1. An apparatus comprising: one or more interfaces configured to provide communication with a client device via a communication network; a memory device to store a hierarchical index system of unique identifiers corresponding to sub-polygons in a region of interest; and a processor, in communication with the one or more interfaces, to: process a location query received from the client device, wherein the location query includes a location identifier associated with the client device; determine a query identifier corresponding to the location identifier; compare the query identifier with the index system to determine that the location identifier provided by the client device is within the region of interest; and provide a service associated with the region of interest to the client device over the communication network; wherein: the unique identifiers and the query identifier include location identifiers based on a hierarchical encoding scheme, and the processor is to: compare one or more bits in the query identifier with bits in the index system to determine that the query identifier is represented in the index system and that the location identifier provided by the client device is within the region of interest, and compare a first set of bits of the query location identifier, corresponding to a lower-precision sub-polygon, to the index system before comparing a second set of bits of the query location identifier, corresponding to a higher-precision sub-polygon.