Wireless LAN Technology. Chapter 13 Chapter 10 (Pahlavan)

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1 Wireless LAN Technology Chapter 13 Chapter 10 (Pahlavan)

2 Wideband local wireless networks WLAN Coverage area Data rate Batter consumption IEEE and HIPERLAN WPAN IEEE , Bluetooth, HomeRF Data-oriented and voice-oriented MAC

3 History of LAN Industry WANs are offered as service Cost of infrastructure Coverage area LANs are sold as end products You own, no service charge Analogy with PSTN/PBX

4 LAN History-2 Emerged to enable sharing of expensive resources such as printers & to ease wiring problems Early 1980s: Three standards are developed (Ethernet) (Token Bus) (Token Ring) Distinct PHY and MAC layers & topologies, but same management and bridging ~1985: Think coax Thin coax TP wiring Shorter segments, but ease of installation, lower cost, increased data rate

5 (Token Ring) Distinct PHY and MAC layers & topologies, but same management and bridging ~1985:

5 500 m per segment 185 m per segment MAU Thick coax MAU MAU Terminator Thin coax with BNC T-connector AUI cable 10 Mbps clients Server 10 Mbps clients Thick Coax Installation Server Thin Coax Cheaper-net Installation MAU: Medium Attachment Unit AUI: Attachment Unit Interface UTP: Unshielded Twisted Pair 100 m UTP 10BASE-T Repeater Hub-and-Spoke Architecture Server Figure 10.1: Evolution of the LANs from thick to thin cable and then to star topology using TP.

Attachment Unit AUI: Attachment Unit Interface UTP: Unshielded Twisted Pair 100 m UTP 10BASE-T Repeater

6 Need for higher data rates Thick/Think/TP ~ 10Mbps Interconnect LANs in different buildings to share computing resources High speed multimedia applications Interconnect LANs FDDI (fiber distributed data interface): 100 Mbps in mid-1980 Mid-1990: 100 Mbps fast Ethernet (802.3) Mid-1990: 100VG-AnyLAN (802.12) Late-1990: Gigabit Ethernet (802.3)

Interconnect LANs FDDI (fiber distributed data interface): 100 Mbps in mid-1980

7 Backbone Network Router Figure 10.2: Hierarchical LANs

8 LAN History-3 Mid 1990: ATM LAN (LANE) Emulation IEEE 802 Standards 802.3, 802.4, are wired LANs 802.9: ISO Ethernet 802.6: MAN , , : Wireless local net Cable modem Security management

9: ISO Ethernet 802.6: MAN 802.11, 802.15, 802.

9 IEEE Security 802 Overview and Architecture IEEE Management MAC PHY MAC PHY MAC PHY Higher Layers IEEE Logical Link Control MAC PHY IEEE Bridging MAC PHY MAC PHY MAC PHY MAC PHY MAC PHY MAC PHY Figure 10.3: IEEE 802 Standard Series

6 PHY IEEE 802.1 Bridging 802.9 MAC 802.9 PHY 802.11 MAC 802.11 PHY 802.12 MAC 802.12 PHY 802.

10 WLAN Industry WLAN vs. WAN Cellular Networks Data rate (2 Mbps vs. 54 Mbps) Frequency band regulation (Licensing) Method of data delivery (Service vs. own)

11 Early Experiences IBM Switzerland Late 1970 Factories and manufacturing floors Diffused IR technology Could not get 1 Mbps HP Labs, Palo Alto Kbps DSSS around 900 Mhz CSMA as MAC Experimental licensing from FCC Frequency administration was problematic, thus abandoned Motorola ~ GHz Abandoned after FCC difficulties

around 900 Mhz CSMA as MAC Experimental licensing from FCC Frequency administration

12 What we learned Complexity and cost Bandwidth Coverage Interference Frequency administration

13 Unlicensed Bands FCC dilemma WLAN requires ~o(10 MHz) WWAN uses 2*25 MHz tens of billions FCC solutions (mid 1980) Avoid 1-2 GHz, approve higher frequencies Motorola Altair (18-19 GHz) Release unlicensed frequency bands ISM bands (May 1985) Public vs private public use etiquette

higher frequencies Motorola Altair (18-19 GHz) Release unlicensed

14 Products, Bands, Standards By late 1980s, products with diff. tech MHz licensed bands Spread spectrum technology in ISM bands IR 802.4L Shoe-box sized APs (LAN extension) LAN WLAN did not materialize

18-19 MHz licensed bands Spread spectrum technology

15 More bands WINForum created to obtain more license from FCC 20 MHz in PCS band 10 for voice, 10 for data Rules (based on CSMA) Listen before talk Low transmit power Restricted duration

16 Three basic rules 1. Listen before talk (or transmit) LBT Protocol 2. Low transmitter power 3. Restricted duration of transmissions Figure 10.4 Unlicensed PCS Bands and their Spectrum Etiquette

17 Even more bands 1992 HIPERLAN completed 23 Mbps 200 MHz, & GHz FCC responded by U-NII bands in 1997 OFDM based WLANs

18 Shift in Marketing Early 1990 s expectation of LAN WLAN shift did not happen Two new directions 1: Boost the power, directional antennas Cross-building interconnect Alternative (T1) were expensive Range is fairly good (Tens of kms) 2: Reduce the size to PCMCIA card Targeted for notebooks Use SS, low power, unlicensed bands

interconnect Alternative (T1) were expensive Range is fairly good (Tens of kms)

19 Building Cross-connect PCMCIA cards and Laptops (c) Wired Backbone (b) (a) Shoebox type LAN Extension Figure 10.5 Different forms of WLAN products (a) LAN-Extension (b) Inter-LAN Bridge (c ) PCMCIA cards for laptops

20 Shift in Marketing Horizontal vs. vertical integration Traditionally horizontal (end products) New vertical markets (solutions) Barcode industry Financial services Health care WCANs Horizontal markets now.

