A system and method for handoff in an integrated cell. A user equipment selects an integrated cell as a target cell supporting a target network based on a white list and physical cell identities. A cell-to-cell handoff is performed to the target cell. After the cell-to-cell handoff, a base station of the target cell establishes a communication session directly to a service. Then, the user equipment determines whether or not a physical cell identity of a base station of the target cell is an integrated physical cell identity. The user equipment turns on a module for the target network when the physical cell identity of the base station is determined to be the integrated physical cell identity. A heterogeneous-network handoff is then performed, and the base station communicates directly with a service server using a mapping table in order to seamlessly provide the service to the user equipment.