IWS2005 Thursday
Keynote speech
WLAN, Fixed Wireless and Cellular all have adopted space-time transmit diversity
Only WLAN’s really use special MUX
Celullar may never see special MUX

Cognitive radio may present a challenge to spatial MUX in WiMAX
MIMO in networks is different from MIMO in isolation

Networks not prepared to cut down on power(loose channels) to include spatial diversity

UWB panel discussion
CSEM – built small, low complexity UWB solution
Low data rate
Tx 3.5 mW
Rx 7.5 mW
Radiated power 100uW
Uses analogue spread spectrum and multi-path diversity
Use of other MAC layer may reduce power further, WiseMAC, S-MAC

Delivering Broadband from a high altitude, quasi stationary plane/airship
120Mb/s symmetric links
Delivery to rural areas, blocks of flats and moving train, using steerable antennae
Optical links for backhaul 48/47GHz 31/28GHz
University of York UK, NICT Japan
60Km diameter user area coverage, single or multiple cell
Possible backhaul via satellite
802.16, 802.20, 802.11 , ETSI Hiperaccess, hiperMAN, DVB
802.16sc is best overall choice
WiMAX, possible depending on regulators
17 – 22 Km above the ground
Dish sizes less than 30 cm
Issues: HAP station keeping and moving train
Antennae: mechatronic and smart
Use 8X8antenna array to block out interfering signals

Test system in Sweden delivered 4Mb/s throughput 802.11b and 1.25Gb/s freespace optic link
Dr. David Grace [email protected]
200-300 000 euros for test tethered platform

This has given me an idea!!! Why not put an AP on an advertisement gas balloon as a hop between Jhb and PTA?

Improved Triangulation Method using a Movement model
Localisation done in Bluetooth
Inquiry procedure provides RSSI
Movement model variables: Speed, direction based on previous measurements
Without prior knowledge: Speed truncated normal distribution with a mean of 1m/s and std dev of 0.5m/s
Direction uniform between -180 and 180
With prior knowledge, previous measurements used to determine speed

Planning of Large-scale WLAN infrastructures, Methodius University, Macedonia
Planning either done using educated guesses or with auto planning
Dominant path approach used for propagation modelling
Propogation Modelling, Coverage optimisation and channel alloc optimisation
Wireless Indoor Design Tool, version 1 (WIDT v1) to be released soon
Possible use in indoor mesh?

0 thoughts on “IWS2005 Thursday

  1. The gas balloon sounds like a good idea. The only problem is getting a sponsor to set one up. If I remember correctly there used to always be a balloon up in Midrand(about a year ago). I dont know if it is still up or even nor do I know whose balloon it was.

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