Introduction To Cellular And Wireless Networks

Introduction to Cellular and Wireless Networks

Lesson ContentIntroductionCellular Networks – 1.0 to 3.5G and BeyondWireless Networks – WiFi and WiMAXSummary and future trends© NDI Communications ©

Wireless and Cellular Networks - HistoryIn 1905, Guglielmo Marconi invented the first Radio application for Naval requirementsIn 1912, with the drowning of the Titanic, Radio communications became essentialIn 1930, the First mobile transmitter was developed. First – Simplex communications.

Wireless and Cellular Networks - HistoryIn 1935, FM – Frequency Modulation developed. Later used in WW2 by the USIn 1942, a Patent for Frequency Hoping was registered by actress Hedy Lamarr and composer George Antheil. Later developed to CDMA. They called it “Secret Communication System ”During the years 1946-1968, wireless communications developed for government services – Police, Fire departments etc…

Wireless and Cellular Networks - HistoryIn the mid-late 90’s, development of 2.0G+ cellular networks, along with the emerging of wireless data networks.Since the early 2000’s, fast cellular and wireless services, along with advanced, IP-Based services1979 in Tokyo, Japan. Later in the early 80’2 in the US and Europe – the first real mobile hone, including handoff.In the early-mid 80’s, various technologies came, like WLL, LMDS, and Wireless LAN.

What do we have today ?Cellular technologiesStarted 1.0G, analog communicationsToday (2009), 3.5G moving to 4.0G LTE technologyWireless technologies:Wireless LAN (WiFi), for close areas, mostly private networks, moving to mobilityWiMAX for high bandwidth, SP networks

Early Technologies – 1G to Early 3G Evolution3GPPWCDMA R.99[2Mbps]GRPS (2,5G) and EDGE (2.75G)[Upto 384Kbps]Cdma2000(1.25/3.75MHz)[307-2048Kbps]cdmaOne(ANSI-95-B)[64-115]D-AMPS(TDMA)ANSI-136IS-136(ANSI-136-A/B)[Upto 64Kbps]TDMA-EDGE(IS-136HS)[Upto 384Kbps]Early 3.0G2.5G2G1GGSMNMTcdmaOne(ANSI-95)TACSAMPS2005199020001995

Wireless and Mobile 3G Technologies Evolution3GPP MIMO/ HSDPA R7SAE/LTE R83GPPHSUPAR63GPPHSDPAR53GPPWCDMAR.993GPP21xEVDVRevA3GPP21xEVDORev03GPP21xEVDORevBIEEE 802.16e-2005/ETSI HiperMANSISO/OFDMAIEEE 802.16e-2005/ETSI HiperMANMIMO/Beamforming/OFDMA3G to 4GIEEE 802.16-2004/ETSI HiperMANOFDMWiMAX200820052010200720092006

Where is it in the Network?Core/Switching Network Service NetworksFirst Mile AccessVideoCMTVDirect TVContent Aggregator FO TechnologiesInternetAOLEarthlinkDSLAMYahooVoicePSTN WirelessCellularSkypeVonage

Some Wireless Principles – Radio CommunicationsIn wireless / mobile communications, the principle is to get the maximum capacity from the air, or what called – the air interface.For this purpose, we use the following techniques:Frequency bands – that we are allowed to useModulation – that carry the information over the radio waves Multiplexing – that shared the air interface between different users.

What is the whole story here?How much bps can we get from every Hz ???(The Shannon’s Theorem)C = W * log2 (1 + SNR)Claude E.ShannonChannel Capacity[Bits/sec]SignalBandwidth [Hz]Signal to Noise Ratio[Number]

Lesson ContentIntroductionCellular Networks – 1.0 to 3.5G and BeyondWireless Networks – WiFi and WiMAXSummary and future trends

1.0GAnalog Systems2.0GTDMA/GSM/CDMA2.5GGPRS/1XRTT3.0G-3.5GUMTS/CDMA 2000HSDPA/HSUPA1xEVDO/DV4.0GLTESpeechSMSWAPVideo Streaming, Video conference, High speed Packet DataSpeech and packet based Data Services10’s Mbps data transferSpeech OnlyVoice30-40Kbps DataVoice5-100Mbps DataVoiceNo DataVoice1-5Mbps DataVoice100-200Kbps DataWireless and Mobile Communications – Cellular Networks20102003200119851992-2000Voice Over IP

How it works – The beginningTraditional mobile service was structured in a fashion similar to television broadcastingOne very powerful transmitter located at the highest spot in an area would broadcast in a radius of up to 50Km.

