Srinivas Varadarajan, VP (Sales and Business Development for Asia), Polaris Wireless
Location Based Service and its importance for the safety and security of people in India.
One of the most important roles played by high-accuracy location in countries across the world is as a counter-terrorism tool. However, the technologies behind high-accuracy location vary widely, and accuracy is not the only measure Indian government authorities should use in choosing which technology to deploy. In addition, privacy concerns must be acknowledged and alleviated for the population to support the government in its deployment of high-accuracy location to save lives and selectively deploy resources to prevent attacks. With the ability to effectively identify and locate suspected terrorists, India can make significant advances in its efforts to locate and defeat terrorists before they strike.
Not all location methods are created equal
There are numerous location technologies in use for applications ranging from emergency calling to location-based advertising to navigation. Most of these do not provide the level of high-accuracy that is required for surveillance applications. The ones that do offer the highest-accuracy can be categorized as handset, or device-based, such as Global Positioning System (GPS), or network-based. And of the network-based, the most widely-deployed for surveillance and anti-terrorism is RF Pattern Matching (RFPM).
RFPM is the only high accuracy, software-based, scalable location solution that requires no additional hardware changes/additions to the mobile phone or at the base stations. It compares mobile measurements (signal strengths, signal-to-interference ratios, time delays, etc.) against a geo-referenced database of the mobile operator’s radio environment. RFPM works extremely well in non line-of-sight conditions such as dense urban and indoor environments, where GPS based solutions face severe challenges. Since it is independent of line-of-sight conditions, RFPM is highly reliable and is ideal for mission-critical and safety-of-life applications.
RFPM is based on the observation that the radio environment varies from location to location, and if enough elements of the RF environment can be measured with sufficient accuracy, each set of measured values will provide an RF signature that uniquely identifies a particular location. Because the control or overhead channels of a wireless network are broadcast at constant power, they provide a signature that is predictable and repeatable. The RFPM ‘Location Engine’ is comprised of proprietary algorithms that estimate the location of the handset by comparing the time series of reported signal strength measurements to the values stored in a proprietary database containing a detailed knowledge base of the surrounding terrain, its RF ‘fingerprint’. These algorithms employ a very complex set of statistical pattern matching techniques. RFPM provides a single time-tagged location estimate after a fixed time interval or it can provide a continuous stream of time-tagged handset location estimates if such information were required for tracking purposes. When changes are made to the terrain, a new building is put up or a new cellular tower is installed, the database is automatically updated.
Meeting the mandate
Additionally, RFPM is the only location technology to obtain the accuracy thresholds outlined in India’s Department Of Telecommunications (DoT) May 2011 mandate for location-based systems. The trials were conducted by Bangalore-based Polaris Wireless over a period of two weeks in the North East telecom circle of India, at Agartala, to demonstrate the effectiveness of RFPM in urban, suburban and rural environments and remote areas. A prior trial with another major wireless network operator in Bangalore exceeded the DoT requirements in urban and indoor environments.
The DoT mandate specifies accuracy levels of 30 to 95 percent within two years of adoption for a range of 50 to 300 meters in urban areas. RFPM achieved accuracy levels of 67 to 100 percent in its field trials in urban areas. For suburban and rural areas, the mandate specifies accuracy levels of 50 to 80 percent within three years for a range of 100 to 500 meters. RFPM achieved accuracy levels of 88 to 99 percent. For remote areas, the mandate specifies accuracy levels of 50 to 70 percent within three years for a range of 300 to 500 meters. RFPM achieved accuracy levels of 87 to 99 percent. RFPM is the first location solution to exceed the DoT mandate in all categories, proving the attainability of the mandate thresholds.
Accurate Mass Location as the differentiator
RFPM is the only high accuracy location technology that uniquely supports mass location of all subscribers on a mobile network. To date, high accuracy location enabled mass location surveillance of all users was not feasible. This is primarily because most “high accuracy” location technologies are either not available or are unable to handle the volume of precise locations required for mass location surveillance. RFPM allows for mass location of all subscribers in the entire network or in a user-defined geographic area of choice, such as the area surrounding a government building or airport – anywhere terrorists may strike and that governments want to protect. The figure demonstrates high traffic areas (the ‘heatmap’) in a mobile operator’s network within a given busy hour. With this capability, Indian authorities can constantly monitor at-risk locations, view every mobile device in the vicinity, and stop known terrorists or other unauthorized persons well before they breach the perimeter of the protected location.
Overcoming the ‘privacy’ hurdle
With any surveillance technology, privacy concerns may be raised. ‘Privacy’ is a relative term which varies between countries’ legal systems and cultural norms. In some countries, mass location is not currently deployed as it would face legal hurdles to identify the location of all mobile users without probable cause. In other countries where it has been deployed, mass location is legal, sometimes after the passage of legislation which specifically addresses the issue. From a privacy perspective, there is a dramatic difference between tracking someone's location over time, versus locating one's position for a specific purpose and handling the location information only within the confines of a secure wireless network. Useful applications such as surveillance employ the latter method.
Methods using a client application with handset-based location on the mobile device, such as GPS, bypass the wireless network and instead rely on an IP connection to transmit information from the client application to a server on the Internet. These user-plane location methods are already widely in use for location-based services. Handset applications are inherently vulnerable to hacking and privacy intrusions, as the recent spate of mobile viruses on Android has highlighted.
Alternative, network-based, or control-plane, methods make use of the wireless services provider's network elements to keep location information wholly behind the security of the operator's firewall, employing highly standard protocols for security and privacy. Control plane location methods like RFPM are used for today's safety-of-life applications, like surveillance, where security and privacy are prime considerations.
When the Indian government makes the decision to deploy high-accuracy location technology to augment its anti-terrorism surveillance efforts, it must seek a solution than not only provides the highest accuracy, but also addresses vital security and privacy concerns. Only RFPM has proven itself to be the essential tool in real-life deployments in many of the world’s terrorism hot-spots.