CA2087542A1 - Cell-type telephone system with extended cell - Google Patents
Cell-type telephone system with extended cellInfo
- Publication number
- CA2087542A1 CA2087542A1 CA002087542A CA2087542A CA2087542A1 CA 2087542 A1 CA2087542 A1 CA 2087542A1 CA 002087542 A CA002087542 A CA 002087542A CA 2087542 A CA2087542 A CA 2087542A CA 2087542 A1 CA2087542 A1 CA 2087542A1
- Authority
- CA
- Canada
- Prior art keywords
- cell
- telephone system
- radio station
- base radio
- type telephone
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W84/00—Network topologies
- H04W84/02—Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
- H04W84/10—Small scale networks; Flat hierarchical networks
- H04W84/14—WLL [Wireless Local Loop]; RLL [Radio Local Loop]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
A cell-type telephone system having an extended cell, particularly designed to be used in rural areas is provided, comprising a commutation and control unit (CCC) connected to the national telephone network (RNT) and in communication with several cells, each cell being provided with a receiving and retransmitting base radio station (ERB) comprised of a tower and an antenna array, said tower being preferably of great size and constructed on an elevated site and having high power antennas in order to cover a great area, and a plurality of fixed terminal stations (ETF), each said fixed terminal station (ETF) being provided with a high detection power directional antenna coupled to a transreceiver to make out a subscriber's terminal.
Description
WO ~/21215 2 ~ 8 7 ~ ~ 2 "CELL-TYPE TELEP~ONE SYSTE~ WITK rXTENDED CELL"
Background of the Invention Field of the lnvention The present Inventian gener~lly relates ro cell-type tclepnonc systems ~nd. mor~ spcclfically, to ~ cell-type ~ lcphone system having an ex-en~e~ cell which i~
particul~rly suita~le for use in rural areas.
~cscription of thc Prior Ar-Generally, the pro~L~ion of an efficient telophon~ system for ~ural areas poses a numoer of problemc, ~mong whicn are :
(1) low papula~ian ~onsity due ~o natural disperslon of peoplo;
~ ii) great ~is~ances -o be cove~e~ wnic~
practically ~r~ng a~out expenslvn ~mplemencae~on of a ca~le telephone network servin~ all prospectlve use~s; and ~ iil) d~fficuity ~ stretching and maincain~n~
telephane netwar~ ca~les. ~n vLew of ~eographlc profiles.
ln vlew ~f s~ch difriculCies e~ere ~s. Lnter al~a, a greae een~ency towar~s e~e ~se of ~adioeel pn~ny fo~
the supply of telecommunicat~on eo ~ural areas.
Tlplcally, a ~u~al ~a~i~telephone ¢y~Cem such 3 the one prcsently ln ~se comp~ses interconnece~n~ small v111ages ar settlemene~ ~nrougn ra~ioeelepnony an~. ae g1ven s1te, conne~eln~ 3~ a~ioeelephone sy~eem eo ene national telecommunicatLcn necwo~.
Th~s solutlon~ ~owe~e~, apare from noc ~eten~n~
all prospectlv~ u~e~ lso ?~esene. ~^rlou~ p~e~Lc~mene~
malnly rel~eed tO e~e nl~nly e~pen~Lve ~nsCallseLon of ene ~0 whole lnfra~truccu~e ~a~L~e~ ve~y ~m~ll v~L~a~ c~
seetlement and tne compLec~ t ~o~ of p~ cy ~n tne communlcation, ~nce anyone m~ inC-~epG B ~ven c~ll Lf ne ls provlde~ wlcn a ~u~e~}e ^~uLpm~ne.
Alm~ng tO ~ol~e ~ ove-~sc~s3e~ p~o~lem~ an~
~5 pro~l~e ~n efficienc eelecommun~c3t~0n ~ysCem for r~ral areas, It was proposed eo use a cel1~eype eelephone ~yster.:.
Br~efly, a c~lL-Cyp~ CeL~pnone s~em ~g 3 raalotelep~one ~vstem in wnicn Ch~ dvsil~ale f.~3unnc~ ~an~
Background of the Invention Field of the lnvention The present Inventian gener~lly relates ro cell-type tclepnonc systems ~nd. mor~ spcclfically, to ~ cell-type ~ lcphone system having an ex-en~e~ cell which i~
particul~rly suita~le for use in rural areas.
~cscription of thc Prior Ar-Generally, the pro~L~ion of an efficient telophon~ system for ~ural areas poses a numoer of problemc, ~mong whicn are :
(1) low papula~ian ~onsity due ~o natural disperslon of peoplo;
~ ii) great ~is~ances -o be cove~e~ wnic~
practically ~r~ng a~out expenslvn ~mplemencae~on of a ca~le telephone network servin~ all prospectlve use~s; and ~ iil) d~fficuity ~ stretching and maincain~n~
telephane netwar~ ca~les. ~n vLew of ~eographlc profiles.
ln vlew ~f s~ch difriculCies e~ere ~s. Lnter al~a, a greae een~ency towar~s e~e ~se of ~adioeel pn~ny fo~
the supply of telecommunicat~on eo ~ural areas.
Tlplcally, a ~u~al ~a~i~telephone ¢y~Cem such 3 the one prcsently ln ~se comp~ses interconnece~n~ small v111ages ar settlemene~ ~nrougn ra~ioeelepnony an~. ae g1ven s1te, conne~eln~ 3~ a~ioeelephone sy~eem eo ene national telecommunicatLcn necwo~.
Th~s solutlon~ ~owe~e~, apare from noc ~eten~n~
all prospectlv~ u~e~ lso ?~esene. ~^rlou~ p~e~Lc~mene~
malnly rel~eed tO e~e nl~nly e~pen~Lve ~nsCallseLon of ene ~0 whole lnfra~truccu~e ~a~L~e~ ve~y ~m~ll v~L~a~ c~
seetlement and tne compLec~ t ~o~ of p~ cy ~n tne communlcation, ~nce anyone m~ inC-~epG B ~ven c~ll Lf ne ls provlde~ wlcn a ~u~e~}e ^~uLpm~ne.
Alm~ng tO ~ol~e ~ ove-~sc~s3e~ p~o~lem~ an~
~5 pro~l~e ~n efficienc eelecommun~c3t~0n ~ysCem for r~ral areas, It was proposed eo use a cel1~eype eelephone ~yster.:.
Br~efly, a c~lL-Cyp~ CeL~pnone s~em ~g 3 raalotelep~one ~vstem in wnicn Ch~ dvsil~ale f.~3unnc~ ~an~
2 ~ 8 ~ 2 PCTIBR92/~WK~
;. ''' ~
is divided into ~roups of frecucinc-es diisignated as cells, which ce~ls are geographically distrisu~e~ in such a way that groups of frequencies from twa adj~cent cells always differ from each othcir in ordcir ~o -l_minate any possible interference in the communication.
Similarly, the f-ci~uonc~es in a given group of frequencies are only rep-~~ed when ~:ne distancci ~etween Che cells is enou~h t~:o assure t'nat :i~.ere ~ no morci be any interferonce betwecin such f-~i~uenc.~ic in a c~ill and ~-te same froquencles used in anothor ^~
Sincci oV~ t~ it~ Wi'i~''i a ~,_'i-i-, rj-"'i?
of frequencies, it is p~ssi~ile tCi perform or conduc~ a cer~ain numcer ~f simul'ai-ie3u~ c~-r~ri-,a~~3ns. Yowevci~, a~ -`ho areas coverod ~y each cei; ".~ sen~ differen~ .e!e?nono trafflc loads, the dimensian cif ChQ cslls may chan3e in accordance wlth the fluctuat~on of said telephone t~affic load. In other words, dependin~ on ~he traffic loa~. c~e si~e of the cell may have a radius ~etweon approximatsly l and km ~one and five kilomeeers~.