And thenWith one antenna – limited cover and number of usersTherefore – split into many low power transmitters

The Solution - CellsFrequency reuseDifferent color – different frequencyIn the example N (Reuse factor) =7

Practical Frequency reuse – Cell Splitting EMacro cellsFD AGCEFD B AMicro cellsGCEFD B AGC BPico cellsWe start with Macro-CellsRural areasThen Micro-CellsMore crowded rural areasThen Pico-CellsUrban area

Moving between Cells BaseStationBaseStationMobile phones moves between cellsThe handset should not be disconnectedF2

The Solution - The Handover Process RSSIRSSIRSSIFRQ BFRQ AFRQ CHandover Happens HereHandover Happens HereRSSI - Received Signal Strength Indicator

Handset to Network ConnectionWhen Handset is turned on – it looks for the best receive on FCCTransmit to the MSC his location on the BCCStarts talking on FVC/BVC Forward Voice ChannelReverse/Backwards Voice ChannelForward Control ChannelReverse/Backwards Control Channel

FrequencyCodeCodeFrequencyTimeTimeTimeCodeFrequencyFDMACDMATDMAAccess MethodsThe Major Air-Interface Methods are:Frequency Division Multiple Access (FDMA)Time Division Multiple Access (TDMA)Code Division Multiple Access (CDMA)

The Cellular Network StructureThe UserThe AccessNetworkThe SwitchingNetworkThe ServicesCircuit SwitchingMobile InternetAirInterfaceMWFO CablesFO CablesIntelligentNetworkPacket SwitchingCell phonesThe CoreNetworkThe RadioNetworkIntelligent NetworkAdvanced Services

The Cellular Network Structure – 2.0G-2.5GTRAUPSTNMSCBSCVLRBTSHLRMobileDeviceCircuit SwitchingPacket SwitchingPCUGGSNPacket NetworkIP netBTSSGSNData NetworkBTS – base Transceiver StationBSC – base Station ControllerTRAU - Transcoding Rate Adaptation Unit MSC – Mobile Switching CenterHLR – Home Location RegistrarVLR – Visitor Location registrarPSTN – Public Switched Telephone NetworkSGSN - Serving GPRS Support NodeGGSN - Gateway GPRS Support NodePCU – Packet Control Unit

3.0G - IntroductionStarted as IMT–2000 (International Mobile Telecommunications-2000): Used worldwide Used for all mobile applications Support both packet-switched (PS) and circuit-switched (CS) data transmission Offer high data rates up to 2 Mbps (depending on mobility/velocity) Offer high spectrum efficiency

The IMT-2000 VisionIMT-SC* Single Carrier (UWC-136): EDGEGSM evolution (TDMA); 200 KHz channels; sometimes called “2.75G”IMT-MC* Multi Carrier CDMA: CDMA2000Evolution of IS-95 CDMA, i.e. cdmaOneNow – 3GPP2IMT-DS* Direct Spread CDMA: W-CDMAEvolution of GSM - UMTSNow - 3GPP; UTRAN FDDIMT-TC** Time Code CDMAOriginally from 3GPP; UTRAN TDDCame from China; TD-SCDMAIMT-FT** FDMA/TDMA (DECT legacy)

3.0G – UMTS / W-CDMAUMTS - Universal Mobile Telecommunications SystemSpread Spectrum radio technologyAll sites transmits in the same frequenciesThey differ by codesHigh capacity for voice and data applicationsStandardized by 3GPP

Basic 3.0G UMTS Cellular Network ArchitectureUMTS Access Network3GhandsetRNCNode BSGSNPacketSwitchedNetwork

HSDPA/HSUPABoth known as HSPA – High Speed Packet AccessPrimary target of HSDPA/HSUPA is to enhance system throughput with minimum changes in network architectureIs an extension to WCDMA Release ’(”99”)Release 5 - HSDPA (High Speed Downlink Packet Access)Downlink – 14.4Mbps, Uplink – 384KbpsRelease 6 - HSUPA (High Speed Uplink Packet Access)Downlink – 14.4Mbps, Uplink - 5.76MbpsFollowing technologies (2009)HSPA+ (Release7)

LTE – Long Term EvolutionPeak download rates of 326.4 Mbit/s for 4x4 antennas, 172.8 Mbit/s for 2x2 antennas for every 20 MHz of spectrum. Different terminal classes – from simple voice to high bandwidth multimediaAt least 200 active users in every 5 MHz cell. Co-existence with legacy standards – GSM and W-CDMA-based UMTS and cdmaOne or CDMA2000) networksFull support for IP services - Mobile TV, Radio and television broadcasts and more

What is Wireless LAN (WiFi)?General:A wireless LAN or WLAN is a wireless local area networkBased on the IEEE 802.11 standardsPerformanceTypical range is on the order of 10’s of meters10’s of Mbps, depends on standard Reasonable reliability, low cost devicesFree frequency band – no licenses required !!!

