BSTJ 50: 2. February 1971: The Picturephone System: The 850A PBX. (Anderson, H.P.)

11.7 MB·English

The Picturephone® System:

The 850A PBX

Dy Hl, P, ANDERSON
(envi ceva eptember 2,100)

Th ths paper oe dora the sytem ececation, operation, and
apparatus of the 870A PAX, a Msturephone® Switching Spe. The
hjetien of the 860A. PIX inthe Ball Systm Wictuphone atric plan
‘oul the design approach taken are discussed,

14 Genera

For fusines poople, pemasclopersen operation is the most
complete means of eommirieating; therefore, the Brvrajor usaea of
Preturephoos even ans likely ta ba sores poatns:

‘Switching eystamn such av 4 Private Boanch Bxchaoge (PBX), oF
fey loleshune arenment are an integea part of most business
Ccommunivations seeps. ‘To obtain ful tiaition of the existing
fnlepone netwivc, Piturephone eorvce ia ta beaded se an inl
prt of telephone sevice; tharefore, Mietureghona service must be
fadded ta these ayatame serving the busines community.* ‘The 860A
[PBX has beon designe! to provide Picturephone service to customers
served by OID oF 7674 eletroresiiesl PBX

12 Objectives
"The ubjerliow of die BOA PRX isto provide Pesorephone sorte
on TOIT and TBA types ef cleccomesbasieal PRs, svp-by-step
(XS) and croatber OL-bar) receetively, wih w common ruthie
In edition, the BWA PHY i to provide the same ecrviees on Pietro
‘hone service chat the estomer us on telephone; therefor, tho 850A.
[ovides Pisturphone service on all the Communiestioe Service
Packages serien 100,200, 800 sud centers (CD) T and TL
‘exits af the 880A in working with either SXS or X-bar PBXs
is achieve by using the BS0A in parallel withthe existing exslomer
letephnne switiing ey, In the RGDA Bzburephone Wleiione ays
$880 mum oe evaTHNG mECREUCAE TONAL, MARE TE

tem, normal telephone calls generuied ata Picturephons station are
titebed to and enrinl by the telephone evitehing equipments all
Piotwrophone fraio (ncuding the audi} is proces by the BEOA,
Teenuse of this parallel operon, the 800A performs the sume
switching fanotons tequized byw voloe PBX, and it hus Uhe additions!
tireuile required for ideo evitcing and tranamission, inne the B30,
Jen complowe PRX, it ean be mosifed to operate as w stand-alone
Ticturephone PBX, ie, provide only Dictursphona sarceo tw eu
tomar if ho a desires

"The AGIA PBX is « colid-stcte machine wills 1 building-block
‘euipment acrangemert which allows for eary growth om 10 to 89
Picturephore aes, Growible aPitching networks aze obtained by the
tue of alugsin fered packages, Specie) maintencnee features inehuce
inservi thecks aueh as guaranteeing «good Joop Loa Pisfwrephone
ation, belure connection and ringing on incon cll

"Phe 860A trunk sirvate have been desgnod to operate aver PBX
leap ranges up 10 2000 chins and aze compile with Unigange Cen-
tral Office (GO) ines, Allowion of impairments on the vide iane-
thision of the SGOA ro given in Raf 2. ‘The S804 has vieu eases
fn the raoeiva pair feu wach sation and cach CO Tine. A Key Tele
phone Syetem (ETE) eqilier 2 ueed in tha etandant video loop,
{hie oqualizr ie used to orovide video loopback ‘independent of whe
optional xterdant vp se.

"To achieve low rearfanringeorts, the lie and cnet pac aise
‘were ehogen to be the sume ae a high production PRX—the €004.*

“The utilization of thie system with the major clectromcehanial
[PBXs end abe smiley of Ihe apparatus with othorelactronic PIX
allow anifrmity of ranutaetur, intallatinn, and maintenance

2 flanaral Systeme Arrangement

A Bloc Siagra of he
ig 1

Pieturephone station equipment! consists of I2-button Pouch
one® (clephove, w deplay unit, anc coxtol unit ‘The 12-button
‘Touok-Tone telophone ik required ror Pelurephons service. The
DPiztureghone service ter initiates a video all By pressing the 12th
button designed, ard Wien “ial the regular Ualephone number
‘of the person hein calling. A nezral voie-anly call it erginated jn

wrephave PDX. systems ie shown in
ABA eax 387

a
8 = = | ts

1g 1 Sytem intormoncetion plan,

he usual manner Dy dialing the noiser without che 3 pref. Am
Incoming Pictaephone ellis ehusnoriad by 0 deta ring ere
sad br a tone ringen

in th intel phase of Piturephone cervice, only the No.5 costbar
‘ental fica will bo modified to aniteh viden calle; this sopabilty will
ley be providod by the No. 1 Blectonie Switebiag Syetem (1588) in
Ihe fntie, Pieurephone service curomere served by other types of
\eleshono antral effres such ae panel, SXS, ete, will have their
Pirtwreghone ‘gilts roated 4o the neazert No, 5 cz No. 1 BSS
‘fie sandided for Pieturephone sevice,

