The reducing of energy consumption for various nodes in wireless sensor networks
plays an important and essential role in the prolonging of the life of these networks. In
order not to be the energy consumption in some node is very high and in other
s is less or
very low, the choice of distribution algorithms of the nodes role, as a router node or
terminal nodes, and switching between them, plays an important role in prolonging the
lifetime of wireless sensor networks.
This paper presents an algorithm for the distribution of WSN nodes roles, including
allowing the applying of many tree patterns to a single network. This offers the potential to
alter the network nodes roles centrally by coordinator and switching between these tree
patterns whenever the need arises according to the indicators of energy consumption in the
nodes. The results show that the use of the algorithm leads to a significant improvement in
the network life ranges between 2 and 4 times, according to the allowing the nodes to sleep
and wakeup, or not, for different transmission rates where the scenarios have been tested
for ZigBee based wireless sensors networks using NS-2 simulator.
The use of wireless sensor networks to monitor and control the precise agriculture is one of the areas which received broad concern in recent times, for the services, facilities and the reliability provided by these networks on the monitoring and con
trol level.
This research contributes to the study of the application of this technique in greenhouses deployed over large areas in our country. It offers solutions for networks of monitoring and control, in real time, and ensures a good performance according to the essential evaluating criteria, such as reducing the time-delay, and increases throughput, increases the delivery ratio of packets, and reduces the number of packets lost along with increased network load.
In order to do that, a number of scenarios are proposed. These scenarios are similar to the reality of the construction and operation of the greenhouses in our region relying on ZigBee technique. Wireless sensors networks of these scenarios have been tested, using simulation in order to make conclusion and recommendations to guide the work while installing such networks in place to work as their best for different areas and a large number of lounges
The spread of the modern data transfer techniques, in modern industrial and agricultural applications, and service areas, leads to the need to transfer this data effectively and flexibly, within installations parts.
This research aims to apply the h
ybrid mechanism, based on the use of ZigBee technology, and CAN Bus together to ensure the best performance, in accordance with the performance indicators required by the networks of these facilities, in near-real time operation. The study attempts to compare this mechanism with other mechanisms proposed in similar research.
The proposed solution supports the use of a hybrid data transfer networks, based on the internetworking of CAN Bus networks, using a backbone based on wireless ZigBee technology. This solution proposes an appropriate structure for gateways between the hybrid parts of the network. The research has concluded that the proposed mechanism preference, compared with the proposed mechanisms in similar research, according to the standards of performance indicators, is suitable for this kind of networks, as it allows us to recommend the use of this mechanism in the service and industrial applications. The NS2 network simulator is used to evaluate and compare the obtained results.
The wireless sensors network applications are widely used in health monitoring systems. In fact, they contribute to the qualitative development of these networks so as to ensure the tireless clock surveillance, and improve and regulate the quality of
monitoring. Associated with improving the performance of wireless medical sensor networks WMSN is improving data transfer mechanism which is one of the most important areas of interest to research and study in recent times.
Hence the importance of this research lies in the study of the structures of wireless sensor networks that can be used to control the wards in hospitals, health centers and monitoring care. The research also draws necessary recommendations and suggestions for the selection of appropriate medical wireless sensors networks structure and proposees appropriate medium access control mechanism in order to build networks of different sizes.
This has been done by proposing appropriate scenarios for surveillance applications to perform simulation that is similar to the working conditions of the networks. This can ensure the transfer of nodes data to the main access point and can give an opportunity to study the impact of network architecture and how to use the data transfer technology, specifically the use of ZigBee technology, both with beacon mode enabled inenabled. Improvement was evaluated based on the basic parameters in such networks, such as throughput, the time delay, and the delivery ratio. The study found a set of recommendations regarding the size of the network, the type of structure and the mechanism used to access medium.
The tracking using wireless sensor networks is one of the applications that are
experiencing significant growth. Due to considerations of wireless sensor networks in
terms of limited energy source, researches continue to improve methods of routing
and
transforming information to ensure lower power. Therefore, we have in this research
improved the routing of target location information within WSN by providing a new
algorithm, which takes advantage of the concept of clustering for wireless network sensors,
with the addition of the possibility of interaction between field sensors that belong to
different clusters, where in other cases, they cannot interact with each other in the
traditional case of cluster networks. to get rid of repeating the same information transfer,
we depend on the parameter intensity of the received signal from the target in the sensors,
which will reflect positively on the network age, and give a more accurate indication of the
target site. We have implemented the proposed algorithm and showed the results of using
the simulator OPNET which is one of the best simulators in the field of various types of
networks.
