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Telecommunications in ITS WiFi and WiMAX

Telecommunications in ITS WiFi and WiMAX. Martin Srotyr srotyr@fd.cvut.cz. Agenda. Content: Classification of wireless systems WLAN 802.11 a / b / g 802.11 n / p 802.11 e / i / r WMAN 802.16 d / e Comparison of 802.11 with 802.16 End. Classification of wireless access systems.

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Telecommunications in ITS WiFi and WiMAX

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  1. Telecommunications in ITSWiFi and WiMAX Martin Srotyr srotyr@fd.cvut.cz

  2. Agenda Content: Classification of wireless systems WLAN 802.11 a / b / g 802.11 n / p 802.11 e / i / r WMAN 802.16 d / e Comparison of 802.11 with 802.16 End

  3. Classification of wireless access systems

  4. Access systems CATV Metalic xDSL Fixed PLC Ethernet Optic AON Access network PON WiFi Fixed Wireless WiMAX Nomadic GSM,UMTS Mobile Satellite

  5. Access systems CATV Metalic xDSL Fixed PLC Ethernet Optic AON Access network PON WiFi Fixed Wireless WiMAX Nomadic GSM,UMTS Mobile Satellite

  6. Classification of wireless access systems According to the signal type: Radio networks - the most common type, range up to tens of km, different transfer rate, the highest type to several Gbit/s, licensed vs. unlicensed. Free Space Optics (Visible Light Communication) – range up to several km, line of sight, high data transfer rate - up to several Gbit/s. Infrared Networks- short range, line of sight, more security, transmission capacity limited only by transmitter power, infrared networks are not regulated.

  7. Optical link (TereScope 5000)

  8. LED link (RONJA)

  9. Radio link

  10. Classification of wireless access systems By the support of the mobility of objects: Fixed networks – networks for communication in idle state without moving objects. Nomadic networks – networks for communication objects that are at rest (or in a state of approaching calm), but subject is between the idle state in move. (At petrol stations, light controlled intersections, during parking, etc.). Mobile networks – networks with full support for mobile communicating objects.

  11. Classification of wireless access systems High mobility Middle mobility Mobility Low mobility Transfer rate By the support of the mobility of objects:

  12. Classification of wireless access systems Accordingto theapplication: • WAN(Wide Area Network) • MAN(Metropolitan Area Network) • LAN(Local Area Network) • PAN(Personal Area Network)

  13. Classification of wireless access systems Accordingto theapplication: • WAN(Wide Area Network) • MAN(Metropolitan Area Network) • LAN(Local Area Network) • PAN(Personal Area Network)

  14. WLANWireless Local Area Network

  15. WiFi – IEEE 802.11 WiFi – Wireless Fidelity • First version accepted in 1997 • Range up to several kilemetrs (directional antenna, direct visibility,…) • Network configuration: • ad-hoc (p2p) • infrastructure • Main standards 802.11 a / b / g / n / p • Additional standards 802.11 f / i / r / …

  16. IEEE 802.11 – standard summary

  17. IEEE 802.11b Approved in 1999, CTO authorized this standard to use in 2000 2,412 – 2,472 GHz (60 MHz) 13 channels with intervals of 5 MHz, channel width is about 22 MHz Max. transfer rate 11 Mbit (11, 5,5, 2, 1 Mbit/s) Ad-hoc (P2P), Infrastructure DSSS (Direct Sequence Spread Spectrum) 30 – 40 % of capacity is used by the 802.11 protocol

  18. IEEE 802.11b 802.11b channel width

  19. IEEE 802.11b/g Schematic distribution of 802.11b/g channels

  20. 2,4 GHz channels

  21. IEEE 802.11a Approved in 1999, CTO (Czech Telecommunication Office) authorized this standard to use in september 2005 5,470 – 5,725 GHz (255 MHz) 11 non-overlapping channels with intervals of 20 MHz Max. transfer rate 54 Mbit (54,48,36,24,18,12,9,6 Mbit/s) Ad-hoc (P2P), Infrastructure OFDM (Orthogonal Frequency Division Multiplexing) BPSK, QPSK, 16-QAM, 64-QAM

  22. 5 GHz channels INDOOR OUTDOOR

  23. IEEE 802.11g • Approved in 2003, CTO authorizedthis standard to use in 2000 • 2,412 – 2,472 GHz (60 MHz) • 13 channelswithintervalsof 5 MHz, channelwidthisabout 22 MHz • OFDM a DSSS (forcompatibilitywith 802.11b) • Max. transfer rate 54 Mbit OFDM: 16-QAM (54, 48, 36, 24 Mbit/s) QPSK (18, 12 Mbit/s) BPSK (9, 6 Mbit/s) DSSS: (11, 5,5, 2, 1 Mbit/s)

  24. IEEE 802.11n Approved on 11.9.2009 2,4 GHz, 5 GHz with 20 and 40 MHz channels Compactibility with 802.11a/b/g MIMO technology (Multiple Input Multiple Output) Available max. transfer rate 300 Mbit (Draft 2.0) Max. data rate up to 600 Mbit (4 spatial streams, 64-QAM 5/6, 40 MHz channels, short guard interval) 24

  25. IEEE 802.11n 25

  26. IEEE 802.11n – 40 MHz in 2,4 GHz 26

  27. IEEE 802.11p Approved in November 2010 WAVE (Wireless Access for the Vehicular Environment) Licensed band 5,9 GHz For road safety application and inter-vehicle, infrastructure communications For speeds up to 200 km/h Max. transfer rate 27 Mbit/s Range up to several km Cooperation with CALM, DSRC