Thou~ the smallest siz~ of the cell is limiced by the presently avsila~le ~oc;nnot~gy to a r3dlus of approx~mately ' km ~one ~ meter`l. since ~elow s~c~ lim~t enere may arl3e lntsrfsrenoo pro~lnms whicn can no~ ~e ~olve~
w~thi~ eh~ g~oup of f~e~n_ios ~o~. th~ hi3h~C'. ~ of ~n~
cell now depen~s on th~ usor'~ ro~oiv~r dee~etiQn ~pa_i r~, ene ~ntènn~ of wn~ch of~ n ~ee~en~ low ~o~oc~l~n power.
Thus, the aver~e size of c~Ll~ n e~ pr~onel~ ~n~wn ~
type telepnone syst~ms incorpor~e~ i w~ehin ~ ^~n~e of S
to 15 ~m ( flve to f~fe^en '~iomn~er-~.
~0 T~p~ o~ lL-~.y~n ~ nn !~y9tem compr~3es:
~ mm~ n~ n.
c~nne~t~ th~o~h ~a~ n~ n~ ph~ n~ ~W~ n~
Ln commun~cation w~e~ .~evoJr~l e~o11~7 a~ io wa~os;
~5 ~ reCelv~n~ ~n`~ reGransmiccin~ o~e radio ~e~tion (ERB~ ~n e~èry cel~ m~sing a ~,~wor an~ an antenna array: and (lLil a pll~L~ L~ m~ n-C
W092/21215 3 2 ~ 8 7 ~ ~ 2 PCT/BR92/nWK~
O
~rovided with low detection power ~ntennas and able to establish radiofrequency communicatian with every b~se r~dio st~tion r~ferred to in the precedin~ paragrapn.
In view of tho ~ov~-discussed problema- related to traffic load, cell siz_ and interferenca between f~e~uencies, con~ention~l ce~l-ty~e telephone sys~ems. in their ~se r~dio stationC. use l~w power antennas ~ssemsla~
on rel~tiveiy low towers prefer3~ly conatructod on not ~oo elevated sites, in order o avai i a_ much as pOSa~bl any interference ~etween the fro~uenc ~a of each grou~.
Summary of ~he Inven~l~r.
Thus, there is ~ need to provide an efficieQ~
telephona system for rur3l ~rO~ ;-. c-. i. one af ~~.e e~e-~C
of the present invention.
Anaeher o~Jac ~f ~he ?~esent Lnvencion is tne provlsion of such an efficient tolep~one system Sor rural areas whlch may 3erve all prospec~iva users.
An addition~l o~ec~ of the p~esent inveneion is the provlsion of such an efficien~ radiotelephone syseem for 20 ru~al ~ress wnlcn doec not p~es~nt the a~ovo ~iscussed pro~lems relsted to hi~hlv expensive inseall~on ~n~
difflcult ca~le seretchin3 ~nd ma~n~enanca.
Stlll anot~e~ o~ece of tne presenc invention is tne prov1s1on of such ~ tolophono Cystem for ~u~al ~n3s 25 wnicn does not present er~ ovo-~iscusse~ pt~o~lams ~elato~
to expen~l~^ lmplemenc~c~on of infra3truceuro for conventlon~l ~ural radioeelep~ony.
One addieional o~ece oC Cha inven~lon is ehe pro~lslon of suc~ a t~lepnone ~y~e m for rural areas whLcn does noe pre~ene en~ ~a~ u~e~ ~o~lem~ rel~ee~ eo 1~CK
of prlv~cy ln the communLc~eLon.
Accor~ln~ eo 5~e preS~Qe ~ nveneion, ;a~ accs are fulfllled Gv tn~ pra~ L~n oC a call-eypa ra~io-~lep~one syscem p~rc~cularly ~e~inei ~ ~a t~ed in rtl~al areag, ~5 cnaracterlza~ ~y compr~in~ a a~m~taeion an~ conerQl unit connected to tne natLan~l ~elaonone netwoF~ an~ in communlcatlon wltn ~evaral caLl~: a r a ~v~ng and retran~mittin~ ba~e radi~ ~t~e:~n n e~er~ nll. aa~d ~3~a W092/2l215 ~ 4 PcT/BR9~WKK
~, . . . ..
20%75g2 ~
radio station being comprisea o, ~ ~ower and an antenna array, said tower being pr~f~ra~ly a large one and constructed on an elova~e~ site an~ provided with high power antennas in ordar to cover 3 gre~r ~rea; and a plurality of fixed tarminal stations distribut-d wl:nin the reach of eacA
a~ove-m~ntioned ~ase r~dio staeia~, each fixed torminal station ~eing provided with 3 ;~igh deteceion power directional antenn3 coupl~td ~s sama ~r.ich is ~irecse~ towards said baset radio station.
According to ~ha pre~n- invention, the base radio s~3tion 3ntann~ powa- nc~a3_ct, ~heir ins~a.la~io., on an elevated site and tha lncraase in rhe detecrion car,acity of fixed termir,al s;atior., wn.e~. 3~a row ccuple~ ~o a ;n.~h det~ctlon power ~irac~iorai an~-nna -~hi_h is ~irnc~e~ s~wa~C
lS t~e ~ase radio station, maka ,- p~ssi~le to increasa ehe si~ct of each individual cell to a ra~ius of approxim~tnly 60 km (slxty kilometers~ on a fla- surfaca, pracrically qua~ruplicating the radius of ehe iarg~st cells in cnll-type ra~lotelephone syscems of Che prio~ are.
Thus, ~y inve~t~ng the ~asic princlplas ~f call-type ra~lotelephone syseems of e~e prior art, ~.~o si~a of each cell may ~e extaertde~ C~ ~ne naCu~3L ga~gr~ohical ~oundarles wiehout po~in~ any inc_r fnranc_ pro~lnm ~aeween groups of fr~aqu~ncies of ewo ~ a~ar.~
Addleionally an~ ^anerar~ t.o wh~t. ~ r~ln~ ~.n conventlonal c~ typ~ ra~iotai~aphona ~y~tAmS~ th~a ~as~a -~io ~e~eion aneenna power incr~sa ~o~s not ~mply 3ny interferenc~ pro~lem, sLnce en~ e 3n~ iis~ Q~on of cells ln addiCion ea tne low ~ p~or.~ ~r~fri~ loa~ norm~lly oG~erve~ in rural ~re~3 el~m~na-e ~.n~s ~in~ ef ~ro~ n~~, ~rlef Descrlption o~ Dr~win~s Tne pr^~ent ~n~n-ior. wi~ n~ hara n after in Rre~ter ~eea~} wie~ r~rerence ~ ~he non L`~ ve em~odiment ehercof ~h~wn ir. ~.h~ ~eeached ~r~ n~ ~s ~n ex~mple, in wn~cn :
Figure L ls ~ sc~am~ r~?r~en~.~e~n ~f ~ ~oll-type radlotelepnone ~ystam ~c_i~r~i.n~ t~ eh~ prosen~ nvanel3n snOwing a central~o~ conf i~r~e~?.~ n~
WO92~21215 5 2 ~ 8 7 ~ 4 2 PCT/B W2/~N~
. .. ..
Figure 2 is ~ schem~ c r~rasentation of a cell-type radiotelephone system accordin~ eo the present invention showing ~ decentr31ized confi~ur~tion.
~escription of the Prefarr~d ~mbodi~ent With referenco now more particularly to the dr~win~s, 3 c~ typ~ r~dio~eleonano system havin~ an extended cell ~cco~din~ eo the presen~ invention is shown in Figures 1 ~nd 2, The syse m comprises, basically, commutation and control uni~ CC~. ~ ?lurality of ~ase r3dio qtations E~B and a plurality of fixed cerminal stations ETF.
The commuta~ic-. ~n~ .o ~ni~ C~C ic a ii~ ~31 electronic commutation e~uipmen~ which uses ~istributed processing and stored pra~r3m c3n~~0 ape~ati~nal eechni~ue-c to control ~as~ radio s,ations _~3 and fix~d :erminai stàtlons ETF in or~er to provi~e an efficient communication system.
