Data collection is one of the most important research topics in WSNs. In literature, many studies have proposed centralized solutions to cope with the data collection problem. However, most of them considered controllable mobile sink which is controlled by an algorithm to determine its speed, path, stop locations as well as the performed task. In fact, the uncontrollable mobile sink can be also applied to collect data from a given set of deployed sensors. A number of studies assumed that the sink is fixed and all sensors transmit their data to the sink. However, it leads to the problems of unbalanced workload and network disconnection. Some other studies scheduled the controllable mobile sink. However, the algorithms developed by adopting the controllable mobile sink cannot be applied to the scenarios where the uncontrollable mobile sink is adopted. The main reason is that the stops and arrival time of the uncontrollable mobile sink are unknown. In addition, the problems including the high hardware cost and energy limitation of the controllable mobile sink are still needed to be overcome. This paper proposes a distributed data collection mechanism, called Distributed Bus-based Data Collection (DBDC) algorithm, which considers the bus as mobile sink aiming to maximize the amount of collected data and the network lifetime of wireless sensor networks. Applying the proposed DBDC, each sensor negotiates with its neighbors based on a bidding procedure such that the sensor that buffers more data can obtain more sharing slots instead of increasing its power level. To prolong the network lifetime, the sensor with higher remaining energy can enlarge its transmission power, aiming to release more sharing slots to cooperatively help the neighbor that buffers more data. Experimental study reveals that the proposed DBDC algorithm outperforms related works in terms of throughput, network lifetime and fairness.
