BSTJ 50: 7. September 1971: TH-3 Medium-Haul Application: Protection Switching . (Cooney, R.T.; Griffiths, H.D.; Lanigan, F.H.)

14.4 MB·English

Protection Switching

Dy RT, COONEY, H. D, GRIPEELTIS, and PE TANTGAY,

Tis poows S00 ond the oxitery chenvel poten
ceiling sytem whic pr antinty of couse 4 THA weve rat
din spon Bah ation etching aptams eprae on a ayo
Frequency erety hans. Me SH. fee baseband. beuion

Droetsthe wouaye ew aed. Te marley han
ort the ative at iar tet autopsies ith TP an
Inetcn fropueneie, tin Henge setdoratians eo vate spent
Sor, Swing wid ate enshes ad nlrb cir cus, ae

Pratcetion svlehing syecems yeoriding comity wl rssaage ener
ioe ates neveeeury past af ane rede eemamuniention sles. For
Tene-tac] applies, ve THA van spaters nes the 2008 TF-to TF
protection sitshing yan Jer cho radio poston of the speicrs ud

fhe 2008 Li-to-ousc und nal hasehardeto-T® prateedon szehing
syst for th EM termi wu ere vor Tink portion of che eystem
‘Fa sepatate evitching eysiams sm roined snes writing eeesons
fer ton conzetel in saver lve verging redio toxtse are often

ileteonrected:€ IF facetcacies Poe erliaehan) agpleatine, the
‘TH eyataun is gener y sorptaed af a ingle smitesing eztion

Fat terminals ee each ov. Twefoe, asehatseea-hesebend evitein,
senmessing bo the rio ard atch port af the rao spe
emis a wore otizan ermargesien! Ta ddim, sine ENE ROA
Gf seview on nse meduaa-onfeatllations ie expected tn be reen
Cee elow sik vaio shennel ofthe message eepueity of TIES
ial be adequate for sany years. Thesefore, a eyetom having ete
egulor channel tarrying rien abd ate pootection ebsanel serving
BOIS te wets ne TeASIOML SoMRNAL, SEPTENER 6T1

22a hackop ie apprepeste ‘Ta mest theeo mous, the 300A, wne-by-o4e,
‘ascdand-to-hasebans, protertion. aviling sya wns cevelope

Tn tis seston, the seo vaso ebannele are pertanensly Weide’ ot
luo trating ul of The ewirhing section and ae smtehed at the
receiving end of Ue sfiter, The eveeting end ccuipmes: iueludes
A uoxeroverive sil chavo? wonene, end cont tonetions. A
lied desesighon othe 300A. i given ita Berson TL

‘The susiliany radio chancel is art uo the total maeesge as
usin by she TLL nue sy em ae ao olen mit
ing arsters wich 'ssepucate from cLe 300A eysiea.’ The wusiiary
leaaiel pein idse eins foe ure ithis the epseehingeoobion to ary
tedercvite, slamm, nad contol imation, Thos ecru hace np
pverannss at caah ofthe racio stone wong the rue Tus Feiabil
Gl servin, the eaniliary chanssls ez inserted on bork the rsxulae
and proractios chances et thy suo eaten, he ivy elvnel
rolslinn sriching equipment we the sescliag sun statin éctor-
lhizce whee” ee aniiary share) damnds ating egaipmn i rane
sneeteg to the regular o* the protestion eharse. The sepeacer station
Protection siching i slaon’ tov the vain seation suiprent atl
fporctce ia aenconse ill ‘L,"The susiliaey chav ne" wi cine
peter is deseo in Sration TT

1 SOBA onoenon sane Sasa

A ones sac ing sention stitsing che 300A ester is show in
Fig, The sepion ieticen one or more eso. a9pa with IM cormizale
sad wine uo zartnce Hrke ¢: caeh end, The entrance Hake aay be
fennecied exci: Lu i elling npstem if asied. The eranezitting
fen of the JOD yale fence We Tawrban’ sight ‘ver oth eFanrele
by sarane of « lbp taratorner, The Evbsid ale oouslee £ oon
‘inuilyoiot oil balay whannele. A it rms assess 20
the protection ean] for cannpoaey malonate oF for her pure.
"The finer gt tan recip eud fe to movitor the quality of the
hance’, perfor the sexes cogie nul sv Cauebirte, at
Site ets rhe tn ete

“Au “omovniew of thin aya ie ean eho eksanel roniters weed ea
Altering channs® quaity ae loess afer the rsoaiving sito. The
facramtee oF Us eave ix that he sage i he ADDS ayatern
ootentx: by Lie swing alee, Ae m cmmanenae uf Ul aera
Ion, the chance’ waits er oh assed wih 2 pertcsle ri
ani

lose Yorn Mo Saas ORBLE AE
BER rn ares avRTROE TFEMIOAE TONNE, STIPOABER OT1

and, ut uy be eccneeted to eithe: axe cepening on th parton
fof the ewiteh. ‘Tho working monitor is connected 20 thn output of the
‘osiom Uutt de carping serve, and therfore will sneicate silure
very snus serve is lost. Of eons, ifthe teadoy channel is areil-
able, the failure aboalé not lar: lenger than ie takes Lo aomplele
{itah, whieh fe shout one mlisesond, The etazchy monir ix con-
‘eet to the ebannel nn carving, eve.

