A study was conducted to explore the difference in cognitive styles, between electrical and mechanical engineering students, through the delivery of comparable course materials by professors from both fields. Most concrete thinkers require to know the application(s) of any given theory before fully accepting the theory. However, abstract thinkers can easily accept the theoretical framework prior to, and in some cases without, being exposed to real world applications. This paper explores such differences in cognitive styles between electrical and mechanical engineering students and instructors. The findings of the study confirm that electrical engineering students are abstract thinkers while mechanical engineering students are concrete thinkers. In addition, the study also reflect that abstract thinking instructors are required to adjust their teaching techniques when dealing with concrete thinkers, to accommodate their need for having a practical real-life application. On the other hand, concrete thinking instructors are not required to modify their teaching approach when dealing with abstract thinkers, because despite the lack of need of understanding how a theory is utilized in real life, it is always appreciated by abstract thinking engineers to see that connection. In addition, this study suggests that these cognitive styles may also be responsible for individuals, interested in studying engineering, selecting a specific field of engineering.

It is often advocated that a solution to the problem of interference to digital subscriber line networks (DSL) from a power line communications (PLC) network is to prevent the PLC networks from utilizing the DSL spectrum. However, this solution will render PLC networks inoperable with the introduction of wide-band DSL technology like G.Fast. We propose utilizing an interference cancelling scheme to ensure the co-existence of DSL and PLC networks within the home environment. A measurement campaign is conducted where a set of 480 measurements are collected within a residential house to characterize the PLC-to-DSL interference environment for two DSL modem installation scenarios. The interference cancelling scheme is based on an adaptive frequency domain interference canceller (FDIC) that utilizes the common mode (CM) PLC interference to estimate the differential mode (DM) PLC interference. The effectiveness of the FDIC, which is insensitive to the non-stationarity of the PLC channel, is demonstrated using analysis that incorporates the measured PLC-to-DSL coupling channels.

Recent advances in power line communications (PLC) have made it popular for in-home networking. This makes PLC an increasingly relevant source of interference for digital subscriber line (DSL) networks within the home environment. This paper presents measured PLC-to-DSL coupling channels for a worst case DSL deployment scenario. We then propose an interference cancelling scheme based on a frequency domain interference canceller (FDIC) that utilizes the common mode (CM) PLC interference to estimate and remove the differential mode (DM) PLC interference. The mean square error (MSE) of the proposed FDIC is derived and compared to the minimum MSE achieved by an optimum Wiener filter. Improvement in the signal to interference plus noise ratio (SINR) achieved by using the FDIC is also presented. Both mathematical analysis and simulation results demonstrate the effectiveness of the proposed FCID in reducing the DM PLC interference on the DM DSL signal.

Cognitive Radio Networks (CRNs) provide a solution for the spectrum scarcity problem facing the wireless communications community. To be able to utilize CRNs in practical applications, a certain level of quality-of-service (QoS) should be guaranteed to the secondary users (SUs) in such networks. In this paper, we propose a packet scheduling scheme that orders the SUs' transmissions according to the packet dropping rates and the number of packets queued waiting for transmission. A medium access control (MAC) protocol, based on the mentioned scheduling scheme, is proposed for a centralized CRN. In addition, the scheduling scheme is adapted for a distributed CRN, by introducing a feature that allows SUs to organize access to the available spectrum without the need for a central unit. Extensive simulation results are presented to evaluate the proposed protocols, in comparison with other MAC protocols designed for CRNs. The results demonstrate the effectiveness of our proposed protocols to guarantee the required QoS for voice packet transmission, while maintaining fairness among SUs.