Trinity SkyTrack Application Architecture :
Communications engine
Trinity SkyTrack is among the pioneering applications in the Indian Telematics Industry and has been in continuous use since 2002. At it's heart is a live communications engine. The SkyTrack communication engine can collate information from the Mobile Asset through multiple channels. The communication engine interfaces with an array of GSM modems to collect data from the SMS channel. The engine has an SMPP Application module to directly connect with the SMSE of the GSM operator and fetch the SMS data sent from the devices. The engine primarily uses an IP application to collate data from the Vehicle Mounted Units over the GPRS Network. The multiple data acquisition threads are optimized for performance with redundancies built in.
Database Engine
Telematics systems are about information and requires to optimally perform with large volumes of data. The real measure of a system lies in it's ability to provide timely and appropriate responses to users' requirements. SkyTrack Database leverages on the Industry Benchmark features and performance of IBM’s DB2 and is designed to meet exacting user requirements and can be customized to suit specific user contexts.
Middleware Platforms
SkyTrack Versions run on Linux and Windows platforms. SkyTrack is delivered over IBM’s state of the art WebSphere Application Server that integrates the Java based application layer, Database, GIS Engine and the Communication Modules.
User Interface
Our objective has been to provide applications that are usable by anyone in a short while. The emphasis was to minimize the requirement for training or manuals or help systems, hypertext or otherwise.
Our approach to user interfaces has been intuitive and has resulted in the application not only looking different but delivering benefits that are clear to measure. Our quest for improvement is ongoing and customer feedback provides us with ever increasing challenges that we will continue to rise to.
The Global Positioning System (GPS)
Introduction to GPS
The Global Positioning System (GPS) is a satellite-based navigation system made up of a network of satellites placed into orbit by the U.S. Department of Defense. GPS was originally intended for military applications, but in the 1980s, the government made the system available for civilian use. GPS works in any weather conditions, anywhere in the world, 24 hours a day.
Global Positioning System (GPS) comprises of three parts:
- 24 satellites that orbit the Earth
- Ground control stations which monitor the satellites
- GPS receivers can be attached to persons or animals, or mounted on an object, such as a vehicle
The satellites are synchronised to emit encoded navigational information (exact positioning and exact time). Any vehicle equipped with a GPS receiver will intercept these transmissions. Using a simple mathematical formula derived from triangulation, the receiver is able to calculate its own longitude, latitude, velocity and even altitude. For companies implementing GPS applications, this information, most often, would be transmitted to a central dispatch or control location.
Originally designated the NAVSTAR (Navigation System with Timing And Ranging) Global Positioning System, GPS was developed by the US Department of Defense to provide all-weather round-the-clock navigation capabilities for military ground, sea, and air forces.
Since its implementation, GPS has also become an integral asset in numerous civilian applications and industries around the globe, including recreational uses (e.g. boating, aircraft, hiking), corporate vehicle fleet tracking, and surveying. GPS employs 24 spacecraft in 20,200 km circular orbits inclined at 55 degrees.
These spacecraft are placed in 6 orbit planes with four operational satellites in each plane. The full 24-satellite constellation was completed on March 9, 1994. GPS receivers use triangulation of the GPS satellites' navigational signals to determine their location.
Essentially, the GPS receiver compares the time a signal was transmitted by a satellite with the time it was received. The time difference tells the GPS receiver how far away the satellite is. Now, with distance measurements from a few more satellites, the receiver can determine the user's position and display it on the unit's electronic map.
A GPS receiver must be locked on to the signal of at least three satellites to calculate a 2D position (latitude and longitude) and track movement. With four or more satellites in view, the receiver can determine the user's 3D position (latitude, longitude and altitude).
Once the user's position has been determined, the GPS unit can calculate other information, such as speed, bearing, track, trip distance, distance to destination, sunrise and sunset time and more.
