A multilayer link quality estimator for reliable machine-to-machine communication

An ever-growing number of embedded devices supports different kinds of applications, such as healthcare, surveillance, gas monitoring, and others, that require an elevated level of communication reliability. However, the expected high density of those embedded devices increases the competition for frequency spectrum, making it difficult to achieve a reliable machine-to-machine (M2M) communication. To overcome these difficulties, the use of link quality estimators (LQE) is crucial to provide a solid communication. In order to provide robust and faster communication under harsh conditions, this paper proposes a new LQE, called PRR², which uses two metrics and two levels of PRR (Packet Received Ratio). The use of two PRR sliding windows captures link quality variations in the short term and also considers the long-term. PRR² is compared against the state of the art on a prototype using USRPs, and the results show that the proposal reduces the number of retransmissions and increases the delivery rate, which are two important metrics for link layer reliability.