The Ihstnbuted Queue Dual Bus (DQDB) protocol, wliich has been specified by the IEEE 802 6 ;is the Metropolitan Area Networks (MANS) standard, has an undesirable feature that busy slots that has been alreadb received ( I e read) continue to propagate d0wti:;tre'Wl riiinecessarily The use of special nodes, known as erasure nodes. allows conversion of read slots to empty, so that downstream nodes...

In a market-based scheduling mechanism, the allocation of time-specific resources to tasks is governed by a competitive bidding process. Agents bidding for multiple, separately allocated time slots face the risk that they will succeed in obtaining only part of their requirement, incurring expenses for potentially worthless slots. We investigate the use of price prediction strategies to manage s...

All-optical wavelength division multiplexing networks are the most promising candidate for the next generation wideband backbone networks. To improve the utilization of wavelength, time division multiplexing technology is introduced. The routing, wavelength and time-slots assignment problem was studied in such time-space switched networks. Two new dynamic algorithms were proposed which distribu...

This paper proposes a TDD-SDMA/TDMA system with a multi-slot assignment to deal with asymmetry traffic in wireless networks, where the packet-based data services is supported. The proposed system assigns more than one time slots for downlink to each terminal so as to deal with the asymmetric traffic. We also present an efficient algorithm to decide the priority of time slots for downlink, by wh...

IEEE 802.16 standard lacks a Media Access Control (MAC) scheduling architecture to enforce Quality of Service (QoS) requirements of different services classes. In this paper, we propose an opportunistic and optimized scheduler that meets connections’ QoS requirements while it pledges fairness among admitted connections. Our approach involves separating the scheduling problem into two sub-proble...

Cervical spinal synovial and/or ganglion cysts can occur at various periarticular sites and should be considered in the differential diagnosis of intraspinal-extradural or paraspinal masses of the cervical spine. The first report of a ganglion cyst of the cervical anterior longitudinal ligament presenting as a retropharyngeal mass, is presented. The histopathology, etiology, and clinical aspect...

We have performed SQUID-NMR measurements on rhodium nuclei at ultralow temperatures. With initial polarizations of up to p = 0.95, the susceptibility data showed clear indications of an antiferromagnetic tendency, but nevertheless no signs of nuclear magnetic ordering. The lowest actually measured nuclear temperature was 280 pK, whereas the lowest nuclear temperatures achieved were below 100 pK...

Work-conserving disciplines may be implemented with the use of scheduling calendars. Since calendars have finite resolutions, theoretical emission times that determine the positions of frames within the calendar slots have to be rounded to match the boundaries of the slots. The selection of a rounding method affects the performance of a work-conserving discipline. In this paper, we present an e...

In this paper, we compare the use of two packet models in slotted optical ring networks: a model where each packet has to be routed in consecutive slots, and a model where the slots that form a packet can be routed independently. We first focus on the algorithmic complexity of the related problems. Then, we give the results we obtain with an OMNET simulator in terms of packets’ overdelay and ji...

It is shown that a Partitioned Optical Passive Stars (POPS) network with g groups and d processors per group can route any permutation among the n = dg processors in one slot when d = 1 and 2⌈d/g⌉ slots when d > 1. The number of slots used is optimal in the worst case, and is at most the double of the optimum for all permutations π such that π(i) = i, for all i.