Multiple interface management and flow mobility in next generation networks

Includes bibliographical references (leaves 79-80).Next Generation networks will consist of a number of different access networks interconnected to provide ubiquitous access to the global resources available on the Internet. The coverage of these access networks will also overlap, allowing users a choice of access net-works. Increasingly, mobile devices have more than one type of radio access interface built-in. In current mobile devices, a single primary radio interface performs all communications with the service provider. The availability of multiple different radio interfaces proves most beneficial if all these interfaces can connect with the service provider and carry data in collaboration or individually. This means that a control system is needed to route the correct traffic over each different interface, depending on the requirements of that traffic. Having multiple interfaces available provides the opportunity to aggregate two or more interfaces for faster transfer speeds and can provide redundancy. If one interface is expe-riencing high packet loss or no coverage an alternate interface will be available. Multiple interface schemes aim to enable traditional networks to support devices with more than one interface. This is usually achieved by introducing a new agent into the network architecture that acts as the packet redirection point. Incoming packet flows are routed to the different interfaces of the mobile device by this agent according to the traffic types of each packet flow. In this thesis an evaluation platform is developed to investigate whether the possible functionality of a multiple interfaced device provides useful traffic routing options. The evaluation platform consists of three key components evident in schemes from the literature, namely a Corresponding Node, Mobile Node and Router. The Router is emulated with a script-based routing software and configured as the packet redirection point in the evaluation platform. Four test scenarios emulate traffic travelling over two interfaces of a practical mobile node. A mid-flow handover from one interface to the other is investigated to determine that this process can be seamless under certain conditions. Dual Interface Aggregation shows good performance when the limits of each interface are not exceeded. Distinct improvement in combined packet loss of two lossy links carrying duplicate packet streams shows that two interfaces can provide a reliable link in critical situations where both interfaces have poor performance when used separately. Finally, a Bandwidth-on-Demand scenario shows that having two interfaces can allow automatic bandwidth allocation when data-rate is increased beyond the limits of one interface