GeoFencing

A geofence is a virtual boundary drawn around an area, or point of interest. The Stay In Touch Mobile ClipBook platform knows when a user is crossing the boundary of the geofence both when entering and when exiting. Messages can be delivered to a device upon either event. Below is an example of tracking a device into and, eventually, out of a geofenced area:

Figure 1: The mobile device being tracked (the blue pin) is moving south down La Salle Blvd. The first sample taken is when the device is outside of the geofence.

Figure 2: The next location sample is taken and the device is now inside the geofence. Because it is the first sample of the device inside the geofence, an entered event is triggered inside the ClipBook platform and any messages set to "On Enter" will be sent to that device.

Figure 3: The next sample, the user, while having moved further south, is still inside the geofence. The ClipBook platform keeps track of the number of location samples that a device is inside the geofence, but does not trigger any event. So, in this case, no message is sent.

Figure 4: Finally, the device has now moved outside of the geofence. Because this is the first sample from outside an exit event is triggered in the ClipBook platform and any messages associated with the "On Exit" event will be sent to the device. It should be noted that if we started tracking with the person in the location indicated in Figure 2, that would still represent a enter event because, the last sample (which could have been days before) the device was not in the geofence, but is at that point in time. The ClipBook platform is actually more flexible than the above illustrates. We could, for example, only send messages after the device has been in an area for some set period of time or some number of location samples. The basic user interface, however, only supports the above geofence triggering. Because location samples aren't always accurate, the ClipBook platform has various algorithms that help to filter out some of the noise. In addition, the ClipBook supports what are called Trigger Guards that prevent the same message from being delivered to the same device in a certain period of time. This can help prevent spamming a person with the same message over and over if they happen to be on the edge of a geofence. Geofencing will be most appropriate for the use cases that involve having a smart client application that allows for continuous tracking of a device using the GPS system built into most smart phones today. It can also be useful for carrier based tracking. The ClipBook platform supports scheduling the tracking of a set of devices for some fixed length of time. But, carrier based tracking will be less effective due to the cost associated with acquiring each location sample as well as the relatively poor accuracy associated with carrier based location.