BSTJ 50: 2. February 1971: The Picturephone System: Maintenance Plan. (Dougherty, H.J.; Peterson, E.B.; Schachtman, M.G.)

13.1 MB·English

Maintenance

‘The Picturephonc® System:

Maintenance Plan

By IL J. DOUGHERTY, B, B, PETERSON and
MG, SCHAGHTMAN

The addition of Peturephoue® vere tothe conmwrications services
aie by telephone operating companiea requires tht adiional main
leans tnt be performod by the pl! feroee. The Meturophone plan
‘previ th erate fr ier fin ne vids slephowe wteauct
nations with exiting tdephoxe asnenance fusctons. Meeimum ae
ff builesn tating feature an he auithing mockine and the faces of

sama tenting fase thet are a legion extension of tephont
tenting rangement provide cemomizal and comprehensive tools for
cccampliaking the complex tars 0} intliaton, eet acceptance and
trouble Staton, The esiity of the plan permite the canmdiation of
advonced taciiqus to the fld ob well a8 prompt appraiel of fel

Th plan ie deserted in terms of te major eenmont, in maintenance
{or switshing, Ives and trans, The Snteretion f th maicuanes hard
toare acragenent eth the Pictatsphone plan! i ondind together with
(a cere of the work Loations a ezample of lasts to be cepts,

‘Mainterunce plunning for Piclwvephone service bas proceeded con
ument ly wit the overall planning of equipmers and servoe wreangee
tons, Subscribers will expect Plctuyphone wervicw to be wl high
Auality and to provide naz'y troublo-re2 opersting performance, Ae
scenic the ocher popere ia this lave, the complex eletronis used ta
provide Pieturephne service hus the potzntial to complicate the tredi-
tions] maiztensnes fenetiers 0: trouble detectica izlaton, end zeal
Asin other aspects of the basis concept af Pietunephone service, the
tmeivlenane ll be integrated with the curent miitennes and ad
tninistratioe opertions of the telephone company, providing dstine!
cost advange.
(Maintenanoe end Plant Operation jn the telepbone operating com
rane be elas into these broad heuings

(9) Prepacny for servos,
(a) Previcing service,
G5) Sustaining seve.

‘The fist of chase categorie involves selection of eable pita snd
verifies om tl telephone plant is suitable lo provide service ordered
by a customer ob an appropriate ervieo dave. Normally, a suitable
pool of unesegaod equipment is available to provide the serve £0
thas the noed or holding s sevice order ean be avuidet. Ness te m=
plementation ofthe serve order requires tht the selectad equipment
bo eoonectod end theeby dedicated to the ase of « single evetomsr
im the tare of individual Hes or the eagregale of customers in the
taza of trunk and central office equipment. Verification that ese
fequipmente and intaronnations arg in fact operable ia zequired he
fore the eevice may be started. Finally, thore will be ocessions after
‘the stant of serve When toxble ass, requiring msintensnes selon.

Planning for mainlenanee bas also recomised taal Mlturephoe
service ia new and complex service thee initially will be provided
fon o liuited basin, When caaidering rsincenenee, the eamplenity
‘and imied seope of inital Pistwphone serview wore al cos pur~
poses, Complexity (and newness) oupled with inexperienced erait
Deople sugget tae need fr ivaieate aad expansive vee entipment de-
ied to make decisions for che exait people (GO-NO-GO testing). A
Timited ite! network, however, ean il afford higirpriced hardware
since the pereustamer cows bacoms exeassive, The stadeof! betwezn
fheee factors ee decided by the projected growth rale during the inie
‘Hal years. I he abecote of clo indication that a erong growth of
service would oot in the snitial period a large expendilare [or eom-
plex taintenshos hardare i not juctied. An aecgpiable alteroive
Je the ase of les expensive baniwaee, operated on mzual buss,
oupled wth owrfulteening of ert people capsble of adapting to n
‘riety of staationa, The aburage oF elled manpower vomlicetes
itis approvel, but it ie antcioned chet the measured grow of the
service wil tot overshelm existing training espabilty. During the
Jail sevice perod, additional infermasion wi be gathered to guide
‘ho devign of the next generation of complex end aulomalic haréware
capable of quality maintenance for 2 system of incensed sige and
ising generally available oraftanen,
ane TREANER MAN ms

21 Bosie

‘onsidraions

‘Tie philoophy dhot hse guided the planning of Pistnephone maine
‘eounet opaations hs bean based upsin seri of objertivs, nekading:

(2 Acrangements vo insur service incegrity and change sey
(G3) Fenturs for antometcelly detecting utd idankying trouble,
(G8) Mentures Zor manna trouble veriteation, Ineation, and reper
With centred sting fetes here fis

(8) Provision for one-man test opernous tothe maimum exten
possible,

(0) Capedilty of adding additional automstic txt arrangements
ss serve demande incre,

