Mona Ghassemian

Bio: Mona Ghassemian is an academic researcher from Shahid Beheshti University. The author has contributed to research in topics: Wireless ad hoc network & The Internet. The author has an hindex of 12, co-authored 52 publications receiving 438 citations. Previous affiliations of Mona Ghassemian include BT Group & University of Greenwich.

Performance analysis of Internet gateway discovery protocols in ad hoc networks

Abstract: When an ad hoc network is connected to the Internet, it is important for the mobile nodes to detect the available gateways providing access to the Internet. Therefore, a gateway discovery mechanism is required. The two main approaches for discovering Internet gateways are the reactive and the proactive one. This paper compares the performance of these approaches in various scenarios by means of simulation. We show that the proactive approach performs better in the simulated scenario.

QoS enabled routing in mobile ad hoc networks

Abstract: The aim of this work is to present a QoS enabled routing protocol in ad hoc networks and compare it with a normal routing protocol. Results demonstrate how a QoS enable routing mechanism makes the resource consumption more efficient by minimising the unnecessary signalling and stopping the sessions that cannot meet the demanded QoS requirement. The performance of both routing and QoS routing protocols are evaluated in the presence of information achieved from the link layer. The QoS enabled routing protocol shows a significant improvement in the protocol performance metrics applied in our measurements, such as packet delay and protocol overhead. The results achieved from this experiment lead us to analyse our proposed mechanism to add link layer information in control routing messages. Measuring wireless resources, such as bandwidth, with the help of periodic signalling packets makes both the routing and the QoS routing protocols react slower to wireless link changes. This problem can be overcome by more frequent advertisements.

An Adaptive Algorithm to Improve Energy Efficiency in Wearable Activity Recognition Systems

Abstract: Activity recognition systems are used in rehabilitation centres to monitor activity of daily living in order to assess daily functional status of elderly. A low-cost, non-invasive, and continuous wearable activity monitoring system can be realized by one or multiple wearable sensor nodes to form a self-managing wireless medical body area network. There are several arising challenges essential to be dealt within developing wearable activity recognition systems, namely sensor node lifetime and detection accuracy. This paper investigates existing solutions, which address the key opposing challenges. We propose a feedback controller algorithm to dynamically adapt sampling rate for maintaining the tradeoff between the energy efficiency and accuracy. The Number of samples and transmitted data packets is the main sources of energy consumption that impacts the system accuracy. To validate the accuracy of our proposed algorithm, a public wearable activity recognition data set is constructed. The data set is collected from 20 healthy subjects over 7 activity types excluding the transition states, using up to four accelerometer sensors connected with IEEE 802.15.4 enabled nodes in our setup. Our proposed feedback controller algorithm nearly doubles the activity recognition system lifetime. This, in turn improves the users’ quality of experience by reducing the demand for battery replacements while the accuracy of detection is maintained at the same level.

Smart plugs for building energy management systems

Abstract: Due to rising value of energy supplies, the need for managing electrical energy sources becomes prominent. In this paper, a smart plug device is presented; which provides features to measure energy consumption and recognizes the type of attached electrical devices. Furthermore, the proposed framework enables home controller systems to monitor and control home energy consumption efficiently. Subsequently an analysis of energy consumption of a pilot house, prior and after the installation of the smart plug, based on a hypothetical scenario, is provided. The results present positive impacts of using the smart plug on energy consumption rate; especially during peak hours.

A Low Power Cryptography Solution Based on Chaos Theory in Wireless Sensor Nodes

Abstract: Unobtrusive personal data collection by wearable sensors and ambient monitoring has increased concerns about user privacy. Applying cryptography solutions to resource constraint wireless sensors as one of the privacy-preserving solutions demand addressing limited memory and energy resources. In this paper, we set up testbed experiments to evaluate the existing cryptographic algorithms for sensors, such as Skipjack and RC5, which are less secure compared to block cipher based on chaotic (BCC) on existing IEEE802.15.4 based SunSPOT sensors. We have proposed modified BCC (MBCC) algorithm, which uses chaos theory characteristics to achieve higher resistance against statistical and differential attacks while maintaining resource consumption. Our comparison observations show that MBCC outperforms BCC in both energy consumption and RAM usage and that both MBCC and BCC outperform RC5 and Skipjack in terms of security measures, such as entropy and characters frequency. Our comparison analysis of MBCC vs BCC suggests 13.44% lower RAM usage for encryption and decryption as well as 6.4 and 6.6 times reduced consumed time and energy for encrypting 32-bit data, respectively. Further analysis is reported for increasing the length of MBCC key, periodical generation of master key on the base station and periodical generation of round key on the sensors to prevent the brute-force attacks. An overall comparison of cipher techniques with respect to energy, time, memory and security concludes the suitability of MBCC algorithm for resource constraint wireless sensors with security requirements.

A Survey of Intrusion Detection Systems in Wireless Sensor Networks

Abstract: Wireless Sensor Networking is one of the most promising technologies that have applications ranging from health care to tactical military. Although Wireless Sensor Networks (WSNs) have appealing features (e.g., low installation cost, unattended network operation), due to the lack of a physical line of defense (i.e., there are no gateways or switches to monitor the information flow), the security of such networks is a big concern, especially for the applications where confidentiality has prime importance. Therefore, in order to operate WSNs in a secure way, any kind of intrusions should be detected before attackers can harm the network (i.e., sensor nodes) and/or information destination (i.e., data sink or base station). In this article, a survey of the state-of-the-art in Intrusion Detection Systems (IDSs) that are proposed for WSNs is presented. Firstly, detailed information about IDSs is provided. Secondly, a brief survey of IDSs proposed for Mobile Ad-Hoc Networks (MANETs) is presented and applicability of those systems to WSNs are discussed. Thirdly, IDSs proposed for WSNs are presented. This is followed by the analysis and comparison of each scheme along with their advantages and disadvantages. Finally, guidelines on IDSs that are potentially applicable to WSNs are provided. Our survey is concluded by highlighting open research issues in the field.

Wireless communication systems

Abstract: A wireless communication method in a system in which subscriber stations are each operable for communication with a base station is provided. The base station is capable of performing simultaneous communications with a plurality of the subscriber stations simultaneously by exchange of packets each conforming with a layered protocol of said system. The packets include a first portion for defining physical layer (PHY) parameters and a second portion for defining media access layer (MAC) parameters. Furthermore, communications between the subscriber stations and the base station are performed wholly or partly through at least one relay station. In this system, the method includes, in the relay station, receiving a plurality of packets from the subscriber stations, detecting the second portion of each of the packets, combining the detected second portions to form a second portion of at least one new packet, and transmitting the new packet to the base station.

Bandwidth Estimation for IEEE 802.11-Based Ad Hoc Networks

Abstract: Since 2005, IEEE 802.11-based networks have been able to provide a certain level of quality of service (QoS) by the means of service differentiation, due to the IEEE 802.11e amendment. However, no mechanism or method has been standardized to accurately evaluate the amount of resources remaining on a given channel. Such an evaluation would, however, be a good asset for bandwidth-constrained applications. In multihop ad hoc networks, such evaluation becomes even more difficult. Consequently, despite the various contributions around this research topic, the estimation of the available bandwidth still represents one of the main issues in this field. In this paper, we propose an improved mechanism to estimate the available bandwidth in IEEE 802.11-based ad hoc networks. Through simulations, we compare the accuracy of the estimation we propose to the estimation performed by other state-of-the-art CoS protocols, BRulT, AAC, and CoS-AODV.