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Energy Systems and Technologies for the Coming Century ...

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When an appliance is turned off or it has finished its task, <strong>the</strong> CS will detect this as adeparture event. If <strong>the</strong> paused appliances list is not empty, <strong>the</strong> CS will evaluate <strong>the</strong>following equation:1max_ consumption x i xNi1pausedwhere x paused is <strong>the</strong> power consumption of <strong>the</strong> paused appliance found in <strong>the</strong> pausedappliances list. If equation (3) st<strong>and</strong>s, this paused appliance will receive a resumecomm<strong>and</strong> from <strong>the</strong> CS <strong>and</strong> will be removed from <strong>the</strong> paused appliances list.Fur<strong>the</strong>rmore, if <strong>the</strong> paused appliances list still contains paused appliances, <strong>the</strong> CS willevaluate equation (3) again until <strong>the</strong>re are no more appliances left in <strong>the</strong> pausedappliances list or <strong>the</strong> maximum consumption is reached. The CS evaluates <strong>the</strong>appliances in <strong>the</strong> paused appliances list in input order, FIFO (first-in-first-out), as <strong>the</strong>ywill all have <strong>the</strong> same priority, low priority.(3)4 Teletraffic Theory RevisedTeletraffic engineering is <strong>the</strong> application of probability <strong>the</strong>ory <strong>and</strong> stochasticma<strong>the</strong>matical modeling <strong>for</strong> solving problems concerning network planning, evaluatingnetwork per<strong>for</strong>mance <strong>and</strong> deriving <strong>the</strong> relationship between grade-of-service <strong>and</strong> systemcapacity [1]. The aim is to dimension <strong>the</strong> network accordingly <strong>and</strong> establish <strong>the</strong>appropriate traffic controls. In case of different services, traffic classes are used toaggregate <strong>the</strong> services according to <strong>the</strong>ir grade-of-service requirements. The user flows,or <strong>the</strong> data to be transmitted by <strong>the</strong> users, are divided in classes. This division is used as<strong>the</strong> basis <strong>for</strong> differentiated processing <strong>and</strong> service.The Reversible Fair Scheduling (RFS) algorithm presented <strong>and</strong> used in this paper has itsorigin in teletraffic engineering. It is a b<strong>and</strong>width allocation scheduling algorithm <strong>and</strong> itsaim is to allocate resources dynamically to networks supporting multiple services. Theresources are allocated depending on <strong>the</strong> type of user request.There<strong>for</strong>e, <strong>the</strong> service requiring <strong>the</strong> highest amount of resources will be served, as longas, <strong>the</strong> total capacity or defined limit of <strong>the</strong> system is not exceeded. As shown in Figure3, a communication link consists of n channels <strong>and</strong> k buffers. The total number ofsupported services classes is N, which occupy <strong>the</strong> resources of <strong>the</strong> communication link.The system will receive requests from <strong>the</strong>se N classes to use some of <strong>the</strong> n channels incommunication link. When a request is received <strong>for</strong> one of <strong>the</strong> classes that requires lesschannels than <strong>the</strong> available number in <strong>the</strong> link, it can be served immediately [1, 2].Fig. 1: Resource allocation in a network communication link [3].Risø International <strong>Energy</strong> Conference 2011 Proceedings Page 159

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