Stefanos A. Nikolidakis

Energy-Efficient Routing Protocols in Wireless Sensor Networks: A Survey

The distributed nature and dynamic topology of Wireless Sensor Networks (WSNs) introduces very special requirements in routing protocols that should be met. The most important feature of a routing protocol, in order to be efficient for WSNs, is the energy consumption and the extension of the networks lifetime. During the recent years, many energy efficient routing protocols have been proposed for WSNs. In this paper, energy efficient routing protocols are classified into four main schemes: Network Structure, Communication Model, Topology Based and Reliable Routing. The routing protocols belonging to the first category can be further classified as flat or hierarchical. The routing protocols belonging to the second category can be further classified as Query-based or Coherent and non-coherent-based or Negotiation-based. The routing protocols belonging to the third category can be further classified as Location-based or Mobile Agent-based. The routing protocols belonging to the fourth category can be further classified as QoS-based or Multipath-based. Then, an analytical survey on energy efficient routing protocols for WSNs is provided. In this paper, the classification initially proposed by Al-Karaki, is expanded, in order to enhance all the proposed papers since 2004 and to better describe which issues/operations in each protocol illustrate/enhance the energy-efficiency issues.

Energy Efficient Routing in Wireless Sensor Networks Through Balanced Clustering

The wide utilization of Wireless Sensor Networks (WSNs) is obstructed by the severely limited energy constraints of the individual sensor nodes. This is the reason why a large part of the research in WSNs focuses on the development of energy efficient routing protocols. In this paper, a new protocol called Equalized Cluster Head Election Routing Protocol (ECHERP), which pursues energy conservation through balanced clustering, is proposed. ECHERP models the network as a linear system and, using the Gaussian elimination algorithm, calculates the combinations of nodes that can be chosen as cluster heads in order to extend the network lifetime. The performance evaluation of ECHERP is carried out through simulation tests, which evince the effectiveness of this protocol in terms of network energy efficiency when compared against other well-known protocols.

Energy efficient automated control of irrigation in agriculture by using wireless sensor networks

We propose a model that calculates quantity of water needed for irrigation.The system efficiently manages water in cultivated fields in an automated way.The historical data and the change on the climate values are considered.The model uses a threshold for data collection to minimize the sensor energy. Many agricultural activities can be highly enhanced by using digital technologies. One of these activities is the regulation of the quantity of water in cultivated fields, a process which is directly interwoven with the sustainability and the productivity of crops, since insufficient or excessive irrigation may not only be obstructive, but also destructive. This paper proposes a scheme based on the collaboration of an integrated system for automated irrigation management with an advanced novel routing protocol for Wireless Sensor Networks (WSNs), named ECHERP (Equalized Cluster Head Election Routing Protocol). At its core, the proposed system aims at efficiently managing water supply in cultivated fields in an automated way. The system takes into consideration the historical data and the change on the climate values to calculate the quantity of water that is needed for irrigation. In case that the change on the collected values is above a threshold more frequent data collection is proposed to minimize the necessary quantity of water. On the other hand, in case that the change of the values is below a preset threshold then the time interval to collect data can increase to save sensor energy, leading to a prolonged sensor lifetime. The results show that network lifetime using ECHERP is improved up to 1825min and if a round is 110s the model provides energy efficiency using smaller water quantities.

An Analysis of Bluetooth, Zigbee and Bluetooth Low Energy and Their Use in WBANs

A rapid development of services and technologies in the field of health care has been witnessed in the last few years. In this paper we present an analysis and an extensive comparison of radio communication technologies, namely Zigbee, Bluetooth and Bluetooth Low Energy, that have been proposed as likely candidates to provide wireless connectivity between body sensors and the health care system and consequently to lead the development and extended deployment of Wireless Body Area Networks. After the description of their characteristics, we concentrate on the security that these technologies offer since security is extremely important for the sensitive health care clinical information communicated and the protection of patients’ clinical information privacy.

Energy-efficient routing protocols in wireless sensor networks for health communication systems

Wireless Sensor Networks (WSNs) have their own unique nature of distributed resources and dynamic topology. This introduces very special requirements that should be met by the proposed routing protocols for the WSNs. A Wireless Sensor Network routing protocol is a standard which controls the number of nodes that come to an agreement about the way to route packets between all the computing devices in mobile wireless networks. Today, wireless networks are becoming popular and many routing protocols have been proposed in the literature. Considering these protocols we made a survey on the WSNs energy-efficient routing techniques which are used for Health Care Communication Systems concerning especially the Flat Networks Protocols that have been developed in recent years. Then, as related work, we discuss each of the routing protocols belonging to this category and conclude with a comparison of them.

Spatio temporal emergency role based access control (STEM-RBAC): A time and location aware role based access control model with a break the glass mechanism

The ever-increasing use of information systems and networks in every aspect of our lives has made possible the transfer of data to a wide range of different users and applications. In recent years, several architectures and models have been proposed in order to limit access to resources and ensure that data are available only to authorized users, programs or processes. These models in most cases are not dynamic and the permissions assigned to users are granted based on a static policy. A mechanism that will allow exception access to data, for example to medical information, in case of an emergency is needed. In current systems, emergency access techniques are not well defined and are used in an ad hoc manner on top of the access control mechanisms implemented without using parameters such as time, location or hierarchy of the actors involved in the system. In this paper, we present a model that provides both a normal access control based on roles and also a mechanism that is used in order to provide exception access to data in case of an emergency. The proposed emergency access mechanism is time aware and takes into account the mobility and location of users, also it grants exception access with a controlled manner in case of an emergency utilizing role hierarchies.

Towards utilizing Tcpcrypt in mobile healthcare applications

The evolution and growth of networks has made the personal data of the users available to many applications. In this direction, one of the main concerns is to protect the sensitive personal information, while at the same time avoid delays in the provision of services like healthcare to the general public. An extension of TCP, the Tcpcrypt, is a promising technology that can be used on this field. Tcpcrypt is designed to provide end-to-end encryption in the transport layer with low overhead, rendering it a very promising solution in order to protect medical data that are often handled by devices with limited resources. In this paper Tcpcrypt performance is evaluated against TCP, in terms of additional overhead incurred in the total size of the transmitted data and the total number of CPU instructions that are executed. Moreover, a solution for reducing overhead through fine-grained packet handling is proposed.

An Automated System for Integrated Service Management in Emergency Situations

The integration of Wireless Communications and Computer Science can lead to the development of advanced systems and services. This paper presents the development of an automated management system for road traffic control in emergency situations. This system consists of a Wireless Sensor Network (WSN) and a centralized control system. The performance evaluation of the system is accomplished through various scenarios of use.