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Perspectives in risk management in Italy: the impact of WiMAX and WiFi

Summary. What is Wi-Fi?What is WiMAX?Wi-MAX tender in Italycapacity of WIMAXWIMAX scenarioanother scenarioincreasing the frequency ...bibliography. What is Wi-Fi?. Stands for Wireless Fidelity (1997)Wireless network extension of already existent successful Ethernet LAN.2,4 GHz Free frequenc

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Perspectives in risk management in Italy: the impact of WiMAX and WiFi

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    1. Perspectives in risk management in Italy: the impact of WiMAX and WiFi Dr. Ing. M. Mozzo, Dr. Ing. F. Boella, Dr. Ing. F. Panin, Prof. L.Giuliani Istituto Superiore per la Prevenzione e la Sicurezza del Lavoro 17/12/07

    2. Summary What is Wi-Fi? What is WiMAX? Wi-MAX tender in Italy capacity of WIMAX WIMAX scenario another scenario increasing the frequency ... bibliography

    3. What is Wi-Fi? Stands for Wireless Fidelity (1997) Wireless network extension of already existent successful Ethernet LAN. 2,4 GHz Free frequency band with limited power emission. Multiple Access with collision avoidance. prone to interference signals by other access-point DS and FH Spread-spectrum modulation and OFDM multiplexing Portable and mobile stations

    4. Wi-Fi Cell coverage and throughput (declared by manufacturer ) Access Point (Outdoor) Frequency bands: 100 MHz near 2.4 and 5.7 GHz Transmit Power: up to 100 mW (20 dBm) Minimum useful signal : -94 dBm (1 Mbps) ÷ -72 dBm (54 Mbps) Throughput and range: 54 Mbps 45÷60 m 11 Mbps 190÷235 m Antenna gain at access point : 5 ÷ 13 dBi

    5. Impact of Wi-Fi to radio environment The scenario is going to be hot-spotted isolated coverage with 100mW at 2,4GHz unlicensed ISM bands (industrial, scientific medical) freely maintained by local administrators in public areas (airport, train station, office, school park, etc.)

    6. What is WiMAX? Stands for World-wide Interoperability for Microwave Access. also known as Wi-fi maximized The industry trade group WiMAX ForumTM has defined WIMAX as the “last mile” broadband wireless access (BWA) alternative to ADSL service.

    7. specifications 2004 Air Interface for Fixed Broadband Wireless Access Systems (IEEE 802.16) whose primary bands of interest are 10-66 GHz, where line-of-sight (LOS) is necessary and multipath negligible. Frequency below 11GHz provide a physical environment where, due to longer wavelength, LOS is not necessary and multipath may be significant. many physical layer specifications (PHY)

    8. specification (continued) The ability to support near-LOS and non-LOS (NLOS) scenarios requires additional functionality, such as the support of advanced power management techniques, interference mitigation/coexistence and multiple antennas the wirelessMAN-OFDM is based on OFDM modulation and designed for NLOS operations in the frequency bands below 11GHz 2005 Mobile amendment (IEEE 802.16e) .

    9. some technical details At 3,5GHz, wavelength is 8cm and radiowave can reach 50Km, pass through trees and rain (drizzle). Robust narrow-band modulations (QPSK,QAM) ~100 sub-carrier frequency or time duplexing

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