BSTJ 50: 2. February 1971: The Picturephone System: Key Telephone Systems. (Daskalakis, A.)

10.6 MB·English

‘The Picturephone* Syste

Key ‘Telephone Systems

My A. DASKALAKIS
‘oust era Ona 21, 180)

Initiliy, Vietuophone™ sore wi amet to 0 lege eto of boy
lephone eytons (KES) Dat vot cat ubieriert 6 Anne motte
tccnet Pitarephine Cental Ofice or Prise ranch Bachange (°BX)
Tina af wold ar fo Petatepkoue intrcns, ddtbon-cnferance expabalily
will go Be vaante, Jn she paper, Pcturophune RPS opaation, opie
sd coma, and physical chavasteiatics ave decried.

A kay telephone system (CTS) ia « eustomer-eontoled svitcing
system which permis var of» stating sat for mere dex oue Central
(ico, Private Besach Escherge (PINK) or intoroom Tine By switching
from one lire to another. Generally eptukin, eusiomers ean sigoel
fom oe sation 2 another, anefer ols bebween ration, hole a
all on ave Tne while Lalling an another, ené sonverssetmeen st
tions without meking uae of» Central Uiiee (CO! or PBX linat
Plebwryione rv alsa ne dimension to key sylema in hat now
video aswell ae sid ewitching mom tale place to aonmest one Pi-
birephone tation at to a cutcbor of Pitwrephone CO ax PBX lines oF

“Five Key eystem sorvics wil ho offered for Picturphone service:*
‘vo Central Oioe or ISX lino serves (x inleeam serviees an on
tuli-orecanieenee stzviee. Tho line cezvions will peril (@) boca!
feetwitey acces to. one Piclunephane CO or TRX ng and (8)
Saved aosese of one ino by s nimbur of bosy/errotary groups, The
fist of thse sarvices i rferred to as singe-group line service wile
Ube second ie referred to as multigroup line srviea, The intereom
services Wil consist of () a singleink Pirephone iotercom thut

Heelies mead to 0 “Line?
@
5088 rum rm, svnrmne rmnTrca POCHEAL, HOMOARY 107

will provide dia! survive for up Wo ven stations on one xudio/video
nk and (fi) » multiline Pictureyhono inlereom that wil provide
texviee for mxinue of 27 stations en thc cudio/video links. Add-
‘on-nonferencing wil he aveilable Between oles or one Tine and one
fnereom eeation,

‘A Pouch-Tonc® telephone cet und a speskerphone aro an inherent
part of the Piotuephone station’ nnd one ray be used for normal
“alephone calling, iciaeyphone serving ix provided as an adjunct to
epalar telephone serves, tho only retention being the provision for
Toush-Tone rignoling, Key arstem Tine trvies interface with the
erring Central Offer or PBX over thos cable pars: one palr for
‘sadio cemmunientione val wo pairs for video,

‘rom a aubecribr's point of view, calls can be place either on a
‘video or studio base ia all of the key vervites mentioned aimply by
oreeeding (or nat) the ealled number wilh the 3 digi, Tneoming
Pleturephone’ ella age distinguished by x tone ringer (bell Far teloe
phone) end a red line lamp (white for leephore). Normal hey system
Tam Mashing retee axe weed to inoue wold, ringing and busy. A
logle 2ed and whive lap assembly ied nde each ine button for
visa esting

2a Goneral
single Group werice a fended to serve braafaoreary arrange:
swunte And genrta smoltaneoue eudio wove to both witcions, Howe
rer, Vdhe acces ig provided on a reach bain and if both
boss wid seecstary ate o-oo on the stn Tne, aly the bass ell
Ive a viden eazaestion. Mlultigroup Line serviewallowa a number of
bos/seerolary gramps to sha one Pizturepkens Kin, The Bit eletion
swith 2 group to esse Ue Line will led out all oshar groupe

‘a8 Single hop Service
"The bode dgeun in Fig. 1 shows s typical key eytam line install
tion. single Tine ptked tp by a boss gad a eoreary i shown; how
tren, aditional Tite mey be ennnected to & station by adding line
‘Grote video evite wad a video cable equalize por lise.

‘To iluctrate che operlion of this svvic, incoming and oatgoing
video ale wll be desribed, Telephone calls follow stendard KTS
prasee aus will therefor net be discussed. On an ineoming Picture=
Phone call, the CO or PBX appli ke Viloo Supervisory Signed
soy meurrnon stems 60

i

|
JL

Vig. L-Slesoap Mencvntone ine cece.

