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Telos Zephyr Xstream Two-Way Radio User Manual

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USER’S MANUAL

Appendix 10 – Glossary 351

DS1‐DigitalSignalLevel1ThesecondlevelupthedigitalratehierarchyusedbytheTelcos.

Thisis24timestheDSØrateforatotalof1.544mbps.SeeDSØ.SeealsoT1.

DS2‐DigitalSignalLevel2Datarateof6.312mbps(4timestheDS1rate).SeeDSØandDS1.

DS3‐Digi

talSignalLevel3Datarateof43.232mbps(28timestheDS1rate).SeeDSØandDS1.

DSL‐DigitalSubscriberLineTraditionallyreferstoanISDNcircuitorsometimesaT1line,

althoughthetermisalsofrequentlyusedtomeanthenextgenerationbeyondISDN.Someti

mes

xDSLisusedtoindicatethatthewriterisreferringtoanyofanumberofemergingDSL

technologies.

DSU‐DataServiceUnitSeeCSU/DSU.

DSX‐1‐DigitalCrossConnectlevel1(USA&Canada,primarily)DefinedaspartoftheDS1(T1)

specificationandisacloselyrelatedsignal.Th

etypeofsignalswitchedbyaDigitalCross‐

ConnectSystem(DACS).TheFDLisstrippedoffattheDACSinterface.DSX‐1isalsothetypeof

signalthatarrivesattheusersideofaCSUonaT1line.ADSX‐1cableislimitedto655f

eet(200

meters).

DTE‐DataTerminalEquipmentWhenusingserialcommunicationssuchRS‐232,V.35,orX.21,

theDTEisthedevicesending/receivingfromamodemorCSU/DSU.IncontrasttoDCE.

DTMF–DualToneMultiFrequencyThestandardtone‐pairsusedontelephoneterminalsfor

dialingusingin‐ban

dsignaling.Thestandardsdefine16tone‐pairs(0‐9,#,*andA‐F)although

mostterminalssupportonly12ofthem(0‐9,*and#).Thesearealsosometimesreferredtoas

“TouchTones”.Notethatwhiledigitaldataterminalshavethesamesymbols,ISDNuses

“commonchannelsignaling”(o

vertheDchannel)andthereforedoesnotnecessarilygenerate

anytonesatall.Howevermanyterminalsstillgeneratethetonessincetheywillstillbeusedon

occasiontoaccessservices(suchasvoicemailorautomatedattendant)atthefarendusingin‐

bandtones.

E1Acommontyp

eofdigitaltelephonetrunkwidelydeployedoutsidetheUSandCanada.Has

31available64kbpschannels(calledDS׎’s)plusasync/controlchannelforatotaldatarateof

2.048mbps.

E‐1SeeE1

ESF‐ExtendedSuperframeAtypeofLineformatsupportedonT1circuits.TheTelco

deter

minesthelineformatandlineencodingofyourline.SeeLineFormat.

ETS300ThepanEuropeanISDNprotocolstandardizedbyETSI.Thisprotocolisusedthroughout

EuropeandhasbeenadoptedinmanyothercountriesoutsidetheUSA&Canada.Seealso

MSN.

ETSI‐EuropeanTelecommunicationsStandardsInstituteEu

roISDNSeeETS300.

ExchangeAnothernameforaCentralOffice(mostoftenusedinEuropeancountries).Alsoused

intheUSA&Canadatorefertoaparticular3‐digitprefixofa7‐digittelephonenumber.See

CO.

ExtendedSuperframeSeeESF.

FDL‐FacilitiesDataLinkAbi‐directionaldatali

nkavailableonT1circuitswhentheESFline

formatisused.TheFDLisprimarilyusedbytheTelcotopolltheCSUforerrorstatistics.

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