A Modified SI Epidemic Model for Combating Virus Spread in Wireless Sensor Networks

We study the dynamics of virus spread in wireless sensor networks (WSNs). We first analyze the susceptible-infective (SI) epidemic model for WSNs. In the SI model, once a sensor node is attacked by a virus, the infective node then, using normal communications, spreads the virus to its neighboring nodes, which further spread the virus to their neighbors, the process continues until the whole network fails. To combat this drawback, we propose a modified SI model by leveraging the sleep mode of WSNs to perform system maintenance. The modified SI model can improve the network anti-virus capability and flexibly adapt to different types of virus, without causing any additional hardware effort and signaling overhead. We derive the explicit analytical solutions for the modified SI model, which can capture both the spatial and temporal dynamics of the virus spread process. Extensive numerical results are presented to validate our analysis. The proposed model and analysis method are expected to be used for analysis and design of information (including virus) propagation mechanisms in distributed wireless or computer networks.