Amber Alert GPS sells online for $199, and requires a monthly service that ranges from $19.99 to $49.99, depending on usage. Why the monthly service fee? Amber Alert GPS leveraged both GPS and cellular technology to provide real-time tracking.

Specifications:

Figure 1: What's in the Box

Amber Alert GPS ships with the following items in the box:

• Amber Alert GPS
• Two Lithium-Ion rechargeable battery packs (3.7V 800mAh)
• AC Power Adapter that can charge 2 battery packs at once (one in the battery charger, and one in the GPS)
• User Manual
• 2 Amber Alert Stickers

Figure 2: Amber Alert GPS

About the size of a small pager, Amber Alert measures just 1.8-inches x 2.5-inches x 0.65-inches thick. The device has a thin rubber-like protective coating that feels similar to a ThinkPad laptop.

Figure 3: Amber Alert GPS, SIM Card Slot

Removing the battery cover exposes the SIM card slot, shown above.

Figure 4: Amber Alert GPS, Side

The USB port, indicator LED, SOS button, and power button are located on the side of the GPS.

Once the battery has been fully charged (takes around 3 hours) and the SIM card inserted, Amber Alert GPS is ready for use.

Using Amber Alert GPS

Figure 5: Powering on Amber Alert GPS

Pressing and holding the On/Off button until the indicator light turns on powers on the GPS. Within 3-5 minutes the until will acquire GPS and cellular reception. The green LED indicator will blink every 4 seconds to indicate the unit is powered on and functioning.

Amber Alert GPS differs from other real-time GPS tracking devices I've tested in that all functions are performed via SMS messaging That means you'll need to have an SMS-capable cell phone in order to operate Amber Alert GPS as well as receive location alerts.

From your mobile phone, call the GPS (you'll dial the phone number associated with the SIM card). The call will automatically go to voicemail, or a "subscriber unavailable" message may be heard. Hang up, and within seconds Amber Alert GPS will send an SMS message containing location information back to that cell phone number. The SMS message sent is of little use unless you can paste it into a web browser. Here's what the typical location SMS message looks like:

Figure 6: SMS Location Message

Note that by default Amber Alert will accept location requests from the first 5 cell phones that call its number. You can also lock the GPS by sending a special SMS message that restricts which cell phones Amber Alert GPS will respond to.

Clicking on the SMS message on an Internet-enabled smart phone, such as a Blackberry or Apple iPhone, will display the location data in a much more useful way:

Figure 7: Amber Alert Location Report

The location report includes GPS and battery signal information, speed, lat/long coordinates, altitude, and Date/Time. The physical location of the GPS is also displayed on the map, which can be zoomed in/out. The report is specially formatted to appear correctly on the small screen of a smartphone.

Figure 8: Amber Alert GPS SOS Button

Pressing and holding the SOS button for 4 seconds will cause Amber Alert GPS to send location reports to all authorized cell phones (up to 5) 3 times within 10 minutes. It will stop sending the alert when any authorized number replies by texting "help me!" to the GPS.

The SOS feature works well and I especially liked the fact that the device alerts all authorized cell phones. However, I would have liked to see email alerting options as well the ability to extend the alerting longer than 10 minutes. Still, this is a great feature for a tracking device, especially at the sub-$200 price, and will be a selling point for families/parents.

Amber Alert GPS support Geo-Fencing. A GeoFence is a geographic boundary that you define, and then receive SMS alerts if the GPS breaks that boundary. For example, a child's parent might configure a Geo-Fence around the home and receive an alert if the child leaves the house. Or a parent could configure a Geo-Fence around the school address, and receive an alert when the child is on the way home.

Geo-Fencing is also useful if you want to be notified when the GPS moves from its current position. For example, you could initiate a location request by calling the device, then use the lat/long coordinate contained in the location alert text message to configure a Geo-Fence around Amber Alert GPS's current position. When the device moves outside the boundary of the Geo-Fence, it will send an alert.

