Adaptive Channel Coding and Modulation Scheme Selection for Achieving High Throughput in Wireless Networks

Modern wireless communication demands reliable data communication at high throughput in severe channel conditions like narrowband interference, frequency selective fading due to multipath and attenuation of high frequencies. Traditional single carrier systems address this set of problems by the use of complex, computationally intensive equalization filters. The Orthogonal Frequency Division Multiplexing (OFDM) based system, as opposed to single-carrier systems, is considered to be the future of the wireless communication and is being used to achieve high data rate by overcoming severe channel conditions without the use of these complex filters.This paper discusses the problem of Adaptive Modulation scheme selection through an OFDM based system over parallel frequency selective fading channels. An adaptive coding scheme is proposed by using Generalized Concatenated Codes (GCC), which have simple structure and are designed in such a way that they are best suited for fading channels. GCC are based on binary cyclic codes. The criterion of the proposed research is to optimize the throughput of a wireless system. Depending on the quality of sub-channels an adaptive modulation selection scheme and code assigning method is proposed. The proposed research combats against channel impairments better than those used in conventional systems by exploiting individual sub-channel condition. Results show better performance in terms of higher throughput by minimizing the bit error rate

LCART: A Cross-layered Transport Protocol for Heterogeneous WSN

Lightweight Congestion Aware Reliable Transport protocol (LCART) is based on cross-layering the prevalent or reciprocal functionalities of Transport, MAC and Wireless-Physical layers in order to achieve energy efficiency and meeting QoS objectives of heterogeneous WSN1 including multimedia. LCART intelligently overcomes network congestion by the simultaneous use of Packet Service Time, Packet Inter Arrival Time, Buffer Occupancy Level and Channel Loading threshold limits and ensures packet level reliability by the use of β parameter entirely being dictated by the nature of traffic flow. LCART has been evaluated against TCP-Westwood+ (TCP-WW+), TCPWestwood (TCP-WW), TCPNewReno and TCPReno for 24 mote ad-hoc topology. The results reveal that LCART outperforms others by exhibiting highest good throughput of 0.3112 Mbps, average End to-End (E-2-E) packet latency of <; 80 msec for multimedia and <; 130 msec for scalar information, 1.014% average percentage packet drop and overall exhibits energy efficient behavior

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

Wireless multimedia sensor network technology: a survey

Wireless Multimedia Sensor Networks (WMSNs) is comprised of small embedded video motes capable of extracting the surrounding environmental information, locally processing it and then wirelessly transmitting it to parent node or sink. It is comprised of video sensor, digital signal processing unit and digital radio interface. In this paper we have surveyed existing WMSN hardware and communicationprotocol layer technologies for achieving or fulfilling the objectives of WMSN. We have also listed the various technical challenges posed by this technology while discussing the communication protocol layer technologies. Sensor networking capabilities are urgently required for some of our most important scientific and societal problems like understanding the international carbon budget, monitoring water resources, monitoring vehicle emissions and safeguarding public health. This is a daunting research challenge requiring distributed sensor systems operating in complex environments while providing assurance of reliable and accurate sensing

Prioritizing Information for Achieving QoS Control in WSN

Achieving QoS objective in Wireless Sensor Network (WSN) that deals with multimedia information is of paramount importance in the WSN research community. From the application point of view, meeting application specific QoS constraints is equally important as designing energy efficient embedded circuitry for WSN nodes. Among various WSN communication protocol stack, the transport layer functionality has gain fundamental fame lately in addressing the application specific QoS objectives by supporting Source prioritization besides the reliability and congestion control aspects of the design that helps in gaining high throughput with minimum end-to-end packet latency. This paper present the design of a new transport layer protocol that prioritizes sensed information based on its nature while simultaneously supporting the data reliability and congestion control features.The proposed transport protocol is tested in three possible scenarios i.e. with priority, without and distributed priority features. Simulation results reveal that by prioritizing the Source information and prioritized intermediate storage and forwarding reduces the End-to-End (E-2-E) latency of Source packets having 400 msec which is quite significant. Simulation test has been performed for distributed prioritized intermediate storage and forwarding among which the network distribution with node K as prioritized intermediate storage node (DIST-K) outperformed all of the mentioned cases by having 100% achieved Source priority,0% packet drop rate and 0.28 Mbps achieved bit rate

LCART: Lightweight Congestion Aware Reliable Transport Protocol for WSN Targeting Heterogeneous Traffic

This paper presents energy ecient transport layer protocol for heterogeneous WSN, named as LCART. LCART fuses the prevalent or reciprocal functionalities of Transport, MAC and Wireless-Physical layers in order to achieve energy eciency and meeting QoS objectives of heterogeneous WSN. LCART intelligently provide congestion control by the simultaneous use of Packet Service Time (TPST), Packet Inter Arrival Time (TPIAT), Buer Occupancy Level (mi) and Channel Loading Threshold limits (Threshold) constraints to formalize new source rate plan for avoiding congestion. LCART achieves packet level reliability by using explicit NACK and parameter entirely being governed by the nature of the trac. LCART has been tested for 24 mote ad-hoctopology and results reveal that it exhibit highest good throughput of 0.3112 Mbps, < 80msec and < 130 msec average End-to-End (E-2-E) packet latency for high and low prioritized packet information, 1.014% average percentage packet drop and overall exhibits energy ecient behavior (lowest per packet communication cost) in comparison to TCP-Westwood+ (TCP-WW+), TCPWestwood (TCP-WW), TCPNewReno and TCPReno

Priority Enabled Transport Layer Protocol for Wireless Sensor Network

Achieving Quality of Service (QoS) objective in Wireless Sensor Network (WSN) handling the multimedia information has significantly gained the importance lately besides energy efficient hardware designing. Transport layer of the WSN communication protocol stack plays a significant role in meeting the QoS objective of WSN. This paper presents a light weight transport protocol for WSN that can handle packets from a numbers of sources having different sensed information and having different priority levels. The protocol assigned middle motes are intelligent enough to achieve prioritization in transmission based on the priority level and packet's Time-To-Live (TTL) information. Extensive simulation is carried out for the three different modes of the envisaged protocol having no prioritized enabled storage, complete prioritized enabled storage and distributed prioritized enabled storage. The results reveal that the significant improvement is observed in case of distributed prioritized enabled storage, approximately 3% data loss occurred, in comparison to 7% data loss for without prioritized enabled storage mode

Applications of wireless sensor networks in pharmaceutical industry

Advances in wireless sensor networking have opened up new opportunities in healthcare systems. The future will see the integration of the abundance of existing specialized medical technology with pervasive, wireless networks. Radio frequency identification (RFID) and Wireless Sensor Network (WSN) are the two key elements of Pervasive computing and are considered as interrelated technologies. Although RFID has been used in various areas but it lacks intelligence that is its ability to process information and respond to real world events. People are using large scale WSN to monitor real-time environment status. RFID technology, if combined with other sensors, may enable a range of other applications that can exponentially increase visibility and monitoring. Combined with RFID a general sensor can be upgraded to intelligent wireless sensor (Smart node), having sensing, computation, communication into a single small device Field Programmable Gate Arrays (FPGA) With dazzling wireless technology now available, it's tempting for manufacturers to snatch up any wireless sensor that comes along as a means of optimizing processes and plant performance. This is especially true within the pharmaceutical industry, where vendors are plying industrial-strength wireless sensors for temperature, humidity and pressure, as well as sensitive process-monitoring wireless devices to support PAT applications. In this paper we surveyed the existing wireless sensor and RFID based technologies that target the healthcare application