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Bringing location-based apps where GPS can't reach

Improving positional accuracy improves the what, where and when of location-based apps.

By Steven Max Patterson on Thu, 12/13/12 - 11:55am.

CSR has delivered indoor location-based services (LBS) with enhanced accuracy that is tightly integrated with Android and consistent with Android’s location package API. CSR, a developer of silicon and software for location awareness, picks up LBS when GPS is not available because the smartphone owner is indoors or the GPS signal is compromised by environmental effects, such as urban canyons.

CSR’s SIRFusion software merges multiple radio signals and applies proprietary algorithms including pedestrian dead reckoning (PDR) to improve the accuracy of the typical GPS receiver from 30 meters to 3 to 10 meters and providing a navigation and positioning alternative that works deep indoors when the user is out of contact with GPS satellites.

SIRFusion is CSR’s client software library implementation. When a smartphone user steps out of GPS range, SIRFusion's proprietary PDR algorithms take over. It uses Wi-Fi and cellular triangulation to fix position. Where no radio signal is available, SIRFusion uses the smartphone’s accelerometer and gyrospcope to maintain a fix on longitude and latitude with a low-error growth rate of less than 5 meters per 50 meters traveled. The error can be corrected when cellular or Wi-Fi networks or GPS satellites are reachable.

With so many developers, product managers, marketers and brands experimenting with the context of a smartphone user’s relative position, SIRFusion is a very interesting technology because it tracks smartphones indoors, where users spend 70% of their time obscured from GPS satellite coverage. SIRFusion’s Android library is implemented within the constructs of the Android location package API that does not require a change in classes or methods that developers already use to capture longitude and latitude. Developers just select a new "provider" to gain the increased accuracy of SIRFusion.

One of the primary applications of LBS is geo-fencing where location is used as a conditional value. For instance, certain sensitive data might only be viewed within a specific location on a smartphone or tablet or a retailer could recognize that an opt-in customer is in the store and might push a special offer for a new product or service. Where applications need accuracy beyond the capabilities of SIRFusion, CSR will deliver a Bluetooth beacon based on the latest Bluetooth SMART technology. This low-power, low-cost beacon can be installed indoors to increase accuracy while preserving precious smartphone battery by deploying Bluetooth. A diversion from the ad hoc triangulation of GPS, Wi-Fi, and cellular, purposefully positioned Bluetooth beacons can be installed to improve accuracy.

The Bluetooth beacon prototype pictured above is about 3cm-by-4cm. Most of the area is needed to accommodate the displacement of the battery. These are the first pictures of the Bluetooth beacon released to the public. According to Anthony Murray, senior vice president for CSR, "with the advances in Bluetooth low-energy it is possible for a Bluetooth beacon to be designed and sold for under $5 with a battery life of more than five years." For example, a Bluetooth beacon installed on the underside of a grocery store shelf could be used to help a customer accurately navigate to an item.

Location-based services are still evolving. Many applications, such as LevelUp and foursquare, use it. Many companies are experimenting to improve their mobile advertising, marketing and brand strategies with location data. An improvement in accuracy means a better understanding of context and a higher probability that whatever information that the app developer chooses to push will be welcomed and not perceived as an interruption.