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Wi max and military applications

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introduces WIMAX principle and its applications within the military

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Wi max and military applications

  1. 1. WIMAX WORLDWIDE INTEROPERABILITY FOR MICROWAVE ACCESS Souheil Ben Tekaya
  2. 2. Introduction     802.16 as a standard WiMAX as a marketing term WiMAX forum, 802.16 working group History:  90s, standard missing,  IEEE first version of the standard in 2001 
  3. 3. Plan      Definition Techniques Topology Military Applications Advantages and drawbacks
  4. 4. Definition   WiMAX forum develops guideline aka profiles First two commercialized versions: d (2004) and e(2005), define  PHY and MAC layers  Frequency below 11 GHz  Version d: fixed services  Version e: mobile services
  5. 5. 802.16 technology specifications Specificati on Year of ratification Description 802.16 2001 802.16a 2003 MAC and PHY definition for fixed broadband wireless access in the 10-66 GHz bands Contains new PHY definitions for the 2-11 GHz bands. Also includes mesh network modes of operation 802.16c 2002 System profiles for 10-66 GHz operations 802.16d 2004 Contains 802.16, 802.16a, and various MAC enhancements. Known as 802.16-2004, considered the base fixed broadband wireless specification 802.16e 2005 Amendment to the 802.16d specification, explicit support for mobility. 802.16f 2005 802.16 Management Information Base (MIB) 802.16g 2007 Network Management (management plane control procedures) 802.16h 2010 Coexistence in license exempt frequency bands 802.20 In progress Mobile broadband wireless access standards group. Initially formed as a study group Within the 802.16 working group focused solely on mobility, supporting train-like speeds.
  6. 6. Techniques  Duplexing:  Time-Division Duplexing:  Wireless medium divided in time,  separate periods of time allocated for Uplink Channel and Downlink Channel  Single frequency channel used  Half-duplex  Frequency-Division  UC Duplexing: and DC separated in frequency  Full-duplex and half-duplex  Pro: Use of different modulation types  Con: Static assignment of UL and DL  Less flexible than TDD
  7. 7. Techniques (PHY)  FDM: is a special form of Multi-carrier Modulation transmission technique.  MCM: sub-carrier separated by guard band, No overlap  Badpass filters in receiver to separate the spectrum of sub- carriers  OFDM: employs densely spaced orthogonal subcarriers and overlapping spectrum no bandwidth filter required.
  8. 8. Technique  Modulation: 802.16a/d defines 7 combinations of modulation and coding rates (trade-offs of data rate and robustness) Quadrature phase- 0 BPSK 1/2 0.5 Peak data rate in 5 MHz (Mb/s ) 1.89 shift keying (QPSK)  1 QPSK 1/2 1 3.95 2 QPSK 3/4 1.5 6.00 3 16QAM 1/2 2 8.06 4 16QAM 3/4 3 12.18 5 64QAM 2/3 4 16.30 6 64QAM 3/4 4.5 18.36 Binary phase-shift keying (BPSK)   Quadrature amplitude modulation (QAM) Rate ID Modulatio n rate Codin g Information bits/symbol
  9. 9. Technique     Coding: Adaptive Modulation and Coding (AMC) is the standard approach in WiMAX standards. Dynamically adapt the modulation and coding scheme to the channel conditions highest spectral efficiency. 802.16 uses Reed-Solomon block code+ inner convolutional code. Turbo code(optional feature):improve coverage/capacity, at the price of increasing decoding latency and complexity.
  10. 10. Topology   PMP: point to multi-point (Base Station, Subscriber’s Stations) Mesh : Subscriber Stations serve as routers to enable multi-hop routes.  Pro: coverage  Con: less throughput
  11. 11. Military Applications   Jamming resistant (mesh topology), new routes Power amplifier: NATO Band I (225 to 400 MHz) has tested under 802.16 OFDM 64QAM modulation, the average output power is 25 W throughout the bandwidth   Works in high frequency Doesn’t disturb other freq. ranges 2 scenarios: Border surveillance using cameras installed on the WiMAX towers  Communication between ship to share SATCOM with HQ  cost effective.  Rescue operation: replace wired connections destroyed amid disasters 
  12. 12. Advantages     Mesh topology: larger range, and jam resistant Strong QoS, good bandwidth efficiency (thanks to AMC) Flexible architecture Non-LOS connection (using OFDM ), can be improved using directional antennas
  13. 13. Drawbacks    Limited Mobility: up to 145 km/h for 802.16e 802.20: support up to 240 km/h, allows it to be implemented in relatively fast vehicles such as UAVs…. still cannot reach weapons or aircraft range.

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