Before we begin explaining why the sentryGPSid™ is a much better option than the RFID based location systems, we will start with an explanation of the underlying technologies of each.
The sentryGPSid™ utilizes GPS technology. GPS is an abbreviation for Global Positioning System, the key word here being Global. From Wikipedia:
The Global Positioning System (GPS) is a global navigation satellite system (GNSS) developed by the United States Department of Defense and managed by the United States Air Force 50th Space Wing. It is the only fully functional GNSS in the world, can be used freely, and is often used by civilians for navigation purposes. It uses a constellation of between 24 and 32 Medium Earth Orbit satellites that transmit precise microwave signals, which allow GPS receivers to determine their current location, the time, and their velocity.
In contrast, RFID (an abbreviation for Radio-frequency identification) is a much more locally based system. Information is sent to and read from RFID tags by a reader using radio waves. In passive systems, which are the most common, an RFID reader transmits an energy field that “wakes up” the tag and provides the power for the tag to respond to the reader. In active systems, a battery in the tag is used to boost the effective operating range of the tag. You may be familiar with short range RFID systems if you have ever used a proximity card for a door at work or a parking garage with secure access.
So, just by looking at the respective definitions of the two technologies you can start to see how the sentryGPSid™ and it’s GPS based technology is far superior to RFID based location systems. But the fact a sentryGPSid™ can be located most anywhere in the world is not the only advantage that separates the sentryGPSid™ from other child and adult locator devices. The sentryGPSid™ also provides what is known as “bread-crumbing”, or the storage and display of historical points of data. By default, when a user logs into the SentryGPS web portal he or she will automatically be provided up to the last 50 points of data which were transmitted by their sentryGPSid™. This means that a directional history can be derived even if the exact location of the GPS device can not be ascertained due to severe environmental conditions.
With an RFID based system, there is no data basing of previous locations or bread crumbing due to the fact the position of the transmitter is only considered relevant to the location of the receiver – not the actual position of the device on the globe. So if no signal an be picked up by the receiver, than there is no way of telling which direction to even start searching for the missing child or adult.
Also, while on the topic of the transmitter and receiver for an RFID system, that brings up another great benefit of the sentryGPSid™ over RFID based systems. RFID based systems require two pieces in order for the system to work: 1. the device on the child or Alzheimer’s patient, and 2. the receiver or “locater”. If the receiver is not readily at hand, the transmitter on the child or Alzheimer’s patient is almost worthless. Some of the systems out there today for Alzheimer’s patients require the local sheriff to invest as much as $3,000 for these RFID receivers in order for the programs to even be offered in your county.
With the sentryGPSid™ you can locate your GPS device through any internet connected computer, anywhere in the world. All you need is your username and password to the SentryGPS webportal and you will be able to track your device. So there is no expensive equipment for the sheriff’s office or local law enforcement agency to purchase. Additionally, we are developing applications for the iPhone, Windows Mobile phones, and other smart phones that will allow you to easily track your GPS device directly from your cell phone through a similar map-based interface. We are also going to give you the ability to send a text message to our webportal that will reply with the exact location of your device and a link that will open up your phones internet browser to display a map.
Those are just a few, brief examples of why the sentryGPSid™ is a far superior option to any of the RFID based child or Alzheimer location systems on the market today. I’ll make certain to outline more benefits in the very near future while we also release some great new functionality!


