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  • 1. WiMAX and Non-Standard Solutions
    • Developed by:
    • Ermanno Pietrosemoli, EsLaREd
      • Creative Commons License: Attribution
      • Non-Commercial Share-Alike 3.0
    Unit 14
  • 2. Objectives
    • Describe WiMAX technology, its motivation and compare it with WiFI.
    • Review some non-standard commercial solutions that have been used in the implementation of medium and long range wireless community networks.
  • 3. Agenda
    • Introduction
    • Standards for wireless networks
    • WiMAX
    • Non standard solutions
      • Alvarion
      • Canopy
      • MIKROTIK
  • 4. Standards for wireless networks IEEE UIT ETSI WAN W ide A rea N etwork PAN P ersonal A rea N etwork LAN L ocal A rea N etwork MAN M etropolitan A rea N etwork 802.15 802.11 802.16d 802.20 802.16e HiperPAN HiperLAN HiperMAN HiperACCESS IMT-2000 802.22
  • 5. Introduction
    • 2000: Public auction in Venezuela of the 3400-3500 MHz frequency band to provide voice and data services
    • Unsuccessful for the following reasons:
      • Absence of standards
      • Need for line-of-sight between the base station and each client.
    • Both factors have a strong impact on the cost of deployment and motivated the establishment of a standard for networks of medium and long range, preferably removing the line of sight requirement. These features are met by the IEEE 802.16 standard, on which WiMAX is based .
  • 6. IEEE 802.16
    • Born as a standard for wireless metropolitan networks (high speed, reaching tens of km) for frequencies between 11 and 66 GHz.
    • Point to Point or Point-to-Multipoint.
    • First amendment to extend the range of operation at frequencies below 11 GHz and allowing OFDM, which paves the way for non line of sight operation.
  • 7. Burst adaptive Profile
    • Burst Profile
    • Modulation and FEC allocated dynamically according to the link conditions: Exchange of capacity for robustness
    • The capabilities of the SS are known at the time of initialisation
  • 8. Duplexing schemas
    • TDD
      • The upstream and downstream links share the same RF channel
      • Dynamic asymmetry. Efficient use of the spectrum, but requires guard time. Optimized for packets.
      • SS does not transmit and receive simultaneously, which allows costs reduction. Requires more power.
    • FDD
      • Static asymmetry. Requirement of guard band.
      • In Half Duplex cost is low
  • 9. IEEE 802.16
    • Built in Quality of Service (QoS) to meet the needs of interactive traffic (voice and video)
    • Takes advantage of multipath by using MIMO
    • Better spectral efficiency and a wide variety of techniques for using the channel, SC, OFDM, OFDMA, TDD, FDD
    • Flexibility in managing bandwidth and spectrum, variable and asymmetric channels, licensed or unlicensed bands
  • 10. 802.16 vs 802.11
    • QoS Multimedia, no contention for channel access (802.11e offers QoS)
    • Many additional users
    • Higher transmission rates, up to 75 Mbps in a 20 MHz channel (but 802.11n has even greater transmission rates)
    • Greater range
    • Variable bandwidth channels
    • Better spectral efficiency, ~ 5 bps / Hz
      • (802.11n has better spectral efficiency)
  • 11. Two different markets
    • In countries with limited telecommunications infrastructure, to provide fixed or nomadic access to voice and data using external antennas, possibly in combination with other technologies such as WiFi, PLC or Ethernet.
      • Based on the d amendment of the 802.16 standard approved in 2004
    • In countries with good telecommunications infrastructure, mobile access to voice and data
      • Based on the e amendment of the 802.16 standard approved in 2005
  • 12. WiMAX : Wireless Microwave Access
    • Nonprofit organisation sponsored by several companies to define "profiles" within the standard and ensure interoperability of products.
    • Interoperability tests performed by two independent laboratories in Spain and South Korea.
    • Promoting technology in a manner similar to what the WiFi Alliance did for 802.11.
  • 13. Fixed and mobile WiMAX
    • The two versions of the standard are incompatible because they use different medium access techniques
    • Some manufacturers offer devices that implement both versions of the standard
    • Fixed and Mobile WiMAX are differentiated, although there may be overlap
      • The mobile solution has a much smaller range, on the order of a few kilometres, while the fixed one, with external antennas can reach tens of kilometers if there is line of sight
  • 14. WiMax vs WiFi
    • Wi-Fi was designed for networks with very few clients at close range
    • It has a lot of limitations when applied outdoors at distances of several miles, due to the problem of the hidden node and the waiting time to receive ACK
    • Commercial solutions such as Solectek and Lucent use a non standard mechanism, polling, to resolve this limitation
    Solectek Antenna,1997
  • 15. WMM: WiFi Multimedia
    • Another limitation is that Wi-Fi had no mechanisms to provide QoS.