‘Na tndtiectans are zequited on tae existing 2-wira wine loops
‘ht connect a customer telephone to the on-premise svitahing
rouipmeent. The ON-OVP sritehieck sionals, Toush-Tone dialing
Sienula, and the voiee portion of Pictarephone calls are tranamitted
tor the voice pur, Je addition, va pair of ree im the standard
‘elephone exbles are cesgned forth transrssion ofthe video portion
of the eal, one pair for tra txvamiesion in eech dicen, Video
qualier" are inzerad et apsvoximatcly ong-rile intervals betmeen
‘he PBX an cho central fie. A PiatwrpLons eal othe local entra
office is etablched over s dedicated sixcwine Picturophone trun, At
‘hc lncal centre fics, the voice pair ie connected to the exiting
slepione switsh in the conventions! way. The video «quad i come
588 re DUEL eveTEaS nuNiow. soomxAL, FFRMDARY HL

ested to a separate feur-miteewiteb which ia controled by the tle
phone swiving rye the sad puis of this eixenire wrunk is never
teed or woie-only tral

Al the pesipherel equipment ae systoms to the 850A are discus
in desl lle adel in thi soe.

ss System Operation

To illorrave the operntion of the syeem shows in Fig 1, when 8
‘nll is Srtintee by ea “ul-honl," the txo-wte au oop 38 o2-
‘neta to te rite cei of the RANA and Lo Tine finer or reyater
in the evoialad PAX, eating dul-lone (o be reeured tothe eation

er. The deleeion of the fet “dialed” character ws an & by the
A rexseer oases thie ayers to dion the rogulee PRX anc to
‘pply 4 am’ ndiestion ta the line appesranee in tbe lelephone
ryalem, Oulening Plcbsephone ells are eared over the deceated
Srewire cums and pmooeeteg by tho evra fine (tho cea iit
thos not require e af signal in thie ease sie Lie equipment ean only
be teed by a Piofwophone ell). Arnatvely, f the allot number
not prefixed by 3, the S508 regieter rleaod itelf and wppliss =
boty ficeation om the ASDA tio appearance. The call wil chen be
halted ns. sora voigeonty telephone eli #32 c2ual menor by
the aceeiatad PBX. A regular Direl-Ch.ward-Diated (DOM) tole
hare eal nitited by a Peturephone sation, after provesszx by Ube
‘aint PBX, will be eonnceted vie the regular studio (rink £0 the
Ferving tlephone entra oe

‘S504 Picriephone lace ean lho Ie voiee-only extensions equipped
vith either @ Poueh-Tone ofa rotary dial t provide ah servings as
Sorters pickup. A video es ecm he anewered oo such extension
Dowever inthis eee, chy rlor Wi hove a bleak rere ual 4
nll i peed up by Plcturephene aet. Rotary dial extensions est
nly intiste tlophon calls fe eom frensier a Pictonephone all to
Ihuother Plturephone line by calling tha aetenduat who, in van, ill
ot he trae.

‘Options whith ape seeavsl yy the customer include allelant
video eggubiy ada Video Tnsup-Cnarater (VIG) which trams
{fired iunpe to the eelling perty while the aliendurs, gages
Bisel,

‘a2 Common Control
"The 8508 PEX ie ¢ solis-rate wired-Jgie, common santral wih
ag system, the leek diagrau, of whieh is shown in Px 2
"Phe commen concrol 9 aa eeynehtonous eieutt wit the exception
08. nex a0

(=)

2-The #504 PBX bleh dram

ef Ue Sinoseanner portion which i elovked at a 10 XH vite, The
enon wana pote the netseary lope “ar establishing enanee-
tone betmeen Pizturentone eervice cireit through the Pistercptone
swatehing network,

‘series eco" sch us line eve trunk, rite, le, bide for
Ue corsman eontol whieh determine the mode of operation aoeeseary
te provide eorviee wo This iran After Mntfying The “oswesting
titeut, the cores voto Tacks ont all ether requests ul Uhe
intial request has born satefed, The eexanon conse exarincs the
svailable dala from the eequesting ezcut, marks ion the lang
retmors and lelarminas whabathereevies etl, if any, are aeeded
fovaatiefy the request An idle circuit of the type request ix selected
fd also even the network, With the “na tears on Un opposite
500 SE wes aYRTIME SRERMNCSL JOLIN, PRBREAE TL

sides of the tron, the enon eonteelensbler Ue netiork conto
Iviie estabiabes the conaeelion, The common control shen resets and
is uly Uo voneio the nat requet.

