irl the wircless telephDny art, transceiYer modules in Iht b~se transceiver station are
also referred to ~s ch~nnel cArd modulcs and radio mc~dul~6.
When wireless telephony traffic in a first ~ector or ceD incre~se~ to the point where
adequate ser~ ice i5 not provided to wireless telephone subscribers in the first sector or celL lil~e
during rush hour traffic on a hi~hw~y~ in accordance with the tea~kin~ of the present invention
9 ~7 14 13 FRI~ F3~ 7 I~ bl3 232 ~ P~GE: 0~E~-2 . . CA 0222~901 1997-12-24
D~132~ Remu~ely L'onuollcd ~}~u C'~nlrol O~Tr~ iVa Uccd To Inlcr~q~ ~'uele~ lcl~phne~ To A i~ir~dbu~d Ne~
the wireless telephone Syslem may be remotely reconfigured by RASP 117 to reassign one ~r
more RADj 1 18 from one or m~re nearby ~ectors or cells, where those ~A~s I I g have
overl~ppin~ signAl cov~ra~e wi~h t~e fir~t sector or c~lL ~o handle the ex~ess wireless
telephony traffi~ in the first sector cell.
ln Fi~ure I ar~ shown three rows of R~Ps I 18. Typically a number of R~I)s 1 18 are
spaced alon~ and connected t~, bro~dband dis~ ution network 112 to pro~id~ overla,ppin~
sign~l transm~sion and reception covera~e for the entire wireless teleph~ne system. Some of
the RADs 11~ are physically l~eated ne~r the bounJ~ry between tw4 or more cells or sectors
1 n and, ~epe~ on the frequency of operation th~ are set to, can be used to handle ui~eless
telephony traffic in o~e or more of the sectors or ceils Let us ~ssume lhi~t RADs I 1~ ~,h~i in
the bottom rov~ are physica]ly lac~ted along bro.l lb~nd distri~ution system I 1~ and ~re
configured to handle wireless telepholly tr~ffic in a first ~ctor tha~ includes a highway. I:~unn6
early mornin~ and late afternoon every work day there is nl~h hour traffic that creates pe~k
15 wireless telephone trdffic that c~useY UqR ~c~ptable sen~ce delays in the first sector. Let us also
a~s~me that the RAPs 1 1 ~d,e,f in the middle row in Fi~ure I ~re confi~ured ~nd locat~d to
handle wuele~s telephone traf~ic in a se~ond. adj~cent ~eetor but they ea~h have an ~rea of
signal operation that overlapj the hi~h~ay in the fir~t sector
O One or more of RADs l 18 d,e,f may be dynan~cally reassi~ned by R~SP ] 17 to the
first sector lo h~ndle the increased t~lephony traffic oniginating ~om the highway ln addition,
~5 necesja~, addition~ ASP 117 ~hannrIc may be a~ igne~1 ~nd additional modules in base
tran$~eiver station 1 15 may be assigned to handle the excess wireless teleph~ny traffic firom the
first ~e~tor To do this RASP I 1 ? sends control ~i~n~ls to the ~elected remote RADs d,e,f
which ~ill cause the frequenGy at which they operate to be changed lo mat~h the frequency of
RADS 1 18 g,h i that are nonnally as~ d to handle wirele~s telephone traffic in the first
sector ~t the end of the peak traffic per~oJ RASP I 17 may jend control siynaJs to the
previously re~llo~ted ones of RADs 1 I 8 d,e,f to C~ jSe lhe frequency at which they operate
CIEC-ZY 97 14:14 FROM: CA 0222590l l997-l2-24 bl3 _3~ ~4413 Pf~GE:10
1~43~ . Rcmah~ C~-~llc~ 13D~J) ~ ol (~rl'n~i~a U~ To ~ l Wucles~ ~I'dcph~nc~ T4 A ~r~dbu~ ~e~ rl~
b3ck 10 th~ir original settinys ~ they are reassigned to handle wireless telephony traffic in the
second sector ~lo~-ever, the r~-assignrnent may be permanent dependin~ on t~affic patterns
encollntered
Typically ~here are a nurnher of R~s 1 18 ~-i spaced ~long snd connected to
broa~l-~ntl distnbution network 112 to pra~ide overlappin~, si~nal trAnsrnission and reception
coverage fior the entire w~reless telephone system Each RA~ 1 18 has anter~n~s 120, 121, 12
used to transmit to and receive jiynals from remote wireless telephones 1 19. Anlenna 120 is
used to transmit telephon~! signals to wireless telephones 1 l~, while antennas 12i and 1'2 are
used to receive lelephony signals firom ~ireless t~l~,nl~nes 119. ~ultenna 121 is called the
pnnnary antenna, and ant~nna 1~ is called the diversily ~nteMa Antennas 121 ~and 1~2 are
physically spaced and c~opera~e to minJrn~ze signal fading and ther~by provide continuous
si~nal r~ception from wirelL~s telephones 1 19.