    • These mechanisms have been incorporated in 802.11e, which provides 4 categories of priority traffic:
      • Voice
      • Video
      • Best Effort
      • Low Priority
  • 16. Scalability and throughput
    • WiFi uses 20 MHz channels; WiMAX is flexible allowing channels from 1.5 MHz to 20 MHz, with spectral efficiency superior to that of 802.11 a and g , but lower than that of 802.11 n
    • The transmission rate can be different in the up and downlink channels, and for near and far clients
  • 17. WiBRO
    • Is a WiMAX variant, first to be commercially installed (South Corea, 2006)
    • Nowadays is part of the mobile WiMAX standardised profiles
    • Implements handover at speeds up to 80 km / h.
    • Video quality and fast transfer of files.
    • VoIP in small mobile terminals
  • 18. WiBRO
  • 19. WiBRO
  • 20. WiBRO
  • 21. WiMAX, now a UIT standard
    • Extension of IMT-2000 to the frequencies between 2,5 GHz and 2,69 GHz
    • Part of IMT-2000 standards
      • W-CDMA
      • CDMA- 2000
      • TD-SCDMA
      • OFDMA TDD WMAN
  • 22. New spectrum adjudication for WiMAX by UIT Potential to reach 2700 million people http://www.dailywireless.org/2007/09/10/luxor-wimaxed/
  • 23. IEEE 802.22 and Cognitive Radio
    • Reuse of TV spectrum between 54 and 862 MHz.
    • Suitable for rural communications due to its greater range.
    • Maximum power of 1W for fixed devices and 100 mW for mobile.
  • 24. Non-standard solutions
    • Alvarion
    • Motorola Canopy
    • Mikrotik
  • 25. Alvarion
    • Offers a variety of wireless equipment for different applications.
    • Originally proprietary equipment, but now WiMAX approved.
    • In Merida, in 2002, a link was installed from a station that collects atmospheric data located at 4765 m altitude, to the Universidad de Los Andes, located at an altitude of 1800 m, and at a distance of 15 km.
    • A webcam transmits images of Pico Bolivar (5000 m) and other data in real time:
    • http://www-imk.fzk.de/imk2/mira/Merida/Merida.html
  • 26. Instruments installed in MARS
    • Receiver for the 270 GHz signal. Note the quality of the antenna reflector and the use of liquid nitrogen to reduce the receiver's noise temperature. Alejandro Humboldt Station, Pico Espejo, Merida State, Venezuela. http://www.cecalc.ula.ve/redbc/estaciones/estacion_pico_espejo_mars.html
  • 27. Alvarion DS 5800, Pico Espejo IDU ODU
  • 28. Alvarion 4 motion
    • Alvarion's WiMAX mobile solution is being deployed in Rosario (Argentina) by ERTACH in the 3,5 GHz band
    http://www.dailywireless.org/2007/10/10/
  • 29. Motorola Canopy
    • The Canopy line is a flexible solution for both PtMp and PtPt networks
    • It offers a variety of transmission speeds reaching up to 300 Mps
    • It works in all bands that do not require license in the United States: 900 MHz; 2,4 GHz; 5,15 GHz; 5,4 GHz; and 5,8 GHz
  • 30. Motorola Canopy Base Station
  • 31. Motorola Canopy
    • 26 dBi gain with reflector, 8 dBi without reflector
    • PoE
    • UTP cable lighting protection
    • Being ported to WiMAX
  • 32. Mikrotik
    • Sells a linux based proprietary operating system that runs on different platforms, allowing long distance links, with different functionalities depending on the acquired license.
    • It also offers hardware with preinstalled operating system
    Board that accepts up to 3 radios
  • 33. Canopy Interference Immunity
    • Optimised for rejecting interference
    • The radios are designed to work with a mere 3 dB C/I
    • Not affected by self-interference, thanks to the synchronisation between different units using a GPS receiver
    • Compare with other systems that require between 8 and 25 dB C/I
  • 34. Conclusions
    • The IEEE 802.16 Standard is the basis of WiMAX
    • There are two versions of WiMAX, one for fixed clients, based on IEEE 802.16-2004 (802.16d) and another for mobile clients, based on IEEE 802.16-2005 (802.16e)
    • While WiMAX has many technical advantages with respect to WiFi, the latter continues progressing and filling many of the gaps in the original standard and, at the same time, maintaining a significant economic advantage
      • The five main points that you must remember in this unit can be summarised as:
  • 35.
      • 4. WiFi is more amenable to organisations that want to install their own infrastructure, while WiMAX is usually installed by a big operator
      • 5. Although there are commercial solutions for wireless networks that may be the most suitable in some cases, it is generally preferable to use standard solutions with better guarantees of continuing support
    Conclusions