Chartel curlily i aelerrivol ow Ue her of the preerse ot
agree of he contin pila: and on the Teva oF noiee in a eloe
lott al 102 Ms, Lihor loss of ple or exvonsire nose ie con
sidered» cline fvilure whieh, if emsanting drom the working

Tonio, wall ate a ite. Taree from the standby mouitor
‘ell sii alan, Te moive enbold whic «ies file ii
cations yiven frum the woking ehannel romor eoresponds to a

oie lovel of 55 ¢yned in the Yop mmeccagecieait. The aandly mast
Hor i ec st a noise leva, of 59 dened to iantr jsiive ewitel ng

"The continuity pilot Fequeney of 1.890299 Me wae chosen for
‘he flloging reasons:

(i) Te ean bo weed om aystems corning viinw r gia signee
Whose inte-ision eroubemes wreince Ihe ove of low=trensese
pilot.

i) The frequecey sptetram inthe viinty of 1.88 Aba ia clear
of eay incerfesone from the radio eystetn and 9 tone at. thas Frequency
Noes not zien ilarfenrace ant the vadia =Feten oF ino the 300A

oie lor,

(6) Whew fwenunoy redulat? on the agin aeaen, the Rama
border eels 0° Pie TURR-MHs pil flection
the achacert ohennel signal, Thi reves the posbility of edesent
chine interfere,

(io) Modulution products eluted ¢o the frequeney difference be-
toveen the pant an the axliary channel camer 111.386878 MH;
fall at lotction whieh cause minim! intestarence

"The trenseittcd pilot level of 7 Ain0 sorrepands to Hreqursey
deviation of €9 ka rm on the pre-emphasized THL3 syeters, whien
is mithin CIR zeeommerdations for his ‘ype of pila. This level was
Alsermine fer emnideeacon of reveal intersted system carte

‘esistee and cites Hmitetions. Twas desirable to inser the plot at
the: lowe site level to cninige inerfrenes an modultion
problems and to loud the suessaxe base! ns litle as posse. On
anmzenios SeTeMNE aan

the otber sam, high silat levels wuld allow vider gilt desetor
Ines for a rut rt piketa-noise rain, tareby enabling Ps
Cleese fo oporsts with getter speed Tie above level REE 4 eoIne
ppmmisa between those fers

"The pila detector trip pon (where tae channel monitor inate
lacs of plot) was eboeen to he —17 Brad ar 10 UB below the evel
of the trvssoited pile, Allowing 6 IR. for misalignment ard for
T188 MLL rollfT in tle vaca ster, 9 minim pila-totsp- point
slo of 8B zemaine, The mr ie considered seesetry for zehisble
etesor oration.

‘A letcolar oabdiideh of 12 KHz wa ehosen eo insure st ian
caonot sinutste the plot ane. « fechiw due ve nsies hae arauro
This besdWth ie aufecenty wie “o allew velatvely louse res
rants on the frequency stability uf Ui ilo. oseltor end ox che
felectivity of the pile stortor Biter, THth shese charaeteicties, che
pilot deinotoe segs to los of palat within one williveond at noe
Towns eeoeting 35 dene

‘The nake slot is located 102 MH and has bandwidth of 20
Kelle. Gonsidersinnesohieh le to this eeleetion are we follow:

i) This foqueney ie above the 10-Mls basebuad wn fe Ivlow a
ptertal souree of irteercre frm =yszem cones t¢ 1085 MH. Tee
tay Toe engueh to ellos gomd earcaticr between woe iu the slat
fd soins 'n the moasage eens.

{ai Tho handwidth i > eye as posse cansstnt it wealistr
selecivcy roqurensnts en te na elena Alter. Phe bedi is
filleeatiy wide tw provide rasonuble speed of recozition 0! Wid
hoise levels Spe! tecngnsion uf exe nnise ie dependent upon
the tine coninns of he deterer eee the raca of sbange of noe
Tse, and the eta sive level, With the bandwicth and the éetestor
parameters eos, the eter all edicace channel flue in suk
Ti licens for a sudan elcaye iy noi level from no wake
hse dD gree 1 thon the apie fil pst. Since the fasts. foes
fvelycxsced 1 aR per 10 nullsewwn's, Tie speed of sespunse is
Ilogeste Te sboulé be net theteqignse fh ae leteted maneh
tuum rapilly by the cont pot deveta