In Fi~ure 2 is shown ~ ~eneral block dia~ram of Remote Am~nna l~riv~r (RAD) ~18
The~e is a first circuit 20~ of ~AD 218 that receive~ telephony 5i~nals or~inatine at telephone
system 1 16 2nd carr~ed ~ia R~~SP 117, ~ro~dl~and network 212, and tra~s~ts them via
antenna 220 of a RAD 1 18 to a remote wireless telephone I 1 g (not shown~. There is ~lso a
sec~nd circuit 209 of R~D 218, that is shown in det~il in Figure 3, that receives ~eiephony
2 0 si~nals origin~lin~ at a ~ireless teleph~ne I 19, and t~n5mits them via broadband distribution
netwo~L 21~ lO RASP I l 7~ ~nd ~hen~ lo ba~e t~ er ststion ~ nd telephone system~16.
RAl) circults 208 and ~0~ are connected to and controlled by a microprocessor 210.
2 5 Frequency multiplexed with the telephony signals calT.ied beIween ~ASP 1 17 and each of
RADs 218 a-i are signals for controllin~ ~ain control circuitry in each of remote RAD~ ~18 a-i
in a-~ordance with the teac;hing ofthe present invention The ~ain control circuitry in RAD
c}rcuit 20~ , alle~ by RA~SP 1 1~ to adjust its output signal level so th~l the power level
I~EC-i~4 97 14:14 FRQM: CA oi22S9ol lgF'97-l2-24 Tn~ 32 ~1~4~3 Pfll~E:
D432~ - Ronolely ~ ll~ Cil~ul CantrDI 0~ ~r~i~la U~ed To lr~c~ le~ Telqhon~ l~o A l~rol~b~ Nonvort;
of telephony si~nals inpul to R~SP 1 17 is wilhin a relatively narrow ran~e acceptable to RASP
1 17. This is rrpeated for all rernotely loc~ted ~ADs 11~ a-i distnbuIed along and ~o~ulected ~o
the ~roadband distributian network 21~.
Microprocessor ~10 sends a conuol aignal via leBd ACi~ to RAD circuit ~09 which
causes the output of an ~scill~tor 342 ~aïn tone si~ , w~th known si~nal le~el, t~ be
~-on~bined with any teleph~ny signal~ and transmitled to RASP 117 ~ria bro~band di6tribution
network 112.
The gain tone siKnal level is of a low a~rlit~de that does not interfere with Ihe
elephony si~snals with ~hich it is mixed, bllt is s0pasated from the telephony si~nals at ~ASP
1 17 RA SP 1 17 lnalv~es the amplitude of the received g~qin tone signal~ which will reflect
gains and losses in ~AD 218 and brc~hand dislribution network 212, hS part of a
~etennination whether or nut t~ chan~e attenu~tor 330a, 330b and 336 settin~s in RA~ 21
This operation is repe~ted fur each remotely located RA~ 21~ so that lhe power level of
telephony signals input to RASP 117 is ~vithin a relatively narrow range acceptable to EtASP
117.