Prsfera~ly, t~e cammueaelon and control unlt CCC
19 of ~ type known in e~e seate a~ tne art whic~ is a~le Co commutàte volce and daea c~rcuitry ~nd perform analag~ itsl ~A/~) and dlgltal-analog (D/A~ conversions and tnus it shall not be descrl~ed ln details ~elaw. T~e ob~ectiv_ of tne commutation and control unie CC~ ~ 3 eo provi~e an interface ~etween ~ase radio stat~ons E~8 in t~e ce;l-type ra~lotelephone 3yseem nav~n~ an axc~n~e~ cell ~cc3r~n~ eo the present invenelon an~ cna naeianal t~laphone natwor~
tnrou~n RNT caGlè~. Sai~ ~nte~face may ~e ~oen local and trafflc ~epen~ent.
Thus, enrou~ C~a comm~tae~on ~nd con~rQ~ unlt CCC i t 19 poggl~l~ tO affor~ an ~tom~t~e ineerc~nnc^tion ~etw~en a flx~d e~m~n~l sc~e~on ~ an~ a cele~h~r. central 0tatlon of both naelonal ~n~ ~nt^~n~cionaL ~xtene.
The commueae~on an~ conC,ol un~t C~ is 3a ically comp~se~ of a m~ln cone~ol un~C CCP and a commutatian unlt CC. The funceion of e~e m~n cont~ol ~n~t CCP i5 eo eJta~lish an interfaca ~eeween e~e ~pe~rato~ 3ni th~ syscem.
for wnlcn purpose it is pro~e~ w~C~ a ~ata ~ank for tne whole system, and allow ~Q~ e~ perfo~m3nc~ o~ s~seem managemene an~ maint~nan~o func~.3ns ~ro~gh prosocol~
W092/21215 ~~ 6 PCT/BR92/~WXK
208~42 ~
designed for man-machine communica-ion. On the other han~.
the objective of the commutation ~nie CC is to control call processin~, monitor base radio sta~ion ERB equipment and perform management and mainrenanc~ fu~o~ionc commencA~ ei~her at peripheral equipment in the main con~rol unit CCP or at ;
local t~rminal interface o~ ~h~ c~m~u~3eion uni~ CC ~s_lf.
Additionally, the cammut~tion uni~ CC ic responsi~le for all call connec-.ion and disconnec~ion phases including signaling, supe~vision. commutation and a}loca-l~n of radlofrequency channels.
The oase ra~lo ;ba:i3ns --Ra which ~efiî.e individual cells are conn~c~e~ ~o ~he commutation an~ conerol unlt CCC Oy means of a four w~re analcg or ~i~i~al ci^.ann-!.
the communicatlon between ce~ls oa~n3 carried ou~ -hrou3n radlofrequency, PCM ~eam or o?~ica} f~berâ, in ~ccor~anco w~th the speclfication of eacn pro~ecC. ~n such a communlcatlon system eher~ is a ~oice and data flow. ~owever wlth a spec~Slc data l~n~ for Qen~ing and rec~iving conc~ol.
supervl~lon and lnformativa me~sa~es.
The maln funceion of each base radio stat~on ERB
19 to lnterface local su~scr i~ers wieh one anoeho~ snd/or interface local â~cacr~e~s w~th na~ional telephonn nerwork RN~ su~scrl~ers.
For r.hlS purpase eh~ ~ase ra~io ~eac.on E~B
snoul~ preferaoly compr~s~ ab ~ CwO racks ~n~i~n~tea as radiofrequency and ord~n~ nes w`n~^n ara ~onnn~ee~ ~s ewo omnldlrectlonal antennas as~em~la~ at ~ suita~le heL~e wnLcn may affor~ a complete covera~e w~tn~n an ~varag~ r3~us of ~0 km (slxty kllometer~ a~oun~ e~e ~e ~a~o seat/oQ ~3. ~nus conflguraeln~ an excen~e~ c~Ll.
~ no commun~c~e~on of ~n~ oa~e radlQ ~cacion -~B
w~th flxed eerm~nal ~cac~on~ r~ i~ c~rrl~ ou `nrou~n raalofrequency c~anne~ w~Lch u~ sCan~rd proc~cols ~s~
sendln~ ~nd recelv~ng concr~l ~aea ~n!~ ~o~ca ~nals~ such commun~cation ~eing car~^a ouc e~rou3~ fr~aquenc~ mo~ulaei~n ln a radlo system operacing wiC~n Che ~00 ~2 ~n~n. ~n other words, t~e communLcae~on ~ecwe~n C~a ~sa r3~ eaelOn ERB and a g~ven fixaa C~rmin~l ~caci~n ~T~ 3rrL~ ~u-WO92/21215 7 PCTIBR92/~HXK
~ 2~7~-~2 through control and voice channels.
~ he control ch~nnel supplios data between the ~ase radio station ER~ contrcller 3nd the fixed terminal stations ETF of each cell, ~nd i ta functions aro to: send information to fixed torminal sta; ans and monitor their registers, inclu~ing messa~o regis~o- parameters and tho frequency transmitte~ to fixe~ ~erminai stations; control st~rted and completed calls; and datormine the avai~abil7ty of fixed terminal stations ~o~ raceiving a call.
The voice channel pravides an audio interfaco ~etween fixed torminal sta iona ~ and the commuta ior. uri~
CC, Through the volca channo' are 30nt the audio supe~ision tone TSA and Cho signalins -ono TS.
The voic~ channels 3~ 'O supply the 3udio li~k and signal converslon to 3~s~.3ir. ehe call; ~oni~o~ -ha radlofrequency slgn~l intensity; monitor ehe fixed ~armina}
statlon for access of facilities to subsc~i~er: and dlsconnect the audlo super~ision eone ~SA during the c~ll.
The flxed terminal scacions ETF comp~e a low power transrecelver coupled eo a ~i~actional antenn~ whlc~ ~s dlrected towar~ ene ~ase ~a~lo seaeion and is ~lso provided wlth the s~bscri~ers~ te~mlnaL. whic~ L5 fixed and ~f ~peciai ~nterest to the cell-ty~c te~aphone ~ystem of th~ pfesene ~nventlon.
2S ~he oper~Clon o~ tne ceL!-type e lnp~one ~yseem wlth exeen~ed cell accor~n~ e3 e~ p~ sene in~ene.~n ~all ~e descrl~e~ nereln as foLlows w~e~ refsrence eo e~ree ~in~s of call~ ~ one call f~o~ a f~xe~ e~mlnal ~e~tLon '~F eo t~e natlon~1 telepnone neewor~ RNT: on~ call tram e~e nac~ona}
telepnone networ~ RTN to ~ f~x ~ ~erminal st~elon _TF; and on~ call from a flxe~ Ce~m~n~L ~e~e~an ETF eo ~notner f~xed t~rminal station TF.
In tne call from 3 f~e~ Cermln~l ~t~eion TF to the nacional telep~one neewor~ RTN. ~nen e~e f~xe~ ee~minal seation ETF 3u~scri~er starC~ e~- call, Che ~ase radlo staclon ERB r~cel~e~ and L~eneL~es t~e re~uesc ~roug~ the control cnannel and ~en~ sam~ e~ e~e commueaG i on unie CC
to~et`ner w1tn all otner ~nformaci~n rAqui~e~ e~ ~mpLete cne WO92/21215 2 ~ g ~ ~ 2 PCT/BK92/0X~
call, ~iz: the subscriber's ~-laphone number, the subscriber's se~ial number and the diaied number.
Th~ commutation unit CC ~hen selects a vacant channel tO b~ used in the eall 3nd signals the base radio station ERB to instruct the Lixe~ ~erminal station ETF to use the selectad channel. Addi~io~al~-f, ~ha commutation unit CC
carries out the v~lldation of ~he dialed numbers to assure that the su~scriber can then make ~he call an~ to ~etermine the required route as well aâ :h_ ~ype of call.
