Congestion control has long been chased by researchers and there are many proposed algorithms to alleviate congestion in VANET. However, the challenge is the high speed of the vehicles, intermittent network connections, inter-vehicular meeting time, mobility dynamics and so forth. I would suggest you to survey the previous research ideas that are published already (which I think are easy to find out online), and then look for some interesting or novel idea of your own.

I personally think, that the frequency with which cars disseminate information (for instance beacon messages), such congestion is inevitable, but it can definitely be decreased and that is what previous schemes are doing.

I hope it partially answers your query.

Regards,

thank you thats is intersting

I will investigate this area in depth

You might want to consider content dissemination in VANET as well.

Congestion control is a quite mature technology, but in my humble opinion, researchers are still focusing their efforts on it due to its applicability to other kinds of networks, as well as the different novel technologies that allow you to solve the problem more and more optimally and efficiently.

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