Presentation on theme: "TELECOMMUNICATIONS CONCEPTS"— Presentation transcript:
1TELECOMMUNICATIONS CONCEPTS & COMPONENTSTrunks, Lines & LoopsThought For The WeekNo Question Is A Bad Question!
2Key PointA Loop Is Like a Road That Can Carry Different Types of Traffic. The Type, Or Size, Of A Road Can Influence The Type Of Volume of Traffic The Road Can Carry.
3LESSON OBJECTIVES At The End Of Lesson 3, You Should Be Able To: In This Lesson, We Will Review the “Products” of the Telecommunications Business: the Main Methods of Transmitting Information Across a Connection.At The End Of Lesson 3, You Should BeAble To:Explain the Difference Between A Trunk AndA LineDescribe The Most Common Types Of LocalLoopsExplain The Difference Between Analog AndDigital Signals
4Telecommunications Terms The Telecommunications Industry Uses SeveralSpecial Terms To Define And Classify Its TransmissionServices.Central Office - A Telephone Facility Where Telephone User’s Lines And Trunks (Local Loops) Are Joined To Switching Equipment (Class 5 Switch) That Connects Telephone Users To Each Other.
5Distant Central Office Telecommunications NetworkDistant Central Office(212) 123-….Residential Line CircuitsFXTrunkLocal Central OfficeLocal Central Office(732) 560-….(732) 435-….TieTrunkOUT-WATSCO TrunksIn-WATSOUT-WATSCO TrunksIn-WATSDID TrunksPBXPBXStation Line CircuitsStation Line Circuits
6LinesA Line Is A Circuit That Connects An IndividualTelephone To A Telephone Switch Such As AClass 5 Central Office Switch Or A PBX.A Line Can Be More Generally Understood As ATransmission Path That Connects:A Piece Of CPE To A Class 5 Switch At ACentral Office.An Employee’s User Equipment Such As A Telephone, Fax Machine, Etc. To A PBX.
7Residential Line Circuit Residential Line Circuits Are Usually Made Up Of OnePair Of Copper-Wire Cable For Each Circuit.Class 5 CO SwitchA Residential Customer’s Line Circuit May Be JoinedIn The Local Loop With Other Lines To Form AMulti-Pair Cable Such As A 100-Pair Cable.What Are The End-Points Of A Residential Circuit?
8Business Line Circuits For Businesses With A PBX, Line Circuits Are Pairs OfCopper-Wire Cable For Each Circuit.Internal Business LinesBusiness TrunksClass 5 CO SwitchThe Cabling From The PBX To The Central OfficeClass 5 Switch Is Classified As A Trunk.What Are The End-Points Of A Business Trunk?
9Business Line Circuits - Continued It Is Recommended That Line Circuits WithinCommercial Buildings Be Installed To Meet StandardsSpecified Within The EIA/TIA 568 And EIA/TIA 569Standards.EIA/TIA 568 – Commercial BuildingTelecommunications Cabling StandardEIA/TIA Commercial Building Standard ForTelecommunications Pathways And Spaces
10A Loop, Or Local Loop, Is The Physical Connection That Links the Demarc At TheCustomer Premises To The TelephoneCompany CO.Class 5 CODemarcLocal Loop
11The Local Loop Can Be Formed By Several LoopsThe Local Loop Can Be Formed By SeveralSuitable Transmission Media, Including:Copper Wire(Ex. 4-Pair UTP)Optical Fiber(Ex. 2-Pair)
12The Local Loop Can Be Formed By Any Loops - ContinuedThe Local Loop Can Be Formed By AnySuitable Transmission Medium, Including:Coax Cable(Ex. Plenum)Wireless LinkWireless NIC
13Trunks A Trunk Specifically Describes The Connection Between Switching Systems.Trunks Can Be Classified According To ThreeMajor Characteristics:DirectionCapacityTransmission Type
14Trunk Directions Trunks Are Offered To Business Customers In Three Configurations:Incoming Trunks Carry Calls From A COSwitch To A PBX.Outgoing Trunks Carry Calls From A PBX ToA CO.Two-Way Trunks Can Be Used For BothMaking and Receiving Calls.
15Trunk Directions - Continued Can You Identify A Type Of Business ThatMight Use Incoming Trunks?Might Use Outgoing Trunks?What Is A Business Incentive For A BusinessTo Install Incoming Trunks and/Or OutgoingTrunks?
16Trunk Capacity Capacity Means The Information-Carrying Ability Of A Telecommunications Facility.Trunks Usually Have Higher Capacities ThanSingle Lines.The Capacity Of A Trunk Can Be Measured ByThe Number Of Individual Lines It Provides.Trunk Capacity Is Also Expressed As TheNumber of Channels the Trunk Can Carry.
17Analog Transmission“Analog” Means a Signal Is Carried As APattern Of Continually Changing Waves.There Are Two Basic Qualities Of AnAnalog Signal:FrequencyAmplitude
18Analog Transmission Frequency Refers To The Number Of Times Per Second a Wave Swings Back and Forth In ACycle From Its Beginning Point To Its EndingPoint.On The Frequency Diagram, The High-Frequency(Closely Spaced) Waves Would Create A High-Pitched Sound, And The Low-frequency (LooselySpaced) Waves Would Create A Low-PitchedSound.FrequencyVaries
19Amplitude Refers To The Height Of A Analog TransmissionAmplitude Refers To The Height Of AWave, Or How Far From The Center TheWave Swings.On The Amplitude Diagram, TheFrequency Does Not Change, But TheAmplitude Does.Amplitude Varies
20Channels and Bandwidths The More Frequencies A Medium CanHandle, The More Channels OfInformation It Can Carry.Each Assigned Slice of Frequencies IsCalled a Band.The Information-Carrying Capacity OfAn Analog Transmission Path Is CalledIts Bandwidth.