802.11 published in 1997. Works in The 2.4GHz Band. BW – up to 2 Mbps Uses DSSS/FHSS Modulation802.11a Published in 1999. Works inThe 5MHz Band. BW – up to 54Mbps Uses OFDM modulation 802.11b Published in 1999. Works in the 2.4GHz Band. BW up to 11.0 MbpsUses DSSS modulation 802.11g Published in 2003. Works inThe 2.4GHz Band. BW up to 54MbpsUses OFDM modulation 802.11n Published in 2007 (Draft). Works in The 2.4/5.0GHz Bands. BW up to 248Mbps. Uses OFDM and MIMOWireless and Mobile Communications – WiFi

The 802.11 ArchitectureAPAPAPFixed Terminalsf1f2f3

Nomadic Access802.11 LANSTA1BSS1ESSBSS2STA1STA2802.11 LANAccess Point - Station integrated into the wireless LAN and the distribution systemSTA (Station) – A wireless nodeBSS – (Basic Service Set) - Group of stations using the same radio frequencyEES (Extended Service Set) - Interconnection network to form one logical network. based on several BSS802.x SecuredLANOrganization Network

Ad-Hoc ArchitectureDirect communication within a limited rangeStation (STA):terminal with access mechanisms to the wireless mediumBasic Service Set (BSS):group of stations in range and using the same radio frequency802.11 LANSTA1STA3BSS1STA2BSS2STA5STA4802.11 LAN

The 802.11 Architecture – the Physical LayerFixed TerminalsMobile TerminalWired networkaccess pointApplicationApplicationTCPTCPIPIPLLCLLCLLC802.11 MAC802.3 MAC802.3 MAC802.11 MAC802.11 PHY802.3 PHY802.3 PHY802.11 PHY

Unlicensed Frequency BandsShortwave RadioFM BroadcastInfrared Wireless LANAM BroadcastTelevisionCellular (840 MHz)AudioNPCS (1.9 GHz)UltraLowExtremelyLowVeryLowVeryHighVisibleLightUltra-violetUltraHighSuperHighLowMediumHighInfraredX Ray5.15-5.25GHz5.25-5.35GHz5.725-5.8252.4 – 2.483GHzUltra-low frequency (ULF) -- 0-3 Hz Extremely low frequency (ELF) -- 3 Hz - 3 kHz Very low frequency (VLF) -- 3kHz - 30 kHz Low frequency (LF) -- 30 kHz - 300 kHz Medium frequency (MF) -- 300 kHz - 3 MHz High frequency (HF) -- 3MHz - 30 MHz Very high frequency (VHF) -- 30 MHz - 300 MHz Ultra-high frequency (UHF)-- 300MHz - 3 GHz Super high frequency (SHF) -- 3GHz - 30 GHzExtremely high frequency (EHF) -- 30GHz - 300 GHz

802.11b/g Channels11 Non-overlapping channels22MHz channel bandwidth, 5MHz channel spacing1 2 3 4 5 6 7 8 9 10 1151049385MHz2722MHz11162.483GHz2.441GHz2.400GHz

The ISM Frequency BandsThe ISM (Industrial, Scientific and Medical) frequency bands (900 MHz & 2.4 GHz) are un-licensed in most of the worldThe ISM rules varies depending on the country: In the US, the FCC allocates both the 900 MHz and 2.4 GHz band with 1W maximum powerIn Europe, the ETSI allocates only the 2.4 GHz band with 100 mW maximum power

802.11 Spreading TechniquesFHSS, DSSS802.11OFDM802.11aDSSS, HR-DSSS802.11bHR-DSSS, ERP-DSSS, OFDM802.11gOFDM, MIMO802.11nSpreading/Modulation TechniqueStandard