(VSS) to the incoming wdan pair es Least 100 ms before apply
siasing fo the audio pair. After dctostiog VS anc within cho 100-ms
inerval, the eablo equslier evilebs the Line eneul ito the vigeo
rade, When singing is detected by Ue line cnet, « dntineive ing
{tone ringer) and e lacking ed lnnp alot the station user. Whex tho
call is anewerod, singiyg brea, se ro lamp gas saucy sad the
ideo vwiteh extend the video and lymenose signed to the ealled
Preturephone sation. thecal s placed on hold te in ret pro-
vinlor winking rod Iniap te (he Telephone a ‘Tho video evite ie
telease in the hold state resulting in w blank sercen to both parties
Tipen re-entezing the connostion, video 2 wall ar silo forming
‘tons may be sontinued

‘When a station is placed of-haok t erizinato a Peturephone eal,
the line eivouit fights tho corresponding whice Iam inthe wy Phe
(Bouton iv depretnd folowet iy he teephore number of the
Called etaion, When the CO or PRX “eles Uae video eall has been
tiled, a burst of VS ie ot to the video eable equalier, The apne
incr coramand the line el fo the videw made; te line creat in
‘ua avitehes the upp in the telephuze se fom stead wie ta steady
ted. The spetem goes idle whan al tions are on-hook.

"A video loopback’ is provided between the tranamit and reesive
fro rae mm. crerme Tecmo JOURNAL, FEBRUARY 127.

pairs of the line ne he exble equate civ, This loopback 5 eon
bested whan che syetom is ile ad is removed when the Tine exit is
in the video mode and a station ie of-eak. Onoo remove, he oop
beak will et be eesonneetad unt the spam eile, VSB no. being
reorived andl all stations on-howk. Tals logic allows e video signal 0
‘be Leanamiled cbrough the evstamur lyop fos ‘anemicion tating *
{ealko prevents « person frotneotng mel the penoon to whe he
js ralling goes onenook. In the ent of peaes failure, either at the
Tine ere, ue ecble equalize, ur the station ect, leaped is removed
%o prevent the CO or PBX fror: completing vido calle vo thet line.

2 Multigroup Serise

Muligroup PYelurephone line service was designed to provide
shared-line service to a aumber of boee/seretery groupe. The enull=
iroup eystam ce shown in Fig. ?ullse ine cial,» exble qualior,
fod e common control and lockout eituit Ie shows bose/ecertary
‘groups one through nine shaving one Picturephone line. In tis ust
tion, seaetaree heve video aeosse; however, audio-nly service may
he proved for cearetarce. When eny ove greup (station) is wing the
lie, ova devin tall oer groupe (talons), Any Picturephone
soup that inadverwently goes of-buok on & Kae Ute ie in use will
-ecivo a bney tone. Poisson of Uc Tine en be eonsfrred ro anocher
sooap by placing the ine ox old and uiough exteral signing
rote, ireeting another roup i pics up the line. Mukisroup equip~
sunt aerangements wil allow up ls wn Piotarphine groupe ta share
ainda line.

Tf sho secretary withia a group is equipped with a Piturephone
station, single-groap rules apply. That iy, Ue eusomer maw choose
hierarchical video onder for the two Piclwrephone ststione but both
stations within the group have auio access,

Teoming and outgoing vale, ineofar ce distinctive audible end
‘vial shgoling and ell completion are eoneermed, ere ftndled the
sane Way atin eingle-group Picturephone eeice with one exception
‘That i, on incoming calls one group (ston) will usually be desie-
nated ob the attend group end all inoming oul wil rng end Sach
‘the attendant location. Ding zinging, the lamp associated wi
‘ash line is lighted ctondy ot all nossttendunt stations, HZ a zon
‘llordant station goes of-hoote duvingvinging, it will reeive © ny
tone. When the atlendent detennines the station to whieh the elling
party wlibes to bo connected, she mey placa the incoming eall am bald
fg, through extemal signaling mesna, sdvise the proper station lo

FR map uuu svoun seoenen, roman, ramocaRY 2an

pick up the lis, When te wee station pie wp the cull will be
‘eanetemed fo the! station and tae attend as Wel aval er hge groupe
vrll be loned out