GPS Applications
One of the fast-growing GPS applications is vehicle tracking. GPS-equipped fleet vehicles, public transportation systems, delivery trucks, and courier services use receivers to monitor their locations at all times.
Automatic Vehicle Location (AVL) is a technologically advanced method of remote vehicle tracking and monitoring using GPS.
Each vehicle is equipped with a module that receives signals from a series of satellites, and calculates it's current geographical location, speed, and heading. This information can be stored for later retrieval or, frequently, transmitted to a central dispatch/control location where it is displayed on a high-resolution geographical map.
Public safety services, police, fire, and emergency medical services, are using GPS receivers to determine the nearest service vehicle to an emergency, enabling the quickest response in critical situations.
Recently, automobile manufacturers are installing moving-map displays guided by GPS receivers
Wire less Communication Networks
The Global System for Mobile communications (GSM: originally from Groupe Spécial Mobile) is the most popular standard for mobile phones in the world. GSM service is used by over 2 billion people across more than 212 countries and territories. GSM is a cellular network, which means that mobile phones connect to it by searching for cells in the immediate vicinity. GSM networks operate in four different frequency ranges. Most GSM networks operate in the 900 MHz or 1800 MHz bands. Some countries in the Americas (including the United States and Canada) use the 850 MHz and 1900 MHz bands because the 900 and 1800 MHz frequency bands were already allocated.
One of the key features of GSM is the Subscriber Identity Module (SIM), commonly known as a SIM card. The SIM is a detachable smart card containing the user's subscription information and phonebook. This allows the user to retain his or her information after switching handsets. Alternatively, the user can also change operators while retaining the handset simply by changing the SIM.
General Packet Radio Service (GPRS) is a Mobile Data Service available to users of GSM. GPRS is different from the older Circuit Switched Data (or CSD) connection included in GSM standards. In CSD, a data connection establishes a circuit, and reserves the full bandwidth of that circuit during the lifetime of the connection. GPRS is packet-switched which means that multiple users share the same transmission channel, only transmitting when they have data to send. This means that the total available bandwidth can be immediately dedicated to those users who are actually sending at any given moment, providing higher utilisation where users only send or receive data intermittently. Web browsing, receiving e-mails as they arrive and instant messaging are examples of uses that require intermittent data transfers, which benefit from sharing the available bandwidth.
The GPRS capability classes
Class A
Can be connected to GPRS service and GSM service (voice, SMS), using both at the same time. Such devices are known to be available today.
Class B
Can be connected to GPRS service and GSM service (voice, SMS), but using only one or the other at a given time. During GSM service (voice call or SMS), GPRS service is suspended, and then resumed automatically after the GSM service (voice call or SMS) has concluded. Most GPRS mobile devices are Class B.
Class C
Are connected to either GPRS service or GSM service (voice, SMS). Must be switched manually between one or the other service.
A true Class A device may be required to transmit on two different frequencies at the same time, and thus will need two radios. To get around this expensive requirement, a GPRS mobile may implement the dual transfer mode (DTM) feature. A DTM-capable mobile may use simultaneous voice and packet data, with the network coordinating to ensure that it is not required to transmit on two different frequencies at the same time. Such mobiles are considered to be pseudo Class A. Some networks are expected to support DTM in 2007.
Code division multiple access (CDMA) is a form of multiplexing and a method of multiple access that divides up a radio channel not by time (as in time division multiple access), nor by frequency (as in frequency-division multiple access), but instead by using different pseudo-random code sequences for each user. CDMA is a form of "spread-spectrum" signaling, since the modulated coded signal has a much higher bandwidth than the data being communicated.
Whereas the Global System for Mobile Communications (GSM) standard is a specification of an entire network infrastructure, the CDMA interface relates only to the air interface—the radio part of the technology. For example, GSM specifies an infrastructure based on internationally approved standard while CDMA allows each operator to provide the network features as it finds suited. On the air interface, the signalling suite (GSM: ISDN SS7) work has been progressing to harmonise these.
