A look to the future of global navigation satellite systems

Tekdis

Monday, 13 February, 2012


‘Global Navigation Satellite System,’ or ‘GNSS’ is a generic term used for a constellation of satellites with worldwide coverage that function to send positioning and timing signals to receivers located on Earth. It is this technology that allows us to perform simple applications from determining location and finding addresses to more sensitive asset tracking and military operations.

The most mature system is the GPS, developed and maintained by the US. As the need for GNSS grew, different nations including Russia, Europe and China started developing their own systems. Currently, in addition to the popular GPS, other systems such as GLONASS, GALILEO and COMPASS are under construction and are expected to mature in the next decade. It is crucial for module providers and device manufacturers to recognise these changes and develop next generation products that will satisfy demands in different markets.

The first ever satellite navigation system created was 'Transit,' introduced in the 1960s by the US military. It was primarily used by the navy to provide accurate information for its submarines and ships. Since then, researchers have been developing and testing a more stable system with increased location accuracy for both civilian and military use. The relentless search for new technology finally gave birth to the GPS in 1993. As telecommunication technology matured, hand-in-hand, the number of GPS users reached an exploding number in the beginning of the 21st century. With this, other nations decided to develop their own GNSS and to obtain independency from the American system. The following is a brief introduction to the systems that are currently functional or under construction:

GPS

Developed and operated by the US Department of Defense, the GPS (also known as NAVSTAR-GPS: NAVigation System with Timing And Ranging Global Positioning System) has been fully functional since 1993. Currently, there are 24 satellites out of the planned 32 in orbit at an altitude of 20, 180 km around the Earth. These satellites are organised on six orbital planes at an inclination of 55° to the equator, ensuring that at least four satellites are in radio communication with any point on Earth. Signals from individual satellites are encoded and distinguished using Code Division Multiple Access (CDMA) and broadcast on L1 and L2 bands.

GLONASS

Currently, the only other fully functional GNSS, GLONASS, was developed and is maintained by the Russian government. It was created in 1976 and has undergone various transformations and restorations since. In late 2011, the system was restored to its complete capacity of 24 satellites, which are located on 3 orbital planes with an inclination of 48° from the equator. The Russian government has been promoting the civilian use of GLONASS, requiring the production of GLONASS-compatible vehicles by car manufacturers starting from early 2011. Like GPS, GLONASS transmits on L1 and L2 bands, however, it uses Frequency Division Multiple Access (FDMA) to distinguish between satellite signals.

GALILEO

GALILEO is the GNSS currently being developed by the European Union. When complete, it will consist of 30 satellites located on three orbital paths around the Earth with an inclination of 56°. One of its main objectives is to provide a system that European nations can depend on, separate from GPS and GLONASS, which can be disabled for commercial users in times of international conflict. The system was set to become operational in 2012, but due to political and financial reasons, has been delayed until 2014. When functional, GALILEO will signal on L1, E5, and E6 bands, using CDMA techniques to differentiate satellite signals.

COMPASS

The Compass Navigation Satellite System (or otherwise known as Beidou-2) is a second generation navigation system being developed by China. This second generation system is a completely new system, different from Beidou-1, which only had regional coverage. When complete, it will have a total of 35 satellites with signals based on the CDMA protocol, transmitting through E1, E2, E5B and E6 bands. The system’s tenth satellite was launched at the end of 2011 and is set to start services in Asia-Pacific in 2012.

In general, all satellite systems work the same way. It involves a complete system that consists of three parts: a network of satellites in space, a control station on Earth that manages the satellites and devices with receivers set to detect and accept signals from the satellites.

So, how does it work? Each satellite constantly sends out signals in the form of radio waves to the Earth. Each signal carries with it all the information about the satellite it came from and a time-stamp record of when it left the satellite. Receivers located on Earth pick up these signals and use their information to calculate location. For the receiver to calculate a 2D position (latitude and longitude) it must be locked to a minimum of three satellites. Four satellites or more are required for calculating 3D positions (latitude, longitude and altitude).

The ability of GNSS technology to calculate location information becomes extremely valuable when applied to the business process. It allows organisations to have greater control over business transactions, improving both productivity and efficiency while decreasing costs. Three recognisable GNSS applications - location based services, tracking and turn-by-turn navigation - are explored in the remainder of the section.

