GPS
Now, GPS is a very different beast from RFID. While it also uses radio waves to transmit data, it does so using, well, the global positioning system of 24 satellites, as opposed to specialized scanners here on the ground. Radio waves sent out from this system of satellites transmit their time and orbital data to receivers down on Earth. Using the data from multiple satellites, receivers can then triangulate their position relative to the satellites, and thus on the Earth’s surface.
GPS, thus, is best suited for tracking anywhere in the world—but because of the sheer distance of the satellites, the signal is weaker, and is easier to jam, or even just not get a signal. Civilian models particularly are not as accurate in certain situations as one might like, for instance at the bottom of a canyon or indoors.
Emergency homing beacons, car trackers or navigational devices tend to be the most well-known civilian uses, which don’t require accuracy within a few inches, but happen on a large scale where no other infrastructure such as RFID or radio towers are set up. GPS is, by definition, global, and so the sort of tracking it’s best at happens on the scales of tens or hundreds of miles.
RFID
RFID stands for Radio Frequency Identification, and it does exactly that: provides identifying information on a tag that may both receive and transmit information at radio frequencies. This information can be anything, from your heartbeat to the name of your dog to the owner of a cow and is useful for a huge variety of purposes. The strength of the signal from the tag to the receiver may also be used as a locator, especially when used with multiple lo caters to triangulate the position.
There are three types of RFID tags: active tags, which contain a battery and are constantly transmitting some sort of data such as vital signs, passive tags, which require external source such as a scanner to create a signal in an otherwise battery less device, and then battery assisted passive, which function as something of a hybrid of the two in that an external source is required to activate the battery functions. Each of these have their nuances of use.
GSM
GSM (Global System for Mobile communication) is a digital mobile telephony system that is widely used in Europe and other parts of the world. GSM uses a variation of time division multiple access (TDMA) and is the most widely used of the three digital wireless telephony technologies (TDMA, GSM, and CDMA). GSM digitizes and compresses data, then sends it down a channel with two other streams of user data, each in its own time slot. It operates at either the 900 MHz or 1800 MHz frequency band.
In today’s market GSM / GPS tracking technology is being widely implemented in cars using GSM vehicle tracking, in cell phones, watches and in/on any other asset that one may be interested in tracking. With devices nearly as small as a pack of matches, placing a GPS / GSM tracker is now easier than ever!
Both GPS tracking and GSM tracking are accomplished by a receiver collecting data from at least 4 satellites in order to determine precise position. GPS GSM tracker devices accomplish this task by referencing information from the cellular tower that is closest to the GSM / GPS tracking device. Between the two technologies, GPS systems are capable of much more precise location measurements, within a meter, whereas with GSM tracking technology, positioning can only be determined within 10 meters.