A robust intrusion detection architecture for a distributed wireless mobile network is of significant importance as it is necessary to secure these networks against malicious attacks and sustain availability of services to various applications. In this paper, we examine the limitations of a layered approach to security in mobile networks. We consider a detection framework that encompasses multiple layers of the node?s protocol stack using cross-layer communications. We discuss the functional advantages of the parameter interactions in intrusion detection, with regard to a few parameters. We present the metrics that characterize an efficient detection system and analyze the benefits of a multi-level intrusion detection architecture.