Lecture 2 - Sonoma State University

EE 443 Optical Fiber CommunicationsDr. Donald EstreichFall SemesterLecture l-fibres/1

Telecommunications is Very Wide RangingToday a new definition of telecommunications is required:Telecommunications is the suite of technologies, devices, equipment,facilities, networks, and applications that support communication at adistance.The range of telecommunications applications is broad and includes telephonyand video conferencing, facsimile, broadcast and interactive television, instantmessaging, e-mail, distributed collaboration, a host of Web- and Internetbased communication, and data transmission.Telecommunications Trends in 20191. Telecoms lock onto 5G (rapid expansion)2. Internet of Things (IoT)3. AR and VR technology4. Mergers & ytelecom-industry-needs-a-crm/2

An Optical Fiber e 26/march 2015/features/scaling optical fiber networks challenges and solu/3

Applications of Optical Fibers I Communications/Data StorageWide use of optical fiber communication systems for data transmission,including long distance backhauls, computer data communications(LAN, MAN, WAN), voice signals, Internet traffic, submarine cablesfor intercontinental communications. Broadcast/CATV/Cable TelevisionDigital video distribution, high-definition broadcast signals, closed circuittelevision, etc. Passive optical networks: Fiber to the Curb, Fiber to theHome, etc. Most cable television providers use optical fiber networksfor content distribution. NetworkingInterconnection of computers within buildings, across local networks,metropolitan networks and wide area networks. Used in a wide varietyof networks requiring fast data transport and/or massive datatransmission (such as in storage networks).4

Applications of Optical Fibers II Industrial/CommercialUsed in applications that can’t tolerate electromagnetic interference.Also, used in sensor applications, for monitoring places hard to reachor have harsh environments. Examples: Communication cabling inautomobiles, aircraft and boats; also used in factories, etc. MilitaryMilitary requires highly secure and hardened fibers for militaryequipment in combat environments. MedicalUsed for light guides, imaging tools and lasers for surgery. A goodexample is the Endoscope. Lighting and ImagingIllumination used for decorative effects, signs, and light distribution. Spectroscopy5

Some Interesting Applications of Optical FiberWiFiWestminster RotatingFiber Optic LightAardvark WaterproofWireless InspectionCamera Attachment forAndroid & ml6

Optical Fiber Communication SystemInformationSourceElectricalEncodingOptical DriverOptical Fiber An Optical Fiber Communication System uses lightwave technology to transmit voice, video and data overa fiber by converting electronic signals into light.7

Optical Network Structure 1 2Optical nodes 1Light paths(logical links)Optical Fiber Links(physical links) 2From Figure 15.2, page 970, of John M. Senior, Optical Fiber Communications,: Principlesand Practice, 3rd edition, Pearson, 2009.8

Hierarchy (i.e., Layers) in NetworkingLong-HaulNetworksMetro InterofficeNetworksAccessNetworksLocal 9

Data Communication Network TopologiesA data communication network is a collection of interconnectednodes (consisting of computers, terminals, or other devices inmany locations) connected by data links which arecommunication channels providing data paths between nodes.BusFull MeshMeshRingStarTreeFrom D. B. Estreich, ES101A, Lecture 9, 2015.10

Circuit-Switched Networks versus Packet-Switched NetworksPacket-switched and circuit-switched networks use verydifferent technologies in sending messages and data from onepoint to another point.Circuit switching was first designed in 1878 to send telephonecalls over a dedicated channel. This was the landline telephonenetwork that dominated telecommunications for many decades.Packet switching evolved from the Defence Department’sARPANET network and does not use dedicated connections toroute packets over the network. The Internet is a packetswitched network.From D. B. Estreich, ES101A, Lecture 9, 2015.11

Circuit-Switched Networks versus Packet-Switched NetworksCircuit Switching originated to build telephone networks. Wiresand switches used to make a dedicated wireline connection,resulting in a fixed connection from start to finish.In Packet Switching the message is broken into limited-size datapackets. These packets are sent over the network by specialpurpose computers called “routers.” Routers send packets overthe network seeking the most effective path to travel as data linksbecome available. Packets don’t necessarily travel by the shortestroute, rather the paths chosen are the most efficient in termsof network utilization. Since packets often travel overdifferent routes, they must be reassembled in correct order at thedestination.From D. B. Estreich, ES101A, Lecture 9, 2015.12

Circuit-Switched NetworkPSTN public switched telephone networkCallerCentral OfficeMany paths arepossible, but onlyone is selected lephoneSwitchTelephoneSwitchSubscriber lines(or local loops)TelephoneSwitchOnce a connection isestablished, thisconnection ismaintained until callis terminated.Trunks(links betweenExchanges)Central OfficeTelephoneSwitchTelephoneSwitchCentral Office Dedicated connection (point-to-point)From D. B. Estreich, ES101A, Lecture 9, 2015.13

Public Switched Telephone Network (PSTN)The public switched telephone network (PSTN) is the aggregate of the world's circuitswitched telephone networks that are operated by national, regional, or local telephonyoperators, providing infrastructure and services for public telecommunication. The PSTNconsists of telephone lines, fiber optic cables, microwave transmission links, cellularnetworks, communications satellites, and undersea telephone cables, all interconnected byswitching centers, thus allowing most telephones to communicate with each other.Before the Internet and other data networks, telecommunications had a clear meaning:The telephone (and earlier the telegraph) was an application of technology that allowedpeople to communicate at a distance by voice (and by encoded electronic signals). Thetelephone service was provided by the public switched telephone network (PSTN). Mostof the U.S. network was built and operated by American Telephone & Telegraph (AT&T) –that changed starting in 1984 when the AT&T monopoly was broken up.https://en.wikipedia.org/wiki/Public switched telephone networkhttps://www.nap.edu/read/11711/chapter/314