‘An optional Diseet Stavion Seletion (D35)_erangement ean bo
vided for the attendant to adie steton of an incoming Pictore-
‘hone cll. With this orange, che atlendant operates the proper
DSR bunton hich activates « Boeing re lamp and audible tone

nye inal seeciatad wit the Piturephone line to be picked up by
‘hat station, Ae ahve, when the ation pieke up, the eal! sll be
trwralera wa thealtedant sl be Tock ot

‘Am applionen of Malignsap ecrvieo i given in Pig. & Te shows
thaws bors/sereury groans sharing tro Pesto ney Fattaries
hee ascio only!” A lulton appestenee per ‘ino e roouinsl = each
Malina 1 tho prineipal rer af group 13 of hook on Lin, the lap
teceeiated vith the ine in tna wll Light steady at sacl alion ape
Prarance in all chee groups. Teither « aroup 2 or gry Station goes
‘chon on the some line Ih sation will rocive a busy tone If the
fcrelany in group 1 gpm of-heok, she will gat audio aces 10 that
Pietntophone ine

4 Gora

‘Toro “ype of Piturephone interom sorvlees wi he fered to
handle eneeoncer witching needs: single Tink anil milks servic.
Single nk cervite i intended forthe small weer and wil aerommodats
‘onazinum of fn stations, Malik inerear series i imo athe
Tages user aid wl serve 2 ragmum of 97 etnbions on xian of
iver inks, AL basin ey talepoae fnsures are provided on asc ofthe
lwo evotoms; fey Piskep, Bold ianps, ablibe signals, ad-en-eons
Terenea, ee

Tntereor eervi is entirely snparace ftom che ospe of line a-vise
oecn, Hor estaple, aatgns ving aocss to the sig’ Tink itereom
fan hove ether anglo-greap or rulligem Piturephone line service
te vlephone-only line saree. A button appesranee is requtel a ote
Selva tase hn agceas #0 am inéeroom,

Single Link Introom Soses

‘This servi provides private intoreommunicating on «3 plus
one-igtdiling basis among a group often or ces taions, semi er all
OF whith are equipped far Picturophone cervoe. Singe-Enk intercom
dey uauess STETIE sm

Tig, 3-Netiemup Piers one Te sroo—appasin

servo is ynovide by the units show in Px. 4, eonsisting ofa tation
Seek ges sat, esnton eoge, to allow areas ta one stetion and
tlude al thine, cone anc lamp wool ntl Pouck-Tone dal receiv
sn equipzen:

"The ovignetion alternation of walle follow the procedares de-
seribed Jor line vervives isofa™ a5 dialing ené ele ton alerting are
fensemed. If» cull in proxrere, she intrsom line lea will light
sly ab all stetios Raving inerrom aoces IE station gow o-ho0k,
ile neal is n progr, Lut eatin wll vive Dory tone

‘The basie cone ofthe ang. Prlnsaphono intercom i the 182
Ais eelevive istercom (endo onlr} prowtly avilable te the Sel
Video etching, lockout, swerve features have been added to
result in ¢ complete Petarvphnnc inlerrom syste. "The features ef
the suglelink intereom are privoey, system busy tone, bold, boss)
secretary bridging of one inlorom line appearance, sation hunting
fomn 2 primary to 2 eovondazy shen sho primary is Dory on another
Tine, aud lion conieseacing Rotary da] note for andivealyatstons
‘re pormtid

‘When stlion is place of-hook: to orisinte ell the ettion and
omnmoa toniml civ ate seized, preventing other stations from
Cvignatiog a eal on she ictereom, ‘Ta steon se eontete toa haters
Feat eirvuih and to the temineted video path, The calling ration 7
‘tive diel tone and all tations eracive a seesay white lamp signal. 1
Std mae aa extant wreNDIOKT, ToDRSAT, MEMEO 171

comm "ager |

the 3 dip icicle, ndionting a Pieturephone cul i being pec,
‘the lemps change vo steady ve

‘Usan completion of cling, the common cortro) cireit rakes a
‘busy test of the called party. Ifthe called parby ie bosy on anatler
Tin, busy tone is rete to the ealling station; if the elled prey i
ite raging ie soplied. Whe tbe alle wlavion anewers, the ealled
splay ani ie Ged! ON, te video wate are commenced together
oper tctsmitlerstnreeiver fashion, and Whe ringer ix seid, ‘The
yale senens in Une busy stale ual die Ise eatin placed on
oak

‘On an established intercom all, ne of the talking pentce may
choose to anawer an insoming ell ow a Line while Ue other inarcom
party remedies ul-hook, Aiter answering. te insole tay
then retar to cho itoreom ax Ton we she ule pty reno hook,
‘Thosefre,inteneem uscrsaze provided a ucans for holding an inter-
om eal

‘Boss/seeretary bridging of one inercom line xppearanos and ste
ion Tunting from a pritsary 29 @ scrondary when abe primary ie
bury on another fine sre suo key system featares and will not be
owered here. "The opsional feature af add-on-eanfrence, which i
‘avalnble with Uhe singlectinke Peeurephone intercom, js denise in
Section TY.