~fter processinR the ~in tone signal received alon~ with telepllony signals ~orn each
2 0 of the RP~Os ~18 t~ determine Jf the si~ l le~rels are too 3Ow or too high, RASP I 1~ sends
4din t-)ne cc)ntr~l ~ignal back lO e~eh RAD 218 in which the siKnal level has to be ~dju~ted
Thl~ control sianal is received by m~croprocess~r 210 on lead~ CTRL ~om RA~ ~ircuit ~08
Micrnproc~ss~r 210 re~ponds to the gain tone control si~nal re~eived ~om R~SP 1 17 ~ end
an AC;C a~justment si~nal vi~ leads AGC ~o ~D circuits 208 ~nd 20g In R~I) circuit ~0
2 5 the A~ adjustment signal results in changes being made to attenuators in circ~it 20~, ~s
described in ~reater det~l with referenee to Figure 3, to adjust the signal level of rhe telephony
signal~ lhar are received by RASP 117. Thi~ ad~ menl a~count~ for losses And y~ins nnt only
in RA~ 218, but ~1so in bro~b~nd distribution ne~w~rk 212 ln this manner the power level
GEC-Z~ 97 14:15 FROI~l: CA 022i590l l997-l2-24 TO:~13 232 844~3 P~GE:l~
D4~26 - R~nolcly Cuo~llcd Giul C~ol ~ Tr~ce~ v~ cd rO In~r Cqulta Wuclai~ Tcll.~n~ T~ tbi~d !~'~wor).
of ~i~nais received by l~SP 117 from all RADs 218 s-i are within a relatively narro~v range
n~rt ~~1~ t~ SP 1 1 7
RAP 218 may also receive an intetroga~ion control signal ~t sny time from RASP 117
u~hich ca~es rr~croprocessor 210 to send information about R~) 21~ back t~ R~SP I 17
This information includes the s~tings of attenuator pads 330a~ 330b and 336, the semperature
at which each RA;~ 218 is operatin~, and other information The inf~rmation list~d in the last
sentence i5 used by RASP 1 17 in n~aking decision6 re~arding controllin~ the si~snal level of
each RA~ 218.
In Figure 3 is shown a detailed block diagram of RAD circuit 30~ within novel, Rern~te
Anterma Driver (RA~) 1 181 ? 11~ that carries telephony signals frorn a wireless telephone 1 19,
via broadband distribution network 1 12, to RASP 117 and b~se tr~nsceiver st~ti4n 11~ This
cireuit is shown as ~AD circuit 20~ in FiE~re 2.
Briefly, pnmary receive antenna 3~1 is connected to a first por.~tion of the ~ uitry in
Fi~ur~ 3, and th~t circuitry is identical to a second porti~n of lhe circuit~y that is connected to
diversity receiYc ~ntenr~a 3~2. The telephony si~nals received by ~oth antemla~ 321 ~nd 3'~2
from a wireless tel~phone 1 ] 9 (not shown in Fi~ure 3) are initiall~ processed in puallel~ then
2 0 the two si~nals are frequency multiplexed together and are both returned via broA~b~n~
distribution network 1 12 tO r~m~te RASP I 1~. This operAtion is deseribed in the f~llowinR
puaEraphs.
Telephony sign~ls from ~ wireless t~l~p~onc 1 19 (not shown~ are received by pnmary
receive anteMa 321 These si~nal~ are ~nput to an isolator 323a which isolates antenna 321
from RA~ circuit 309 The t~l~phnny si~,n~l is then input to directi~nal coupler 324a that has
a ~econd si4nal input thereto firom power di~ider 34~ which is the ~forelnentioned low level,
gain tone si~nal that is u~d for g~in control purposes in accord~nce with ~he present inventinn
- 10-
ClEC-i~4 ~7 14:15 FRO~1: CA 0222S90l l997-l2-24 TO:61~ 23~ 10 PHGE:13
D~13~ - Rcm~41y C~lle~ Giin C~,lr~l OrTs~L~ei~,a U~d ~o Inm~Yu~ w~ b Tcl~hc~ To A ~o~db;lnd N~twor~
liain Tone Oscillator 342 is controlled al its input 342a by nucroprocessor 210 whieh is
responsive to ~ontrol signals ~om ~SP 1 17. The analo~ ~ain tone si~nal O-ltpUt from ~ain
tone oscillator ~42 is at a known a~nplitude and is m~xed with the telephony signal wh~ch is a
digit~ pread spectmm format that is ~eli known in the art. lt is this gain tone signal thal is
5 de~ected at RASP 117, processed and used to make a decision to change lhe settings of
attenuators 330a, 330~ and 3~.
