A Context Gathering Framework for Context-Aware Mobile Solutions

One of the fundamental design issues in context-aware mobile services development is the necessary support for adequately powerful yet efficient querying of the sensory data. This issue argues for research into the creation of a technology-independent, high-level software application programming interface (API) that provides mechanisms for dealing with the heterogeneity of sensors providing raw context data. In this paper, we review approaches in existing context-aware platforms especially those that consider with sensory data acquisition. The review formed the basis for the design and development of the context gathering framework which consists of sensor data model, messaging and communication protocol and software application programming interface. These components form as one of the enabler to support the development of context aware mobile applications

Performance Evaluation of Reactive Routing Protocols for IEEE 802.11

The progress of communication technology has made wireless devices smaller, less expensive and more powerful. This has initiated everyone to use various wireless network technologies such as 3G, 4G of cellular network, Ad-Hoc, IEEE 802.11 based Wireless Local Area Network (WLAN) and Bluetooth. The performance of the routing protocols AODV, DSR and LAR are compared using Qualnet 5.0.2.Network Simulator with the metrics like average jitter, throughput, end-to-end delay, total number of bytes received and packet delivery ratio successfully routed to their destination

Performance Evaluation of Connection Admission Control for IEEE 802.16 Networks

Quality of Service (QoS) provisioning to the various kinds of network traffic is one of the major design criteria of IEEE 802.16 WiMAX standard. The MAC and physical layers of 802.16 standards are designed to support different types of real time application by providing QoS. Scheduling, Connection Admission Control (CAC) and traffic policing are the major issues to ensure QoS. In standard, scheduling and admission control are kept as open issues. Admission control is the ability of a network to control admission of new traffic based on the availability of resources. As per the specification the CAC considers minimum reserved rate of a connection as an admission criterion, in which the system can admit more connections, but packets of admitted connection may encounter large delays. In this paper average data rate (avg-rate CAC) and maximum sustained rate (max-rate CAC) of the connections are considered as admission criteria in CAC, along with minimum reserved rate (min-rate CAC). The performance of the WiMAX network is evaluated and compared for min-rate, avg-rate and max-rate CAC by considering the performance metrics such as number of connections admitted, throughput and delay using QualNet simulation tool

Effect of integrated nutrient supply on yield and uptake of cardamom (Elettaria cardamomum L. Maton.)

Field experiments were conducted for seven years (2000 to 2007) to assess the effect of integrated nutrient supply with Azospirillum and the combination of Azospirillum, FYM and graded levels of nitrogen on yield and uptake of cardamom. Results revealed that application of FYM @ 5 or 10 kg/plant with or without Azospirillum did not influence the yield components as well as yield levels appreciably. Application of FYM @ 5kg/ plant + 75 % recommended N + Azospirillum yielded 163.53 kg/ha similar to that of FYM @ 5 kg / plant + 100 % recommended N (175.42 kg/ha) and FYM @ 5 kg / plant + 50 % recommended N + Azospirillum yielded 141.20 kg/ha similar to that of FYM @ 5 kg / plant + 75 % recommended N (146.34 kg/ha), thereby providing 25 % saving in inorganic nitrogen. Further, FYM @ 5 kg / plant + 100% recommended N + Azospirillum, responded with 186.48 kg/ha but found on par to FYM @ 5 kg/ plant + 100 % recommended N (175.42 kg/ha). Integrated nutrient management treatments recorded higher nitrogen in plants compared to pure organic treatments. Influence of Azospirillum is not that conspicuous on nitrogen uptake by plants

Development of a Multimedia Courseware as a Teaching Aid for Children with Dyslexia

Dyslexia is a language based learning disability resulting in people experiencing difficulties in reading, spelling, writing and speaking. These problems are sometimes compounded by short term memory difficulties, a lack of organisational skills and time management issues which all have an impact on learning. This paper focuses on the planning, analysis and design of an e-learning courseware to teach dyslexics to read using the ‘picture thinking’ model. The development of this e-learning courseware involves transforming the traditional content of printed books from passive prints and illustrations into interactive multimedia content. The interactive multimedia content will focus on clear presentation of materials, good navigational assistance and a variety of multimedia options to tap into visual, auditory and kinaesthetic skills to support dyslexics. The targeted users will be children with dyslexia and pre-schoolers aged 5 to 7 learning to read Bahasa Melayu. A successful implementation of this courseware will be useful to the dyslexic learners as it will use picture thinking model and multisensory approach to the best of their ability instead of approaching them with the same teaching approaches used to teach their non- dyslexic counterparts

