Performance evaluation of different transport layer protocols on the IEEE 802.11 and IEEE 802.15.4 MAC/PHY layers for WSN

Wireless Sensor Networks (WSN) has gathered lot of attention from the research community lately. Among other WSN communication protocols, transport layer protocol plays a significant role in maintaining the node?s energy budget. In this context we have carried out extensive testing of various transport protocols using IEEE 802.11, IEEE 802.15.4 MAC/PHY protocol and Ad hoc On-Demand Distance Vector Routing (AODV) routing agent for WSN having multi-hop ad-hoc and WPAN network topology. The main contribution of this paper is to find out the dependency of Transport layer on MAC layer. Simulation results indicate that the underlying MAC/PHY layer protocol along with Transport layer protocol plays a vital role in achieving the high throughput, low latency and packet loss rate in WSN. For IEEE 802.11 with RTS/CTS ON high throughput, low packet drop rate and increased end-to-end packet delay is observed. While for IEEE 802.15.4 similar behavior as for IEEE 802.11 (except for UDP) but with improved power efficiency is observed. This has led the foundation for the future development of the proposed cross layered energy efficient transport protocol for multimedia application

CR-MAC: A multichannel MAC protocol for cognitive radio ad hoc networks

This paper proposes a cross-layer based cognitive radio multichannel medium access control (MAC) protocol with TDMA, which integrate the spectrum sensing at physical (PHY) layer and the packet scheduling at MAC layer, for the ad hoc wireless networks. The IEEE 802.11 standard allows for the use of multiple channels available at the PHY layer, but its MAC protocol is designed only for a single channel. A single channel MAC protocol does not work well in a multichannel environment, because of the multichannel hidden terminal problem. Our proposed protocol enables secondary users (SUs) to utilize multiple channels by switching channels dynamically, thus increasing network throughput. In our proposed protocol, each SU is equipped with only one spectrum agile transceiver, but solves the multichannel hidden terminal problem using temporal synchronization. The proposed cognitive radio MAC (CR-MAC) protocol allows SUs to identify and use the unused frequency spectrum in a way that constrains the level of interference to the primary users (PUs). Our scheme improves network throughput significantly, especially when the network is highly congested. The simulation results show that our proposed CR-MAC protocol successfully exploits multiple channels and significantly improves network performance by using the licensed spectrum band opportunistically and protects PUs from interference, even in hidden terminal situations.Comment: 14 Pages, International Journa

Rf Interference Minimisation in Bio-Applications using Cr-Ad Hoc Network

The E-health applications uses wireless technology to transmit and receive vital information. However, Firstly there are certain associated risks like, electromagnetic interference exposure to bio-medical devices by wireless devices could critically affect their performance and secondly since different types of e-health applications have different priorities. So access to the wireless channel by the corresponding devices needs to be prioritized. In this paper a novel cognitive-radio-based approach to address these challenges in wireless communications for e-health applications in a hospital environment, is introduced. It protects the medical devices from harmful interference by adapting the cross-layer based cognitive radio multichannel medium access control (MAC) protocol with TDMA, which integrate the spectrum sensing at physical (PHY) layer and the packet scheduling at MAC layer, for the ad hoc wireless networks. Such kind of a protocol enables secondary users (SUs) to utilize multiple channels by switching channels dynamically, thus increasing network throughput. The proposed cognitive radio MAC (CR-MAC) protocol allows SUs to identify and use the unused frequency spectrum in a way that constrains the level of interference to the primary users (PUs)

Cross Layer Aware Adaptive MAC based on Knowledge Based Reasoning for Cognitive Radio Computer Networks

In this paper we are proposing a new concept in MAC layer protocol design for Cognitive radio by combining information held by physical layer and MAC layer with analytical engine based on knowledge based reasoning approach. In the proposed system a cross layer information regarding signal to interference and noise ratio (SINR) and received power are analyzed with help of knowledge based reasoning system to determine minimum power to transmit and size of contention window, to minimize backoff, collision, save power and drop packets. The performance analysis of the proposed protocol indicates improvement in power saving, lowering backoff and significant decrease in number of drop packets. The simulation environment was implement using OMNET++ discrete simulation tool with Mobilty framework and MiXiM simulation library.Comment: 8 page

Adaptive link-weight routing protocol using cross-layer communication for MANET

Routing efficiency is one of the challenges offered by Mobile Ad-hoc Networks (MANETs). This paper proposes a novel routing technique called Adaptive Link-Weight (ALW) routing protocol. ALW adaptively selects an optimum route on the basis of available bandwidth, low delay and long route lifetime. The technique adapts a cross-layer framework where the ALW is integrated with application and physical layer. The proposed design allows applications to convey preferences to the ALW protocol to override the default path selection mechanism. The results confirm improvement over AODV in terms of network load, route discovery time and link reliability

A Cross-Layer Design Based on Geographic Information for Cooperative Wireless Networks

Most of geographic routing approaches in wireless ad hoc and sensor networks do not take into consideration the medium access control (MAC) and physical layers when designing a routing protocol. In this paper, we focus on a cross-layer framework design that exploits the synergies between network, MAC, and physical layers. In the proposed CoopGeo, we use a beaconless forwarding scheme where the next hop is selected through a contention process based on the geographic position of nodes. We optimize this Network-MAC layer interaction using a cooperative relaying technique with a relay selection scheme also based on geographic information in order to improve the system performance in terms of reliability.Comment: in 2010 IEEE 71st Vehicular Technology Conference, 201

Dynamic Queue Utilization Based MAC for multi-hop Ad Hoc networks

The end-to-end throughput in single flow multi-hop Ad Hoc networks decays rapidly with path length. Along the path, the success rate of delivering packets towards the destination decreases due to higher contention, interference, limited buffer size and limited shared bandwidth constraints. In such environments the queues fill up faster in nodes closer to the source than in the nodes nearer the destination. In order to reduce buffer overflow and improve throughput for a saturated network, this paper introduces a new MAC protocol named Dynamic Queue Utilization Based Medium Access Control (DQUB-MAC). The protocol aims to prioritise access to the channel for queues with higher utilization and helps in achieving higher throughput by rapidly draining packets towards the destination. The proposed MAC enhances the performance of an end-to-end data flow by up to 30% for a six hop transmission in a chain topology and is demonstrated to remain competitive for other network topologies and for a variety of packet sizes