Section: New Results

MAC mechanisms

Participant : Nathalie Mitton.

In the era of the Internet of Things (IoT), the number of connected devices is growing dramatically. Often, connected objects use Industrial, Scientific and Medical (ISM) radio bands for communication. These kinds of bands are available without license, which facilitates development and implementation of new connected objects. However, it also leads to an increased level of interference in these bands. Interferences not only negatively affect the Quality of Service, but also cause energy losses, which is especially unfavorable for the energy constrained Wireless Sensor Networks (WSN). In [25], we develop an explicit formula of outage probability in a distributed wireless sensor network (WSN), assuming the MAC layer protocol being a slotted-ALOHA. And adopting a Markovian approach, we develop a model that analyses the performance of the slotted-ALOHA in order to improve these performances, in particular, by adding a preliminary stage of channel reservation, we show that this modification is important to have a high performance distributed wireless sensor network.

Several wild animal species are endangered by poaching. As a solution, deploying wireless sensors on animals able to send regular messages and also alert messages has been envisaged recently by several authorities and foundations. In that context, we have proposed WildMAC [35], a multichannel, multihop wireless communication protocol for these specific wireless sensor networks that have to collect data from unknown large areas with different QoS requirements. WildMAC is a TDMA based MAC protocol that leverages long range communication properties to propose an efficient data collection mean. Its performance evaluation shows it meets QoS requirements. To size the different parameters of WildMAC, we relied on the results of the study of [25].