The distributed publication and subscription for the Internet of Things is a model of communication between devices that is simple and powerful. In comparison with other variant problems of ME, the problem considered here is a group mutual exclusion problem. The specificity of an IoT system is that a process can be in more than one group at the same time which is not the case of the algorithms mentioned in the literature where a process request one group in advance for each request. In this paper, we define formally the notion of group. Furthermore, we propose a distributed algorithm for automatic group generation and we will show that this problem is maximal cliques’ problem. This leads us to a new kind of distributed Maximal cliques algorithm to compute the groups suitable for IoT systems. As an application, we propose an IoT-based intersection traffic light management system for vehicles.