ABSTRACT
Introduction ........................................................................................................ 134 Problem Defi nition ............................................................................................. 134 Context-Aware Personalized Services over Enterprise
Wireless Networks .................................................................................... 136 Service Discovery .............................................................................................. 138
Discovery Functions and Characteristics .................................................. 139 Service Core Functions ................................................................. 139 Discovery Scope ........................................................................... 140 Naming ......................................................................................... 141
Service Retrieval and Selection ................................................................ 141 Web Services and Semantic Solutions ...................................................... 141 Security Aspects ........................................................................................ 143 Summary ................................................................................................... 143 Access Control .......................................................................................... 146 Access Control in Enterprise Settings ...................................................... 146 Access Control Policies ............................................................................ 146 Context-Based Access Control ................................................................. 147
A Practical Example of Emerging Solution Guidelines: The S-MIDAS Framework ........................................................................ 149 The S-MIDAS Metadata Model ................................................................ 149
Lessons Learned, Emerging Trends, and Conclusive Remarks ......................... 152 Emerging Trends ....................................................................................... 153 Open Research Challenges ....................................................................... 154
References .......................................................................................................... 155
Modern enterprise networks offer a wide variety of wireless connectivity to their recognized users, thereby enabling them to work in geographically distributed offi ces, including the premises of their business partners. In practical terms, this often requires the integration of heterogeneous wireless access solutions, heterogeneous security mechanisms, and a decentralized autonomous management of security. For instance, IT workers in multinational companies usually move between different, possibly geographically distributed, departments of the same company, or sometimes visit the offi ces of a collaborating company with well-established business relationships. All these networks have Wi-Fi (Wireless Fidelity) access points with different implementations, as well as enterprise-level Bluetooth or WiMAX (Worldwide Interoperability for Microwave Access) base stations from different vendors. Furthermore, the security policies for each subnetwork are usually adopted independently of the others taking into account the constraints and requirements of only one administrative environment. Thus, security management is performed autonomously in each locality. This integrated scenario poses novel and challenging security issues. In addition to the well-known low-layer vulnerabilities due to the nature of wireless access, the additional challenges include the secure discovery and access to enterprise resources and services. In other words, the design assumptions of traditional enterprise networks, where users were assumed to be mostly sedentary, will have to be re-examined. The main thesis of this chapter is that novel approaches to secure wireless access to services must take into account the operational and environmental context in the personalization of security/service provisioning over enterprise networks. A review of security in enterprise wireless networks, with a specifi c focus on secure discovery and secure access control, would give a guide to the advantages and disadvantages of each solution in practical situations. It also reveals the open challenges that remain to be solved in order to make these solutions ready for the industrial market and for their wide-scale exploitation.
