A Modified Deficit Weighted Round Robin traffic Scheduling Algorithm for GPON Networks

In this paper, we propose the modified deficit weighted round robin (MDWRR) traffic scheduling algorithm for Gigabit Passive Optical Network (GPON), which guarantees the real-time priority traffic. The proposed scheduling algorithm is a variation of the deficit weighted round robin (DWRR) algorithm and it assures the highest priority traffic transmission with minimization of delay. WRR algorithm to be aware of bandwidth and improves the fairness. But for certain traffic types, fairness is not the desired behavior. To achieve predictable service for sensitive, real-time traffic, a priority level for scheduling needs to be introduced. By enabling strict priority, or by offering several priority levels and using DWRR scheduling between queues with the same priority levels, service assurance with regards to delay and loss protection can be achieved for demanding traffic types, such as voice and real-time broadcasting. By offering several priority levels and using DWRR scheduling between queues with the same priority levels, service assurance with regards to delay and loss protection can be achieved for demanding traffic types, such as voice and real-time broadcasting

ADM : A Density And Priority Levels Aware Protocol For Broadcasting In Vehicular Ad-Hoc Networks

The broadcasting communication mode is widely used in Vehicular Ad~hoc Networks (VANETs). It is used for sending emergency messages, road-traffic information or to help routing protocols to determine routes. This communication mode is known to be hard to achieve efficiently since it depends on the network density. Indeed, broadcasting methods may cause network congestion if they are not well designed. This paper introduces a novel Autonomic Dissemination Method (ADM) which delivers messages in accordance with given message classes and network density levels. The proposed approach is based on two steps: an offline optimization process and an online adaptation to the network characteristics. ADM allows each node to dynamically adapt its broadcasting strategy not only with respect to the network density, but also according to the class of the message to send: emergency (high-priority), road-traffic (medium-priority) or either comfort message (low-priority). The ultimate goal of ADM is to make effective use of radio resources when there are many messages to send simultaneously. This approach increases the efficiency of the broadcast process in terms of message delivery ratio, latency and interferences reduction. The autonomic computing paradigm improves the robustness of protocols

Self-Stabilizing TDMA Algorithms for Dynamic Wireless Ad-hoc Networks

In dynamic wireless ad-hoc networks (DynWANs), autonomous computing devices set up a network for the communication needs of the moment. These networks require the implementation of a medium access control (MAC) layer. We consider MAC protocols for DynWANs that need to be autonomous and robust as well as have high bandwidth utilization, high predictability degree of bandwidth allocation, and low communication delay in the presence of frequent topological changes to the communication network. Recent studies have shown that existing implementations cannot guarantee the necessary satisfaction of these timing requirements. We propose a self-stabilizing MAC algorithm for DynWANs that guarantees a short convergence period, and by that, it can facilitate the satisfaction of severe timing requirements, such as the above. Besides the contribution in the algorithmic front of research, we expect that our proposal can enable quicker adoption by practitioners and faster deployment of DynWANs that are subject changes in the network topology

‘Keeping it real’: the politics of Channel 4's multiculturalism, mainstreaming and mandates

This article is a post-print version of the published article which may be viewed at the link below. © The Author 2008. Published by Oxford University Press on behalf of Screen. All rights reserved.When Channel 4 decided how it was going to fill what was described in the Annan Report as ‘the empty room of British broadcasting’, it was agreed that Britain's Africans, Caribbeans and Asians were to be important residents. This was meaningful for Channel 4 because it was tasked with providing what Stephen Lambert then described as ‘opportunities for talents which had previously not been fully served’ and with serving needs ‘which have not been fully defined’. And yet the recent history of the channel has been characterized by the closing stages of a particular kind of ‘public service’ approach; one in which ethnic minorities have become simultaneously integrated in and disconnected from mainstream output in distinct ways. Twenty-five years on, the channel is caught up in the difficulties facing the structuring of public service broadcasting and in the challenges posed by the highly contentious politics of recognition for the settlement of the relation between a variety of social rights. On the one hand, black and Asian Britons, who as part of the postcolonial phase of migration to the UK might be regarded as the ‘old ethnics’, do not now appear to be a priority for Channel 4. On the other, the legacy of the relationship between Channel 4, these communities and broader ideals of ‘multiculturalism’ appears to be strong, not least according to the channel's current claims