Search results for "NETWORKS"
showing 10 items of 3260 documents
Web Tool for Path Analysis in Wireless Sensor Networks to Improve Their Performance
2018
Wireless Sensor Networks (WSNs) are based on tiny autonomous devices, usually named motes or nodes, and are used in many monitoring applications, such as environment, habitat, precision horticulture, etc. These motes are power-limited and most energy is wasted through the communication process when exchanging data packets. Because these motes are quite simple, with low power transmission and simple antennas, these networks usually run multihop routing protocols in order to forward packets between one mote to the sink, or the collector node, using the other motes as relaying motes. Basically, these routing protocols try to find out new routes within these wireless network, optimizing differe…
A mini-slot-based cooperative MAC protocol for wireless mesh networks
2010
This paper proposes a TDMA-based medium access control protocol with cooperative communications enabled in wireless mesh networks. The proposed scheme is based on a multi-hop scenario which is extended from the conventional one-hop triangle cooperative transmission scenario. Benefiting from the elaborate mini-slot design, channel resources are fairly and efficiently allocated to each router so that no handshake is needed prior to every packet transmission. By giving priority for channel access to cooperative transmission performed by an optimal helper which is determined based on the received SNR, higher successful transmission rate can be achieved. Numerical results demonstrate that the pr…
Reliable Data Gathering in Tree-Based IEEE 802.15.4 Wireless Sensor Networks
2007
This paper describes a routing protocol for enhanced robustness in IEEE 802.15.4-based sensor networks, which also addresses typical MAC layer issues, including power management, synchronization and link reliability. The algorithm uses a single-path strategy in error-free scenarios and resorts to using alternative paths when communication errors are detected. Our proposal exploits implicit acknowledgement of reception, a feature which may be provided by data aggregation when a broadcast medium such as the wireless channel is used. Therefore MAC layer acknowledgements are not used and errors recovery relies on a caching and retransmission strategy. The protocol requires synchronization among…
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…
Broadband Internet Access via Multi-Hop Wireless Mesh Networks: Design, Protocol and Experiments
2010
Published version of an article from the journal: Wireless Personal Communications. The original publication is available at Spingerlink. http://dx.doi.org/10.1007/s11277-009-9907-9 While bandwidth for Internet access in urban areas is steadily increasing in recent years, many rural areas are still suffering from the effect of the digital divide. This paper presents a broadband Internet access paradigm developed in the context of the ADHOCSYS project, which was financed by the European Commission under the 6th Framework Program Information and Society Technologies, within the strategic objective of Broadband for All. Aiming at providing reliable Internet access in rural and mountainous regi…