PUBLIC WARNING SYSTEM C GS S IN JAPAN Presented by Sadayuki Abeta, ARIB © All rights reserved What would you do in case of earthquake ?  Save life Hide under the table p p Open the door to secure an escape route Go away from something dangerous (e.g. Knife, Folk) turn off the fire  Secondary disaster is more terrible Secondary disaster is more terrible  What we can do? Notify what happen via cellular NW in a very short time to minimize the disaster 2 © All rights reserved © All rights reserved What would you do in case of earthquake ? After feeling big shake, what people do? They would contact many pepole They would contact many pepole Emergency Your family, Friends …. y, Traffic congestion occurs! 3 © All rights reserved What should Operators do? Under the emergency situation・・・ Following two are keys Following two are keys PWS notify what happens notify what happens Access Control Keep the NW for comunication way Keep the NW for comunication way 4 © All rights reserved Procedure of PWS(ETWS) 1. Detection earthquake (P-wave) by Government 1 2. Government deliveries the information to Mobile operator 3. Mobile operator broadcast the information to users in target area Earthquake Early Warning System Public Warning System Mobile Government operator To target area Warning!! Sensor Earthquake S-wave P-wave (1) Detection at more than two points (2) Earthquake early warning information (epicentre, scale) User action Move! Move! Move! (3) Safety measures against S-wave P-wave: Body wave that is the first wave to arrive to the seismograph S-wave: Waves of energy that travel through the Earth's layers How shortly notify the information is key! 5 © All rights reserved How soon ETWS shall be delivered? Japanese requirement 6 © All rights reserved Example of PWS (1) 緊急地震速報福島県で地震発⽣。強い揺れに備えてください（気象庁）だ（気象） Emergency g y earthquake q breaking g report p Earthquakes occurrence in FUKUSHIMA, Prepare for the destructive shaking (The Meteorological Agency) Rapport de rupture du tremblement de terre en cas d'urgence d urgence Les tremblements de terre survenue à Fukushima, se préparer à la secousse g météorologique) gq ) destructrice ((L'Agence 7 © All rights reserved Example of PWS (2) landslide or flood due to heavy rain byy Typhoon yp Prepare for escape This is Yokohama city Oct 13 Oct. 13, 19:30 19:30, Yokohama city issued a warring the damage from a landslide is the following area… … …. …. …. 8 © All rights reserved Why Access Control is needed? Prioritize Emergency Call/High priority Call Prioritize Emergency Call/High priority Call Minimizing NW congestion to improve of data/call success rate 120 2000000 1800000 1600000 1400000 80 1200000 60 1000000 800000 40 600000 Number of call ercentage of successful call Pe 100 Number of MO‐CS call Number of MO‐PS Call MO‐CS Call Successful Rate MO PS Call Successful Rate MO‐PS Call Successful Rate 400000 20 200000 0 0 Help! l ! Time Help! 9 Help! © All rights reserved Why separate access control for Voice and Data? Percentage of UEs restricted（％）（Packet Traffic Volume [Relative Ratio]） 80 8 About 40% increase in No. of PS Sessions served at the traffic peak 7 70 PS Traffic with DSAC 6 60 No. of Successful PS Session Setup Attempts measured when DSAC was applied 5 Success ratio of PS session setups = 99.5% 4 3 Restriction percentage on CS domain PS Traffic without DSAC 50 No. of Successful PS Session Setup Attempts estimated with assumption that the same restriction % was applied to CS & PS Success ratio of PS session setups = 86.8% 40 30 2 20 1 10 0 0 23:30 23:35 23:40 23:45 23:50 23:55 0:00 0:05 0:10 0:15 0:20 0:25 0:30 0:35 0:40 0:45 0:50 0:55 1:00 Time Restriction percentage on PS domain Traffic Trace taken around the midnight of the new year (2005) eve Is past, protect PS domain (mail, Chat) from huge amount of CS call. Now, protect voice call from PS (keep‐alive, etc) Access control for voice and data separately is essential to mitigate any traffic case. (DSAC in 3G, SCM(Rel.12) in LTE) (DSAC i 3G SCM(R l 12) i LTE) 10 © All rights reserved Summary For disaster, For disaster, “悲観的に準備し、楽観的に行動せよ” “Prepare Pessimistically, Action optimistically” In PWS, there is no “too much” 11