Koenraad Laevens

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This paper describes the use of Congestion Pricing as a means of providing Congestion Control and Di erentiated Quality of Service. The application of the proposed technique to the Internet Protocol has the advantage that it can be simply implemented using Explicit Congestion Noti cation. In particular: the network mechanism is independent of higher level(More)
We investigate the behaviour of an asynchronous optical buffer by means of a continuous-time queueing model. Through a limit procedure, previously obtained results for a discrete-time queueing model are translated to a continuous-time setting. We also show that the same results can be obtained by a direct analysis using Laplace transforms. Closed-form(More)
Optical Burst Switching proposes a future-proof alternative to the current electronic switching in the backbone. The involved optical buffers are implemented with a set of Fiber Delay Lines, and suffer serious performance loss, when compared to RAM. Various existing models trace this loss, but either lack generality, accuracy, or effectiveness. The optical(More)
We present a detailed analysis of the maximum channel utilization and loss performance in an optical buffer having access to a single outgoing channel. As opposed to a conventional electronic buffer, such a system consisting of a number of fiber delay lines can only realize a discrete set of delays to resolve output port contention. This leads to an(More)
In novel switching approaches such as Optical Burst Switching, the involved buffers can only provide a degenerate waiting room, with delays restricted to multiples of a basic value, the granularity. Although the resulting performance loss was already studied analytically, previous work is either limited by the assumption of independent arrivals, or it(More)
In this paper we propose a scheme for detecting and predicting congestion patterns from network feedback. The focus here is on binary feedback messages, such as loss events or ECN marks. Simulations show that, when a fraction of end users modify their congestion control based on these estimations, oscillations in network buffer occupancy otherwise induced(More)
HTTP Adaptive Streaming (HAS) is rapidly becoming a key video delivery technology for fixed and mobile networks. However, today there is no solution that allows network operators or CDN providers to perform network-based QoE monitoring for HAS sessions. We present a HAS QoE monitoring system, based on data collected in the network, without monitoring(More)