Wireless communication in the areas of difficult propagation conditions

1. 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!"

2. AT AT AT AK AK AK STORCZYK Communication System

3. 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) • 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 • 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

4. COTS technology Military applications Radiotechnika Marketing LTD. WLANBOX-Bridge 1-2,4

5. 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.

6. 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 mechanismson 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

7. WLANBOX-Bridge operational parameters • 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

8. System on measuring position

9. 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.

10. Measurements - variable parameters • Signal Strength • Reliability of data transfers during transmission of 10 Mbytes long files. • Error rate • average effective data rate.

11. Measurements result

12. Conclusions • Propagation of waves in microwave bands inforests 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

13. Directional antennas military LAN concentrator sending-receiving unit communication shelter 6m antennas feed coaxial cable tactical optical cable or cat.5 twisted pair field cable tactical optical cable or cat.5 twisted pair field cable sending-receiving unit terminals 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.

14. Implementation……cd 2. Connection between vehicles in motion

15. Implementation…… 3. Communication on difficult area

16. Thank you very much for your attention