Queue management scheme to control congestion in a vehicular based sensor network

Vehicular Ad-Hoc Networks (VANET) is subsumed class of Wireless Networks. Sensors are utilised in vehicles for monitoring physical variables or environmental conditions with ease. The main task of each sensor incorporated is to acquire respective data from the surroundings. The unit (node) which collects the data from the sensor processes it into meaningful information. In a vehicular network such information is sent to other nearby vehicles for various purposes, such as indication of very close vehicles. The ability to route the packet to the next node is the foremost requirements of such vehicular networks. One of the main issues to be addressed in VANET is congestion. When a sudden burst of traffic is detected, the nodes need to forward it towards the destination. The node that is forwarding may also have some packets to be delivered from it. The outgoing packets and transitory packets lead to buffer overflows at a node which in turn lead to packet drops and finally degrades the overall network performance. Congestion control schemes are essential in such situations to increase network performance and ensure a fair use of the resources. This paper proposes a congestion control scheme distributed across the transport, network and MAC layers that can detect and avoid congestion in the network. It provides priority based traffic scheduling with a dual queue scheduler whichfavours transitory packets. When congestion is detected based on the buffer occupancy, source sending rate is updated by the sink periodically with the help of dual queues and route the packets through less congested paths.