Threat Modeling in LTE Small Cell Networks

Small cells, such as femtocells, are becoming a key component in improving the service of wireless networks. These small cells are low-powered, low-range cellular base stations that connect to the LTE core through the Internet or the network operators wireline network, and provide new and diverse ways to increase wireless coverage and bandwidth in high-density areas. These new advances in capabilities introduce new opportunities for adversaries to exploit technology against the public interest. In this paper, we present a threat model of small cell LTE networks from a network perspective. As small cells are an evolving technology and ever increasing in use and importance, threat modelling is important to identify and address the threats introduced by new deployment architectures and designs. Our asset-focused model explores three main categories and the factors that contribute to the risks of: denial of service against the Evolved Packet Core network; unauthorized access to network operator resources; and compromise of end-user privacy, confidentiality, or service availability. While this model is not meant to be an exhaustive list of risks, we hope it raises awareness of the threats discussed, and encourages security discussions on this important aspect of LTE and future 5G networks.