Measurement and modeling of paging channel overloads on a cellular network
IP and cellular networks used to be isolated from each other. In recent decade however, the two networks have started to overlap with the emergence of devices that access the Internet using cellular infrastructures. One important question then is whether actions or threats on the Internet side can impact the telecom or cellular side. We address this problem in the paper and specifically consider the paging channel, which is a key conduit shared by both Internet and cellular traffic. Our contributions are as follows: we illustrate through experiments on a CDMA2000 cellular network that attacks launched from the Internet can significantly increase the paging load and increase the delay of paging messages including cellular call setup requests; we derive a simple but accurate queuing model for the paging system in a CDMA2000 network and use this model to demonstrate that the paging channel exhibits sharp rather than graceful degradation under load; and through this model, we identify critical parameters that impact paging performance. Although our study is focused on CDMA2000 networks, similar problems exist in other types of cellular networks that employ a single control channel with limited bandwidth for both synchronous and asynchronous control messages.