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Wireless communication in the areas of difficult propagation conditions. Krzysztof Wierny Radiotechnika Marketing LTD. Military University of Technology. AFCEA's International Student Conference "Students at Work!". AT. AT. AT. AK. AK. AK. STORCZYK Communication System. - PowerPoint PPT Presentation
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Wireless communication in the areas of difficult propagation conditions
Krzysztof Wierny
Radiotechnika Marketing LTD.
Military University of Technology
AFCEA's International Student Conference "Students at Work!"
STORCZYK Communication System
AT
AK
AT
AK
AT
AK
COTS technology Military applications
1. System EXDWN from Xacta (USA)•Portable access point or bridge•IEEE 802.11 b, g, 54Mb/s, 2.4GHz•Omni and directional antennas both on the mast•security WPA-TKIP,EAP MAC
2.System Battle LAN S-WiFi from Thales•Access point or bridge for using on the vehicles•IEEE802.11b,g; 2-6 GHz,•Output power 1W•Range 1 km in open area (11Mb/s)
3.System TELCOR MeshCom from Telefunken•Access point or bridge •IEEE 802.11 b,g; 2,4 Ghz;•(1-10GHz ),range 300-1500m
COTS technology Military applications
Radiotechnika Marketing LTD. WLANBOX-Bridge 1-2,4
military communication systems requirements
• short deploying time and establishing communication,
• precluding easy localization and detection of communication node
• transmission range big enough to enable dispersion of shelters in the large area
• operation in military frequency bands.
Commercial communications wireless systems:
ADVANTAGES:• provides wide range available bit rates from 1 Mbit/s to
54 Mbit/s,• provides greater flexibility in network construction,• enables transfer modern data transmission technologies
and security mechanisms on military area .DISADVANTAGES:• WLAN have insufficient communication range • operating in commercially available, unlicensed
frequency bands, crowd of users• restricted transmitters power,• need precise positioning of directional aerials in bridge
connections
• output power 4W• bandwidth converter from 2,4Ghz to
1,6Ghz• system is placed in small portable box• operation up to 5 hours from the battery• connection with communication shelters
through the PKS and PKŚ cables• optical indicators of signal level for easy
alignment antennas
WLANBOX-Bridge operational parameters
System on measuring position
WLANBOX-Bridge
• 2 pcs of WLANBOX-BRIDGE 1-2.4 modules
• 2 omnidirectional antennas 12dBi on frequency band 2,4 GHz
• 2 directional antennas 24dBi on frequency band 2,4 GHz
• 2 tripad folding masts at 4m high
• 6m long antennas feed coaxial cables
• 2 pcs.of military notebooks with Pentium M processor.
Measurements - variable parameters
• Signal Strength
• Reliability of data transfers during transmission of 10 Mbytes long files.
• Error rate
• average effective data rate.
Measurements result
Antenna type
freq./output power
Directional 1,6GHz, 4W
Directional 2,4GHz, 30mW
Omnidirectional
2,4GHz, 30mW
max. distance between antennas
800m 220m 130m
transfer rate 500kb/s 300kb/s 250kb/s
error rate 10% 12% 16%
signal strength 22% 18% 18%
reliability Rarely interrupted
often interrupted transfer
often interrupted transfer
distance between antennas
600m 150m ~100m
transfer rate 2Mb/s 1Mb/s 1Mb/s
error rate 1% 3% 3%
signal strength 42% 40% 40%
reliability Stable transfer Stable transfer Stable transfer
Conclusions
• Propagation of waves in microwave bands in forests limited because of strong suppression caused by branches, leaves and trunks of trees
• Range of omnidirectional antennas is insufficient in dense forests area and can used with satisfaction for military application only at distance up to 100m.
• Using of amplifier with 4W output power brought in an increase of signal range of about four times
• Duration of antennas positioning is much longer for directional antennas than omnidirectional
Implementation of wireless WLANBOX Bridge system for military application.
1.wireless bridge can improve connecting remote command post (placed in building, tent) with communication shelter.
Implementation……cd
2. Connection between vehicles in motion
Implementation……
3. Communication on difficult area
Thank you very much for your attention