Routing protocols play an essential role in meeting the quality of service
requirements in the network, but achieving these requirements may require frequent send
and receive operations to build and maintain routing tables, which consume sensors
r
esource If we take into consideration the limitations of wireless sensor networks in terms
of the amount of available energy and storage capacity.
In this research a performance comparison of the on-demand Distance Vector
Routing protocol AODV and Hierarchical Routing protocolHR was carried out in terms of
the packet delivery and loose rate, delay and jitter, and the amount of expended energy in
the Wireless sensor network operates according to IEEE802.15.4 standard in cases where
some of sensors get out of work for limited periods of time.
The results showed that the hierarchical routing protocols perform better in terms of
delay time and transfer rate and the amount of consumed energy than on-demand Distance
Vector Routing protocol routing protocol, but suffer larger packet loss due to routing path
corruption as a result of sensors crashes.
Many wireless sensor network applications like forest fire detection and environment
monitoring recommend making benefit from moving humans, vehicles, or animals to
enhance network performance. In this research, we had improved our previous protoco
l
(Dynamic Tree Routing DTR) in order to support mobility in a wireless sensor network.
First, we had mathematically approximated the speed threshold for mobile sensors, which
enables them to successfully associate with nearby coordinators. Second, we test our
(MDTR) protocol in a network with mobile sensors sending packets toward network's
main coordinator. The simulation results obtained from network Simulator (NS2) showed a
good approximation of speed threshold, and good performance of MDTR in term of delay,
throughput, and hop-count compared with AODV and MZBR Protocols.
The aim of this study is to measure the quality of the service provided by the Syrian
Telecommunications Company from customers’ point of view. Tishreen Telephone
Exchange in Lattakia was examined using the SERVQUAL standard which is modified by
a
dding two dimensions; network quality and communication.
The study shows the process of measuring the quality of provided fixed telephone services
in terms of difference between what customers expect and what they actually receive. The
data was collected using a questionnaire designed by Parasuraman and others. 200
questionnaires were randomly distributed to the company's customers.
The results of the study indicate that there is a gap in all dimensions (Tangibility,
reliability, responsiveness, assurance, empathy, network quality and communication) and
that customers' expectations exceed what the company actually provide. The study
concluded with some recommendations including the necessity of improving the quality of
service, training the staff and adopting quality as a basic standard for work.
The great development of mobile wireless sensor networks has many very important
applications. One of the most important applications that has attracted scientists' attention
recently is to track animals in their homes to follow the behavior and li
ves of some
endangered animals, but monitoring animals activities in the forest is a very difficult task,
especially if the animals to be monitored are teeny, therefore we cannot use the traditional
tracking systems ) like GPS, As well as the harsh and dangerous nature of the forest make
the use of wireless sensor networks the best solution, especially that sensors are low-cost,
small size, which made them suitable for such tasks, in this research we will study new
way to track a group of partridge where sensors are placed on these birds to observe their
life and behavior ,The important challenge in this research is to know the location of these
mobile birds to be able to the help them in appropriate time , so will introduce a new
method that provides us with acceptable accuracy, a simple, easy, inexpensive and low
energy consumption compared with other methods of animals tracking ,based on a set of
predefined reference nodes, where sensors information is sent to a gathering center
through these reference nodes ,then Analyze it and use it to the approximate location of
the animals. We will evaluate this method using Network Simulator (NS2).
Localization is an essential process in many wireless sensors networks applications like environmental surveillance and forest fires detection, where sensors are usually randomly thrown in difficult to reach places, considering the limited wireless s
ensors capability in terms of energy availability and the capacity of computations a low cost and energy conservation algorithms are needed to determine the approximate position of the sensors. In this research a new algorithm was proposed ‘Address Vector Multi-Hop (AV_MH)’ to determine the position of the randomly deployed sensors, this algorithm is based on the idea of making benefit from short address assignment in networks that support hierarchical addressing, considering that the most important techniques used in the field of sensor networks such as ZigBee and 6LowPAN which depend on the IEEE802.15.4 standard support this type of addressing.
The results showed the possibility of obtaining an approximate position of the wireless sensors in a rapid and inexpensive and cost-effective way in terms of the number of sent messages and required calculations.