Spread Spectrum TechniquesDistributes the signal over a wide range of frequencies and then collected back at the receiverInitially adopted in military applications, for its resistance to jamming and difficulty of interception. In the last years, adopted in commercial wireless communicationsIn the 2.4 GHz band, the regulation specifies that systems have to use one of the two main spread spectrum technique: Direct Sequence or Frequency Hopping

Spreading code (PRN)10110100Spreaded Signal10110100 01001011 10110100 10110100Data Signal1011DSSS – Direct Sequence Spread Spectrum MODData SignalSpreading CodeResulting Signal

FrequencyTimeFHSS – Frequency Hoping Spread Spectrum

Basic Modulation TechniquesModulation – Mapping of information on changes in the transmitted signal. Basic modulation techniques are:Amplitude Modulation (AM) – for amplitude changesAmplitude changes with input signalFrequency Modulation (FM) – for frequency changes Frequency changes with input signal Phase Modulation – for phase changesPhase change with input signalMostly used for analog transmission, for example AM/FM radio

Advanced Modulation TechniquesThe main job of the radio modem is to transform bits into modulations of the radio waves, and there are many ways to do that. The modulation techniques that are in used in Wireless and Cellular communications are:FSK – Frequency Shift KeyingPSK – Phase Shift Keying – BPSK (Binary-PSK) and QPSK (Quadrature-PSK)QAM – Quadrature Amplitude ModulationOFDM – Orthogonal frequency-division multiplexing

Modulation Techniques - FSKDataf1f2ModulatedSignalFrequency-shift keying (FSK) is a frequency modulation scheme in which digital information is transmitted through discrete frequency changes of a carrier wave2-FSK (or Binary-FSK) is when two frequencies are used:One frequency (Mark Frequency) for binary ‘1’One frequency (Space Frequency) for Binary ‘0’Binary FSK

Modulation Techniques - PSK90ºQ-PSK:90ºB-PSK:‘01’180º180º0º0º‘00’‘0’‘10’‘1’‘11’270º270ºPhase-shift keying (PSK) is a digital modulation scheme that conveys data by changing, or modulating, the phase of a reference signal (the carrier wave).In Wireless-LAN, PSK is used in two forms:B-PSK (Binary PSK) – when two phases are usedQ-PSK (Quadrature PSK) – when four phases are used

Modulation Techniques - PSK0101001111100001DataDataf1f11800270º18018018000º90º180º00ModulatedSignalModulatedSignal90º90ºQ-PSK:B-PSK:‘01’‘00’‘10’180º180º‘0’‘1’0º0º‘11’270º270º

Modulation Techniques - QAMQuadrature Amplitude Modulation (QAM), is a relatively simply technique. It is simply a combination of amplitude modulation and phase shift keying. In QAM, the QAM order (QAM-16, QAM-64 etc) defines how many signals exists in the scheme.QAM-4 indicates 4 signals – 00/01/10/11QAM-8 indicates 8 signals – 000/001/010/011/100/101/110/111 Etc ….

Example – QAM-8111010010Phase ShiftAmplitudeBit Value0º10000º200190º101090º2011f1180º1100180º21012/270º1/90º1/90º270º1110ModulatedSignal270º2111Data

Modulation Techniques - FDMFrequency Division Multiplexing (FDM) is a technology that transmits multiple signals simultaneously over a single transmission pathFrequency (Hz)Signal BSignal A

Modulation Techniques - OFDMOrthogonal FDM (OFDM) spread spectrum technique is a special case of FDMIt distributes the data over a large number of carriers that are spaced apart at precise frequencies. DCSubcarrier DATASubcarrier GUARDSubcarrier PILOTSubcarrier Channel

The 802.11 Architecture – the Data Link (MAC) LayerFixed TerminalsMobile TerminalWired networkaccess pointApplicationApplicationTCPTCPIPIPLLCLLCLLC802.11 MAC802.3 MAC802.3 MAC802.11 MAC802.11 PHY802.3 PHY802.3 PHY802.11 PHY

Wired MAC (CSMA/CD) Vs. Wireless MAC (CSMA/CA)In Wired LAN – CSMA/CDWhen want to transmit – wait for free mediaTransmit FrameIf collision – stop transmission immediatelyRetransmit after random time (back-off)In Wireless LAN – CSMA/CAWhen want to transmit – wait for free mediaWait a random timeTransmit FrameIf collision – the station do not notice itCollision - erroneous frameIncrease back-off

