Searcharxiv⌕ Search

arXiv subjects

Mouhamed Abdulla

Publications and source records attributed to Mouhamed Abdulla.

At least 19 recordsLinked to original sources
arXiv2021

Remote Teaching and Learning in Applied Engineering: A Post-Pandemic Perspective

The COVID-19 pandemic significantly disrupted the educational sector. Faced with this life-threatening pandemic, educators had to swiftly pivot to an alternate form of course delivery without severely impacting the quality of the educational experience. Following the transition to online learning, educators had to grapple with a host of challenges. With interrupted face-to-face delivery, limited access to state-of-the-art labs, barriers with educational technologies, challenges of academic integrity, and obstacles with remote teamwork and student participation, creative solutions were urgently needed. In this chapter, we provide a rationale for a variety of course delivery models at different stages of the pandemic and highlight the approaches we took to overcome some of the pressing challenges of remote education. We also discuss how we ensured that hands-on learning remains an integral part of engineering curricula, and we argue that some of the applied changes during the pandemic will likely serve as a catalyst for modernizing education.

cs.CY↗
arXiv2021

Latency of Concatenating Unlicensed LPWAN with Cellular IoT: An Experimental QoE Study

Developing low-power wide-area network (LPWAN) solutions that are efficient to adopt, deploy and maintain are vital for smart cities. The poor quality-of-service of unlicensed LPWAN, and the high service cost of LTE-M/NB-IoT are key disadvantages of these technologies. Concatenating unlicensed with licensed LPWANs can overcome these limitations and harness their benefits. However, a concatenated LPWAN architecture will inevitably result in excess latency which may impact users' quality-of-experience (QoE). To evaluate the real-life feasibility of this system, we first propose a concatenated LPWAN architecture and experimentally measure the statistics of end-to-end (E2E) latencies. The concatenated delay margin is determined by benchmarking the latencies with different LPWAN architecture schemes, namely with unlicensed IoT (standalone LoRa), cellular IoT (standalone LTE-M), and concatenated IoT (LoRa interfaced with LTE-M). Through extensive experimental measurement campaigns of 30,000 data points of E2E latencies, we show that the excess delay due to LPWAN interfacing introduces on average less than 300 milliseconds. The proof-of-concept results suggest that the latency for concatenating unlicensed LPWAN with cellular IoT is negligible for smart city use cases where human perception and decision making is in the loop.

cs.NI↗
arXiv2020

Framework for an Integrated Learning Block with CDIO-led Engineering Education

As a CDIO collaborating member, the School of Mechanical and Electrical Engineering of Sheridan maintains a curriculum that is deeply rooted in skills-based learning, experiential learning, and engineering design. To ensure our graduates are agile and ready for the workforce, we are taking proactive measures to further improve their learning experiences. An important challenge still impeding our students knowledge acquisition is the perception that program courses have disjointed learning outcomes. The course map of programs is carefully designed in such a way that technical skills acquired in particular courses gradually build on each other. Despite the traditional existence of prerequisites and co-requisites, the inaccurate view that courses function independently persists among students and, occasionally, among faculty members. One feasible approach to tackle this pedagogical challenge is to combine various courses into an integrated learning block (ILB) having a unified mission and objective. At Sheridan's School of MEET, we are applying an ILB with three engineering courses offered within the same semester for all our B.Eng. degree programs. The ILB deliverables are based on the design of a chosen engineering system or subunit in a project-based learning (PBL) environment. The rationale of this paper is to share our framework for implementing an ILB in engineering programs and to examine the opportunities and challenges related to this type of curriculum design. In particular, we will discuss the methodology by which courses are selected to form an ILB while taking into account their appropriateness for an industry-driven PBL. This will be followed up with some of the strategies that are proposed to evaluate the performance of students in an ILB through formative and summative assessments based on CDIO competencies.

cs.CY↗
arXiv2019

Redesigning Telecommunication Engineering Courses with CDIO geared for Polytechnic Education

Whether in chemical, civil, mechanical, electrical, or their related engineering subdisciplines, remaining up-to-date in the subject matter is crucial. However, due to the pace of technological evolution, information and communications technology (ICT) fields of study are impacted with much higher consequences. Meanwhile, the curricula of higher educational institutes are struggling to catch up to this reality. In order to remain competitive, engineering schools ought to offer ICT related courses that are at once modern, relevant and ultimately beneficial for the employability of their graduates. In this spirit, we were recently mandated by our engineering school to develop and design telecommunication courses with great emphasis on (i) technological modernity, and (ii) experiential learning. To accomplish these objectives, we utilized the conceive, design, implement and operate (CDIO) framework, a modern engineering education initiative of which Sheridan is a member. In this article, we chronicle the steps we took to streamline and modernize the curriculum by outlining an effective methodology for course design and development with CDIO. We then provide examples of course update and design using the proposed methodology and highlight the lessons learned from this systematic curriculum development endeavor.