The telephony signdl received ~om rem~e w~ireless telephone 1 19 and the low level
~ain lone sign~l are applied via directional coupler 324a to a com~ined b~nd p~ss filter and
10 amplifier 325a The ~ ni~ls are amplified and extr~ncous ~ign~ls ~re filt~d ~om the received
~eleph~ny si~nal.
The amplifi~d and fil~ered telephony and gain tone si~nzls are then input to mixer 326a
which is the first of two heterodyning stage~ u5ed to ~nven the carrier ~equency of the
15 t~leF~hr~ y si~n~l tu tb~ ~ele~t0d cArrier firequency for tr~n~ n over brc~hqnrl distnbution
network 1 12 to Rern~te Anlenna Signal Processor (RASP~ I 17, shown in Figure 1 I~,lixer
326a Al~o has inpl~t thereto a signal ~om local o~cillator 32 î. The first heterodyning signal
~om lo~al oscillator 32? is ~nput to power di~der 3~8 which applies the si~nal ~orn local
oscill~tor 327 to both mixers 326a ~nd 326b while p-ovidin~ isol~tion between these tw~
2 0 nuxer~.
The opera~ion of m~xer 326a results in n~ tiple frequenci~s being output ~om theniixer as is known in the art. All the~e signals are input to nurow pass ~and SAW filter and
~mplifier 329a which selects only the dcsired ~quency carrier modulated by the eain lone and
25 telephony Sigllal5 created by nuxe~ 3~6a, and amplifies same.
The trequency xhifled ~rier ~ d~'oted by lhe tel~pl~ony signal is then inpul to step
~ttP~ or 330a which is used to adjust the gain level of the signal in onc ~~~f d~ steps as p~rt
CIEC-~4 97 1!1:15 FROM: CA 0222590l 997-l2-24 ~~ ~ 32 84~3 Pf~iE:14
D~32~ R~a~d~ odG~ nuolofT~iv~u~d~ wu~b55lelc~ ~sloA~o~ n4l~e1w4rlL
of the imple"~cn-ation of the pre~ent invention. The ~n~unt of ~tte ~ l~ion provided by step
attPn~ or 3 30a is controlled by ~ binary wor~ at its control input 3 31 a ~rom microprocessor
210 Microproce~sor ~10 controls the settin~6 of ~tep ~nenu~o-s 330a. 33ûb and 336
respon~ive to the AGC ~ain con~rol signals received from ~SP 117 as previously descnbed.