1~ The connection estaDiishe~ throu~h the digiea commu~ation the commutaTian uni- C_u -^omplatas the ~oica :in'~
from the ~ixed terminal s~ati3n _T~ and the base r-~io station ERB with the nationai 'ei~phone network ~TN.
Alte~natlvel~, in ~r~e~ ~o p~ovide a low cost iS route, the call may ~e rû~e~ ~y c~e ~ommutaCion un~C CC f~om the cell-type telephone system to another commutation unie CC
ln another cell-type tele~hone system to then ~each ehe natlonal telephone netwo~ RT~ acc~ding to the ~ecent~al~ed sy3tem shown in Figure 2.
When t~e call is cQmplete~, any of cne pareins who dlsconnect the commutation unit CC ~eleases all ~esou~ces used ln the call. The ~e~iseer co~esponding Co ~ei~ call is then t~ansmlteed eo the ~in conC~ol unie CCP to ~e use~
su~sequently in th~ p~oducti~n of ~ho ratin~ taoe ~nd t~af~ic analy~ls.
When a call is m~e ~~~m. tne naeiona~ ~olephon~
networ~ RNT to a fixe~ CermLnal seaei~n ~T~. C~ n~C~nsl eelephone necwor~ RTN acces3es ~ Cr~n~ in t~e c3mmuCaion and conerol unlt CCC an~, tn~ou~n ~ ital swiCc~, san~s cne correspondlng inormaclve ~igi~ e~ e~^ fi~a~ e~rmina: seaei3n ETF suCscr~er.
T~ commueac~on an~ c~ne~31 un~t ~ earrias out tne validatlon an~ d~LC Cr~n~l~Cion an~ LnsCru~ eno ~ase ~adlo qtatlon ER3 corre~pon~Ln~ to Che 1~caCa~ area co actlvaee, ~hrou~ e~e control e~nn~}, t~e f~e~ ~ermin~l statlon ETF selected, in ~r~e. C~ ena~l~ iC~ ~inl~c~ge wicn Che nat~onal telept~one network RTN.
~ ~e ~ L ;~ ~ ~ a ~ !. X ~. ~J
WO92/21215 9 PCT/BR92/OWK~ ~
`~2~7~2 terminal st~tion ETF through the control channel and, when the latter answers the call, tha commutation unit CC is instructed by the ~ase radio station E~B to select the vacant voice channel to ~e used in the cal}. The fixed terminal station ETF is informed ~bout the s~lacted channel by the bas~ radio st~tion ER3, ~nd th~ commutation unit CC connects the correspondin~ di~ieal swiCch wnen the ~ixea ~erminal ~tation ETF is ready to recaive the c~ll.
Thus, the base r~dio sta~on ERB is inst~ucted to alert the su~scriber, and the tele?hone set in the fixed termlnal s~at~on E~B starts o rin~. W~en the fixed earmina~
statlon subscrlbe ~nswers ~he call, ~he voice link in ehe natlonal ta7ephane netwa~k ~T~ am?ieeed.
Again, when the cali is completad, 3ny of thA
parties who disconnec~ tne commueae~on unit CC rele3ses al~
r~sourses used ln the call an~ generates a register correspondlng to sald cal}, which register is sent ~o ehe maln control unlt CCP to ~e u~e~ su~seQuently in the productlon af ene rating tape and trsff~c analysis.
wnen a call is ma~e ~rom a fixed termLnal seation ETF to anotner flxed term~nal ~tat~on ESF, wnen 3 f~xe~
su~scrlber start~ tne cal!, it ~s ~rocassed as aDove une~l the dlglt translatlon sCep. ~t e~is point, C~a co~mucaC~on unlt. CC datermlnes t~rough ~es ~a~a ~ank if ena calL was 2S dlreceed toward8 anotner f~xed eermlnal station ETF.
~ cn~s oeher ~xe~ e~ninai staeL~n ~ i9 ~crved ~y the same commutatLon un~ t ~C, ene call 13 pro~essed ln a regular way. On the ~ontrar~. Lf et~e suoscr~er i9 served by anoe~er commut~t~on ~nLe CC, a vacane e~un~ ls ~es~gnatc~ for the call an~ ~e L3 ensn proc~3~ f~xed eermlnal ~taeion ETF eo a ~iK~ e~rminal ~taelon ~F cype call.
The ~uDscr~ call~ s locate~ ~n~, ~y answerlng tne eall, a voLc~ ~annel Ls ~eSlgnar~e~ eo e~ea~ h the volce llnk ~eeween ehe 3tatlons. ~ai~ voLC~
llnk 14 esta~lls~ed ~esre~ng fr~m t~e comm~taclon unle CC of the base radlo station E~3 eo~$pondLn~ e3 e~e fLxe~
~ermlnal statLon ETF wn~ch ~L~inat~ th~ ~al1 e~ eh~
WO92/21215 ~1l; lO PCT/BR92/~WXK
2~g~2 0 commu~ation unit CC in th~ oase r~o station ERB of tnn fixed terminal station ETF ~ime~ at.
When ~ call is compl-t~ ny of the parties who disconnect the commutation un~t CC rel~ases all resourses used in the call and the rn~ist_r corrnsponding tO said call is goneratnd in th~ ori~in ~as- ^ad.o station _R3 ~o bn transmltted to the main contr3l UQie CCP tO be u~e~
subsequently ln the production ~f the rating tape and eraffic analysis.
In thls syseem. ~he calls may be made ehrough a flxed terminal statior. ~. wnor~ ^hn~n is room i~ ehe d~ea bank avallablo for the rog~gto- 0~ calls made by every subscriber.
An importan~ ~e3~r~ n cnll_~y?n ~~nphonn system with extended cnll a__o~r.g ~~ ~e ?resen~ 1nvon~n is the possibility of its ex3ansi3n t~rou~h secto~ng andfor dl~lslon of cells.
Thus, t~roug~ a p~edo~n~~ined pro~ec~. iC ~s possl~le to canfigurate t~e cells roquired for the ~itial coverage of a given area, prec~s~!y d~torminin~ the location and the n~m~er of cell~, and thu3 ~h base radi~ 3cae~ons ERB~ requlred ln Che 3~'~ o~'Vel~. To suppore such trafflc, groups of channeL~ ar~ aLL~cated for 3C~
always proport~ns} eo c~ ma~lLmum e~pact~nd t~a~f~
Hawever, c~e celL-eypo Cel~phone ~yse~m ~ h extended cell of t~e proson' ~n~en~ion, ~ecau~e of 5~n num~er of sucqcrl~er3, t^~Q~ono -r 3f f ~ C loa~ ~n~ ~the~
fac~ors lnclu~n~ topo~rap~ie ones. al~ows for ~ec~r~g an~
dl~l~lon of every cell ~n a sec~n~ ~ea~.
-~0 In tne former c a~ n e~ll iS ~ nto sector~ w~ic~ e~en be~n co ~ w~c~ ~y 5~e ~ommueasion and control unit C~C a~ now cell~ ~n~, ~n sne l~cer _a~e, t~e cell eo ~e ~lvi~ g ic~ e~u_g~ ~y th~
eransmitted power decre~se. ~ em~/ning ~rea ~u~ 3eing covered t,~ a new cell, w~ic~. ~es~!~s ~n ~^ve~l ~Lcrocells lnstead of one macrocell.
T~e invention ~ein~ d~scri~e~. it ~hall ~e understood t~at several mo~ n~ ~n~ v~rl~ ons may ~
W092/21215 11 PCT/BR92/~WXK
2~87~2 made thereto, provided that such mod-f_c tions and variations do nat depart from the spir~t ~n~ scope of the invention as defined in the appended claims.
