This linked file may also help: EverThere_Location_Info.pdf

Location services may be an option offered by your monitoring service.

Libris is equipped with a GPS (Global Positioning System) antenna and Location Based Services (LBS) technology that approximate user location, allowing emergency services to find the Libris user if they are not able to provide their location to the call center.

Verify the location

Location fixes (acquired by either GPS satellite or network) are a tool to help determine physical user location. Ultimately, it is a human decision to decide how much to trust a particular type of fix over another. Always attempt to verify the user location verbally before sending emergency help or ending an emergency call.

When does Libris determine location?

If location services are enabled, there are two instances when Libris approximates its location, also known as a fix.

Interval Fix is when Libris establishes location at a default interval every ten minutes (interval period can be customized by the call center). The resulting information is stored on Libris and is not viewable until Libris is docked in the charger or the monitoring service remotely pulls location data.

Active Call Fix is when Libris establishes user location during an active call. An active call can be initiated in three ways: the user presses the call button, the call center initiates a call from Libris, or a fall automatically triggers a call. Libris attempts to acquire a GPS satellite fix every five seconds during an active call.

How do the two location technologies work?

Satellite technology is the most accurate means of approximating user location. The GPS antenna inside Libris scans the sky to receive signals from GPS satellites rotating around the Earth, which can take up to three minutes.

If the location interval has been set to a frequent period, such as 10 minutes, the GPS module has the ability to keep track of satellites it has previously located and take less time to obtain a fix. If Libris is unable to communicate with a satellite beyond an interval time period, the information becomes stale and Libris scans the entire sky to find satellites.

During an active call, Libris attempts to acquire a GPS satellite fix every five seconds. If it is unable to find one, a network fix will be returned with the user's approximate location. It is possible that a structural obstruction will block satellite communication and force the Libris to report only a network fix. The network fix will not be attempted if the Libris acquired a satellite fix just before the call.

LBS or Network technology uses a back-end service from the network operator (AT&T in the US) to help determine a user's location during an active call and when satellite fixes are not available. LBS (also referred to as network fix, cellular identification (CID), enhanced cellular identification (eCID), or triangulation) works by using the cell phone number associated with Libris to approximate location relative to nearby cell towers.

How accurate are the location services?

A satellite fix usually approximates a location to within 50m or less of the Libris actual location.

Accuracy increases with the number of GPS satellite signals the Libris GPS antenna receives. Libris constantly searches for and prioritizes location fixes determined by satellite. The optimal conditions in which to establish a satellite fix are outside in an open area with a clear sky. Conditions that reduce satellite fix accuracy include structural obstruction (being inside a commercial building or, to a lesser extent, a home), urban density and cloudy weather.

A LBS or network fix usually approximates to within 1000m of the Libris actual location. This location fix type is estimated due to the inherent difficulties related to cellular strength.

Summary of location fix technologies in use on Libris