S This assuJes that the power level of all teleph~ny signals r~ceivéd by RASP 117 from oll RA~s
218 A-i are w~thin the rel~tively narTow ran~e ar,c e~ ~P~ie ta RASP l l 7
The gain tone and leJephony si~nals oulput ~om step attenu~tor 330a are input tomi~er 33~a along with ~ fixed frequency s om local o~ or 333a Mixer 33Za is the
10 secDnd ofthe aforementioned tw~ heterodyning sta~es However, the ~equency of local
os(~ At~r 333B iS different from the frequency of loc~l oscillator 333b l'he result is that the
~rrier frequency of the telephon)~ signal output ~om n-ixer 332a is different than the carrier
frequeney ~utput from mixer ~32b
l 5 The lelephony signals received by prirllaly antcnn~ 321 ~nd divorsi~y ~nt~nna 322, each
now at ~ different carrier frequeney, ~nd the ~ain tone si~nal combined therewith, are
c~mbined into one composite signal by co~nt r-- 334. The colnbined signals are first ~Itered
by band pass filter and ~mplifier 3~ and then input to step ~ttenu~tor 336 to ~ive a fin31
adj-~stment to the ~i~nal level of these combined signals Similar to the op~ration of the
~0 previously des~r~bed step attenuators, this digit~ly controlled atte~uator 33~ is set by
microprocessor 2 l 0 r~sponsiYe to a ~ain contr~l signal received from remote RASP 112 as
part of the novel ~,ain control operation
The freqllency ml~lt~ x~d telephony signals o~tput ~m step atte~ tor 336 are input
25 to si~n~l combiner 3~? which has a second input fron~ control ~i~nal oscillator 338. The
~requency of Gontrul signal oscill~tor 338 is controlled by B bin~ry sigr~l oll control leads 338a
fronl n~icroprocessor ~10 tO set the ~equency of the ~scillato~ RASP 1 1~ is the ori~in ~om
which a conlrol si~nal is received to set ~he frequency o~control signal oseillator 338 The
EC-2~ ~7 14:1~ F~0~ 0~ 5-Z167 TO:~13 232 8~4~ P~E-15
CA 02225901 1997-12-24
~6 - R~ C~oll~ Ouin C~l ~T~I~rU~dT~l~C~w~'~h~Tol~h~TdA~b~d~wk
frequency chosen is tO fall withln Ihe b~nd of frequ~nries used for the telephony si~nals
received via the prirnary and the diversity ante-ulas
Pesror~ e lo different control si~nals received ~om RASP 117, microprocesso~ 210S (FiE~ure 2) sends signals on control inputs 338a. T} ese nucr~processor 210 signals cause
contr~l si~nal oscillator 3~8 to produce ~n info~naticln ~ignal. The inforrnation sienal indicates
~arious inforn~atlon about ~ 218, but particul~rly inel~.di~e the settin~s of step anenllato~s
330a, 330b and 336, to RASP 117 as part ofthe novel giin control operation. RASP 117 uses
~his information tO l~oep an upd~t~d status regar.li~ each of the RAD61 18 a-i
The output ~nm comhiner 337 now has m~l.tiple teiephony and gain tone si6nals
fJequency multiplexed to be re~umed via bro~ d network 112 ~o RASP 117. The signals
are the telephony si~nali rçceived by ~ennas 321 and 322, the gJin tone si~ln~ sed ~s part of
the present invention, and ~he system information ~i~nal output frorn control si~nal oscill?tor
15 33B This 1;equency mllkiple~ed signal output ~om comt,.j~r 337 is inpLlt to band pass filter
and amplifier 33~ ta amp}if~ the signal and to remove any exlr~ne~us si~nals befc~re the si~nal
is ~ pled to bro~d~and distributi~n network 112 and sent to RASP I 17 for proee~cin~ In
addiIion~ per tt~e teachin~ of the present invention, the signal power level of the telephony
5i~11is such that when i~ is re,~eived at ~SP 117 il is within the relatiYely narrow ranBe
O acceytable to RASP 1 17
Iransfor~ner ~nd coupler 340 is used to ~ouple the frequency multiplexed si~nalsdescri~ed in the l~s~ para~raph to broadband distriblnion network 112 The tlansforrner i~ an
impedrnce rnatchin~ r~sfomler ha~ring 50 otun pnmary and 75 ohm secondary windin~s
5 When broa~b~nd distrib~tion network 1 1 ~ uses c~acial cable, the secondary winding of
transformer 340 is wire~l in ~ries w~th the center conductor ofthe v~deo distr~buti~n coa~ial
cable As previously descnbed, RAI:~ ~18 han~ s from the couual cabling of the broadband
[~EC-24 97 l4:lo FRCIM: CA 0222 5 90 1 1997-12-24 Tl~:bl-3 ,32 8~40 P~GE:lb
P43~6 - R~m~ ConUoll~ /:3~ C~ntrol C~ cr U~d To l~on~ Wir~lc~ r.l.ph~ 1 O A ~ nd Nctwa~k
distrib~tion net~40rk 112 to ~ch it is COMe~ted. In other appiicd~ions~ such ~s with fiber
opti¢ cable, other well known frequency conversion and si~nal e,ollplinQ techniques are used.
