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

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

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

Wi-Fi Cell coverage and throughput (declared by manufacturer ) Access Point (Outdoor) Frequency bands: 100 MHz near 2.4 and 5.7 GHz Frequency bands: 100 MHz near 2.4 and 5.7 GHz Transmit Power: up to 100 mW (20 dBm) Transmit Power: up to 100 mW (20 dBm) Minimum useful signal : Minimum useful signal : -94 dBm (1 Mbps) ÷ -72 dBm (54 Mbps) Throughput and range: Throughput and range: 54 Mbps 45÷60 m54 Mbps 45÷60 m 11 Mbps190÷235 m11 Mbps190÷235 m Antenna gain at access point : 5 ÷ 13 dBi Antenna gain at access point : 5 ÷ 13 dBi

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

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

specifications 2004 Air Interface for Fixed Broadband Wireless Access Systems (IEEE ) whose primary bands of interest are GHz, where line-of-sight (LOS) is necessary and multipath negligible Air Interface for Fixed Broadband Wireless Access Systems (IEEE ) whose primary bands of interest are 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. 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) many physical layer specifications (PHY)

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 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 the wirelessMAN-OFDM is based on OFDM modulation and designed for NLOS operations in the frequency bands below 11GHz 2005 Mobile amendment (IEEE e) Mobile amendment (IEEE e).

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

Wi-MAX tender in Italy tender Published on 19th October 2007 Published on 19th October 2007 To licence the use of frequency bands allocated at 3.5 GHz using Broadband Wireless Access (BWA) systems To licence the use of frequency bands allocated at 3.5 GHz using Broadband Wireless Access (BWA) systems Constrains to radio emissions (Maximum EIRP and Block Edge Mask as usual) in Raccomandazione n. ECC/REC(04)05 Constrains to radio emissions (Maximum EIRP and Block Edge Mask as usual) in Raccomandazione n. ECC/REC(04)05 Raccomandazione n. ECC/REC(04)05 Raccomandazione n. ECC/REC(04)05 48 applicants 48 applicantsapplicants

Possible applications of Wi-MAX Besides last mile broadband wireless access in rural areas to overcome the digital divide, possible application are: Besides last mile broadband wireless access in rural areas to overcome the digital divide, possible application are: fixed telephony competitorfixed telephony competitor mobile telephony competitormobile telephony competitor Transport network (backhaul) competitor of radio links or fibre between Wi-fi access points or mobile telephony towersTransport network (backhaul) competitor of radio links or fibre between Wi-fi access points or mobile telephony towers

Tipical Cell coverage and throughput (declared goals) 10Km NLOS point-to-multipoint 40Mbps to mobile, portable and fixed 50Km LOS point-to-point 72Mbps to portable and fixed only. 50Km LOS point-to-point 72Mbps to portable and fixed only. anyway these features become of second order as far as regards maximizing subscribers => capacity constrains. anyway these features become of second order as far as regards maximizing subscribers => capacity constrains.

capacity of WIMAX (2+1)x2 frequency bands of 21MHz (2+1)x2 frequency bands of 21MHz adaptable bit/symbol depending by radio-path impairments (one symbol can use many carriers) Telco operators usually makes maximum use of limited spectrum assets => cellular system

WIMAX scenario Telco operators could implement a cellular system to substitute telephone copper wire to subscriber home, system that resembles the already existent one for the mobile telephony Telco operators could implement a cellular system to substitute telephone copper wire to subscriber home, system that resembles the already existent one for the mobile telephony

system profile example of an implementation case example of an implementation case Antennas, receivers, powers, radio paths and above all interference are almost the same as GSM mobile scenario Antennas, receivers, powers, radio paths and above all interference are almost the same as GSM mobile scenario

another scenario Telco operators could provide broadband wireless access in rural areas Telco operators could provide broadband wireless access in rural areas paraboloidal antenna can be used even though at 3,5GHz they are not so well performing (with a diameter of 80cm=>only 25dB gain, beamwidth 10° ) paraboloidal antenna can be used even though at 3,5GHz they are not so well performing (with a diameter of 80cm=>only 25dB gain, beamwidth 10° ) Rabio base-subscriber home radio channel resembles a radio link Rabio base-subscriber home radio channel resembles a radio link

increasing the frequency... Operators could reuse the spectrum deploying the narrow beam of very directional antennas (paraboloidal) from a high tower Operators could reuse the spectrum deploying the narrow beam of very directional antennas (paraboloidal) from a high tower In this case also the user antenna should be paraboloidal => fixed (not mobile) In this case also the user antenna should be paraboloidal => fixed (not mobile) In this scenario, a narrow beam covers a village from a distant high tower. In this scenario, a narrow beam covers a village from a distant high tower.

Link budget example for DL mobile WiMAX Total TX Power: 20 W Total TX Power: 20 W Power used for link budget: 10 W Power used for link budget: 10 W Penetration Loss: 15 dB Penetration Loss: 15 dB Minimum useful signal : -75 dBm (68 dBµV/m) Minimum useful signal : -75 dBm (68 dBµV/m)

UMTS tech overview Frequency bands: Frequency bands: 1920÷1980 MHz (UL) and 2110÷2170 MHz (DL) Max number of (voice) channels on 2x5MHz : ~196 Max user data rate offered: 2 Mbps (DL) Max user data rate offered: 2 Mbps (DL) Antenna directional gain: 17÷18.5 dBi Antenna directional gain: 17÷18.5 dBi

Link budget example for DL UMTS Total sector TX Power: 43 dBm (20 W) Total sector TX Power: 43 dBm (20 W) P CPICH = 33 dBm (2 W) P CPICH = 33 dBm (2 W) Penetration Loss: 15 dB Penetration Loss: 15 dB Minimum useful signal: -78 dBm (66 dBµV/m) Minimum useful signal: -78 dBm (66 dBµV/m)

Ray-tracing simulation technique: Quick_Plan TM by TeS Full 3D ray-tracing Full 3D ray-tracing Integrated Geographical Information System (GIS) Integrated Geographical Information System (GIS) Oracle DBMS Oracle DBMS Integrated 3D cartography Integrated 3D cartography (terrain + buildings)

UMTS coverage

UMTS far-field exposition

WiMAX coverage

WiMAX far-field exposition

bibliography ANSI/IEEE Std , 1999 Edition (R2003) Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications ANSI/IEEE Std , 1999 Edition (R2003) Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications Cisco Aironet Antennas and Accessories Cisco Aironet Antennas and Accessories IEEE standard Part16:Air Interface for fixed broadband wireless Access System IEEE standard Part16:Air Interface for fixed broadband wireless Access System Eklund: IEEE standard : A technical overwiev of he wirelessMAN air interface for broadband wireless access June 2002 Eklund: IEEE standard : A technical overwiev of he wirelessMAN air interface for broadband wireless access June 2002 Webb : Broadband fixed wireless access as a key component of the future integrated communication environment 2001 Webb : Broadband fixed wireless access as a key component of the future integrated communication environment 2001