An interface for Sector Systems.
A sector is a code for a place. So it can for example equal a sensor somewhere in a detector or be something abstract like the IP.
A sector system is able to take a sector (integer number) and give back information about it. This can be things like the number of the sensor or the rough distance from the IP or such things. Or even neighbouring sectors. But this is all dependent on the circumstances of the detectors and their representation.
What all SectorSystems have in common is the layer: SectorSystems must be able to return the layer of a sector and how many layers there are all in all.