Unfortunately, configuring Geo-Fence boundaries isn't the most user-friendly task, requiring the owner to text specially formatted messages to the device that include the exact lat/long coordinates of the Geo-Fence boundaries. That means you'll have to figure out the exact coordinates of your Geo-Fence using Google Earth of Microsoft Virtual Earth before you can setup a Geo-Fence.

Other real-time tracking devices allow you to visually draw a Geo-Fence area on a map, or define a radius around a specific street address. There's also no way to be notified if Amber Alert GPS enters a specific area -- the Geo-Fence function only supports notification upon EXIT of a defined area.

When the device travels outside the defined Geo-Fence area, Amber Alert GPS will send authorized numbers an alert SMS message that includes the position of the device.

Pros

• Inexpensive compared to other GPS trackers
• Respectable battery life (24-48 hours between charges)
• Includes two battery packs
• High performance GPS receiver (SiRF StarIII) works indoor and out
• SOS button sends an alert to up-to 5 cell phones
• Small size
• Supports Geo-Fencing
• Reports speed; can send an alert if a specified speed is exceeded

Cons

• Requires an Internet-enabled smartphone to view location reports (such as a Blackberry, iPhone, Windows Mobile phone, etc.)
• No alternate methods for obtaining location information, such as the Internet or a telephone hotline
• Can't see where the GPS has been in the past, just where it is at the time the location request is sent
• No 3D Map View
• Configuring Amber Alert via SMS text messages is cumbersome, complex, and error prone (setting up Geo-fence zones is particularly difficult, since you need to know the exact lat/long coordinates rather than being able to draw a box on a map or choose a radius around an address).
• Can only specify one Geo-Fence boundary at a time (so you can't, for example, specify Geo-Fence alerts if the device gets near certain airports)
• SOS, Geo-Fence, and Speed alerts notify all authorized cell phones -- no way to customize which cell phones receive which alerts, nor can you specify an escalation order (alert this cell phone first, then the next phone if the first one doesn't respond, and so on)
• No way to remotely initiate an SOS alert
• No way to configure automatic location updates, or continuous tracking
• Difficult to remove authorized phone numbers from the list of (up to) 5 authorized cell phones

Conclusion

Amber Alert GPS has a lot going for it: with up to 48 hours of battery life per charge, SiRF's high performance StarIII GPS receiver, Assisted-GPS for indoor/outdoor tracking, Geo-Fencing, and speed alerting options, this tracking GPS is a bargain at $199.

Like all other Assisted-GPS tracking devices that leverage both cellular and GPS technologies, Amber Alert GPS requires a monthly service that ranges from $20 - $50, depending on the service plan you choose. $20 is a basic plan and includes a limited number of location requests per month. The $50 unlimited plan includes unlimited location requests. Buyers who choose the $50 plan will also receive a $20 discount on the GPS purchase price.

One of the best aspects of Amber Alert GPS is the long battery life; I was able to get around 24 hours of regular usage per battery charge (it laster longer if I didn't use it much). The device doesn't sacrifice much in the performance department, utilizing SiRF's high performance StarIII receiver for solid GPS tracking both indoors and out.

Amber Alert GPS's weakness is that all configuration and controls must be performed via SMS text messages, making for a less-than-user-friendly experience -- particularly when trying to setup Geo-Fence alerts. There's also no historical tracking data -- the device only reports it's current location, not where it's been in the past.

Some buyers will lament the need to have an Internet-enabled smart phone to properly view location reports, as well as the lack of Internet/phone reporting options, and the cumbersome SMS text-message based controls. Amber Alert GPS isn't the most feature-packed tracking device I've tested, and it's ill-suited to corporate/fleet tracking needs. But if you're a concerned parent or caregiver looking for a good, practical, low-cost solution to answer the terrifying question every parent eventually encounters, "Where is my child?" (and already have an SMS/Internet-enabled smartphone), Amber Alert GPS strikes a good balance between performance and practicality, and serves its intended audience well.

Amber Alert GPS is available for purchase online at AmberAlertGPS.com.