21 New Interest from Military Mid-1990 InfoPAD BodyLAN SUO/SAS

22 Figure 10.7: Fusion of Computers and Communications in the InfoPAD project at the University of California, Berkeley.

23 Figure 10.8: Body LAN or Wearable LAN

24 Figure 10.9: The urban/outskirts combat scenario for the SUO-SAS project

25 New Interest in EU Incorporate into cellular industry ATM-based vision HIPERLAN-2

26 Explosion in 2000 Japan Small office sizes Laptops replacing PCs EU WLAN is seen part of the WWAN Cellular Unlicensed, high-data rate US Broadband Internet access Home networking Low-power personal networking devices

27 To fixed network Connection Point Intelligent Office Smart Home TODAY! Win $ 1000 Ad hoc setup WLAN Position Location Figure 10.11: Wireless Networks: 2000 and Beyond

28 Wireless Home Networking

29 PSTN Telephone Wiring Internet Virtual connection Cable, xdsl, Voiceband modem Cable Net Cable or Satellite Figure 10.12: Today s fragmented home access and distribution networks

30 12 10 Almost doubles each year 8 6 No. of Homes Figure 10.13: Growth of the home networking industry

31 Internet Broadband Home-Access Broadband Home-Distribution or Home Area Network (HAN) Figure 10.14: Two basic technologies needed for home networking

32 What is a HAN?

33 Home Computing Desktop computer Laptop Printer Scanner QuickCam Smart appliances Oven(s) Fridge(s) Washing machine(s) PROGRAM Phone appliances Standard phone Inter Comm Cordless phone Security Systems Motion detectors Door pins System control unit Camera Alarm Entertainment Audio/Visual appliances Analog/Digital TV VCR / DVD Camcorder Stereo system Speakers / Headphones Location / Navigation locating children and pets navigating handicaps Utility metering Electricity Gas Fuel Water Figure 10.15: Classification of home equipment demanding networked operation

34 Why do we need a HAN? LANs do not provide a good solution Applications diversity Number of users Bandwidth requirements Coverage area System administration Installation and maintenance

35 HAN Technologies TP phone lines Relatively good distribution Suitable for Ethernet connection Also used for phone and xdsl Cable from cable TV Poor distribution Used for multi-channel TV signal distribution Cable-modems are required Power lines Excellent distribution Line quality is poor Frequency selective channel & impulse noise Data-rate limitations and complex DSP Wireless Ideal Bandwidth, coverage, security, interference, reliability etc.

36 HPNA Ethernet compatible LAN over home phone lines Stand-alone adapter to connect to any device with 10Base-T interface to phone jacks Shares the medium through FDM Up converts the Manchester coding to HPNA band MAC layer is the same as Incorporates the legacy hardware and software

37 Home Gateway Network camera Laptop Internet Desktop telephone Printer Multimedia PC Webphone Camera Scanner TV and Set-Up Box Figure An example of a HPNA network

38 Figure 10.18: Phone line wirings shared among three technologies using FDM. (a) POTS uses 20 Hz 3.4 khz (b) xdsl uses 25 khz 1.1 MHz, and (c) HomePNA uses 2 MHz 30 MHz

39 Power Line Modems 1 Mbps type rates AM band is avoided Some use in smart appliances Interference, noise, multi-path, fading makes it a challenging medium FSK and QPSK is used for low-rates OFDM for high rates CSMA is used as MAC

40 Figure 10.16: (a) Typical Power line transfer function (b) Typical noise level in the power lines

41 Narrowband applications Wideband applications AM radio 3 khz khz (EU) HF band (1-9 khz khz (US) 30 MHz) frequency Figure 10.19: Frequency bands for low- and high-speed data communications over power lines.

42 Internet xdsl modem Voice band modem Cable modem Electric Company Local Transformer Meter reading communications through outside AC lines to the meter Head control/security Control network on/off, light dimmer, HVAC control High speed computing Sharing Internet connection, file transfer, share printer Security systems Sensors network through power lines Smart appliances Sense other appliances on the power lines, breakdown alert, access through web site, PROGRAM Figure 10.20: Power lines potential applications

43 Security Home Server HPNA Internet Cable, xdsl, v.90 Home RF Power Line PROGRAM Figure 10.21: Evolving Home Area Networks (HAN)

44 Wireless Wired HIPER-ACCESS DBS xdsl Cable Modem Digital Broadcast Satellite Hybrid Fiber-Coax Network PSTN Wireless Figure 10.23: Broadband home access alternatives

45 HomeRF SWAP Grandma s Brownies 3 cups flour 1 cup grated chocolate 1 cup sugar 1 stick butter Control Point USB Phone 1394 Camera Game Pad Printer Cable Stereo Camcorder VCR Multimedia (e.g. 1394) TV HomePNA Figure 10.22: Vision of the Home RF group at IEEE

Wired & Wireless LAN Connections

Lecture 5 Wired & Wireless LAN Connections Network Interface Card (NIC) Ethernet Wiring - Thick Ethernet - Thin Ethernet - Star (Hub) Ethernet Extending LAN - Fiber Modem - Repeater - Bridge - Switch Short