A system comprising a plurality of first subsystems respectively operable to manage a plurality of first regions in a geographic space; and a plurality of second subsystems respectively operable to manage a plurality of second regions in the geographic space, wherein the plurality of first regions and the plurality of second regions are arranged such that at least one of the first regions covers a border of one or more of the second regions and at least of the second regions covers a border of one or more of the first regions.