21Channels and Bandwidths A Channel Is a Basic Building Block OfBusiness Telephone Service.This Process Of Dividing Or CombiningIndividual Channels Is Accomplished ByUsing A Device Called A Multiplexer(Mux).
22Digital TransmissionDigital Communication Is A NewerTechnology That Forms The Basis ForToday’s Telecommunications Networks,Services, And Systems.Digital Technology Is Now Being Used ToCarry Many Types Of Signals On The SamePhysical Media, And Often At The SameTime.
23Digital Transmission“On” Bits Represents A 1 And “Off” BitsRepresents A 0.When Bits Are Transmitted Over Wires, A“0” Is Represented By The Absence OfElectricity, And A “1” Is Represented ByThe Presence Of Electricity.
24Digital Transmission Two Reasons Why Digital Technologies Create More Accurate and Clearer VoiceCommunication Are:First, Digital Bits Can Only Be on or off.Second, Digital Transmission Makes It Easier toDistinguish Between Signal and Distortion, or “Noise.”
25Digital Transmission Digital Signals Are Susceptible To Distortion They Are More Reliable Because ElectronicEquipment Can More Easily Recognize TheOriginal Pattern Of High And Low ElectricalCurrent.
26Pulse Code Modulation (PCM) The Analog Vibrations That Represent The SoundOf Your Voice Are Converted Into DigitalElectrical Impulses Through A Technique CalledPulse Code Modulation (PCM).PCM Is A Sampling Technique.Each Of The Samples Is Converted Into An 8-BitCode That Represents The Frequency AndAmplitude Of That Sample Of Sound.
27Multiplexing Multiplexing Is A Method That Allows Multiple Digital Messages To Share The SameCommunications Channel.To Understand Multiplexing, Imagine ThreeGroups Of People Lined Up To Board The SameEscalator.
28Multiplexing The MUX (An Electronic Device In Real Life) Allows One Person From Each Group To BoardIn Turn.The Pattern Will Repeat With Another PersonFrom Each Group, Until All Have Boarded.There Are Two Dominant Types of Multiplexing:Time Division Multiplexing (TDM)Frequency Division Multiplexing (FDM)
29Time-Division Multiplexing (TDM) The Process Of Encoding Two Or More DigitalSignals Or Channels Onto One Media (Wire, Air,Fiber, Etc.).The Reason That We Multiplex ChannelsTogether In Communications Is Because It SavesMoney.One Example Of Time Division Multiplexing Is AT1.A T1 Contains 24 Channels.
30Time-Division Multiplexing (TDM) Imagine The Difference In Cost Of Transporting24 User Channels From New York To Los AngelesUsing 24 Individual Pairs Of Wires (48 Wires) Vs.Using 4 Wires If A T1 Is Used As The Transport.
31The Information-Carrying Capacity Of A Digital BandwidthThe Information-Carrying Capacity Of ADigital Line or Trunk Is Expressed As TheNumber Of Bits It Can Transmit PerSecond.Digital Bandwidth Is Commonly MeasuredIn Kbps And Megabits Per Second (Mbps).
32Special Access Trunks Trunks Can Come In A Variety Of Capacities, And Provide Various Types Of Service.Some Of The More Common Special Uses ForTrunks Are:Tie LinesPrivate LinesForeign Exchange (FX)Ring DownTrunk Pricing
33Tie Lines A Tie Line Is A Dedicated Circuit, Connected Through A CO That Links Two Points WithoutHaving To Dial A Telephone Number.A Tie Line May Be Accessed By Lifting ATelephone Handset, or Pushing A Few Buttons.Many Tie Lines Provide Seamless BackgroundConnections Between Different Business Systems.
34Private Lines A Private Line Creates An End-To-End, On-All- The-Time Connection Between Two Locations.Each Private Line Is Connected Through A CO.Private Lines Are More Popular For DataApplications Than Voice.Private Lines Are Typically Billed A Flat Rate PerMonth Based On The Amount Of BandwidthLeased And Number Of Airline Miles Between TheTwo Connection Points.
35Foreign Exchange (FX) Foreign Exchange (FX) Refers To A Foreign Exchange Trunk.In This Case, “Foreign” Means A Non-local CO.Companies Use FX Trunks To Provide LocalNumbers in Cities Where the Companies Do NotHave Offices.FX Trunks Are Also Used To Transfer DataBetween Two Distant Locations, Because TheyProvide High Bandwidth And Security.
36Foreign Exchange (FX) An FX Trunk Starts at the Customer’s Location, As Shown on the FX Diagram, Connects To TheLocal CO DACS, and Extends From There To AForeign CO Anywhere in the Country.
37Ring DownA Ring Down Circuit Is A Special TelephoneLine That Rings A Particular DestinationTelephone As Soon As The Caller Picks UpThe Handset.Type of Dedicated Line That PermanentlyConnects Two Telephones; A Ring DownLine Cannot Be Used To Call Other Numbers.Ring Down Trunks Are Used To Connect OneStation Directly To Another.
38Trunk Pricing Trunks Are Acquired Based On How Much They Are Used. Companies Get Flat-Rate Trunks; The CompanyPays A Fixed Monthly Fee And Can Use TheTrunk As Much As Necessary.Companies That Only Need To Use a Trunk Part-Time, Trunks Are Available On a Measured-UseBasis.