In Fi~ure 4 is shown a block cliagram of the circuitry in RASP 1 17 th~t is used ~o
5 monitor the ~ain tone m~xed w~th teleph~ny and conlrol signAI$ received by R~SP 117 from all
RA~ I la a~ bro~b~nd distnbuti~n network 112 There are three inpuIs shown to RF
swit&h 410, desl~ ~ed A, E~ and C Each of these inputs is connecte~l to receive si~nsls from
RA~s I 18 oll one se~tor of broadband distribulion network I 12 All RADs I l B on one seclor
carr~r telephony si~~nals ar ~I ffrsl camer fiequency Thus, input A will receive tolephony si~nals
10 that have ~ first carrier firequ~ncy, input E~ will r~cei~e teleph~ny si~nals that ha~e a secon~
carrier ~equency, and input C will ~ceive telephony si~nal~ that h~e a third carrier fre4uency
ThLIs, with reference to Figure I as ~n example, RA~s 1 18 a-c may all be on one sector and
their car~ier signal i~ connecte~ to input A of the circuit in Figure 4, R~Ds 1 18 d-f may all be
on ~ second seetor Bnd their ~arr~er signal is connected to input E~ of the circuit in Figure 4, and
5 RADs I 1~ i may aîl be on a lhird seGtor and their carrier signal ls connecteJ t~ input ~ of lhe
circ~it in Figure 4 In addition. all the RADs 118 in each sector can simultaneously huidle
multiple calls and additional sec~or~ are defined to handle ~diti~nal traffic. If additional
wireless telephony traffic must be handl~d, and m~re than three sectors are required, an
additional R~SP 1 17 must be plovid~d, and some R~s 1 18 mu&t be re-allocated ~o fùnction
o with the addition~ SP I 17
To p~ovide ~i~nals to the ~, B and C inputs, RASP CilCUit 208 has receiver circ-Jit~y
c~lMecte~ to each of the three inputs that re~eives telephony and control si~nals transmmed
o~ver br~a~b~nd distr~buti~n netw~rk 112 fiom RADs 11~. The re~eiver circuits ~re not
2 5 shown, buI each c~mprises ~n input filter followed by a Si~ llhl divider that applies ~ portion of
t~e received siundl lo th~ A, B and C inputs uf the R~SP 117 circuit sh~wn in Figure 4
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[~EC-24 ~7 1~:17 FF~0~1: CA 0222590l-l997-l2-24 TCI:~13 ~2 8'~413 P~IGE:17
P43~6 - R~no~ C uluollcd Ci~in CMItral 1~ Trsn~ci vn Li~led Tt~ Imcr~ll,ccl Wuele~ Telq~h~ A E~ro~db~ ~el~t~
Switeh 410 is an RF s~t~h that i5 periodically operated by microproces60r 418 toconnect indi~idusl ones of inputs A, ~ and C to the remainder of the circuitry in Figure 4.
