On the Connection-Establishment Request Control Method to Improve Data Packet Delivery Ratio at Densely Populated Areas for Bluetooth MANETs

Bluetooth MANETs are Bluetooth-based communication methods between terminals, and various studies have been conducted for sharing data between mobile terminals such as smartphones in disasters. Recently, by using both Bluetooth Low Energy and Classic Bluetooth complementarily, a fast connection-establishment method have been pro-posed to mitigate the contention for the connection-establishment timing between terminals (hereinafter referred to as " the existing method"). Although the existing method improves the speed of connection between two terminals, the following problems occur in a densely populated area: a terminal receives too many connection requests from other terminals, and the number of successful connections decreases. As a result, the data packet delivery ratio of the network deteriorates. In this paper, we propose a method to establish a connection more reliably by controlling a terminal that sends a connection request based on the information of surrounding terminals (hereinafter referred to as “our proposed method”). Our proposed method utilizes Bluetooth Low Energy broadcast to collect information on surrounding terminals, and it controls the transmission of connection requests to each terminal. We have conducted experiments using an Android terminal and compared the results between our proposed method and the existing method. As a result, we have confirmed that the number of successful connections and the data packet delivery ratio of our proposed method are superior to those of the existing method.