‘The common control ie normally in the ile stale, From the idle
state, the commen eortcol een coer four diferent functional moves
to seve regen, ‘These ages i) oncer of service preference are
read-rogivcr GLE}, sno-tiel tane (DT), earap-un rout (CORO),
land attendant-truiczalouse (ATR). A preference onlor ie assigned
{othe funetinal sade in eo of simultaneous requests, During the
Tigudliog of anatiple ealle, te most mpostant Lype of requese is
served fice

"The svad-serstes rw ia requested by « regetar when is eontenis
au rely soy rondoct, Resdontpeenct wher Tie register ee he
completa number ui digs (8 or 4), or ¢recogsizable I> 2-, or Sgt
tole, or ifthe zegever hon ined ont. Te Ile mode involves the een
Dealing of the ening wire to the called eireut

ined tone rae ie truest by cireuits thet quire reise
‘comection, Sesrning is renuitd beeauca of multiple eireitsrequest-
Jing arse «>the stme time, Theos rquestsSnsude:statlane going
fff-book, DID trunk seizures by the centen! oles, call-trnavar=
indvienal, diloonfere'en, and atendan: trunk seiees. During the
EDT mode, seqestingsiruite are connected ta x mir Uhough the
‘tehing nebo

"The Cemp-On feature is winniotd with PBX ssvies 200 and 200 nd
oplignal with Centrex I ned TE Theeforo, cho exmp-on made is pro-
Wide only wher ite chute, and is sequested by tho camp-on
siceuilperadieal'y when there ic a vomboretred in ne of the thes
tamp-oelocee, The CORO mode cheeks the etete of the ctred “ine,
‘an Cite, conaee!s the etge-o" tank to that no

‘Attandwoletrunk release rroe is sequered by Eke attendant trunk
wien the aivendaut aoie2on from the fron and bath sides of the
thant are eonmeeted to otter crete hough the switching network
"The fanetion of the ATR modo ir to release he allendané tran fom
the conreetios and to eztrblish n now netxare commotion cieetly
‘betwaen Ue tno eireiteprevisy eonneolad 1 che alter tru

Tz adilion co peoviicg the le Tor Ue eurcstion of serice
sinouta, the common contro’ perform ofbe- thneons.axteciated
‘ite Betormions ell

(One of these adcltionsl functions is related to the identity of
ictwephane station, ATI Pzturepkonsstetions ia the system must ht
acsigned 0 the sxane Innireds greup of rambers; this hundreds group
S504 rex so

fs variable from eystem to syvem, Any video call le a number not
jn this hundredt group, og, ¢ telephone number or a vacant code,
is routed to an intereep-receréed samouneemest, A Tesdirotory
faumber (LDN) option is provided thish allows the LDN for &
Cerures-CUT Bpaem a be St difreny ceeds group.

32 common ooatcolseeercing tho eiet-ot-aerice of @ parteulue
‘Piturephon lie, Bash Piturptona ston may bw asigned 20 ay
fone of abt clans of servi. Toes elattee ares CO saanestncta, dial
‘conference nonrestictl; CO nonretrictd,dial-conference retried
CO wallediverte, disheopference nonvesrisied; CO col-Siverta, dial-
conference rstlctet: CO reiiotelia-eonterene nonretzeted: CO
restricted, dial- conference rested One udditionalelate-of-ervie is
provided for use by Dote-Phowi® sialines, This dun elaswol-sersie
3s Dinited Wo Dala-Phone eations wd ie alvuye dial-onterenoe re
ttrete,

Goramon control klip determines when a videu-tontimiiy tot
(CT) shosld be wile on wn eslwblisked sonuestion, Tf che video
path does not puss thie ts, the coramon sontcl wl ease the calling
arly Ww he rotie (oan inteesp!ceurdud uoncuasement tis the
‘ne Hntereoe that e wacd for valle to vacant endes and the wrong

-aunrede gro,

Satin hunting ie also oontrullbg by the eomezon conta, Pete
pons sasione nny be arranged for one-way or tmo-ney husting at
equized to be consctert withthe tlebons PDX,

‘The ommon goal! ie arranged far mulgratie reset under car
tain abnormal conditions, If any eration takes Tonger than an ex
pected amount of time, he common sontol resets, If the commen
fontrel fails to seset, ot the network: ay ful to seta to normal,
22 major alarm signal ie sent Uo the Fuse, Alarm, end Einergeney
‘Transfer Cireu resulting in the tranefer of all Picturaphone linss
ot in to at the tine 0 he exaling selephane awitehing system,
‘hus unvviing al eet elephone eom:unication.