Public Switched Telephone Network (PSTN)TelephoneOperatorsin 1950sTelephone Lines switching-system-from-the-1960sCrossbar-type telephoneswitching system from the l15

Local Loop or Subscriber LoopIn telephony, the local loop (also called the local tail, subscriber loop, or in theaggregate the last mile) is the physical link that connects from the demarcation point ofthe customer premises to the edge of the common carrier’s network or thetelecommunications service provider's network.Historically, the local loop was an electrical circuit in the form of a single pair ofconductors (usually a twisted pair) from the telephone on the customer's premises to thelocal telephone exchange. Again, AT&T established the technical jargon used.A local loop supports voice and/or data communications applications with the followingservices: Analog voice and signaling as used in traditional POTSIntegrated Services Digital Network (ISDN)Variants of digital subscriber line (DSL)https://en.wikipedia.org/wiki/Local loop16

Telephone Local Subscriber Loop (or Local Loop)Traditionally, local loops are composed of twisted pair copper cables. The old local loops haveseveral limitations narrow bandwidth, high attenuation, distortion of symbols, crosstalk's etc.Today, copper wires are being replaced by fiber optic cables for faster and more accurateperformance. Installation of fiber cables is popularly known as FttH (Fibre to the p17

Telephone Subscriber LoopUp to 24 ratorPrimarily to homes and ncentratorMedium & ge/159676.htmlCellular tower& cell phonesModemFAXHomes& Small BusinessesColleges & UniversitiesAfter Jeff Hecht, Understanding Fiber Optics, 3rd edition, Prentice Hall, Inc., 1999. Page 500.18

Packet-Switched NetworkPacket routeMessage brokeninto packets andeach addressedMany paths possiblefor a single message aspackets are routed tothe destination. Packet(Data Packet or “Datagram”)Routeror ssembledto revealmessagePackets are routedaccording to the bestpath available at thetime.Large array of routers and data links.Receiver(destination)From D. B. Estreich, ES101A, Lecture 9, 2015.19

Circuit-Switched Networks versus Packet-Switched on-oriented”“Connectionless”Bandwidth guaranteed onceconnectedWasted Network BandwidthBandwidth is dynamically allocated(aka “adaptive routing”)Better use of Network BandwidthNetwork Capacity not affected byother traffic; but limited # connectionsEach connection is “dedicated”Switches perform connections toestablish dedicated circuit path foreach communication sessionNetwork Capacity independent ofconcurrent transmission of packetsPacket forwarding can use any routein the network (“store & forward”)Routers and protocols determine thepacket routes and adjust to networkconditions (“forwarding on the fly”)If a connection fails a new connectionmust be re-established to recoverCost by connection timeIf one router fails the network stillfunctions by bypassing that routerCost by number of packetsToday both network categories now handle both voice and data.20

Packet-Switched Networks Now DominateModern communication systems today aredominated by packet-switched networks.The Internet is the ultimate packet-switchednetwork.21

ical-networking22

Access, Metro and Core (Long-Haul) ical.php?contents ntr201706fa1.html23

Optical Fiber Network Evolution1st Generation2nd Generation“dynamic”10-6Switching Time (sec)3rd GenerationOptical BurstSwitch10-3“static”“static”10-1Optical CircuitSwitch“dynamic”Optical CircuitSwitch/OpticalPacket Switch(Optical intLate 1980sand 1990s2000s and2010sFutureDeployment Time FrameAfter John M. Senior, Optical Fiber Communications, 3rd Edition, Pearson, 2009; page 968.24

Ethernet LAN Data Rateshttps://slideplayer.com/slide/9668432/25

Four Primary Internet Delivery MethodsServiceDSL InternetAverage speed768 kbps – 1.5 MbpsHigh-end speed3 Mbps – 7 MbpsCable InternetSatellite Internet4 Mbps – 6 Mbps5 Mbps – 10 Mbps10 Mbps – 100 Mbps12 Mbps – 25 MbpsFiber Internet50 Mbps – 100 Mbps1 Gbps – 10 GbpsInternet over Fiber commentary:1. You probably don’t need that much speed2. Limited availability, but getting better3. Expensive to install for providers, which iswhy it is of limited availability26

Internet over Fiber (IOF) – Top Ten ProvidersProviderPopulationNo. StatesMax SpeedVerizon FiOS34,400,00010940 MbpsAT&T Fiber20,400,000211 GbpsFrontier Communications10,920,0008100 MbpsCenturyLink8,150,000501 GbpsGoogle Fiber2,130,000101 GbpsWindstream1,820,000441 GbpsCincinnati Bell1,335,00051 GbpsC Spire Fiber1,265,00081 GbpsConsolidated Communications1,106,000141 Gbps980,00051 Gbps398,00011 GbpsArmstrong Sonic.netNote: Data dated July 2019; Listed 1,246 27

CenturyLink’s Fiber Optic Map in North AmericaBackbone or Core 28

Google dding-30-billion-infrastructure-investment/29

The Privatization of the Internet 1994AT&TUUNETLevel 3Sprinthttps://www.vox.com/a/internet-maps30