Automatic Person Location Technologies and Solutions for Public

Safety Users

Michael NgAsia Regional Director

SEPURA LimitedSingapore

Agenda • Market requirements for APLS for Public Safety users

• The command and control requirements of an APLS solution

• Review of current location technologies

• TETRA services used for location solutions

Market Requirement – APLS • FCC E911 Mandate in the US

Call centres Terminal or Network implemented solutions

50 - 100 metre accuracy for at least 67% of cases

150 - 300 metre accuracy for at least 95% of cases

• EU E112 Mandate in EuropeNo defined accuracy specified !

• Many Emergency Services mandating APLS

Market Requirement - Public Safety

• Specifically for: -

• Safety of the police officer – ability to locate officer in an emergency situation and react accordingly

• Resource (person or vehicle) management

Solution Influencing Factors• Price

– Driven by GSM market – realise only part of GPS abilities

• Accuracy verses coverage– Requirements differ for non emergency– Varying locations - in city, in building

• Ergonomics

• Power consumption

• Timing of solution to reach the market

• Standard solution or proprietary ?

• Can the solution be supported by TETRA ?– Network support and bandwidth requirements

Command & Control Requirements

• Effective management of data

• Bandwidth and network requirements differ from AVLS

• User needs to feel unthreatened by APLS

• Updated positioning details fixed to various duties

• Linking of various systems/databases to provide officer with advance warning of possible dangers

Resource Management• Know where someone is: save LIFE• Better allocation of resources, prompt

reaction to an Emergency: save TIME• Better Control of the fleet: save MONEY

Location Solutions & Performance• Low accuracy, low cost solutions

Triangulation for location determination using RF signals: – Time Difference Of Arrival– Enhanced Observed Time Difference

• Medium accuracy, medium cost solutions1. Standard GPS

• Garmin & Megallan – commercial GPS devices2. Assisted GPS

• Network assisted • Sending information on the states of the satellites

computation of locations to the radios3. Low Signal Strength GPS

• 1,000X more sensitive than std GPS

• High accuracy, high cost solutionsDifferential GPSSolutions combinations

Low accuracy, low cost (terminal) solutions

• Time Difference Of Arrival (“TDOA”)very costly to implement in the networkaccuracy of location is +/- 500 metres

• Enhanced Observed Time Difference (“EOTD”)low cost, no base station support now claimedaccuracy of location is 200m - 2km

• Both technologies Have good indoor/urban canyon penetration, but

with very poor accuracy - a general show stopping issue for network based solutions where location accuracy could be critical

Are bandwidth hungry therefore not suitable for TETRA

Network Based Solutions

W orkstation

LM U

Radio tower

Radio tower Radio tower

PBXTower box

W orkstation

C &CServer

G IS orM apping

Application

G IS orM apping

Application

TETR AN etwork

TETR AG ateway

LM U LM U

LM U

Netw ork Based Solutions

Current Accuracy = 200m - 2kmFuture Accuracy =100m - 500m

Medium accuracy, medium cost solutions

• Standard GPStime to first acquisition (fix) is typically 3 mins>30 metres accuracy, no indoors or urban canyon

coverage• Assisted GPS

time to first acquisition is typically 30 secs>30 metres accuracy, no indoor, urban canyon

• Low Signal Strength GPS (high sensitivity)time to first acquisition is typically 45 secs<30 metres accuracy, indoors/urban canyons

• Note: All the above have a location accuracy of <10 metres for 95% of cases in open space

Standard GPS - medium accuracy

W orkstation

Radio tower

Radio tower

Radio tower Radio tower

PBXTower box

W orkstation

C&CServer

G IS orM apping

Application

G IS orM apping

Application

TETRANetwork

TETR AG ateway

SD S

GPS

High accuracy, high cost solutions

• Differential GPS– Open space accuracy <10 metres off– Expensive to implement with land based

differential base stations required and regular network broadcasts

– Network bandwidth hungry

• Solution Combinations (GPS+Beacons+Odometer)– Accuracy anywhere between 0 - 10 metres– Very expensive beacon network required to

support this

GPS - High accuracy

W orkstation

Radio tower

Radio tower

Radio tower Radio tower

PBXTower box

W orkstation

C&CServer

G IS orM apping

Application

G IS orM apping

Application

TETRANetwork

TETRAG ateway

SD S

G PS

O dom ete r

BeaconRece iver

G PS

dG PS S ta tion

Data over network - Size of problem!

• Typically, position report messages could carry some or all of the following:

Date, Time, Latitude, Longitude, Altitude, Speed, Heading, Fix type, Confidence Level, Status, Fix Reason, Terminal ID, User Defined Field.

• Amount of message traffic generated by APLS systems is much larger than for AVLS

Requires sophisticated filtering at command &control

TETRA services for APLS• No specification for data amount or structure

of GPS messages

• TETRA services allow use of SDS messaging for transmission of GPS data:- EN 300 392-2: TETRA (Voice plus Data (V+D), part 2: Air

Interface, v2.3.2SDS4 and SDS-TL delivers variable length messages to

2047 bits(255 bytes)

• Working papers:-WG101161, Efficient transfer of location information over

TETRA networks, UK Home office, Oct 2001WG103020, Study into TETRA SDSWG303040, Transfer of location information Sepura (and others) presenting papers to WG3

Standardisation of location report messages and associated commands

Sepura APLS Update• This year! – SRP2000 sGPS• The worlds first fully working TETRA

handportable with built-in ultra sensitive GPS.

• Locates and track people even in built up city centres.

• Offering tangible benefits by providing user safety and resource management

Conclusions

• Many different location technologies available

• Technology for both location based and TETRA is rapidly changing

• Low Signal Strength GPS currently provides the best fit for public safety requirements.

• Sepura has an ongoing programme to identify solutions and bring these quickly to market

MANY THANKS

• Contact details:-Michael Ng

Asia Regional DirectorSepura Ltd

+65 9088 6863 email: michael.ng@sepura.com