C G S S PUBLIC WARNING SYSTEM IN JAPAN Presented by Sadayuki Abeta, ARIB 

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
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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!
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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
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Procedure of PWS(ETWS)
1. Detection earthquake (P-wave) by Government
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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!
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How soon ETWS shall be delivered?
Japanese requirement
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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
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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…
…
….
….
….
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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!
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Help!
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Why separate access control for Voice and Data?
Percentage of
UEs restricted（％）
（Packet Traffic Volume [Relative Ratio]）
80
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About 40% increase in
No. of PS Sessions served
at the traffic peak
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70
PS Traffic with DSAC
6
60
No. of Successful PS Session Setup
Attempts measured when DSAC was
applied
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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)
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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”
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