What Are Location-Based Services?
Who would want to live without wireless communications and networking – voice, data, video, broadband, really, everything – today? Answer: no one.
Wireless has achieved what many of us working in the field saw decades ago: It is today the preferred - and often the default and even only - means of communication for the vast majority of users, irrespective of application or venue.
In fact, for many if not most of us today, our primary computing and communications devices are so mobile and convenient that they literally have no way to connect to a wired network!
But wait - there’s more.
While most of us tend to think of wireless only in terms of coverage, availability, and especially throughput, wireless has another interesting capability – location and tracking. Specifically, it’s possible (and actually quite easy) to locate and track the motion of a wireless station.
Of course, such has been the case for years. Radar, which involves bouncing a radio signal (a variety of frequencies are used here, depending upon application) off of a moving object, is about 80 years old. Take enough samples, and very good accuracy of both location and track results.
And, of course, everyone today knows about, and likely uses, GPS. This technique involves the reception of timing signals from a constellation of satellites orbiting the each. One can locate one’s position on the Earth, with very good accuracy, with just the signals from just four satellites arriving at a given receiver.
Increasing the number of satellites seen improves results significantly; many modern GPS receivers support up to 12 simultaneous channels. And, finally, the E911 capabilities built into cellular networks mostly offer pretty poor location capabilities via a number of different techniques and technologies, with resolution of only 100-300 meters, but they’re better than nothing and may improve to around 50 meters over the next few years. Realizing such an improvement is pretty important, after all – just as safety always is.
But none of the above work very well indoors, where a key application of wireless location and tracking known as Location-Based Services (or LBS) is seeing increasing demand. LBS is the provisioning and often customization of services based on the physical location of a given user, and is generally enhanced via user identity information.
The technologies we discussed above, though, don’t help very much - ultrasonic or infrared radar will see application in robotics, but radio-based radar is problematic due to the many people and things in indoor spaces. GPS requires a clear view of the sky, and wireless E911 won’t help find someone indoors.
Instead, we can apply two proven communications-centric wireless systems that have been around for years: Wi-Fi and Bluetooth.
Most Wi-Fi-based location and tracking solutions today rely on simple and repeated sampling of signal strength. While any single sample could be quite unreliable, calculating location based on many samples can often yield excellent results.
For example, a few years ago we tested the built-in location and tracking capabilities of Aerohive APs, and found, with very little work, accuracy down to about one square meter – pretty amazing. Very importantly, Wi-Fi location and tracking requires no modifications, hardware or software, to client devices.
Like Wi-Fi, BLE Beacons, as they’re commonly known, use single strength, but most implementations here only transmit a unique (to a given beacon) ID and software on the mobile device recognizes this signal.
A “near/medium/far” estimation results, and looking up the Beacon in a database (usually via Wi-Fi, by the way) derives relative location. Given the low power and limited range of BLE, many overlapping Beacons might be required to cover any area, although a trade show booth, for example, might need only a few.
No matter which technique is used, it’s possible to “geofence” a given area and offer location-based services within these zones. That’s it for the basic enabling technologies of LBS – low cost, great accuracy, and, as we’ll discuss next time, way more applications and potential than most people have considered.
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