;. ''' ~
is divided into ~roups of frecucinc-es diisignated as cells, which ce~ls are geographically distrisu~e~ in such a way that groups of frequencies from twa adj~cent cells always differ from each othcir in ordcir ~o -l_minate any possible interference in the communication.
Similarly, the f-ci~uonc~es in a given group of frequencies are only rep-~~ed when ~:ne distancci ~etween Che cells is enou~h t~:o assure t'nat :i~.ere ~ no morci be any interferonce betwecin such f-~i~uenc.~ic in a c~ill and ~-te same froquencles used in anothor ^~
Sincci oV~ t~ it~ Wi'i~''i a ~,_'i-i-, rj-"'i?
of frequencies, it is p~ssi~ile tCi perform or conduc~ a cer~ain numcer ~f simul'ai-ie3u~ c~-r~ri-,a~~3ns. Yowevci~, a~ -`ho areas coverod ~y each cei; ".~ sen~ differen~ .e!e?nono trafflc loads, the dimensian cif ChQ cslls may chan3e in accordance wlth the fluctuat~on of said telephone t~affic load. In other words, dependin~ on ~he traffic loa~. c~e si~e of the cell may have a radius ~etweon approximatsly l and km ~one and five kilomeeers~.
Thou~ the smallest siz~ of the cell is limiced by the presently avsila~le ~oc;nnot~gy to a r3dlus of approx~mately ' km ~one ~ meter`l. since ~elow s~c~ lim~t enere may arl3e lntsrfsrenoo pro~lnms whicn can no~ ~e ~olve~
w~thi~ eh~ g~oup of f~e~n_ios ~o~. th~ hi3h~C'. ~ of ~n~
cell now depen~s on th~ usor'~ ro~oiv~r dee~etiQn ~pa_i r~, ene ~ntènn~ of wn~ch of~ n ~ee~en~ low ~o~oc~l~n power.
Thus, the aver~e size of c~Ll~ n e~ pr~onel~ ~n~wn ~
type telepnone syst~ms incorpor~e~ i w~ehin ~ ^~n~e of S
to 15 ~m ( flve to f~fe^en '~iomn~er-~.
~0 T~p~ o~ lL-~.y~n ~ nn !~y9tem compr~3es:
~ mm~ n~ n.
c~nne~t~ th~o~h ~a~ n~ n~ ph~ n~ ~W~ n~
Ln commun~cation w~e~ .~evoJr~l e~o11~7 a~ io wa~os;
~5 ~ reCelv~n~ ~n`~ reGransmiccin~ o~e radio ~e~tion (ERB~ ~n e~èry cel~ m~sing a ~,~wor an~ an antenna array: and (lLil a pll~L~ L~ m~ n-C
W092/21215 3 2 ~ 8 7 ~ ~ 2 PCT/BR92/nWK~
O
~rovided with low detection power ~ntennas and able to establish radiofrequency communicatian with every b~se r~dio st~tion r~ferred to in the precedin~ paragrapn.
In view of tho ~ov~-discussed problema- related to traffic load, cell siz_ and interferenca between f~e~uencies, con~ention~l ce~l-ty~e telephone sys~ems. in their ~se r~dio stationC. use l~w power antennas ~ssemsla~
on rel~tiveiy low towers prefer3~ly conatructod on not ~oo elevated sites, in order o avai i a_ much as pOSa~bl any interference ~etween the fro~uenc ~a of each grou~.
Summary of ~he Inven~l~r.
Thus, there is ~ need to provide an efficieQ~
telephona system for rur3l ~rO~ ;-. c-. i. one af ~~.e e~e-~C
of the present invention.
Anaeher o~Jac ~f ~he ?~esent Lnvencion is tne provlsion of such an efficient tolep~one system Sor rural areas whlch may 3erve all prospec~iva users.
An addition~l o~ec~ of the p~esent inveneion is the provlsion of such an efficien~ radiotelephone syseem for 20 ru~al ~ress wnlcn doec not p~es~nt the a~ovo ~iscussed pro~lems relsted to hi~hlv expensive inseall~on ~n~
difflcult ca~le seretchin3 ~nd ma~n~enanca.
Stlll anot~e~ o~ece of tne presenc invention is tne prov1s1on of such ~ tolophono Cystem for ~u~al ~n3s 25 wnicn does not present er~ ovo-~iscusse~ pt~o~lams ~elato~
to expen~l~^ lmplemenc~c~on of infra3truceuro for conventlon~l ~ural radioeelep~ony.
One addieional o~ece oC Cha inven~lon is ehe pro~lslon of suc~ a t~lepnone ~y~e m for rural areas whLcn does noe pre~ene en~ ~a~ u~e~ ~o~lem~ rel~ee~ eo 1~CK
of prlv~cy ln the communLc~eLon.
Accor~ln~ eo 5~e preS~Qe ~ nveneion, ;a~ accs are fulfllled Gv tn~ pra~ L~n oC a call-eypa ra~io-~lep~one syscem p~rc~cularly ~e~inei ~ ~a t~ed in rtl~al areag, ~5 cnaracterlza~ ~y compr~in~ a a~m~taeion an~ conerQl unit connected to tne natLan~l ~elaonone netwoF~ an~ in communlcatlon wltn ~evaral caLl~: a r a ~v~ng and retran~mittin~ ba~e radi~ ~t~e:~n n e~er~ nll. aa~d ~3~a W092/2l215 ~ 4 PcT/BR9~WKK
~, . . . ..
20%75g2 ~
radio station being comprisea o, ~ ~ower and an antenna array, said tower being pr~f~ra~ly a large one and constructed on an elova~e~ site an~ provided with high power antennas in ordar to cover 3 gre~r ~rea; and a plurality of fixed tarminal stations distribut-d wl:nin the reach of eacA
a~ove-m~ntioned ~ase r~dio staeia~, each fixed torminal station ~eing provided with 3 ;~igh deteceion power directional antenn3 coupl~td ~s sama ~r.ich is ~irecse~ towards said baset radio station.
According to ~ha pre~n- invention, the base radio s~3tion 3ntann~ powa- nc~a3_ct, ~heir ins~a.la~io., on an elevated site and tha lncraase in rhe detecrion car,acity of fixed termir,al s;atior., wn.e~. 3~a row ccuple~ ~o a ;n.~h det~ctlon power ~irac~iorai an~-nna -~hi_h is ~irnc~e~ s~wa~C
lS t~e ~ase radio station, maka ,- p~ssi~le to increasa ehe si~ct of each individual cell to a ra~ius of approxim~tnly 60 km (slxty kilometers~ on a fla- surfaca, pracrically qua~ruplicating the radius of ehe iarg~st cells in cnll-type ra~lotelephone syscems of Che prio~ are.
Thus, ~y inve~t~ng the ~asic princlplas ~f call-type ra~lotelephone syseems of e~e prior art, ~.~o si~a of each cell may ~e extaertde~ C~ ~ne naCu~3L ga~gr~ohical ~oundarles wiehout po~in~ any inc_r fnranc_ pro~lnm ~aeween groups of fr~aqu~ncies of ewo ~ a~ar.~
Addleionally an~ ^anerar~ t.o wh~t. ~ r~ln~ ~.n conventlonal c~ typ~ ra~iotai~aphona ~y~tAmS~ th~a ~as~a -~io ~e~eion aneenna power incr~sa ~o~s not ~mply 3ny interferenc~ pro~lem, sLnce en~ e 3n~ iis~ Q~on of cells ln addiCion ea tne low ~ p~or.~ ~r~fri~ loa~ norm~lly oG~erve~ in rural ~re~3 el~m~na-e ~.n~s ~in~ ef ~ro~ n~~, ~rlef Descrlption o~ Dr~win~s Tne pr^~ent ~n~n-ior. wi~ n~ hara n after in Rre~ter ~eea~} wie~ r~rerence ~ ~he non L`~ ve em~odiment ehercof ~h~wn ir. ~.h~ ~eeached ~r~ n~ ~s ~n ex~mple, in wn~cn :
Figure L ls ~ sc~am~ r~?r~en~.~e~n ~f ~ ~oll-type radlotelepnone ~ystam ~c_i~r~i.n~ t~ eh~ prosen~ nvanel3n snOwing a central~o~ conf i~r~e~?.~ n~
WO92~21215 5 2 ~ 8 7 ~ 4 2 PCT/B W2/~N~
. .. ..