cs.CY↗
arXiv2017

Fine-Grained vs. Average Reliability for V2V Communications around Intersections

Intersections are critical areas of the transportation infrastructure associated with 47% of all road accidents. Vehicle-to-vehicle (V2V) communication has the potential of preventing up to 35% of such serious road collisions. In fact, under the 5G/LTE Rel.15+ standardization, V2V is a critical use-case not only for the purpose of enhancing road safety, but also for enabling traffic efficiency in modern smart cities. Under this anticipated 5G definition, high reliability of 0.99999 is expected for semi-autonomous vehicles (i.e., driver-in-the-loop). As a consequence, there is a need to assess the reliability, especially for accident-prone areas, such as intersections. We unpack traditional average V2V reliability in order to quantify its related fine-grained V2V reliability. Contrary to existing work on infinitely large roads, when we consider finite road segments of significance to practical real-world deployment, fine-grained reliability exhibits bimodal behavior. Performance for a certain vehicular traffic scenario is either very reliable or extremely unreliable, but nowhere in relative proximity to the average performance.

cs.IT↗
arXiv2017

Fine-Grained Reliability for V2V Communications around Suburban and Urban Intersections

Safe transportation is a key use-case of the 5G/LTE Rel.15+ communications, where an end-to-end reliability of 0.99999 is expected for a vehicle-to-vehicle (V2V) transmission distance of 100-200 m. Since communications reliability is related to road-safety, it is crucial to verify the fulfillment of the performance, especially for accident-prone areas such as intersections. We derive closed-form expressions for the V2V transmission reliability near suburban corners and urban intersections over finite interference regions. The analysis is based on plausible street configurations, traffic scenarios, and empirically-supported channel propagation. We show the means by which the performance metric can serve as a preliminary design tool to meet a target reliability. We then apply meta distribution concepts to provide a careful dissection of V2V communications reliability. Contrary to existing work on infinite roads, when we consider finite road segments for practical deployment, fine-grained reliability per realization exhibits bimodal behavior. Either performance for a certain vehicular traffic scenario is very reliable or extremely unreliable, but nowhere in relatively proximity to the average performance. In other words, standard SINR-based average performance metrics are analytically accurate but can be insufficient from a practical viewpoint. Investigating other safety-critical point process networks at the meta distribution-level may reveal similar discrepancies.

cs.IT↗
arXiv2016

Vehicle-to-Vehicle Communications with Urban Intersection Path Loss Models

Vehicle-to-vehicle (V2V) communication can improve road safety and traffic efficiency, particularly around critical areas such as intersections. We analytically derive V2V success probability near an urban intersection, based on empirically supported line-of-sight (LOS), weak-line-of-sight (WLOS), and non-line-of-sight (NLOS) channel models. The analysis can serve as a preliminary design tool for performance assessment over different system parameters and target performance requirements.

cs.IT↗
arXiv2014

Large-Scale Fading Behavior for a Cellular Network with Uniform Spatial Distribution

Large-scale fading (LSF) between interacting nodes is a fundamental element in radio communications, responsible for weakening the propagation, and thus worsening the service quality. Given the importance of channel-losses in general, and the inevitability of random spatial geometry in real-life wireless networks, it was then natural to merge these two paradigms together in order to obtain an improved stochastical model for the LSF indicator. Therefore, in exact closed-form notation, we generically derived the LSF distribution between a prepositioned reference base-station and an arbitrary node for a multi-cellular random network model. In fact, we provided an explicit and definitive formulation that considered at once: the lattice profile, the users' random geometry, the effect of the far-field phenomenon, the path-loss behavior, and the stochastic impact of channel scatters. The veracity and accuracy of the theoretical analysis were also confirmed through Monte Carlo simulations.

cs.IT↗
arXiv2014

Simple Subroutine for Inhomogeneous Deployment

Spatial modeling of wireless networks via analytical means has been considered as a widely practiced mechanism for inference. As a result, some geometrical deployment models have been proposed in literature. Although practical in certain simulation instances, these models do not always produce inhomogeneous nodal geometries in an effective and simple manner for practical deployment situations. Therefore, we conceptualized a flexible approach for realizing random inhomogeneity by proposing the area-specific deployment (ASD) algorithm, which takes into account the clustering tendency of users. Overall, the developed spatial-level network tool has the distinct advantage of automatically producing infinitely many random realizations of users' geometry by simply entering three parameters to the simulator: the size of the cellular network, the number of deployment layers, and the overall quantity of nodes.

cs.IT↗
arXiv2013

Analytical Coexistence Benchmark for Assessing the Utmost Interference Tolerated by IEEE 802.20

Whether it is crosstalk, harmonics, or in-band operation of wireless technologies, interference between a reference system and a host of offenders is virtually unavoidable. In past contributions, a benchmark has been established and considered for coexistence analysis with a number of technologies including FWA, UMTS, and WiMAX. However, the previously presented model does not take into account the mobility factor of the reference node in addition to a number of interdependent requirements regarding the link direction, channel state, data rate and system factors; hence limiting its applicability for the MBWA (IEEE 802.20) standard. Thus, over diverse modes, in this correspondence we analytically derived the greatest aggregate interference level tolerated for high-fidelity transmission tailored specifically for the MBWA standard. Our results, in the form of benchmark indicators, should be of particular interest to peers analyzing and researching RF coexistence scenarios with this new protocol.

cs.IT↗
arXiv2013

Can Research be Taught?

