Browsing by Author "Neco Ventura"

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    Multiple Interface Management and Flow Mobility in Next Generation Networks
    (2007) Abrey_GR; Neco Ventura
    Next Generation networks will consist of a number of di erent 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 networks. 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 di erent radio interfaces proves most bene cial 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 tra c over each di erent interface, depending on the requirements of that tra c. 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 experiencing 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 ows are routed to the di erent interfaces of the mobile device by this agent according to the tra c types of each packet ow. In this thesis an evaluation platform is developed to investigate whether the possible functionality of a multiple interfaced device provides useful tra c 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 con gured as the packet redirection point in the evaluation platform. Four test scenarios emulate tra c travelling over two interfaces of a practical mobile node. A mid- ow 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 impovement 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 iii having two interfaces can allow automatic bandwidth allocation when data-rate is increased beyond the limits of one interface. The results of these tests show signi cant bene ts in transfer speed, link reliability and bandwidth-on-demand under most conditions. However, certain test parameters show that problems do occur when packet ows undergo a handover from one interface to another. The worst problem is out-of-order packet arrival and this was observed in certain scenarios. Despite this, it is shown that the distinct bene ts of using a multiple interfaced device can outweigh the complexity of a multiple interface management scheme and its inherent problems.