Thus, the poltion ~f circuitry p~st ~witch 410 has input theretol on an indiv~dual basis, the
rnulliplexed telephuny si~nals ~om all }~Ds 118 within a ~ector to which it is connected at
each mornent in time The telephony si~nal froln each RAD 1 I R has ~ spread spectn rn~
digicized t~310phony 6~nal and the an~ ain tane 6i~na]. The received c~mposite signal frorn
all RADs 1 18 within a sector is first amplified by P~nrlifier 411 an~i then input to rn~xer 41'~
alon~ with the o~tput firom IDC~I ~scill~tnr 413. The stuldard heterodyning process of mixer
41~ o produces a number of spurio~ls si~nals. The output of mixe~ ~t 12 ;6 input tD IOW pass
? ~ filter 414 ct~ red around the gain tona which filter6 out most ofthe jpread spectmm signal
and the spunou~ si~nals ~o~ ~h~ mixin~ process. This increases the rel~tivo level of the ~a~n
tone received from each RAD 1 18 with resp~ct to the ren~oinin~ ener~ of the telephony
signal. The resultant ii~nal i5 then ~mrlified at amplifier 415 and input to analog to di~ital
eonverter 4~ ~ to chang~ the remain~ng sien~l to a digital signal which is input to digital ~i~nal
process<~r 417 for filreher p~oce~ing. The fi~rther p. OC~ 3 thal is performed by Jigital si~nal
p~ocessor 417 in dl~ital fonn are the same step~ that have jusl been described for ~he analog
ci.euits in Figl~re 4 The digital si~nal that i~ inpl~t to digit~l signal processor 417 is ~igitally
heterodyned and low pasj fillered to get ~id of moro, but not all of the r~ in~ telephony
5i~nal. The re~ult is that the ~in lone signal n~ has a 30 dB ~un with rcspect to the
O t~lephony si~nal, as compared to the ini~ial p~wer ratios ~enerated by the RADs 118
The ~in tone signal ~om the R~Ds 118 in a soctor is processed ~y microprocessor
~18 and its signal lev~] is compared a~a~nst a st~ndr ~ ~ignal level. ~f the amplitude of the ~~ain
tone signal is toQ 10-4~ mi~:roprocessl~r 418 causes ~ ~ain control si~nal to be sent b~ck over
2 5 distr~bution n~tworl~ 1 12 ta the panicular RAD 118 Ihat has the too lo~ gain tor~e This
control si~n~l has an address pre-fixed thereto which causes nnly the particular R~ 118 to
receive The gain tone conttol signal. Microprocessor ql~ (Figure ~) in the partiGular RAD ] 1
responds to the gain tone con~rol signal and causes a signa1 to ~e output on lead ~GC to
[~EC-2497 14:17 FROI'l: CA o222~905 ~9197 12 24 TO:61;~ 232 ~3'14E~ PfiGE: 18
P432~ Ron~tely Coltu~liod O~ Tr~civa ~IR~ To Im4r~ne~:t w~ Telepw~eY To A 13r~n~ N~two~
circuit 20~ (Figure 3) The AGC si~nal is applied to the digital control inputs of step
attenuators 330a. 3~b and 336 and causes the attetl~3tion they insert in~o the circuit to be
decreased The effect is to i~-cr~asc the power level of the telephony signals ~nd ~ain tone
frorn ~ain tone Oscillalor 34~ that i~ combined with the tel~pho~y si~nal and receiYe¢l by th~
CuCult in Fi~ure 4
lf the amplitude of Ihe gain tone is too high microprocessor 418 causes a gain control
~i~n~l to be sent ~ack over distribution net~;ork 11~ to the partic~ r RA~ that ha~ the too
high ~ain tone. This gain control si~nal has an ~ddress pre~fixed theret~ which c~uses only the
O particular RAD I 18 to receive the 8ain control sign~l. Micr~proc~ssor ~10 (Figure ~) in the
particular R~l) 1 18 responds to ~he gain control 6i~nal and causes a si~ndl ln be output on
lead AGC to cireuit 20~ (Figure 3) The AGC signal is spplied IO the digital c~ntr~l inputs of
step attenuators 3~0~ 0~ and 336 and c~uses the ~ttenuation they insert into the circult to
~e incre~sed The effect is to decrease the power level of the telephony si~nal and ~ain tnn~
1~ transrnitt~d over bro~dband distribution network 112 to R~SP I 17 including the circuit shou~
m Flgure 4
If ~he ~,ain tone si~nal level received and analyzed by the RASP 117 circuil in Fi~ure ~
is eorrect, no ~ain control ~ignals are sent to the pa~ticular RAD 118 to modify tbe setting3 of
2 0 the step anen~ators ~30a, 33~b and 336. As previously descnibed, RAD 1 18 r~ports the
~ettings of its attenuators alld other cir~uits to RASP 11~ using c~ntrol signal oscillator 338.
While what has been dcsc, il~ed hereinabove i8 the preferred embodiment of the ~n
control oper~tion oYer a broadband distribl~tion network, it can bc under5tood that numerous
2 5 ch~~,eg m~y ~e ~nade lo the gain control ~ircuilry in RA~ 21~ and RASP I 17 by tho~ skilled
in Ihe art with~ut departing from the scope of the invention
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