"The avitcing element tsa the 200A system i «wid sate base-
bund sasteh arta inthe ceigurtion shown in Fg. 1. Tl funetons
cia make bafere break switch eo ine eunlity of sevice wan
rensier between Uve quiet and proiecion sianaele ie made, poo
ign! that ta two thusnels have been tule Jer eheolte dey.
2520 uy wots ersous mates coun, stmaae nL

The cperte time of tho switch is approximately axe mlsceend. The
ssh iz eontoled clesetly from th loge exeut

‘One of the inhecern pnopirtiee of soli stacesmiteh is thet when
power is Tent, Teonsmtion thmaigh Ue suite i Tonk To pewsent
Tesniesion ll Uinongh Uke SODA switch, the eich is powered
from two separate 424-voh, ferders and tho cnet is wrramged to
"aint Leunsneson to the wurkng chanel onept should one of the
feeders fal

The JOUA speter harass baacsand moresge Signals from 00 kis
va 12 Mle with the Zollowing setumasion ebsrorterstie:

Ioserson LeeLee han 1 dB

Froqueney Resnonse—Within UB, 60 XE to 12 Ade
‘Weshin (L098 ef to 10 BULLE

Feturn Loe—Greater ta 3 dB

Tela Crete than $9 JF,

‘Transfer Tise—1 millon, make Dafoe break

Trae Bid
ngetion Lass Ls than 4 dB

Frequency Reeponee Witkin 0.4 AB, 0) Esty 12 MF
IRevre Lows--Gnetar Yn 28 R

Integrated eiruite are weed escbuively to realize lopie atv contol
functions end ate used oa lita! extent in the near eis, The
Iogie ad control eieuits noe Wowuern Fleets Avo RTT. series of
intgeate iret. Tntertaring between the 4volt gid the 24-vall i
fit is aocompished wl lay deveer integrate eres Taal
tecasona nplifiene are ured as de pliers amd ue mmodifed
Seen vigor AY inlgata eirouits wae the 2008 syater soe
exc hybrid in-ogratod eiceite, uch istograted cireue cones:
Gf wsLicea chy meuato! on «verte rubr-rae having a raf frame
to allow application to etineasd parted iting booras, & eepisl
piintad board is shown ia Hig. 2

“Hisld sraintenance ofthe UL aystern ia asoorapihed with ofan
tes equipment generally avaiable im zacio etsione in eonjumesion
‘pith exo eeilstore and x slic pa tilt nto the SONA payee The
theo oeillaios, ane at 192 NIH». al [he wer ab 11.88 ME, ete used
to adjust tho noice and pilot trip points of tke monitor ans, sare
gein nia ate provide to allow quik repair of the 8008 system

Bower sonzoce of +24 vols and ~ 24 role eo rnquted by Uhe 390A
racrzetios swinense 20

4g yield wig nal we alate dee

system. ‘The +2A-valt rource may be ebeained irom thn: ~24-velt
ipply uring de-towe converters nr sinery foom x byllery Waal
Suitable filtering of these supplies la redler noize and trupsents
eeu! with porter supply fillers mouoted in the satse bay 6
the 2004 ecuipecent

Shidiconal voltazes requiral for spweation of the sntereted cic
suits ard-for opesiien of wie *equring zegulaces yolayes nv
hbtaived ‘sich disie regulars asseiatad with the inciviaal vis
‘These voltages ineude 13, —12, snl 62 volte Zor the inograced
siroute and 18 and 18 volts for the moni unite, Redunant
eves fees ate prov ‘usin 's sevenged to peehude lees of
sisson mea angle dese or fooler tie

Onecal Sytes Opera
a Bek Diageo of
‘An spades block digriaa ofthe eeiving ed of a 2008 switeting
system ie shown ip Ig. 8, The “GN” and “OFF” gaves in the diods

Srteh ze eiown srmbu ally ee "neak” ard rks” eantact, 2
wesively. With the exiseh ot ns shona, ehanzel A ia the working
hone! Sad channel Xie tlw sian shennel, The arking aa
Standby pilot ane tole toonitors are wonneeted Go thy respective

Chaamek “arvigh usistive oidging tape These monitors opis the
hecevecry invormation shout tke eondtion of both ehiazele bo he
Entomatic loge, the pilot ain) woiee fail indenting cieat, and he
2822 rem meta xseuse eUsIOAD JOURYAy, AnHSEREIRE 71

lari oiruite, oneed siteh and ebsamel X aecses eontrols «76 pro-
‘ide which operate dircely into the besebead switch control creat,
for maa) ea:trol Ta ewich undies ton cirvuit Mentites te monk
ig channel at al ies.