132 Mulltink Intvoom Service

‘This aystem is ialealel ly fil the inaecommunication needs of
uetomere mho range in sie froma thowe who eam be served by tho tea-
ation singe-link Pcturephone intrcurn to tow who require a
Pizturepione PBX bt co not require full PRX fealure* The multi
Tike iteteom is conamen coutzl syetam designed to provide com
nuneasions to a maximum of 27 stations ¢folares tompleve privacy,
Serves telepione ax well as Beterephone equippod sation, a ean be
‘onuipped for cider lwo of three intaxcommumienting Tinks. Stendand
Iityspsiem fecinressieh a Fo, oes/eeersary bridging of one nter=
‘ome line, and sation hualing rom x gwinary toa ssondary wes the
mary ie buy om another Line are proviced un an optional basi. CO
te PEX Lines een bo conceal ls provide aio addon and video
tensor inv the intaream,.

an System Orpanication
‘Figure 5 Se bck diagram of ie mln syetem, Ie conse of a
sete: control and register, up Wo thawe Lak eizeuila, o cute mari,

fod a eto ene oe vaeh station
576 mR aveTmMe TECHNICAL JOUESAL, MIMUARY WML

‘The register contains the tlc ofthe systema logic and consis of &
Toueh-Tone roacver,w srleriorviroil and a Tole stew for con-
trolling the eystem, ‘Tho link viexit performs the funotions of eall
supervision and selective siaaling, ‘The station cieuit eomneets the
tations to the eyrm and controls tho functions of ideo, mp and
nger switching. The ewitchmastrixconnoete eloted tations ta Bele
‘neu and lose out all other stations

22 System Operation

past Teephoce Calls, Rofesing to Wig, f, whoa a station gos of
hooky the regina sine and prevent ther atone from arignadng
‘nll ot this time, ‘The rier fener She esling ation a alo
‘oables eile Lin, The caabled Link enues the operation ofthe matsix
ferompoink associated arith the ealing party. AL thin point, Ch eling
party tip wn ring Tel re ern la Un ele Tae eile
fhroush the matrix aout. Tones (Gal tne, ringbank, sation Dory and
porrnanont gaa! ere tenemitted by tho Hak tothe osanosted station,
"The Tink eieuit suplie loop curren, datcterotory dil pulses and
ropeate dal pules fo the zepstar. If Foueh-Tane dialing i involved
is roquied to cxginete Pictrepkons calle, the tones aro eapucitivaly
‘pled to the relates,

‘Upon completion of dling cho ogister moker w busy test of the
called party. Ifthe called party ix bony, bu tono will be returned to
the caling party. If the called party i ile the erompoint usoiated
swith the elled sation an dhe state! Tins will be agente. Tho
Terixge will bo release from the mabled Tink waking thavelable to
Ipaslewaother el. Ringiag and vinybaek tou will now be spoled by
fhe tink one. fer the ealled eta anewer, the dink wil rmtin it
the bury state unl the lst statin i placed ex-hook.

‘542 Ploturphone Calis, Picturephone calls are originated in the
same fashion of telephone calls wits the additional requirement of
preceding the called momber with tho digit, Tao register detcte
the digt and eigaale the Link which in rm nts the ation cir nto
‘the Pltureptone modo (2, rod lap, tune ringer). Tho viewing path
‘through the evitch matrix is sonteeled by enh etnéioneireit im mck
‘ray 28 to connoct tho tranittr and rerivets oF tho ealing and
Called partie in Iransnttesnatever entiation in hath ditions
When both the collin und eniled parties have fen wnneeld to the
trrtch matrix, the Tink ere muse prevent aditonsl stations from
being added in» Lctarephone mode wo cho existing bxparty cal
‘Third and fourth partes ena be added, audio only, to wn existing ell