An essential component of the vision of the Internet-of-Things (IoT) is that large numbers of physical and virtual objects are able to interact and cooperate to achieve common goals. These IoT systems often rely on self-organizing networks to enable devices to discover and connect with each other. Bluetooth Low Energy (BLE) is an energy-efficient radio communication technology that is rapidly gaining popularity for various IoT applications. While BLE has been designed for simple and quick data exchange, it still requires pre-defined connection roles that determine which devices can initiate or accept connections. This limits its usefulness for ad-hoc environments, where devices do not fit into the classic master/slave (or client/server) paradigm. In this paper, we propose and evaluate BlueNet, a BLE-based communication framework that allows devices to frequently switch between the peripheral and central roles, thereby providing data exchange opportunities between devices without pre-defined roles. This work further proposes several communication protocols with the goal to efficiently manage connections and to balance the traffic among devices. Simulations based on the MiXiM framework are used to evaluate how these strategies impact communication delays and packet delivery ratios for single-hop and multi-hop ad-hoc BLE communications.