Primary empbasie wes piarat on rete segue? to avure tht ele

rigicated by customers nec vomalied 20 the destinations desi with

securste Feconng of sharps, One aucio aud two video tranemision
paths muse be established between the originating cuslomer and the
istans perty. Feilure to complete ny of thee paths should alas
bi dstectae so esto avoid fake hing and to promply indeabe

‘eed tu redil, Whete povsile, couse detention ehould zee an

Slat. v> Lnnble record ead reicval af Gealty equipiens fom er

ive, Rotsipt of the trouble incication should ease smmodiate action

lay the mointananee Tavees. Barly comeetve notion enhanced if
one-man test operslions ars provided. Automation of maintenance
fueome promises to provita further eum, redustions aa tae weape of

Pioturephowe serve is exparded, As wtiowed i the Sntrecuction,

tloee coordination wth taleabone viinierance wes & nesesery oo

fideracion in ronieing all of ese ubjetives, Work loward mecting

these objectives has reseed in a Siow Alsintenanee Plan, the ube

Jeet oF this actisle. Ta geago she se ef the pln, one st eecognine

‘at the desianers of eerspaneat faults ad eubeyaivnn pect Tor

Wir individual muingstene tho specalans lorkniguee end tans

‘ized for maintenanoe. In general, tse ems Gcatallatin tot set,

Seouble detection eireiss ead alenie and epovial tess sets for touble

fsolatinn snd repair) are talored to the specifi hardvare item acd

‘io nos result ia system inierseions, The Syste Maintenance Plan

‘en's with tae ensemble of wubsyctome tha! wombine to make up the

Preturephone servioe netware
‘Tae plan anticiptes 4 Picturephons ays that ia not static, bul
624 sale 6m, ever aecuNcAL JOUER, PMIRDARY TL

is constantly qroming and cbsaging, New station arrangements, new
subecrber lin, and new trunks betscen switching ofess ms une
‘Senge overall utalation ana avesplanse texting. Addvione and ro
lrrangeiente con adrereiy nfeetajaoent aipenent through human
frtor aud therefore routine performance teaBng is required to delet
‘degrading serviee situations dr Wo the foregoing as well a8 nonal
‘ating ets, Hailunes detected iy routine tests and fallures reported
bby trouble alarine requte that trouble tation testing be instituted
fo aome mor portion of the overall syetex. These three yes of
Seecing on the overall syetm employ similar prinsiles and require
such the sme erafezan trining. In addin, eoneolidation of tain
Ihe progeare win eonan uae of test aes for the three types ut tst=
ing reelt im ooeteavings

ical contdcrutious of adauinistation detated that hardware
development snd the proeeiives forthe three bypes oF testing eon
tinue ta be onienzed tows the separate areas of responsibilty as fol-
lows: (3 cmtral ofc ewitciog, (3) li end station, and (i) trunk
svintenenee, Tae plan envision that administrative procedures and
the orginiaution of teeining programa Bell System Prectice, wud 1eo-
fords be divided aoeording eo those tree rexponsbiliis,

23 Work Decations

igure 1 is a simplified Mosk diagram of « Picturephone svitching
fe, the local area served, and the trunking connecting che aie with
the rmainder of the Pistuveyhono network. The figure shows the
woke locations for switching, line aad (rank mintenance

"Mintennnee opertions eeotintod with the switching mucbine are
frgely automate and teke adventege of the common contol and
tneintenance feolures previded for telephone maintencaco, Tolephone
twitching machines provide for per-esll Lest to very the operation
thd contizity through the ewiteh In sition, as an aid for opera~
tional and. tranemision teting, aulomutio fest terminations are
normilly avilable to enable eraitemon ab distant telephone offices
fr on customers’ premiscr i check cizeute without the need for
‘manual weitance at the evilching aching location Sinilar suto-
tatie tet equipments are planned for the wideband switehing net-
iwork when Picturphone ewitching espability i added ws shown in
Fig.

"Phe manual work location fr evitehing macbine mainéensnee ist
the No 6 ecoutbar master tan frame in the maintenance cesta.
‘Trouble decesed by the avtamutic equipment ie indicated to whe
eanermxcnon Pay 85

“Eifion in esto ith nee spe nd

cralt pepe eae Une, sn werfeabinn tests ape conde using he
text notree provided a the lent frame, Poll mal runt) of he
machine {both telephone an widehend noetons) ix exreied fom
{his work “orton

