In a Wireless Sensor Network (WSN) Nodes are distributed to monitor an area of interest such as a military battlefield, and transmit their data to in-situ Base-Station (BS) through multi-hop paths. In addition to collecting and processing the sensor data, the BS performs network management tasks. Due to such an important role, an adversary would try to locate the BS and target it with Denial-of-Service (DoS) attack in order to disrupt the WSN operation. Locating the BS can be done by intercepting transmissions and then employing traffic analysis techniques such as Evidence Theory (ET). To counter such an attack, this paper presents a novel technique for increasing BS anonymity by establishing a sleep/active schedule among the nodes that are far away from the BS, and increasing the traffic density in selected parts of the network in order to give the impression that the BS is located in the vicinity of the sleeping nodes. The simulation results confirm the effectiveness of the proposed technique in increasing the anonymity of the BS.