Flexible Protocol Stack Framework: Design, Validation and Performance

Multi-mode capabilities are becoming more important for mobile terminal and network devices and can exploit the flexibility provided by SDR technology. The reason for this is that the number of different radio access technologies is increasing with the growing popularity of Wireless Local Area Networks (WLANs) and increasing diversity of cellular radio access technologies with 2G, 2.5G, 3G and now even proposals for 4G air interfaces. Each of these standards is evolving at different rates with many optional enhancement features for providing different QoS, power efficiency and security properties, yielding a much higher software complexity than traditional single-mode protocol stack implementations. Therefore, a single inflexible protocol stack arrangement is no longer an attractive option for multi-mode support. A preferable solution is to allow protocol stack reconfiguration by software download (or peer-to-peer software exchange) to support upgrade, bug fixing and optimisation or customisation of the protocol stack to the context of the terminal whilst ensuring proper operation by thorough validation and supervision of software configurations. Furthermore, this paper investigates the performance of a proposed solution to this problem using platform and language independent support for generic interfaces between protocol stack components.