Abstract: The present investigation deals with M/G/1 retrial queue with unreliable server and general retrial times. The server is subject to breakdowns and takes some setup time before starting the repair. The server renders first essential phase of service (FES) to all the arriving customers whereas second optional phase services (SOS) are provided after FES to only those customers who opt fo...

In this paper, we consider the construction of an optical priority queue with a single (M + 1) × (M + 1) switch and M fiber delay lines. The M fiber delay lines are connected from M outputs of the switch back to M inputs of the switch, leaving one input (resp. output) of the switch for the input (resp. output) of the priority queue. It was known in [8][9] that with an appropriate choice of the ...

In this article, we present a cross-layer adaptive algorithm that dynamically maximizes the average utility function. A per stage utility function is defined for each link of a carrier sense multiple access-based wireless network as a weighted concave function of energy consumption, smoothed rate, and smoothed queue size. Hence, by selecting weights we can control the trade-off among them. Usin...

A number of active queue management algorithms for TCP/IP networks such as RED, SRED, DRED and SDRED have been proposed in the past few years. This article presents a comparative study of these algorithms using simulations. The evaluation is done using the OPNET Modeler, which provides a convenient and easy-touse platform for simulating largescale networks. The performance metrics used in the s...

The paper describes an original approach for the ABR service in the ATM network. It belongs to the explicite rate (ER) class and assumes that the ER parameter corresponds to the instant queue size. More specifically, the ER value calculated by the switch is proportional to the difference between predefined threshold and the actual state of the queue. Therefore, the algorithm can be regarded as ...

For a packet erasure broadcast channel with two receivers, a new coding algorithm is proposed that makes use of feedback to achieve asymptotically optimal queue size at the sender and decoding delay at the receivers, without compromising on throughput. Our coding module is compatible with the drop-when-seen queuing algorithm proposed in earlier work [1]. Hence, it guarantees that the physical q...

In a dynamic reordering superscalar processor, the front-end fetches instructions and places them in the issue queue. Instructions are then issued by the back-end execution core. Till recently, the front-end was designed to maximize performance without considering energy consumption. The front-end fetches instructions as fast as it can until it is stalled by a filled issue queue or some other b...

Abstract We consider the notion of a constant length queue automaton —i.e., traditional with built-in limit on its queue—as formalism for representing regular languages. show that descriptional power automata greatly outperforms finite state automata, height pushdown and straight line programs expressions, by providing optimal exponential double-exponential size gaps. Moreover, we prove can be ...

— We consider in this paper the steady state behaviour of a Queueing System with queue length dependent additional server facility wherein arrivais occur in batches of variable size. Whenever the queue length in front of the first server reaches a certain lenght, the system adds another server. Steady state probabilities and expected queue lengths in Single Server System and Additional Server S...

Long Term Evolution (LTE) uses single carrier frequency division multiple access (SCFDMA) technique as the multiple access scheme in the uplink, due to its low peak to average power ratio (PAPR) compared to orthogonal frequency division multiple access (OFDMA). This advantage is achieved when the Resource Blocks (RBs) allocated to a user are contiguous in frequency domain. Considering this cons...