Standards and Amendments SummaryMesh Extensions:802.11sQoS Extensions:802.11e, 802.11rSecurity Extentions:802.11i, 802.11wRadio and Regulatory:802.11d, 802.11h, 802.11jData Rates:802.11, 802.11a, 802.11b, 802.11g, 802.11n

What is WiMAXWiMAX - Worldwide Interoperability for Microwave AccessFixed (and nomadic) access: 802.16-2004/802.16d (8/2004)Mobile access: 802.16e (5/2005)Typically 2-8 Km’s, Maximum cell size ~45 Km’sMaximum speed 100 Mbps (64QAM/20MHz)

Wireless and Mobile Communications – WiMAXMid-late 90’s Early technologies – LMDS, MMDSNo standardization2001-2003 Early standards, 802.16 - 10-66GHz LOS, 802.16a – 2-11GHz NLOS2004 – 802.16-2004 (802.16d)Revision and consolidation of all of the above2005 – 802.16e (802.16-2005)OFDMA, Mobility, Improved security, Improved MIMO, Competing 4.0G

WiMAX TopologiesFixed P2PBackhaul(802.16-2004)Fixed P2MPBackhaul (LOS)(802.16-2004)Fixed/NomadicAccess Provider/EnterpriseNetwork (NLOS)(802.16-2004/802.16d)Nomadic Broadband complementary to 3.0G-4.0G(802.16e)802.16-2004

802.16d (802.16-2004)IEEE standard for the fixed wireless broadband802.16d supports both services:Time division duplex (TDD) Frequency division duplex (FDD) Used for fixed access:Outdoor – when the antenna is located outside the buildingIndoor – when the antennas are located inside the building

802.16-2004 (previously 802.16d)Fixed WiMAX, OutdoorSubscriber StationDirectional antennas When installed, it’s aligned with base stationIt’s fixed – it never moves locationAlways higher throughput than omni-directional antennaApplicationsRural / Macro-cell deploymentsWi-Fi hot spot backhaulHigh bandwidth residential connectivityChallenging environmentsWi-Fi

802.16-2004 (previously 802.16d)Fixed WiMAX, IndoorSubscriber StationOmni-directional antennaDo not require alignment with base stationPortable but fixed when in useLower throughput than directionalApplicationsConsumer CaTV/DSL-like broadbandCustomer self installationpredecessor for portable/mobile

Portable Client - 802.16eOmni-directional antennaNot aligned with base stationLocation can varyPortable to support both fixed and mobile useCan be moving while in useLower throughput than directional antennaLower throughput than Omni-directional (Indoor Fixed)ApplicationsCompetitor to the 4.0G cellular networks

Lesson ContentIntroductionCellular Networks – 1.0 to 3.5G and BeyondWireless Networks – WiFi and WiMAXSummary and Future trends

IP in the Mobile worldConverged networksAll types of data carried over IP Seamless mobility in the IP levelUser can move between technologies and providers, and still be connectedIMS and the NGN – Advanced multimedia over IP.Services apart from providersContent providers and access providers

Internet/IntranetCall Session Control FunctionSubscriber DBMediaGtwyPSTNDSL/ CableWLANWiMAXGSM/UMTSThe Converged NetworkApplication ServersApplicationsInfrastructure

Seamless MobilityPhoneHomePhoneWeb KioskLaptopPCREMOTEHeadsetDSLPCWLANHOMEPSTNCorporate Fixed / MobileCommunicationsPCLANIPLANOFFICEMOBILITYDeskPhonePBXUserMobilityMOBILEMobile / PDA(eg. P900)DeviceMobilityWiFi / 1x/ 3G PCGSM / CDMAMobile1xRTT / GPRSPDANetworkMobility

Personal Broadband FiberCable DSL3G UMTS-HSPA EV-DO Rev. A/BPRE- LTEtechnologies2G GPRS, 1XRTT4G3.0Mobile WiMAX802.16e2.0WiMAX802.16dMunicipalCommunity Wi-Fi MeshMbps. Speed Broadband1.0Pre-WiMAXBroadband WirelessWi-Fi Hot Spots.5MobileRoamingPortableFixedNomadicSource: Yankee Group, 2006On the Road to Personal Mobile Broadband

SummaryThanks for your timeYoram OrzachNDI Communicationsyoram@ndi.co.ilCloudy Bay Souvignon Blanc 2007New Zeeland

Introduction To Cellular And Wireless Networks

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Introduction To Cellular And Wireless Networks