In a group touring scenario, the group leader can enable his handheld device's Wi Fi hot spot function to let other members to connect with. Then, the group leader can download Point Of Interests' (POIs') data from the content server through 3G/3.5G/4G cellular network and then forward those downloaded data to the connected clients using Wi Fi. That is, the group leader also plays the role of a mobile proxy. Nevertheless, mobile users may move randomly such that they may leave their current group leader and move toward the other group leader. This work proposed a handoff mechanism such that mobile users can move from the currently connected Wi Fi hot spot, for which the received signal strength is becoming weak, and to a new Wi Fi hot spot/mobile proxy, for which the received signal strength is becoming stronger. Since the current handheld device only allows a limited number of handheld devices to connect with its Wi Fi hot spot, it is not so straightforward to tackle the handoff issue. This work devised a K-CAMP clustering scheme to tackle the handoff issue exists in the aforementioned group-based touring scenario.