Figure 2 is ~ schem~ c r~rasentation of a cell-type radiotelephone system accordin~ eo the present invention showing ~ decentr31ized confi~ur~tion.
~escription of the Prefarr~d ~mbodi~ent With referenco now more particularly to the dr~win~s, 3 c~ typ~ r~dio~eleonano system havin~ an extended cell ~cco~din~ eo the presen~ invention is shown in Figures 1 ~nd 2, The syse m comprises, basically, commutation and control uni~ CC~. ~ ?lurality of ~ase r3dio qtations E~B and a plurality of fixed cerminal stations ETF.
The commuta~ic-. ~n~ .o ~ni~ C~C ic a ii~ ~31 electronic commutation e~uipmen~ which uses ~istributed processing and stored pra~r3m c3n~~0 ape~ati~nal eechni~ue-c to control ~as~ radio s,ations _~3 and fix~d :erminai stàtlons ETF in or~er to provi~e an efficient communication system.
Prsfera~ly, t~e cammueaelon and control unlt CCC
19 of ~ type known in e~e seate a~ tne art whic~ is a~le Co commutàte volce and daea c~rcuitry ~nd perform analag~ itsl ~A/~) and dlgltal-analog (D/A~ conversions and tnus it shall not be descrl~ed ln details ~elaw. T~e ob~ectiv_ of tne commutation and control unie CC~ ~ 3 eo provi~e an interface ~etween ~ase radio stat~ons E~8 in t~e ce;l-type ra~lotelephone 3yseem nav~n~ an axc~n~e~ cell ~cc3r~n~ eo the present invenelon an~ cna naeianal t~laphone natwor~
tnrou~n RNT caGlè~. Sai~ ~nte~face may ~e ~oen local and trafflc ~epen~ent.
Thus, enrou~ C~a comm~tae~on ~nd con~rQ~ unlt CCC i t 19 poggl~l~ tO affor~ an ~tom~t~e ineerc~nnc^tion ~etw~en a flx~d e~m~n~l sc~e~on ~ an~ a cele~h~r. central 0tatlon of both naelonal ~n~ ~nt^~n~cionaL ~xtene.
The commueae~on an~ conC,ol un~t C~ is 3a ically comp~se~ of a m~ln cone~ol un~C CCP and a commutatian unlt CC. The funceion of e~e m~n cont~ol ~n~t CCP i5 eo eJta~lish an interfaca ~eeween e~e ~pe~rato~ 3ni th~ syscem.
for wnlcn purpose it is pro~e~ w~C~ a ~ata ~ank for tne whole system, and allow ~Q~ e~ perfo~m3nc~ o~ s~seem managemene an~ maint~nan~o func~.3ns ~ro~gh prosocol~
W092/21215 ~~ 6 PCT/BR92/~WXK
208~42 ~
designed for man-machine communica-ion. On the other han~.
the objective of the commutation ~nie CC is to control call processin~, monitor base radio sta~ion ERB equipment and perform management and mainrenanc~ fu~o~ionc commencA~ ei~her at peripheral equipment in the main con~rol unit CCP or at ;
local t~rminal interface o~ ~h~ c~m~u~3eion uni~ CC ~s_lf.
Additionally, the cammut~tion uni~ CC ic responsi~le for all call connec-.ion and disconnec~ion phases including signaling, supe~vision. commutation and a}loca-l~n of radlofrequency channels.
The oase ra~lo ;ba:i3ns --Ra which ~efiî.e individual cells are conn~c~e~ ~o ~he commutation an~ conerol unlt CCC Oy means of a four w~re analcg or ~i~i~al ci^.ann-!.
the communicatlon between ce~ls oa~n3 carried ou~ -hrou3n radlofrequency, PCM ~eam or o?~ica} f~berâ, in ~ccor~anco w~th the speclfication of eacn pro~ecC. ~n such a communlcatlon system eher~ is a ~oice and data flow. ~owever wlth a spec~Slc data l~n~ for Qen~ing and rec~iving conc~ol.
supervl~lon and lnformativa me~sa~es.
The maln funceion of each base radio stat~on ERB
19 to lnterface local su~scr i~ers wieh one anoeho~ snd/or interface local â~cacr~e~s w~th na~ional telephonn nerwork RN~ su~scrl~ers.
For r.hlS purpase eh~ ~ase ra~io ~eac.on E~B
snoul~ preferaoly compr~s~ ab ~ CwO racks ~n~i~n~tea as radiofrequency and ord~n~ nes w`n~^n ara ~onnn~ee~ ~s ewo omnldlrectlonal antennas as~em~la~ at ~ suita~le heL~e wnLcn may affor~ a complete covera~e w~tn~n an ~varag~ r3~us of ~0 km (slxty kllometer~ a~oun~ e~e ~e ~a~o seat/oQ ~3. ~nus conflguraeln~ an excen~e~ c~Ll.
~ no commun~c~e~on of ~n~ oa~e radlQ ~cacion -~B
w~th flxed eerm~nal ~cac~on~ r~ i~ c~rrl~ ou `nrou~n raalofrequency c~anne~ w~Lch u~ sCan~rd proc~cols ~s~
sendln~ ~nd recelv~ng concr~l ~aea ~n!~ ~o~ca ~nals~ such commun~cation ~eing car~^a ouc e~rou3~ fr~aquenc~ mo~ulaei~n ln a radlo system operacing wiC~n Che ~00 ~2 ~n~n. ~n other words, t~e communLcae~on ~ecwe~n C~a ~sa r3~ eaelOn ERB and a g~ven fixaa C~rmin~l ~caci~n ~T~ 3rrL~ ~u-WO92/21215 7 PCTIBR92/~HXK
~ 2~7~-~2 through control and voice channels.
~ he control ch~nnel supplios data between the ~ase radio station ER~ contrcller 3nd the fixed terminal stations ETF of each cell, ~nd i ta functions aro to: send information to fixed torminal sta; ans and monitor their registers, inclu~ing messa~o regis~o- parameters and tho frequency transmitte~ to fixe~ ~erminai stations; control st~rted and completed calls; and datormine the avai~abil7ty of fixed terminal stations ~o~ raceiving a call.
The voice channel pravides an audio interfaco ~etween fixed torminal sta iona ~ and the commuta ior. uri~
CC, Through the volca channo' are 30nt the audio supe~ision tone TSA and Cho signalins -ono TS.
The voic~ channels 3~ 'O supply the 3udio li~k and signal converslon to 3~s~.3ir. ehe call; ~oni~o~ -ha radlofrequency slgn~l intensity; monitor ehe fixed ~armina}
statlon for access of facilities to subsc~i~er: and dlsconnect the audlo super~ision eone ~SA during the c~ll.
The flxed terminal scacions ETF comp~e a low power transrecelver coupled eo a ~i~actional antenn~ whlc~ ~s dlrected towar~ ene ~ase ~a~lo seaeion and is ~lso provided wlth the s~bscri~ers~ te~mlnaL. whic~ L5 fixed and ~f ~peciai ~nterest to the cell-ty~c te~aphone ~ystem of th~ pfesene ~nventlon.