25 sepiter

Dial Pues uod Povok-Pone pone eoe.on i noeomplishe! in the
ud by the mages cireult. Contestions #o che rogieter exe mede
through Ue ewiiching nebwork. Lize-ide civxite are oonnested to
uskeril terminstions of resstre, and trmk-side econ are con=
neviod vo Tineside rogstor Lemuinstions, The register functions to
revoive diel pulees or Touzh-Tone phone cignels Irom ther line-ride
or trunk-eide circuits; afta reoeiving the enlie number, the register
602m wma svstear mmemsaas, JOUADAT, FEBREABE Ast

signs the common sont. ‘The information in the reser is then
‘sed, under the direction af the commen con, to complete the 2
‘quire connections within Uke PAX. in tke event thet the oalled
tation or trunk i busy {inauding the busy-tone rune, if prove),
‘the regiker returns buay tone co the celine party. Upon
fof the resister, Ue Up, ring, eoeve aad "P-ceteee” lewd are cut

ugh to she walling Tir. Ta conection grounds che sleve lend
‘hic operas the eof? {CO} relay ia the lve euit. The opeetion
GT Use CO relny cunmects tiny tng and seve led to tie wstoiated
tlostromeenanical PRX whieh appeaza ta bie PBX as en. rigiualin
‘The unis PBX after finding the Tine reinrna da! tone to the sat
I the frat character “dialed” i the Pzturephons peli, te rgie=
‘er detect this sigal, Delwelivn of the 4 esusee the reysier fo place
2 signal on the "D-etset” lend which n turn opens de tip and ting
‘nd grounds the sleeve Tond tothe elestromechnienl PBX. Grounding
Gf the tlovve leul tome ta provide the proper busy indieation for
fncoming telephone vals lo this station. The “Pedeee” signal als
allows she conaetion of the battery feo and supervision ciruits of
‘the SBA to the linc; the Piztureptons eal ean then proceed. If the
register detect thit che fr character "dala ie not the a i. places
fgrvund on tao elowye Jegd ofthe 8808 and sin releases from the
foanestion. ‘Ths ell in tis latter eee wil be ploceted ae a tlepone
tell by the aevovite! PRX. in tho event the B50A is mecied se n
fHand-alone Pieturephone Syatem, the ropeter reume isl-cone Sf
the fins shuraeter “dialed” js oor x 4. T telephone stations ure
connected to 4 stand-slone 86, voice calls must be preceded by +.

‘The regieer ss szramged ty soe the 3 and to reaive w threc- 01
Jour-ligit ele fr station nue; bwo~ or Uremdigit ede for confereave
callings aa one-igit ede for CO trunk and attendant tanks. The
Calling purty has approxiantely 10 roconds Lo “dal” the Seat digit
‘iver the applieation af dial tne. I his 10eteond interval is exeneed,
the register drops the eonnedtion wad sllows the 701(TS7) PBX to
time out and return fast busy tone (or attendant intreept). Subec-
‘quent digs must be "inte with time intrvel no lager than 10
econ betseen dit, Tf thir interval ie excoedad, after the 2, the
Tetlstr times ov: wad cngagin common conte) tp connect “ho calling
line to an ile atendans trunk on a itereeok asia he "storing"
tinea determines then all the digits hava been registered; iw valid
fone tor, of thtee-digt ode Su cozevel, the regiver raogaine: the
‘odo, and engages commen contol to complete the eal

‘When digit repetration iv complete! end common contre eugoped,
8508 x co

the register tranmite the ene! number to conan control. Common
antl then instrcte the rgite tu ell ak ie cling lino er trunk
(which ail connected tothe resist. Ou inoroom eal the teri»
fing held ef the callie eetbabea pric lo eilebark, Cail-back identi
fia the citing eisuitend allows commen qasloo Wo est up tho rome

ig pont of tho es aad Lo sghal “he rapa to elec che ong
‘resi. The miter ix then aealal'e for aptber cl

