Congestion diffusion and decongestion strategy in networked traffic

TL;DR

This paper investigates traffic flow and congestion control in scale-free networks, revealing phase transitions and optimal strategies to enhance network capacity and performance.

Contribution

It introduces a combined approach of random neighbor selection and packet-dropping control to improve traffic handling in heterogeneous networks.

Findings

First order phase transition from free flow to congestion with increasing packet rate.

Existence of an optimal delay time T for packet dropping to maximize network capacity.

Random effects contribute positively to network traffic performance.

Abstract

We study the information traffic in Barab\'asi-Albert scale free networks wherein each node has finite queue length to store the packets. It is found that in the case of shortest path routing strategy the networks undergo a first order phase transition i.e., from a free flow state to full congestion sate, with the increasing of the packet generation rate. We also incorporate random effect (namely random selection of a neighbor to deliver packets) as well as a control method (namely the packet-dropping strategy of the congested nodes after some delay time $T$) into the routing protocol to test the traffic capacity of the heterogeneous networks. It is shown that there exists optimal value of $T$ for the networks to achieve the best handling ability, and the presence of appropriate random effect also attributes to the performance of the networks.