A first serving system that serves a first serving area receives a request to connect a call to a mobile station having a last reported location corresponding to a border area. The border area is proximal to a second service area that is served by a second serving system. The first serving system pages the mobile station in a first paging zone in the first service area. If the probability of successfully paging the mobile station in a second paging zone in the second service area is sufficiently high, the first serving system may also have the mobile station paged in the second paging zone by transmitting an inter-system page request to the second serving system. To determine the probability, the first serving system may look up a historical success rate for successfully paging in the second paging zone mobile stations having last reported locations corresponding to the border area.