ABSTRACT

A cost-performance optimised design of GeoComm, Geo-Intelligent Mobile Communication and Tracking system, is presented along with design validation and test results. The unique design features and the potential applications of this design are described.

I. INTRODUCTION

With the proliferation of Global Navigation Satellite System (GNSS) and mobile communication technologies, a host of applications have emerged catering to sectors such as transport, public safety, asset management, utility, healthcare, etc. These are categorised as geo-intelligent applications [1].

A number of designs have evolved for geo-intelligent products. Many of these are proprietary in nature and use proprietary / commercially available tools / platforms for implementation. These tend to make the product and application expensive. Volume sensitivity plays a major part in deciding the price of the product.

To meet cost, quality and time-to-market targets, reuse of designs, reuse of components, reuse of manufacturing processes, and spreading over marketing opportunity channels are required. “Componentizing” the whole product life cycle will ensure that the components can be produced in volumes resulting in volume discounts. Proprietary platforms are giving way to open platforms. The challenge is to realise a cost competitive product which can cater to a wide range of applications.

A geo-intelligent product is a product that knows its location and is an enabler for applications that fall in the following categories;

       1) Personal / Vehicle / Asset locator - Where am I?
       2) Personal / Vehicle navigator - How do I reach my destination?
       3) Personal / Vehicle / Asset Tracker - Where are you?
       4) People / Fleet Tracker – Where are you all?
       5) Location based services – Where are the closest service points?
       6) Location based planning – Where are the closest available resources to carry out a job?

Each of these applications carries an attribute requiring a different logic to implement. However, the common feature of all these applications is the generic requirement of location and time (i.e. the where and the when).

In this paper, the design and development of a generic geo-intelligent mobile communicator and tracker is presented. Some features and specifications of the product ‘GeoComm’ implementing these applications are given.

II. TARGET APPLICATION FEATURES

In order to service the stated applications, following features have been implemented in GeoComm (Figure-1):

Figure-1: ASL's GeoComm

• Pocket size design containing the electronics that is close to 75 mm x 45 mm x 15 mm in dimensions
• Work with external +12V DC supply or internal compact battery to cater to both vehicle or hand-held applications
• Provide indications for GPS 3D fix, Call receive, Message transmit, Communication Network availability
• Provision for Microphone & Speaker outputs for external head set interface
• On-board buzzer for Call/Message receive
• Support GSM/GPRS communication and R-UIM based CDMA communication
• Provision for being polled to determine location and enable track
• Emergency messaging of location and time by click of a button
• Instant call to pre-defined locations/numbers
• Interface to a Map display and an external keyboard
• Over-the-air firmware upgrade for affecting a logic change
• Data logging up to a pre-determined memory space
• Output to a user-friendly application data base

III. DESIGN APPROACH

The technical specifications so determined are:

• A GPS providing a minimum of 16 satellite channels view, a high receiving sensitivity of a minimum -150 dbm, a high position accuracy of 2.5m CEP, half-a-minute cold start and a higher than 1 Hz data update rate
• A serial RS 232/USB output interface
• Connector for GPS/GSM antennae connection
• Interface up to 25 different keys for various functionalities
• Cater to usual polarity protection, noise immunity, internal battery charging
• Replaceable SIM card holder
• Analog input at CMOS level to the electronics board

The GeoComm hardware design has minimized the use of external components by reusing the ARM 7 in the GSM/GPRS module as its main control unit.

The GeoComm embedded software is written using C language. The various software modules are GPS management, Messaging, GPRS connectivity management, Data logging, Key interface, Status indication, all neatly integrated and optimised for a small footprint.

The data from the GeoComm Unit can be extracted via the serial port, or can be transmitted to ASL GeoConnect via GPRS. ASL GeoConnect is a GUI based application software installed in desktop PC[2]. Using this, an operator can query any mobile unit equipped with GeoComm, and obtain its location with time-stamp in real time, or send/receive message. The GeoComm equipped mobile unit can be configured to report location, time, etc. at set intervals and automatically update the database in the desktop PC. This data is readable and displayable on digital map on the PC. It works under Linux operating system with My SQL database and map information in “SHP” data files.

The tracking application allows over-the-air configurability of the GeoComm unit for effective tracking, recording stoppages, over speeding, emergency call/message alert, etc.

The operation of GeoComm along with GeoConnect is represented in the block schematic of Figure-2.

Figure-2: Block schematic of GeoComm with GeoConnect

IV. DESIGN VALIDATION/TESTS

GeoCom has been validated at following levels;

• Electronics board circuit schematic and layout
• Electronics board circuit testing with simulated signal levels
• Testing of GPS with real view GPS satellites confirming signal levels, accuracy and availability
• Testing with GSM communication network for faithful GPS data transmission as messages over GPRS network
• Integration with ASL GeoConnect and Tracking application

Figure-3: Snap shot of GPS data from GeoComm

The GPS data string output from GeoComm and a view of GPRS tracked moving asset using GeoComm are presented in Figures-3 & 4 as a result of design validation / tests

Figure-4: GPRS based Tracking Information on ASL GeoConnect

V. CONCLUSION

GeoComm, a cost-optimised Geo-intelligent mobile communicator and tracker have been presented. The generic location cum communication device targets a wide range of applications ranging from self navigation, emergency location messaging to mobile tracking.

With the vibrant growth of different economic sectors witnessed in India, geo-intelligent solutions utilising Global Navigation Satellite System (GNSS) with GPS combined with Global Mobile Communication, such as GSM/GPRS or CDMA, serve an important role of real time messaging, communication, tracking and management of assets.

VI. ACKNOWLEDGMENT

VII. REFERENCES

       [2] Sakith Devadatta, “GPS/GSM for Ambulance Monitoring, Despatching with Location                        Based Emergency Services”, Paper presented in LOCATION 2006, June 7–9,              Bangalore.