Search results for "ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS"
showing 10 items of 449 documents
IMRR and IMPR Routing Protocols For Inter and Intra Wireless Mesh Communications
2015
Given the evolution of wireless technologies, Wireless Mesh Networks (WMN) have appeared as an emerging low-cost solution to ensure last-mile connectivity to the Internet network. However, providing real-time and streaming applications, such as VoIP (Voice over IP) and VoD (Video on Demand), with a satisfying QoS level is considered as an important challenge within these networks. In this paper, we propose a QoS based routing protocol, called Hybrid QoS Mesh Routing (HQMR), jointly with a clustering algorithm to improve the scalability of mesh networks. HQMR is composed of two routing sub- protocols: a reactive QoS based routing protocol for intra-mesh infrastructure communications and a pr…
Evaluating a bound for MANETs routing protocols performance using graphs with activation windows
2008
In this paper we present an algorithm called STPA (shortest time path algorithm) which aims at providing a comparison tool for the evaluation of a bound for mobile ad hoc networks (MANETs) routing protocols performance. STPA provides an exhaustive evaluation of an ideal routing protocol. Based on the current position and state of the nodes it can determine factors like: how many complete messages get to the destination, which is the smallest amount of time required by a packet to get to the destination, which path followed each packet, and so on. This values would allow a protocol designer to improve or fine tune his proposal. We demonstrate that the complexity of the algorithm is O(sigma2)…
A new way of achieving multi-path routing in wireless networks
2020
In the 21st century, the wireless technology is still developing rapidly and trying to be 'Faster, Higher, and Stronger': faster data rate, higher bandwidth and stronger connectivity. Wireless Mesh Networks (WMN) have been envisioned as an important solution to the next generation wireless networking which can be used in wireless community networks, wireless enterprise networks, transportation systems, home networking and last-mile wireless internet access. They also provide a cheap, quick and effective way for building wireless data networks. Considering the nature of these networks, routing is a key process for operating the WMN. This paper proposes a new way of creating multi-path routin…
An adaptive timer for RPL to handle mobility in wireless sensor networks
2016
This paper focuses on the performance of wireless sensor networks characterized by a hybrid topology composed of mobile and static sensor nodes. The Routing Protocol for Low power and lossy networks (RPL), which is standardized as an IPv6 routing protocol for low power and lossy networks, uses the trickle timer algorithm to handle changes in the network topology. However, this algorithm is not well adapted to dynamic environments. This paper enhances the trickle timer in order to fit with mobility requirements. Most of previous works have improved this algorithm without considering the random movement of nodes. In this work, the proposed timer algorithm takes into consideration the random t…
Throughput and energy efficiency comparison of one-hop, two-hop, virtual relay and cooperative retransmission schemes
2010
Two main types of approaches exist for implementing cooperative communications at the MAC layer: virtual-hop relay and cooperative retransmission. While the virtual-hop relay schemes employ relay nodes to forward packets when higher end-to-end throughput can be achieved compared with the direct transmission, the cooperative retransmission schemes use relays to retransmit data only after the direct transmission fails. However, the performance of the these different approaches has not been compared in the literature, especially when energy efficiency is considered. In order to find out the best transmission scheme, this paper evaluates and compares the performance of the one-hop direct transm…
Latency factor in worldwide IP routed networks
2014
Current Border Gateway Protocol (BGP) serves for worldwide internet backbone connections between different Autonomous Systems (AS) on the routing level. Continuously in real-time changing environment core routers calculate routing decisions based on path-vector database entries. AS path-vector database may contain multiple paths for various Internet Protocol (IP) prefix destinations where smallest entity in the path-vector is AS. In real world AS can be internet service operator, university or any other organization willing to participate in internet network via multi-homed uplinks. Unfortunately, internal part of AS is hidden in path-vector database thus excluding factors like latency, pac…
A hybrid bio-inspired approach to solving the routing problem in mobile ad hoc networks
2018
A mobile ad hoc network (MANET) is an autonomous system of mobile hosts (nodes) connected by a wireless link. However, the problem of designing routing protocols poses challenges to researchers due to the unpredictable and dynamic nature of ad hoc networks. Hence, bio-inspired algorithms are widely used to design adaptive routing strategies for MANETs. This paper proposes a routing protocol based on the hybridisation of ant colony optimisation (ACO) and 2-opt heuristic with the optimisation of ACO parameters. Given the vast scope of the parameters, a genetic algorithm is used to minimise the complexity of the problem. The implementation of the method is realised by MATLAB. To valid the resu…
Reducing Overhearing Energy in Wake-Up Radio-Enabled WPANs: Scheme and Performance
2018
Wake-up Radio (WuR)-enabled wireless personal area networks (WPANs) are more popular over conventional WPANs thanks to WuR's on-demand transmission feature and overwhelming energy consumption superiority. In a WuRenabled WPAN, overhearing occurs when a wake-up receiver decodes and validates the address of a wake-up call which is not intended to it. However, such overhearing consumes a portion of the required reception energy for unintended nodes. To diminish overhearing thus conserve total reception energy in a network, we propose a bit-by-bit address decoding (BBAD) scheme and compare it with another addressing scheme for WuR that uses a micro-controller unit to decode and match the whole …
An analytical model of a new packet marking algorithm for TCP flows: Preliminary insights
2004
In differentiated services networks, packet marking schemes can be devised to differentiate packets belonging to a same TCP flow, with the goal of improving the experienced performance. This paper presents an analytical model for an adaptive packet marking scheme proposed in our previous work. The model combines three specific sub-models aimed at describing i) the TCP sources aggregate ii) the marker, and iii) the network status. Some preliminary simulative results seem to validate the model.
Performance Evaluation of a new Adaptive Packet Marking Scheme for TCP over DiffServ Networks
2004
In differentiated services (DiffServ) networks, packets may receive a different treatment according to their differentiated services code point (DSCP) label. As a consequence, packet marking schemes can be devised to differentiate packets belonging to the same TCP flow, with the goal of improving the experienced performance. The paper presents an extensive performance evaluation of a new adaptive packet marking scheme, applied to a traffic scenario composed of TCP flows with different lengths. The proposed marking scheme is most efficient when applied to a scenario composed of all long-lived flows. In a realistic mixed traffic scenario, composed of both long-lived and short-lived TCP flows,…