Fostering worldwide interoperabilityGeneva, July 2009 Broadband Wireless Communication System for Public Safety Homare Murakami, Masayuki Oodo, Hiroshi Harada NICT / ARIB Global Standards Collaboration (GSC) 14 DOCUMENT #:GSC14-PLEN-071 FOR:Presentation SOURCE:ARIB AGENDA ITEM:6.2

Fostering worldwide interoperability 2 Geneva, July 2009 Background – frequency band– In Japan, digitalization of terrestrial TV broadcasting service to be completed in July, 2011 == > reduce the total bandwidth for terrestrial TV broadcasting current after July, 2011 current analog TV broadcasting (total: 370 MHz) [MHz] 3.ITS 4.cellular system terrestrial digital TV broadcasting (240 MHz) ==> 130 MHz newly available 2. Broadband mobile communications for public safety [MHz] 1.mobile multimedia broadcasting

Fostering worldwide interoperability 3 Geneva, July 2009 Strategic Direction – current and expected systems for public safety– broadband shared by multiple public organizations narrow band fire department local government (prefectural/city/municipal) police agencies narrow band difficulty in interoperability current system -- narrow band voice low data rate transmission -- difficulty in interoperability -- shared by multiple public organizations -- broadband access service (several Mbps) for mobile users (main application: moving pictures transmission) -- highly-efficient spectrum use => OFDM-based system expected system

Fostering worldwide interoperability 4 Geneva, July 2009 Challenges for reliability(1/2) – Radio Propagation Field Tests – delay spread: => ~ 10usec fading performance: => slow temporal variation RSSI measurement => coverage ~ 5 km P4

Fostering worldwide interoperability 5 Geneva, July 2009 Challenges for reliability (2/2) – Transmission Experiments – In order to investigate adequate OFDM parameters, following combinations were tested. Mode #Mode 1Mode 2Mode 3 Channel bandwidth5 MHz FFT Size Guard Interval~10 μsec~20 μsec Pilot symbol occupancy~30% ~17% GSM Typical Urban IEEE Profile A For long-delayed (~ 20μsec) channel environment, Mode2 (narrower subcarrier interval, resulted in good transmission performance. For short-delayed (~ 5μsec) channel environment, no large differences among all modes were seen.

Fostering worldwide interoperability 6 Geneva, July 2009 Toward the realization of broadband wireless communication system for public safety using the VHF bands (a portion of vacant lots after retirement of analog TV broadcasting service), R & D of the system have been progressed. Indoor and Field experiments have been conducted to decide the system parameters (service coverage, PHY parameters etc.). Next Steps/Actions