Establishing a Wireless Sensor Network to Monitor the Temperature in a two storied building

The advancement in information technology and the need for large-scale communication infrastructure has triggered the era of Wireless Sensor Networks (WSNs). Sensor network is a collection of sensor nodes connected wirelessly to one another to gather information about the surrounding environment. In this paper a WSN testbed is established using Texas instruments sensor nodes to monitor the temperature in a two storied building

Wireless Sensor Networks: A Performance Study of IEEE 802.15.4 Standard

Wireless Sensor Networks (WSN) play a key role in sensing, computing and communicating the information in most of the fields bringing substantial improvements in a broad spectrum of modern technologies. Data to be routed from source to destination is very difficult in WSN due to the mobility of the network elements and lack of central administration. In this paper an attempt has been made to evaluate the performance of routing protocol Ad-hoc On-demand Distance Vector routing (AODV) for the wireless sensor nodes(IEEE 802.15.4 standard). The performance of routing protocol is analysed using various metrics like total packets received, throughput, average end-to-end delay, total bytes received and average jitter using Qualnet 5.0.2 simulator

A Performance Study of Proactive, Reactive and Hybrid Routing Protocols using Qualnet Simulator

The advancement in information technology and the need for large-scale communication infrastructures has triggered the era of Wireless Sensor Networks (WSNs). Mobile ad-hoc network (MANET) is a network of wireless mobile nodes which communicate with each other without any centralized control or established infrastructure. Routing is the process of selecting paths in a network along which data is to be sent. Routing is a critical task in MANET where the nodes are mobile. Dynamic and reliable routing protocols are required in the ad-hoc wireless networks, as they have no infrastructure (base station) and their network topology changes. There are various protocols for handling the routing problem in the ad-hoc wireless network environment. In this paper focus is given on studying the performance evaluation of various routing protocols using Qualnet simulator 5.0.2. The performance of the proactive, reactive and hybrid protocols are analyzed with different node densities for mobile and stationary nodes. The metrics used for the performance evaluation include average jitter, throughput, packet delivery ratio and average end to end delay

Performance Study of Bandwidth Request Mechanisms in IEEE 802.16e Networks

WiMAX (Worldwide Interoperability for Microwave Access) is the IEEE 802.16 standards-based wireless technology that provides fixed and mobile Internet access for Metropolitan Area Networks (MAN). The IEEE 802.16 std. includes medium access control (MAC) and physical (PHY) layer pecifications and is consider to be a promising technology. Bandwidth reservation is employed to provide quality of service (QoS) to guarantee different services specified in the standard. A bandwidth request/grant scheme is defined in the IEEE 802.16 standard. There are two types of bandwidth request (BR) mechanisms, i.e., polling and contention resolution, which are defined in the standard. As specified, connections belonging to scheduling classes of extended real-time polling service, non-real-time polling service, and best effort have options to make BRs via both mechanisms, depending on the scheduling decision made by the base station (BS). This paper attempts the comparative study of BR mechanisms for different service classes defined in the standard

Simulation and Emulation Approach for the Performance Evaluation of Adaptive Modulation and Coding Scheme in Mobile WiMAX Network

WiMAX is the IEEE 802.16e standard-based wireless technology, provides Broadband Wireless Access (BWA) for Metropolitan Area Networks (MAN). Being the wireless channels are precious and limited, adapting the appropriate modulation and coding scheme (MCS) for the state of the radio channel leads to an optimal average data rate. The standard supports adaptive modulation and coding (AMC) on the basis of signal to interference noise ratio (SINR) condition of the radio link. This paper made an attempt to study the performance of AMC scheme in Mobile WiMAX network using simulation and emulation methods. Different MCS are adopted by mobile subscriber station (MSS) on the basis of the detected instantaneous SINR. Simulation results demonstrate the impact of modulation and coding scheme on the performance of the system and emulation results defend the simulation results