2S ~he oper~Clon o~ tne ceL!-type e lnp~one ~yseem wlth exeen~ed cell accor~n~ e3 e~ p~ sene in~ene.~n ~all ~e descrl~e~ nereln as foLlows w~e~ refsrence eo e~ree ~in~s of call~ ~ one call f~o~ a f~xe~ e~mlnal ~e~tLon '~F eo t~e natlon~1 telepnone neewor~ RNT: on~ call tram e~e nac~ona}
telepnone networ~ RTN to ~ f~x ~ ~erminal st~elon _TF; and on~ call from a flxe~ Ce~m~n~L ~e~e~an ETF eo ~notner f~xed t~rminal station TF.
In tne call from 3 f~e~ Cermln~l ~t~eion TF to the nacional telep~one neewor~ RTN. ~nen e~e f~xe~ ee~minal seation ETF 3u~scri~er starC~ e~- call, Che ~ase radlo staclon ERB r~cel~e~ and L~eneL~es t~e re~uesc ~roug~ the control cnannel and ~en~ sam~ e~ e~e commueaG i on unie CC
to~et`ner w1tn all otner ~nformaci~n rAqui~e~ e~ ~mpLete cne WO92/21215 2 ~ g ~ ~ 2 PCT/BK92/0X~
call, ~iz: the subscriber's ~-laphone number, the subscriber's se~ial number and the diaied number.
Th~ commutation unit CC ~hen selects a vacant channel tO b~ used in the eall 3nd signals the base radio station ERB to instruct the Lixe~ ~erminal station ETF to use the selectad channel. Addi~io~al~-f, ~ha commutation unit CC
carries out the v~lldation of ~he dialed numbers to assure that the su~scriber can then make ~he call an~ to ~etermine the required route as well aâ :h_ ~ype of call.
1~ The connection estaDiishe~ throu~h the digiea commu~ation the commutaTian uni- C_u -^omplatas the ~oica :in'~
from the ~ixed terminal s~ati3n _T~ and the base r-~io station ERB with the nationai 'ei~phone network ~TN.
Alte~natlvel~, in ~r~e~ ~o p~ovide a low cost iS route, the call may ~e rû~e~ ~y c~e ~ommutaCion un~C CC f~om the cell-type telephone system to another commutation unie CC
ln another cell-type tele~hone system to then ~each ehe natlonal telephone netwo~ RT~ acc~ding to the ~ecent~al~ed sy3tem shown in Figure 2.
When t~e call is cQmplete~, any of cne pareins who dlsconnect the commutation unit CC ~eleases all ~esou~ces used ln the call. The ~e~iseer co~esponding Co ~ei~ call is then t~ansmlteed eo the ~in conC~ol unie CCP to ~e use~
su~sequently in th~ p~oducti~n of ~ho ratin~ taoe ~nd t~af~ic analy~ls.
When a call is m~e ~~~m. tne naeiona~ ~olephon~
networ~ RNT to a fixe~ CermLnal seaei~n ~T~. C~ n~C~nsl eelephone necwor~ RTN acces3es ~ Cr~n~ in t~e c3mmuCaion and conerol unlt CCC an~, tn~ou~n ~ ital swiCc~, san~s cne correspondlng inormaclve ~igi~ e~ e~^ fi~a~ e~rmina: seaei3n ETF suCscr~er.
T~ commueac~on an~ c~ne~31 un~t ~ earrias out tne validatlon an~ d~LC Cr~n~l~Cion an~ LnsCru~ eno ~ase ~adlo qtatlon ER3 corre~pon~Ln~ to Che 1~caCa~ area co actlvaee, ~hrou~ e~e control e~nn~}, t~e f~e~ ~ermin~l statlon ETF selected, in ~r~e. C~ ena~l~ iC~ ~inl~c~ge wicn Che nat~onal telept~one network RTN.
~ ~e ~ L ;~ ~ ~ a ~ !. X ~. ~J
WO92/21215 9 PCT/BR92/OWK~ ~
`~2~7~2 terminal st~tion ETF through the control channel and, when the latter answers the call, tha commutation unit CC is instructed by the ~ase radio station E~B to select the vacant voice channel to ~e used in the cal}. The fixed terminal station ETF is informed ~bout the s~lacted channel by the bas~ radio st~tion ER3, ~nd th~ commutation unit CC connects the correspondin~ di~ieal swiCch wnen the ~ixea ~erminal ~tation ETF is ready to recaive the c~ll.
Thus, the base r~dio sta~on ERB is inst~ucted to alert the su~scriber, and the tele?hone set in the fixed termlnal s~at~on E~B starts o rin~. W~en the fixed earmina~
statlon subscrlbe ~nswers ~he call, ~he voice link in ehe natlonal ta7ephane netwa~k ~T~ am?ieeed.
Again, when the cali is completad, 3ny of thA
parties who disconnec~ tne commueae~on unit CC rele3ses al~
r~sourses used ln the call an~ generates a register correspondlng to sald cal}, which register is sent ~o ehe maln control unlt CCP to ~e u~e~ su~seQuently in the productlon af ene rating tape and trsff~c analysis.
wnen a call is ma~e ~rom a fixed termLnal seation ETF to anotner flxed term~nal ~tat~on ESF, wnen 3 f~xe~
su~scrlber start~ tne cal!, it ~s ~rocassed as aDove une~l the dlglt translatlon sCep. ~t e~is point, C~a co~mucaC~on unlt. CC datermlnes t~rough ~es ~a~a ~ank if ena calL was 2S dlreceed toward8 anotner f~xed eermlnal station ETF.
~ cn~s oeher ~xe~ e~ninai staeL~n ~ i9 ~crved ~y the same commutatLon un~ t ~C, ene call 13 pro~essed ln a regular way. On the ~ontrar~. Lf et~e suoscr~er i9 served by anoe~er commut~t~on ~nLe CC, a vacane e~un~ ls ~es~gnatc~ for the call an~ ~e L3 ensn proc~3~ f~xed eermlnal ~taeion ETF eo a ~iK~ e~rminal ~taelon ~F cype call.
The ~uDscr~ call~ s locate~ ~n~, ~y answerlng tne eall, a voLc~ ~annel Ls ~eSlgnar~e~ eo e~ea~ h the volce llnk ~eeween ehe 3tatlons. ~ai~ voLC~
llnk 14 esta~lls~ed ~esre~ng fr~m t~e comm~taclon unle CC of the base radlo station E~3 eo~$pondLn~ e3 e~e fLxe~
~ermlnal statLon ETF wn~ch ~L~inat~ th~ ~al1 e~ eh~
WO92/21215 ~1l; lO PCT/BR92/~WXK
2~g~2 0 commu~ation unit CC in th~ oase r~o station ERB of tnn fixed terminal station ETF ~ime~ at.
When ~ call is compl-t~ ny of the parties who disconnect the commutation un~t CC rel~ases all resourses used in the call and the rn~ist_r corrnsponding tO said call is goneratnd in th~ ori~in ~as- ^ad.o station _R3 ~o bn transmltted to the main contr3l UQie CCP tO be u~e~
subsequently ln the production ~f the rating tape and eraffic analysis.
In thls syseem. ~he calls may be made ehrough a flxed terminal statior. ~. wnor~ ^hn~n is room i~ ehe d~ea bank avallablo for the rog~gto- 0~ calls made by every subscriber.
An importan~ ~e3~r~ n cnll_~y?n ~~nphonn system with extended cnll a__o~r.g ~~ ~e ?resen~ 1nvon~n is the possibility of its ex3ansi3n t~rou~h secto~ng andfor dl~lslon of cells.
Thus, t~roug~ a p~edo~n~~ined pro~ec~. iC ~s possl~le to canfigurate t~e cells roquired for the ~itial coverage of a given area, prec~s~!y d~torminin~ the location and the n~m~er of cell~, and thu3 ~h base radi~ 3cae~ons ERB~ requlred ln Che 3~'~ o~'Vel~. To suppore such trafflc, groups of channeL~ ar~ aLL~cated for 3C~
always proport~ns} eo c~ ma~lLmum e~pact~nd t~a~f~
Hawever, c~e celL-eypo Cel~phone ~yse~m ~ h extended cell of t~e proson' ~n~en~ion, ~ecau~e of 5~n num~er of sucqcrl~er3, t^~Q~ono -r 3f f ~ C loa~ ~n~ ~the~
fac~ors lnclu~n~ topo~rap~ie ones. al~ows for ~ec~r~g an~
dl~l~lon of every cell ~n a sec~n~ ~ea~.
