Browsing by Author "Mbise, Mercy"

Now showing 1 - 4 of 4
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    Application and Network Level Arbitration for Development of Quality of Experience Metric
    (2003) Mbise, Mercy
    This paper examines an arbitration mechanism where redundant video packets are selectively removed, resulting in an improvement in the video quality whilst freeing up resources for other interactive traffic. The interaction between multimedia streams is investigated, where video and a still image are apparent simultaneously, and the effects of transmitting these media over the same channel examined. Network and application level arbitration policies are examined for a simulated and real network. The relationship between the objective quality of service metrics available from the network & application, and the subjective perception of quality of experience are considered, and used to develop the end-user's quality of experience metric. The findings are consolidated and used to derive policies for network and application level arbitration, to provide maximum quality of experience to the end-user.
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    Arbitration by Selective Removal of Temporally Dependent Redundancies
    (Visual Information Engineering, 2003. VIE 2003. International Conference on, 2003) Mbise, Mercy; Woods, John C.
    This paper examines the transmission of real-time video and still images over the same medium, and presents an arbitration mechanism for efficient transfer of bulky data in the presence of scarce resources, by intelligently compromising the video stream. The arbitration selectively removes video packets based on the observation that if an intra-coded packet is lost, its dependants will not enhance the video but actually degrade it. The identification of this event permits them to be discarded thus freeing up resources at the expense of reduced temporal rate. This principle is also true for packets exceeding the end-to-end delay requirement and it can also be applied towards the end of scenes where information content is low. The freeing of resources improves the mean buffer occupancy; therefore losses and delay are reduced. A series of simulations are conducted to illustrate these points
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    Best packetization scheme for H.263 internet video communication
    (IET, 2004) Paredes-Farrera, M.; Fleury, Martin; Mbise, Mercy; Ghanbari, Mohammed
    The H.263 codec is an efficient way to stream variable bit-rate video sequences. It is proposed that, for equivalent bandwidth and frame rate, a two-slice packetisation scheme results in superior peak signal-to-noise ratio, rather than the conventional one-slice scheme, and that constant inter-packet gap rather than 'bursty' delivery is preferable.
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    Evaluation of Latency Effects of a Long-Term Burst on Video For Selective Removal of Dependant Packets
    (2003) Mbise, Mercy; Woods, John C.
    This paper presents the evaluation of multimedia traffic interaction in terms of induced latency. Experiments are conducted in a distance-leaming platform where long-term burst effects are examined together with video in the same channel. The effects of policy on a user's QoE are examined. If a packet exceeds ITU-T recs. G. 114, it is of no use to a timely play-out device, and should be selectively discarded from forwarding mechanisms. This permits the removal of packets by arbitration mechanisms according to what has happened previously to the stream. The interdependent nature of video packets permits the predictive dependants of intra-coded parents to themselves be discarded, resulting in a temporal compromise rather than an accumulation of errors.