‘The basin yk for Pctweyhona serviae proves ha in nas see,
ho eustomers video service will be logically elated to his tlephane
rervice by Ihe mgilarIelehone vantine ‘Peleprone line saintensne
62h sy MUL orem THEA, JOURNAL, FEBRUARY 167

is ceatelned ino plank sevice center; Pictiephone line msinte-
"bance ean be sccomplished from the sume lostion, Thereby, the Tine
eord earce for both serves ane cooedianted and norm edziistrs-
tive procedures cnn be used to handle all custome trouble, Teepione
Tine testing is reoompliehed fom a tolahone Toeal test desk’ and
Piatwrophone line tering ix aemmplished fm o wideband local tet
Alas of new design. Far both ‘elophone and video, te asoees from
th entraizc’ lest lcestioa to the thossonde o? loos werved Ty the
bie is vn the ewiehing machine, Deperienoe has shown that this
teas of aces for telephone tating is quite laquat; fo veo, the
hiner vavialiaae in mesisresens due to varial pathe throug the
fwich must be considered, although switch peravmarce i minor
fouree of innairments? Figure | shows the work loogsion for video
teming and tbo tet acess oth.

"The recent ren i the route feetng of telaphono orn Iowan
renctatieed contol of tie antomatie vesing,pavtcalesly wheze there
tre Tange number of trunks nd trulegeoupe. La tho inital years,
fhe numer of Pietuephone tous wil be small nnd, ia generar
integrated wit the Itephone networs, Pictercphoneinceraiie trunks
form an independeat network of se-wiee ‘unk Teclitos* diated to
‘Puetureptoneeorvies se, Similarly i 20 expected that the Pctara-
phone NierareSy of switching ofeee il soinrile with t= talepbone
‘crore In ight of the rsltivly small members of rune wn oe,
it ear thie « compler arrangement for centred mniniensnee
ano be jurded ut fis time, In edition, the rerreive perfora
te objectives for (oun aeguiro previee meamarements, «sulin
teckaoal chelienge in ieelf, and. ceniraliation adds the potetis]
be ulitional measuromest emer. In eonimet io Tine, the independenoe
Of Plclureplone tran fom telepne trom eons tht cere ae 10
‘vemiding adminis ive or nvord considerations hat make it mper-
ive to Uist telepbose ard Picttephono trunks fom the same los
tion. The work oeation is a: @ lowtbend in the visiity of the
‘nilehend Piturophone switch (Gee Fig. 1). This nearby location is
goverad by the need to mnlsin neanly davies traneaission per-
formanee in tha teebegotee lh Lo aecompich tho prosine rreneyre~
nents need for frank maintenance, Szort neces irks sing iin)
erties teunsvssion eouipment, achieve the roqired“tranepareaey” ut
Fersonable cut. Cantrabnation, however, met be anticipated, but it
ectning for future eansidertioy. "To hie ead, switched acme wos
thoeen for all wideband test avotes (in voniral lo some Ielephione
practices whore seoes ie om a per-cireit jee buss) boceuse of the
potential for fotore eonteliztion and tho tecnieal compliestions of
providing dediestad pertrunk fack (ype access for the wideband
Sirouite et standard levels ‘vithoue inmodueing intlerable path
Iongth variations.

Be Adsiiona Considerations

In nditon Yo fators such a rinteentoe reqpousbices sad the
stint wore lovations and test sees, provibion of transmission
testing equipment for line and teunk ting bes boen based on tho
Folleting aditions! considerations:

(6) Initial serve analog trassmisson facilities for tines and tronks

county sien.

(G9) ‘Too nature of troubles and their prevalence will not be sell

defined until sevice experiance i obained

(8) Training of erafemen will be Tusitated i texting equipment

fend provetures are antlgpis to those of existing telephone
fd cucrier sytem,

(9) Improvement and pdeting of individual equipment il be

Souiiatd if initially, test ets aro restrict t single catagories
of teste aad exo wo consolidated and i itoreeione betwee
(eet insteurcent ao kept inane,

) Conte and develogmaent inkervabewoulé be minimized if “one
Ghoshal” oommersial tee sete would be ulllgel or csi
for Piturephonn torso

"The system maintenance plen reaulted ‘rom a agathese of all of

the sforemantioned considevtioue of erganizaton, technology, and

cus. Tae folowing seetions det in grout detail wit the lan from
the sinadpoint of the ewiching machine, ines, and tronks

{1 Aainlenance oud Plant Operation Bunations

‘The wee of wideband emitting aotwark similer Zo the audio
rutwor: usa the incuson of Pisteropicne features is existing com
soa contol civeita paris tho Plturephone maintenanoe at pent
operation “wnolions (0 he pxabined with te peesoe aucio Zunetions
Figute 2 Euler te vrajar blake o the Plsturenkone eves ead the
rmaintecance fac'tis for teoox’ing trouble iommation and testing
thoes ina No. emsarcental loo

Inlay Meturgtene vos i mnedopiy fem No, § omar mien
ogee ihn ae ee Reh Mate ge eet
‘Decline win vultebiewidataad aetworke ate develeds