Ts the event that common sale excounters @ Suey connoston in
noaapling to act up «eal it oonmoes tha eallig parcy’ to the busy
tone trunk, Tf the Besy-toas teu is buy ur not provided, the com
‘won oostroleeoonnecte the eemitr to ch ealing eet and instructs
the roxister to transmit busy tone. Atter reconnection tothe risen,
lw ling evel hat approximately 10 seconds to abindon the call
Tih eal i not abandoned ia this time imtervs, tho register times
‘owt and engages eosnmon eontzo co soneet Ub eallig Ise to an idle
‘stiendant tun onan intereeps buss,

a Network

‘Topologiaty, the 80a PDI arden,
toviceh (or gil wire, ‘The autia ane sideo networks ar dine: und
fxparita ne one tigelesaleve related. The sudio.networi oooirol
teste for idle pose wr mckes “te path selertion, When this Function
i eamploadidenienl paths are set 9 inthe aucio wad video nabwerk-

Pee eudio network eonteins she tip and ing, aleve lead and eon
‘gol loud UD-detet) Te vivo nethore containa the transmit pair and
the receive pair for the video portion ef Ue eal, Supervision of a
‘ietanephone ellis alwys dane onthe audin netwerk.

‘There are tno actor sles available forthe 850A PRX; « S7-line
tine whiel has 64-line terminations end 92-runk terminations, end an
SO-ine ie with OB lerinatinas and 18-tunk Leminations. The
ierence of eoven between tocal terminals and usable teminala ae
‘those asisned to cegisles, oe Lino, etsacent franks end the recorded
runes rome

‘Tho svites apourstu i the 299-e7p0forecd. "This freed tomy is
pluggstle and eonel-ueted on epauy-clas asta! eixeul boss in order
fo meet crvele lk rocniexante, The ferreeda arp availabe in 4 x 4,
Axe, and 8 > 8 fe whieh cevialn fons 4 > 4, ty 4 > 8 and one
8 xB vatriee paz ferro ews respeesively, The S504 neler uses
the x Sane 8 % 8 itn in fr he $9 in see neewon, a com
ination of chnoe tris oe Lo forma a 12 > Rswtch forthe secondary
stage. Kuch erospoint of the wtiices ns four dry-reed witch con
SOL my wm, arm TECHNION, JOURNAL, PEBROABY TL

tote which ore closed by pulsing the astocatad solenoid. The pulse
sed in the A504 jn lo 12 amperes and opproxmotely 038 mx wide
26 percent empl and 0-4 ma wide at the baee, Due lo special
magnetic properties of te smite, the eoniucls "remembec” cir last
plea position open o* alazed. ‘Tho magnet struchre also insures
‘Gut any previous¥ operated eantac'a aro reloued thal share either
horizontal ora veriee wih te pulsed pati,

‘Tae ferred aperctingehavsoteristne,ooasicuction wa tiel>opera-
tion in netwonte have boot divureed in detail in sampy grevious
pbliostions.

"Wen a peth though dhe netwons fa requized, che eatin cour
rmarls the appeacunes on te Tina-eida and tanle-ige of the atwerk.
‘Thea mark (zounds) operas « uniguo cot of rluys that select che
‘asocinied: primary and tersry ewiteh, The nebwork eonkral also
recognizes the roles for Ihe naswork and proceeds to select su idle
peti. Given a cetain Iine-ige appearance end a eetain trumkoride
lsppaarsnes, uber aee four pessible paths throug the network. When
atvonding tow xed preferenen an ice path hee been tested und the
econdary avézaheeogted, the pat is etablisbod; tao common ennteo]
land truzk-sice croulte we sigvalad thatthe eonection as been mae
‘When the path i pulse, lhe spprozeata eresspointe are cloud wd
any Jntetering erfepoina are elas she nestor operon i then
‘cmplesed, L? none of the Jour patha are ile sho comcon oneal is
tiven a noclinke-ovaluble (NLA vgn

125 Tranh end Atendant Pasties

‘Since the trunk roils of the AIDA perform the ance functions aa in
ny other PBX syetem, their eperatio ia digoused in general tema
fe reating to tho 8608 PRX, AI! che trunk sits use a mination
of integral cirull yaler,deerete transistor, and miniture velays

‘51 Tozer Trans

Tntee-PDX Picturyphone calle are eowploted through a ¢wo-purt
interoom funk which provider all standan® audio alerting and euper-
visory foacdont ae well as # fourowire video eonneation. A Vi
Supervisory Signal (VAS) ix aly ayplied to acivate the eallng =
tion" Plctirephone zea to eae mdielintivearting eipval st the
‘sled elation.

22 Centrob-Ofiee Travis
Tavoming and ontgsing Pleturephone calls to a Pietwephons