A location-based service, or LBS, is a mobile application that provides information services to users based on their geographical location. These services can range from finding popular landmarks such as service stations and banks, to locating specific people or places. In order for LBS to work, mobile devices with positioning capabilities must be hooked onto a communications network, in addition to the presence of service and data content providers.

The adoption of LBS by businesses has the following benefits:

  1. Location services - LBS is helpful in situations where employees are unfamiliar with the region they are in and are trying to search for a particular service.
  2. Informed decision making - The application filters vast amounts of material available on the internet into relevant information for the user’s current context. Users can see important information, enabling them to make informed decisions on the spot; for example, locating and choosing the nearest service station.
  3. Access to new information - By making relevant information available to users, LBS not only supports timely presentation of data, it highlights information that users may not normally be aware of, such as traffic congestion and bad weather.
  4. Reduce manual operation - LBS can automatically obtain location information and related data, reducing the need for manual data entry when users need to gain access to a certain service.

One of the original uses of GNSS technology in the field was to provide real-time tracking, which allowed vehicles to periodically report their location over a wide area network. Typically, these systems include a map-based interface where the backend or dispatch office can view vehicle location and condition. Some systems also provide more advanced features such as Geofencing, which enables the backend to be alerted when the vehicle disobeys predetermined routes. With real-time tracking, not only is the transportation process made transparent, but vehicle security is also enhanced.

Investing in a tracking system is beneficial because it helps to:

  1. Reduce fuel costs - A GNSS-enabled tracking system helps businesses monitor fuel consumption by identifying vehicles with excess fuel consumption caused by speeding and idling.
  2. Improve customer service - By locating the exact location of company vehicles, businesses can estimate more precisely when a driver will arrive at a user’s location. The backend or dispatch office is able to dispatch vehicles near a customer’s location rather than vehicles located further away which, in turn, saves time, fuel costs and improves service efficiency.
  3. Reduce overtime - By identifying inefficient routes and unscheduled and unauthorised stops, business can reduce the number of reported hours on time sheets, as well reduced work hours due to enhanced productivity.
  4. Increase employee accountability - Businesses can eliminate the possibility of employees using company vehicles to conduct personal errands. When drivers know that their driving behaviour, routes taken and time spent is being monitored, they are more likely to be accountable for their actions.
  5. Increase driver safety - A GNSS-enabled tracking system allows the backend to monitor speeding, which allows unsafe driving behaviours to be identified before an accident occurs.

One of the most popular applications of GNSS technology is the ability to receive 'turn-by-turn' driving directions in real time. In-vehicle navigation systems use GNSS to calculate the user’s current position and then use navigation algorithms to compute the best route for the user’s planned destination. The system provides driving directions, which take the form of voice instructions and visual screen display.

Advantages of GNSS enabled navigation include:

  1. Reduced costs - Unnecessary mileage, caused by inaccurate driving directions, can be reduced, saving both time and money for the organisation.
  2. Improved performance - The ability to navigate in unfamiliar locations decreases the possibility of getting lost or following inefficient routes. This, in turn, translates into improved on-time performance for businesses.
  3. Enhanced efficiency - GNSS navigation allows businesses to reduce travel between stops or activities, which can enable more stops per driver, per day.

The integration of GNSS technology into everyday business operations can no doubt bring about tremendous benefits. Not only does it increase visibility of the supply chain, but it also assists in the decision making process, allowing businesses to reduce associated costs. Hence, devices with GNSS receivers have become popular in the industry, especially where fleet and asset management is concerned.

IEIMobile’s in-vehicle computers use a GNSS receiver module that supports GPS and GALILEO systems. However, with the maturation of the GLONASS system and the regulations drawn out by the Russian government, the demand for GLONASS-support devices has greatly increased, especially for aftermarket automotive products. In response to Russia’s growing demand, the company is currently working with GNSS receiver module provider Ublox to develop devices that will support the system. Ublox’s latest LEA 6H module will be integrated into the company's devices and offered to the Russian market in early 2012.

As the market has received affirmation from early adopters, GNSS technologies are geared for a prosperous growth over the next few decades. However, with the maturity of such technologies and the development of separate systems by different nations, the market will, no doubt, go through a period of change. Compared to the previous era, dominated by the American GPS, different markets must now search for solutions that will support their respective navigation systems. It is critical for module providers and device manufacturers to realise this impact on the development of next generation products.

IEI Mobile products are distributed in Australia by Tekdis.

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