Distributed Data Collection in a Cyclic MobiSpace

In a distributed, intermittently-connected environment, specifically-deployed monitors generates data that represents the status of themselves or environments. The data collection task is to employ multiple moving devices to collect data as quickly as possible. These devices are also called detection devices. Detection devices usually do not have access to the Internet or long-distance communications. Since monitors are usually deployed sparsely and cannot communicate with each other, a detection device can only communicate with a monitor via near-field communications such as Bluetooth or WiFi Direct when they are physically close. A data collection task (e.g., we want to collect data from 500 monitors) is usually initiated by one detection device, which is also called the initiator of the task. To finish the task as quickly as possible, the task initiator needs to disseminate part of the task to the other detection devices when they meet with each other. In this paper, we discuss the possible near-field communications that fit for our scenario, and present an algorithm that helps the task initiator to finish the task in the minimal time. Extensive simulations are conducted to evaluate the performance of the proposed algorithm.