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AML – Advanced Mobile Location
999 – improving precision for mobile calls
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Emergency Calls from Mobile Phones
• 62% of emergency calls in UK from mobile phones - about 45k calls/day
• Network Location Information based on mobile cell site coverage – caller could be located anywhere in what can be a large area
• Calls from mobiles take ~30 seconds longer before despatch - but can take 3 minutes of extra questions for stressed/injured victims*
• About 36k incidents per year involve searches of 30+ minutes because a mobile caller is unable to give location
• 143,000 other cases/year of a caller being unable to speak clearly** and where Police are concerned to request a registered address if available. Currently only 60% where registered address available……………….and an average 12 minute delay to obtain.
* London Ambulance found (2014) that 4,000 calls / month take more than 3.5 mins before despatch
** Background screams, distressed, crying, alleged assaults, repeat callers
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Requirement for Advanced Mobile Location
service (AML) – use the handset’s own location
• No impact on standard emergency call (voice + network’s cell location info)
• Smartphone recognises an emergency call is being made : invisible to user
• Phone turns-on GPS & WiFi facilities if needed and collects location information (for up to 20 seconds)**
• Zero-rated SMS containing location sent to PSAP (not visible on handset, no charge)
• Mobile network configuration to allow SMS when emergency call in progress
• Minimum battery level needed to allow enhanced service
• PSAP matches received location SMS to emergency (voice) call
• PSAP verifies handset GPS/Wifi location is consistent with network’s cell location
• Handset location information made available to 112 call-takers of requested Emergency Service (Police, Fire, Ambulance, Coastguard)
• This is not an App : no end user installation needed, simply call 112 as normal
** Notes (i) where possible this will supplement the existing location information – does not replace it.(ii) maintains privacy : only triggered when emergency call made
UK Emergency Service
BT Public Network
Fixed/Mobile Networks
BT 112 Call Centres
Stage 1 PSAPBT (6 sites)
~ 28m calls/year
Public networks (BT and others)
Police 47%
Ambulance 49%
Fire 4%
Coastguard <1%
999/112
(158 Local Controls – Stage 2 PSAPs)
999/112 call handling : Voice + Location - Voice : Mobile, Fixed, VoIP
- eSMS for hearing impaired ( also ITUv21 text over voice, real time text using special terminals)
- Telematics in certain vehicles that includes a voice call + separate SMS data message
~62% Mobile
>80 Communication Providers (CPs)
PSTN-IP Gateways
VoIP CPs
Location Hub –uses network and handset location
Location VPN
Some handset locations via SMS –AML
Network Location –GMLC for mobiles
Results - Rural
Network location – 2024m radius Handset – 6m radius – GPS
Results - City
Network Location – 195m radius Handset – 22m radius – GPS
Results - Office
Network – 383m radius Handset – 34m radius – Wi-fi
Launched for live use - reaching more handsets and networks
• Live service since June 2014
• Initially HTC handsets on EE – all new models- OTA upgrades for many existing handsets
• HTC handsets also on O2 and Three networks too
• Sony supported on O2 from August 2015
• Alcatel supported on O2 from October 2015
• Samsung launched on O2 on 10 December 2015
Recent monthly figures – Mar 16
• Positions obtained from handset in live use (using AML) are :-
- 40% AGPS/GPS - 33% WiFi- 8% Cell- 19% with no location
• ~91% of AML positions accepted after comparison with network location
• Reject reasons are related to overlap/gap, level of trust, area and time.
Precision of AML Locations - 85%<50m radius
0-9 m12%
10-19 m22%
20-49 m51%
50-99 m5%
100-999 m4%
1km+6%
Time Delay in AML location arrival – 90% within 30 secs
0-4 secs11%
5-9 secs14%
10-19 secs31%
20-29 secs34%
30-39 secs6%
40-49 secs2%
50-99 secs1%
100 secs plus1%
Voice call set-up ~5s
BT999 TTA ~1s
BT PSAP handling ~8s
Police TTA ~6s
Second Location Hub search
Re-query after ~ 20 secs
Timeline to most effectively use the handset location
User makes call
Call answered by Stage 1 PSAP
Police call handling
Time (seconds)
Event
0 5 3010 15 20 25
Call connect initiated.
Call answered by Stage 2 PSAP
First Location Hub search.
Network Location Data Arrives ~1 sec after call answered
Actual Handset Location arrival times
37
90%11% 25% 57%
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Summary
• Increased location precision - shorter time to locate person in need
• Fewer questions about location – reduced caller/call taker stress
• Faster response to patients with life-threatening conditions
• Reduced costs to Emergency Authorities – less questioning +
searching
• Not an App – sustainable, does not depend on end user,
supplements standard GSM voice call wherever possible,
evolves with handsets
• Working better than expected……. still need network cell location
for cases where AML not possible and to eliminate any unreliable
readings