‘22 Anlnonto Suiting
‘With the gons0! exc for the antomtie mode of operation, the base-
hand seh will prate whenever the working monitar indicates a
Failure while ce slendby moui.or indicates good. Immediate follow
ince ean operation fe markg mentor fetes a! anche
aay muir alone «file
Por example, if chanel Ais Ue washing chasse anc it fits while
ragreenios svscease 8

lnmnnel X% gal, antomarie operation of te ewes immediately
rtkes charset X the working ehanrel and the filet channel i=
tomes dn elaniby. If tlw feline wes du to fading, ebsanel A will,
twenver as the fae eleats out Ta the rite 9 noe rvert. Channel
X will eootinae to he worsing channel and ehannel A the scandby
fui X fale while Aa good, Then tho site will eutowaioety
erate azn to make 4 the sock sane! asd

an Mona! Roitiog
‘The svecving site can be foreed ty make ether of se ehniek
‘werking cheno! by mana opevetion of the ‘anced switch cou-
trols, When the foread suite worlivle are erates, tee aucomecie
Togin lose enrol of the baseband switch, Autoratie operation ie
snes when the Toned we ean uly ae we 1a eta,

2.04 Aces Seating
‘A eacane of disnssociaring ehannels nd X s0thet shane As
sonry the *evne trssage series while channel Cis being used for
lergeney resorainy a some acs spetul sexviee i avaale an
fn optional fowsne, When i is farisbec, operation of the necess a=
‘the truesaiting vl cas the Tranamising aoeessewitel to

"This disvnncte ebstmel S. om tse spattine ast aed
je coe tranke thtough the switch to channel X. At the

ope
ceiving end, operation of t22 access cout: forts Uhe rely ag

Stritch to rake A tle working ehanset und X the stoxlby chanel
freviding ele! & is wt false a2 tze time A anfery bit fate
fs provid whieh reverts the ecerving aevess corto) iret rom
zai feline A's ale

a Alarm

‘A scrvien ile lane ie generated whessver the working ohne!
falls and swinot be mae guad Kamaediatosy by sstorvatie mite
‘pectin

"A dclave feinne! A ns exannel X falune charm is gesenutes wher=

eer the stanly chanel fails ad ve i sceane, When

toe soneee vertieh sn eoerate, £2 service fie olatn
f either lace Ei

eaten
Front panel Langs ae pwovids! t indicate which channel isthe
svorkang shure! whale shasale A and X a7e fled ano to reise
2821 nUM may SYeWAC ARCANE. SOCRYS, AROTMNRE MT

or love of plot, and whether shennel failure ie simply a prolonged
fairs of the stendby thane, oF 4 store soreus sevice Tau
LLanipe ara also provided co indicate whethor the evstem ie aerating
in he automatic anode or wheter ane of the Sores: sete or sree
‘itah santos hse eer opens

an Fai Dessiptone

‘tt Bowl Satoh

‘This vnit ie eompriond of four atching elsmencs andl » contol
[Swit invrporated in one yaekage. Ae ahowen in Big. 1, i hee two
Inpuie (A and By sad two outoute (AB end BA}. The eviteh vn
Uilacerel deviee and the ingut and outpue designations are used for
Gescepsive purpeses only. in its nermal state, the A ixpat is con-
bieted 70 the AB tons and the oot ia eonsecteto-he BA extut
Title swivel sce, th sonneetions ane renee, Aes elomenes
fof tie ein are aly topple slates, a ehavaotariakia which be
taken advange o! i Ue design as éevcriba’ below,

‘Exch ewileh clemets, consis of tive dines, own tnansigos, and
thelr ceotictod eusimannia Ae shown iy Fig 4, eat eee
identical, Operation of the etent eouiting of 5, Qty CR2, and
(CRS val now be decribed

To estabieh a con-loes ecxocetion heweca A. gael AB, tnunsistor
GR is turned on, and transistor (Q4 je turned off, choreby forward
Hiing ides C2 and CBS. To aper the connection ietxtan A eed
‘AW, trator Qi ie ar off anu is Tuned on. Dindes CRD and
CCI ine now reverse hina! Ty Ue re a Le ed epi
bay Qi ans by» psnirevulkage on the eataose idee provided by exe
rout irom wajucent snitch elements horing theongh resistors RV end
2. he two dinlos aid [srsitor Qt orm a cotielld Toe (ve pe
nd transistor QU serves atm ctrent vale to tee the erent
Aran by the exit

‘Sinplted equivalent cizeute of a svitehing clement in the ON"
sd "OFF" slater are shown ia Fig. 5 Brom Fig. 5, the insertion loos
of an "ON" site lamers i gteem by:

ao Fagg [Re + DUR + RE
1 DN) = 20 toy [OF BR

a,

2, ~ sourer impedanee — 75 ohms,
By ~ die Gorvard iunpodance ~ 1 oles, and
FR, = shut ingen a Wasing tronic = 3,000 ao,