Medium Access Control (MAC) protocols for wireless decentralized networks in IoT have attracted a lot of attention in both academic and industrial fields. They aim to coordinate access among IoT devices to the shared wireless medium. More specifically, contention-free MAC protocols are known to be more efficient than contention-based ones in the case of high traffic load and dense networks. To face the main communication challenges between IoT devices such as collisions and conflicts as well as mobility, it is crucial to design an efficient MAC protocol. To do so, several solutions have been proposed in the literature. Among recent proposed solutions, Machine Learning (ML) algorithms and game theory models were used to revolutionize the communication in IoT networks, especially for devices with high mobility degree. In our survey, we first start by studying the challenges and requirements of communication in wireless networks. Then, we provide a comprehensive survey on recent contention-free MAC protocols existing in the literature. Next, we compare these solutions based on important metrics such as QoS, robustness, fairness etc., and discuss the relationship between MAC protocols, network type and network mobility. Finally, we investigate a future research direction to solve a major problem, which is the network disruption and delay tolerance in IoT wireless mobile networks.