Towards a robust traffic admission control in homogeneous urban vehicular networks under QoS constraints

In this paper, we consider the problem of controlling the input flow to a homogeneous urban vehicular network such that certain Quality of Service (\mathrm{Q}\mathrm{o}\mathrm{S}) constraints are preserved. In such a network, we model the system with two types of queues: external and internal. External queues represent vehicles waiting to enter the urban vehicular network under control, and the internal queue is used to describe the network's aggregated behavior based on the Network Fundamental Diagram (NFD). While most of the works assume perfect knowledge of the NFD describing the urban vehicular network, in reality we can only approximate it. On these grounds, by taking a model of the NFD with uncertainties, we propose a robust control design approach in order to gate input flow to a protected urban vehicular network such that travel time Quality of Service (\mathrm{Q}\mathrm{o}\mathrm{S}) constraints are preserved within the network. The proposed controller is compared via simulations with controllers assuming perfect knowledge of the NFD and it is shown that it can provide a larger stability region.