  28. IEEE 802.11ac • Approved in January 2014 • Hight throughput – at least 1 Gbps • Multi-user MIMO – up to 8 streams • Wider RF bandwith – up to 160 MHz • 256-QAM • Mandatory vs. optional features • 80 Mhz vs. 160 Mhz • 800ms guard interval vs. 400ms guard interval • Single stream (1-4 in 802.11n) vs. 5-8 streams

  29. IEEE 802.11ac Note: MCS 9 is not applicable to all channel width/spatial stream combinations

  30. IEEE 802.11 – architecture

  31. IEEE 802.11 – MAC layer – DCF CSMA/CA (CarrierSense Multiple Access withCollisionAvoidance) RTC/CTS (Request To Send / Clear To Send)

  32. IEEE 802.11 – MAC layer – PCF Rarelyimplemented, small support, thereis no choiceofpriorities Broadcastingstationsbroadcast „beacon“ framesatfixedintervals (0,1s) CP (Contention Period) – DCF system CFP (Contention Free Period) – PCF systemIsdirectlydeterminedwhichclient has theright to broadcast, theother are forbidden to broadcast

  33. IEEE 802.11e – Wireless QoS Approved in 2005 Adds support for QoS Implements a class of traffic 3 phase certificationWMM – 2004 (EDCA)WMM-PS – 2005 (EDCA)WMM-SA – ? (EDCA, HCCA) Still based on collision approach

  34. IEEE 802.11e – Wireless QoS EDCAPriorities according to 802.1d4 traffic category 8 priority classes HCCASimilarly to PCFTwo sections – CAP (CFP) a CPCAP (Controlled Acces Phase) – initiated anytime by access pointPreference according to priority classesQueuing priorities + reporting informations about queues

  35. IEEE 802.11i – WPA2 Wireless Protected Access Approved in 06/2004 Significantly improves security (compared to the original WEP) Uses a block cipher AES Implemented protocols CCMP – provides confidentiality, integrity and authenticationTKIP – provides the combination of keys for packets, checking the integrity of messages and key exchange mechanism

  36. IEEE 802.11r Fast roaming Aprroved in September 2008 Cooperation with 802.11i Multilevel hierarchy, WLAN controller Ensuring the handover with WPA2 in units of ms vs. specialized software

  37. IEEE 802.11 – equipment Antenna - omnidirectional, sector, directional Frequency, gain, polarization, pattern

  38. IEEE 802.11 – equipment Antenna - omnidirectional, sector, directional Frequency, gain, polarization, pattern

  39. Fresnel zone 5.6m Necessary condition for good connection Ellipsoidal shape 60% of fresnel´s zone ¨ www.afar.net/fresnel-zone-calculator

  40. IEEE 802.11 – equipment Active elemets Interface (USB, Ethernet, miniPCI, PCI, ExpressCard, …) Supported standards, modes, …

  41. IEEE 802.11 – HF cables • HF cables • Attenuation • H155/RF240 – 0,5 dB/m • H1000 – 0,2 dB/m • Lightning arrester (1-3 dB) • Connectors (1 dB) • Broadcast limit:+20 dBm*

  42. WMANWireless Metropolitan Area Network

  43. WiMAX – IEEE 802.16 Working Group was established in 1999 10 - 66 GHz, only Line Of Sight (LOS) Transfer speed up to 134 Mbit/s 2 - 11 GHz, Non Line Of Sight (NLOS) Transfer speed up to 75 Mbit/s Revision 802.16 (3,5 GHz FDD, TDD) Unification previous 802.16 standards Mobile version of WiMAX Equipment supported speed up to 150 km/h

  44. WiMAX – IEEE 802.16 802.16e • Mobile supplement • Allowhigh speed handover 802.16a 2 - 11 GHz licenced band NLOS Support of MESH architecture 802.16b Unlicenced band Brings QoS for real-time applications 802.16c 10 - 66 GHz 802.16d Revision 802.16a andstandards unification

  45. WiMAX – IEEE 802.16

  46. WiMAX – Radio parameters Range / speed RLC (Radio Link Control) QoS (Quality of Service)

  47. Modulation / bandwidth QPSK 1/2 QPSK 3/4 16 QAM 1/2 16 QAM 3/4 64 QAM 2/3 64 QAM 3/4 1,75 MHz 1.45 2.18 4.36 5.82 6.55 2.91 3,5 MHz 5.82 8.73 13.09 4.36 11.64 2.91 7,0MHz 5.82 11.64 17.45 23.27 26.18 8.73 14,0 MHz 11.64 17.45 23.27 34.91 46.55 52.36 20,0 MHz 24.40 32.53 48.79 65.05 16.26 73.19 WiMAX– Teoreticalspeedin Mbps ForOFDM with 256 sub-carrier included MAC and other layers direction.

  48. window/fix antena roof antena indoor/portable antena Type of area <20 Km inNLOS* Rural <8 Km <4 Km Small town <4 Km <2 Km N/A N/A City <2 Km <1 Km WiMAX – Teoretical coverage in km Approximate distance, it is very dependent on area character *<50 Kmis the theoretical maximum for the line of sight.

  49. WiMAX – architecture P2MP (Point-to-MultiPoint) MESH topologie

  50. WiMAX – architecture 4 layers~ agree with 2 lowest OSI layers

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