In future wireless multimedia networks, there will be a mixture of different traffic classes which have their own maximum tolerable bit error rate (BER) requirements. In this paper, a novel medium access control (MAC) protocol called wireless multimedia access control protocol with BER scheduling (in short form, WISPER) for CDMA-based systems is proposed. WISPER utilizes the novel idea of scheduling the transmission of multimedia packets according to their BER requirements. The scheduler assigns priorities to the packets, and performs an iterative procedure to determine a good accommodation of the highest-priority packets in the slots of a frame so that packets with equal or similar BER requirements are transmitted in the same slots. The proposed WISPER protocol has been validated using a software emulator on the cellular environment. Performance evaluation results based on the implementation are also included.

The shadow cluster concept can be used to estimate future resource requirements and to perform call admission decisions in wireless networks. Shadow clusters can be used to decide if a new call can be admitted to a wireless network based on its quality-of-service (QoS) requirements and local traffic conditions. The shadow cluster concept can especially be useful in future wireless networks with microcellular architectures where service will be provided to users with diverse QoS requirements. The framework of a shadow cluster system is completely distributed, and can be viewed as a message system where mobile terminals inform the base stations in their neighborhood about their requirements, position, and movement parameters. With this information, base stations predict future demands, reserve resources accordingly, and admit only those mobile terminals which can be supported adequately. The shadow cluster concept involves some processing and communication overheads. These overheads have no effect on wireless resources, but only on the base stations and the underlying wireline network. It is shown how base stations determine the probabilities that a mobile terminal will be active in other cells at future times, define and maintain shadow clusters by using probabilistic information on the future position of their mobile terminals with active calls, and predict resource demands based on shadow cluster information. In addition, a call admission algorithm is introduced, which uses current traffic and bandwidth utilization conditions, as well as the amount of resources and maximum allowable "dropping probability" being requested. Performance results showing the advantages of the shadow cluster concept are also included.

This paper describes the Shadow Cluster concept, a novel idea that can be used to improve the resource allocation and the call admission procedures in wire less networks.Shadow clusters can be used to allocate resources that need to be reserved for call hand-offs, and to determine if a new call should be admitted to a wireless network based on the call's requirements and local traffic conditions.The shadow cluster concept is targeted for ATM-based wireless networks with a micro/n.ano-cellulararchitecture, where service will be provided to users with very diverse requirements.In these n.etworks, and as a consequence of the small cell sizes, mobile users will typically experience a high number of cell hand-offs during their connections' lifetime.'With shadow clust.ers, the quality of service of mobile calls can be improved by reducing the number of dropped calls during hand-offs, and by disallowing the establishment of new calls that are highly likely to later result in a dropped call.The framework of a shadow cluster system is completely distributed, and can be viewed as a message system where a mobile terminal informs the base stations in the neighborhood about i.ts requirements, position, and movement parameters, so that the base stations project future demands, reserve resources accordingly, and admit onlv

A new multiple access protocol called PROTON (PROTocol for Optical Networks) is developed for optical local area networks based on a passive star topology. PROTON uses wavelength division multiplexing (WDM) and is highly bandwidth-efficient. One of the available wavelengths is used as a control channel. Time is divided into fixed-sized slots. The size of the slots is the same for the control and the data channels. Before transmitting a packet, a station must compete with others for a slot in a data wavelength, using a collision-free procedure. Transmitting stations and the corresponding wavelengths for their data transmissions are determined at each station by a simple arbitration scheme. The protocol is suitable for networks where the number of users can be much larger than the number of available data channels. In addition to propagation delays, it is considered that transmitter and receiver tuning times as well as the times required to process control packets are not negligible. Whenever possible, and to maximize the throughput of the network, tuning and processing times of transmitters and receivers are overlapped with each other and with data transmission times. Also, data slot requests and packet transmissions are scheduled in a pipeline fashion, thus reducing the detrimental effects on throughput and packet delay of long propagation delays. The paper includes an analysis of the maximum throughput characteristics of PROTON. An analytical model is developed, and several performance measures are obtained.>

article Free Access Share on Aitken-Hermite Interpolation Authors: Morris Gershinsky Republic Aviation Corporation, Farmingdale, New York Republic Aviation Corporation, Farmingdale, New YorkView Profile , David A. Levine Republic Aviation Corporation, Farmingdale, New York Republic Aviation Corporation, Farmingdale, New YorkView Profile Authors Info & Claims Journal of the ACMVolume 11Issue 3July 1964 pp 352–356https://doi.org/10.1145/321229.321237Published:01 July 1964Publication History 5citation415DownloadsMetricsTotal Citations5Total Downloads415Last 12 Months20Last 6 weeks6 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my Alerts New Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF