1. A method, comprising: receiving, by a computer, a request from a mobile device, the request indicates that a task is to be triggered upon entry into a specified geographic region by the mobile device; determining, by the computer, a country in which the geographic region is located, wherein determining the country includes determining a mobile country code (MCC) of the country and a bounding box of the country, the bounding box being defined by extreme geographical points of the country; determining, by the computer, a first code division multiple access (CDMA) identifier for monitoring location of the mobile device, the first CDMA identifier being associated with a first CDMA location that intersects the specified geographic region, wherein the first CDMA location is determined using historical data; determining, by the computer, a second CDMA identifier for monitoring location of the mobile device, the second CDMA identifier being associated with a second CDMA location that intersects the specified geographic region, the second CDMA location being inside of the first CDMA location and having finer granularity than that of the first CDMA location; and providing geographic coordinates of the bounding box, the MCC, the first CDMA identifier, and the second CDMA identifier to the mobile device in response to the request.