-~0 In tne former c a~ n e~ll iS ~ nto sector~ w~ic~ e~en be~n co ~ w~c~ ~y 5~e ~ommueasion and control unit C~C a~ now cell~ ~n~, ~n sne l~cer _a~e, t~e cell eo ~e ~lvi~ g ic~ e~u_g~ ~y th~
eransmitted power decre~se. ~ em~/ning ~rea ~u~ 3eing covered t,~ a new cell, w~ic~. ~es~!~s ~n ~^ve~l ~Lcrocells lnstead of one macrocell.
T~e invention ~ein~ d~scri~e~. it ~hall ~e understood t~at several mo~ n~ ~n~ v~rl~ ons may ~
W092/21215 11 PCT/BR92/~WXK
2~87~2 made thereto, provided that such mod-f_c tions and variations do nat depart from the spir~t ~n~ scope of the invention as defined in the appended claims.
Claims (10)
1. A cell-type telephone system having an extended cell, particularly designed to be used in rural areas, characterized by comprising:
a commutation and control unit connected to the national telephone network and in communication with several cells;
a receiving and retransmitting base radio station in each cell, said base radio station being comprised of a tower and an antenna array, said tower being preferably of great size and constructed on an elevated site and having high power antennas in order to cover a great area; and a plurality of fixed terminal stations distributed within the range of each said base radio station, each fixed terminal station being provided with a high detection power antenna coupled to the same which is directed towards the base radio station.
a commutation and control unit connected to the national telephone network and in communication with several cells;
a receiving and retransmitting base radio station in each cell, said base radio station being comprised of a tower and an antenna array, said tower being preferably of great size and constructed on an elevated site and having high power antennas in order to cover a great area; and a plurality of fixed terminal stations distributed within the range of each said base radio station, each fixed terminal station being provided with a high detection power antenna coupled to the same which is directed towards the base radio station.
2. A cell-type telephone system according to claim 1, wherein each base radio station is connected to the commutation and control unit by means of a four wire analog or digital channel, the communication between same is by radiofrequency, PCM beam or fiber optics.
3. A cell-type telephone system according to claim 1, wherein each fixed terminal station comprises a low power transreceiver coupled to the directional antenna, making out a fixed subscriber's terminal.
4. A cell-type telephone system according to claim 1, wherein the base radio stations communicate with fixed terminal stations through radiofrequency channels which comprise control and audio channels.
5. A cell-type telephone system according to claim 1, wherein the base radio station interfaces local subscribers with one another and/or interface local subscribers with national telephone network subscribers.
6. A cell-type telephone system according to claim 1, wherein the base radio station communicates with fixed terminal stations through radiofrequency channels which use standard protocols for sending and receiving control channels and audio signals.
7. A cell-type telephone system according to claim 6, wherein said communication between the base radio station and fixed terminal stations is provided by frequency modulation of a radio system operating within the 800 MHz range.
8. A cell-type telephone system according to claim 6, wherein each base radio station comprises at least two racks interconnected to omnidirectional antennas.
9. A cell-type telephone system according to claim 8, wherein said antennas are installed at a suitable height sufficient to allow for a coverage having a radius of approximately 60 km around the base radio station.
10. A cell-type telephone system according to claim 1, wherein the commutation and control unit is comprised of a main control unit and a switching unit, the former designed to interface the operator with the system and the latter designed to control the processing of calls and all connection and disconnection phases of calls.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| BRPI9102145 | 1991-05-20 | ||
| BR919102145A BR9102145A (en) | 1991-05-20 | 1991-05-20 | CELLULAR PHONE SYSTEM WITH ENLARGED CELL |
| PCT/BR1992/000005 WO1992021215A1 (en) | 1991-05-20 | 1992-05-19 | Cell-type telephone system with extended cell |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2087542A1 true CA2087542A1 (en) | 1992-11-21 |
Family
ID=4051969
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002087542A Abandoned CA2087542A1 (en) | 1991-05-20 | 1992-05-19 | Cell-type telephone system with extended cell |
Country Status (10)
| Country | Link |
|---|---|
| EP (1) | EP0541791A1 (en) |
| KR (1) | KR930702866A (en) |
| AU (1) | AU1797892A (en) |
| BR (1) | BR9102145A (en) |
| CA (1) | CA2087542A1 (en) |
| FI (1) | FI930210A (en) |
| HU (1) | HU9300145D0 (en) |
| PT (1) | PT100498A (en) |
| UY (1) | UY23417A1 (en) |
| WO (1) | WO1992021215A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5822312A (en) * | 1995-08-30 | 1998-10-13 | Com Dev Limited | Repeaters for multibeam satellites |
| US5825325A (en) * | 1995-12-21 | 1998-10-20 | Com Dev Limited | Intersatellite communications systems |
| US6047162A (en) * | 1997-09-25 | 2000-04-04 | Com Dev Limited | Regional programming in a direct broadcast satellite |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5737702A (en) * | 1995-03-08 | 1998-04-07 | Northern Telecom Limited | Cellular radio communications system |
| EP2308902B1 (en) * | 2008-07-08 | 2013-09-11 | Toray Industries, Inc. | Method for manufacturing thermoplastic copolymers |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4658096A (en) * | 1984-09-18 | 1987-04-14 | Metrofone, Inc. | System for interfacing a standard telephone set with a radio transceiver |
| JPS62225096A (en) * | 1986-03-26 | 1987-10-03 | Nec Corp | Radiotelephony system |
-
1991
- 1991-05-20 BR BR919102145A patent/BR9102145A/en active Search and Examination
-
1992
- 1992-05-19 EP EP92917392A patent/EP0541791A1/en not_active Withdrawn
- 1992-05-19 HU HU9300145A patent/HU9300145D0/en unknown
- 1992-05-19 WO PCT/BR1992/000005 patent/WO1992021215A1/en not_active Application Discontinuation
- 1992-05-19 KR KR1019930700183A patent/KR930702866A/en not_active Application Discontinuation
- 1992-05-19 CA CA002087542A patent/CA2087542A1/en not_active Abandoned
- 1992-05-19 PT PT100498A patent/PT100498A/en not_active Application Discontinuation
- 1992-05-19 AU AU17978/92A patent/AU1797892A/en not_active Abandoned
- 1992-05-20 UY UY23417A patent/UY23417A1/en unknown
-
1993
- 1993-01-19 FI FI930210A patent/FI930210A/en not_active Application Discontinuation
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5822312A (en) * | 1995-08-30 | 1998-10-13 | Com Dev Limited | Repeaters for multibeam satellites |
| US5825325A (en) * | 1995-12-21 | 1998-10-20 | Com Dev Limited | Intersatellite communications systems |
| US6047162A (en) * | 1997-09-25 | 2000-04-04 | Com Dev Limited | Regional programming in a direct broadcast satellite |
| US6498922B1 (en) | 1997-09-25 | 2002-12-24 | Com Dev Limited | Regional programming in a direct broadcast satellite |
Also Published As
| Publication number | Publication date |
|---|---|
| BR9102145A (en) | 1993-01-05 |
| WO1992021215A1 (en) | 1992-11-26 |
| KR930702866A (en) | 1993-09-09 |
| HU9300145D0 (en) | 1993-04-28 |
| AU1797892A (en) | 1992-12-30 |
| EP0541791A1 (en) | 1993-05-19 |
| PT100498A (en) | 1994-04-29 |
| UY23417A1 (en) | 1992-11-12 |
| FI930210A (en) | 1993-03-19 |
| FI930210A0 (en) | 1993-01-19 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 19941119 |