Transcript Document
Automatic Person Location Technologies and Solutions for Public Safety Users Michael Ng Asia Regional Director SEPURA Limited Singapore 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 Europe No 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 solutions 1. 2. 3. • Standard GPS • Garmin & Megallan – commercial GPS devices Assisted GPS • Network assisted • Sending information on the states of the satellites computation of locations to the radios Low Signal Strength GPS • 1,000X more sensitive than std GPS High accuracy, high cost solutions Differential GPS Solutions combinations Low accuracy, low cost (terminal) solutions • Time Difference Of Arrival (“TDOA”) very costly to implement in the network accuracy of location is +/- 500 metres • Enhanced Observed Time Difference (“EOTD”) low cost, no base station support now claimed accuracy 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 TETRA Network LMU Radio tower Workstation LMU Radio tower TETRA Gateway PBX Tower box C&C Server Workstation GIS or Mapping Application GIS or Mapping Application Network Based Solutions Current Accuracy = 200m - 2km Future Accuracy =100m - 500m LMU LMU Radio tower Medium accuracy, medium cost solutions • Standard GPS time 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 TETRA Network Workstation Radio tower Radio tower TETRA Gateway SDS PBX GPS Radio tower Radio tower Tower box C&C Server Workstation GIS or Mapping Application GIS or Mapping Application 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 TETRA Network Workstation Radio tower Radio tower GPS TETRA Gateway PBX Tower box C&C Server Workstation GIS or Mapping Application GIS or Mapping Application dGPS Station SDS Radio tower Beacon Receiver Radio tower Odometer GPS 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, v2.3.2 SDS4 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 2001 WG103020, Study into TETRA SDS WG303040, 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 Director Sepura Ltd +65 9088 6863 email: [email protected]