The word 'researcher' is loaded and often confusing. It takes years to become one and to master all of its aspects. In this paper, we investigate whether or not this process of 'becoming' can be catalyzed through education. The focus will be on wireless communications, though the same principle could very well be replicated to other disciplines.

cs.CY↗
arXiv2013

Closed-Form Path-Loss Predictor for Gaussianly Distributed Nodes

The emulation of wireless nodes spatial position is a practice used by deployment engineers and network planners to analyze the characteristics of a network. In particular, nodes geolocation will directly impact factors such as connectivity, signals fidelity, and service quality. In literature, in addition to typical homogenous scattering, normal distribution is frequently used to model mobiles concentration in a cellular system. Moreover, Gaussian dropping is often considered as an effective placement method for airborne sensor deployment. Despite the practicality of this model, getting the network channel loss distribution still relies on exhaustive Monte Carlo simulation. In this paper, we argue the need for this inefficient approach and hence derived a generic and exact closed-form expression for the path-loss distribution density between a base-station and a network of nodes. Simulation was used to reaffirm the validity of the theoretical analysis using values from the new IEEE 802.20 standard.

cs.IT↗
arXiv2013

An Exact Path-Loss Density Model for Mobiles in a Cellular System

In trying to emulate the spatial position of wireless nodes for purpose of analysis, we rely on stochastic simulation. And, it is customary, for mobile systems, to consider a base-station radiation coverage by an ideal cell shape. For cellular analysis, a hexagon contour is always preferred mainly because of its tessellating nature. Despite this fact, largely due to its intrinsic simplicity, in literature only random dispersion model for a circular shape is known. However, if considered, this will result an unfair nodes density specifically at the edges of non-circular contours. As a result, in this paper, we showed the exact random number generation technique required for nodes scattering inside a hexagon. Next, motivated from a system channel perspective, we argued the need for the exhaustive random mobile dropping process, and hence derived a generic close-form expression for the path-loss distribution density between a base-station and a mobile. Last, simulation was used to reaffirm the validity of the theoretical analysis using values from the new IEEE 802.20 standard.

cs.IT↗
arXiv2013

Revisiting Circular-Based Random Node Simulation

In literature, a stochastic model for spreading nodes in a cellular cell is available. Despite its existence, the current method does not offer any versatility in dealing with sectored layers. Of course, this needed adaptability could be created synthetically through heuristic means. However, due to selective sampling, such practice dissolves the true randomness sought. Hence, in this paper, a universal exact scattering model is derived. Also, as an alternative to exhaustive simulation, a generic close-form path-loss predictor between a node and a BS is obtained. Further, using these results, an algorithm based on the superposition principle is proposed. This will ensure greater emulation flexibility, and attain a heterogeneous spatial density.

cs.IT↗
arXiv2013

Cellular-Based Statistical Model for Mobile Dispersion

While analyzing mobile systems we often approximate the actual coverage surface and assume an ideal cell shape. In a multi-cellular network, because of its tessellating nature, a hexagon is more preferred than a circular geometry. Despite this reality, perhaps due to the inherent simplicity, only a model for circular based random spreading is available. However, if used, this results an unfair terminal distribution for non-circular contours. Therefore, in this paper we specifically derived an unbiased node density model for a hexagon. We then extended the principle and established stochastic ways to handle sectored cells. Next, based on these mathematical findings, we created a generic modeling tool that can support a complex network with varying position, capacity, size, user density, and sectoring capability. Last, simulation was used to verify the theoretical analysis.

cs.IT↗
arXiv2013

Harnessing Simultaneously the Benefits of UWB and MBWA: A Practical Scenario

UWB has a very large bandwidth in a WPAN network, which is best used for HD-video applications. Meanwhile, MBWA is a WMAN option optimized for wireless-IP in a fast moving vehicle. In this paper, we propose a practical engineering scenario that harnesses simultaneously the distinctive feature of both UWB and MBWA. However, this in-proximity operation of the technologies will inevitably cause mutual interference to both systems. In light of this, as a preliminary phase to coexistence, we have derived, under various circumstances, the maximum interference power limit that needs to be respected in order to ensure an acceptable system performance as requested by the new IEEE 802.20 standard.

cs.IT↗
arXiv2013

On the Peculiarities of Design: An Engineering Perspective

It is a fact of our existence, that no matter where we are, we most often find ourselves either hearing, seeing, talking, or even engaged in design related activities. Despite this reality, the notion of 'design', and in particular 'engineering design', is often ambiguous, and at times obscure. Thus, the transfer of knowledge of this crucial topic to engineering students engaged in practical hands-on learning or analytical research is usually perplexing to accomplish. In light of this, it becomes worthwhile to dissect and reflect on the abstraction of the design process in engineering. In fact, the aim of this article is to investigate the facets of applied design, and elaborate on its diversity, complexity and elements. Eventually, by concretizing this subject matter, we hope to slightly assist engineering students in alleviating some of the vagueness associated with the principle of design, and enhance their technical skillset during innovative conceptions.

cs.HC↗