Software-Defined Networking (SDN) is a network paradigm introduced to overcome the inherent challenges of traditional networks. Its architecture is either deployed with a single controller or multiple controllers. While the first is not suitable for large-scale networks, the latter is confronted with a controller placement problem (CPP) in a large-scale network environment. CPP involves the challenge of deploying the optimal number of controllers within a network while meeting certain performance requirements considered conflicting in nature such as reliability, load balancing, latency, energy efficiency, and computation time. A single optimal or random placement may not be feasible in CPP and careful planning is of the essence to find an appropriate trade-off among the metrics. To achieve this, several CPP approaches have been proposed, developed, and deployed over the years, each having its unique objectives, strengths, and weaknesses. Therefore, this paper performed a comprehensive review of some of the existing approaches to identify the unique solutions offered, comprehend the different strategies and the challenges that exist as well as provide researchers with future directions aimed at improving the optimum location and allocation of controllers, in particular, for SDN application in wireless sensor network (WSN). The findings revealed several existing solutions and algorithms as well as several challenges such as the need for an efficient algorithm, attack-aware, cost-aware, and energy-aware CPP schemes while achieving a good quality of service.

The swift explosion of Internet of Things (IoT) devices has brought about a new era of interconnectivity and ease of use while simultaneously presenting significant security concerns. Intrusion Detection Systems (IDS) play a critical role in the protection of IoT ecosystems against a wide range of cyber threats. Despite research advancements, challenges persist in improving IDS detection accuracy, reducing false positives (FPs), and identifying new types of attacks. This paper presents a comprehensive analysis of recent developments in IoT, shedding light on detection methodologies, threat types, performance metrics, datasets, challenges, and future directions. We systematically analyze the existing literature from 2016 to 2023, focusing on both machine learning (ML) and non-ML IDS strategies involving signature, anomaly, specification, and hybrid models to counteract IoT-specific threats. The findings include the deployment models from edge to cloud computing and evaluating IDS performance based on measures such as accuracy, FP rates, and computational costs, utilizing various IoT benchmark datasets. The study also explores methods to enhance IDS accuracy and efficiency, including feature engineering, optimization, and cutting-edge solutions such as cryptographic and blockchain technologies. Equally, it identifies key challenges such as the resource-constrained nature of IoT devices, scalability, and privacy issues and proposes future research directions to enhance IoT-based IDS and overall ecosystem security.

Over a decade since transparency was introduced as a first-class concept in computing, transparency is still an emerging concept that is quite poorly understood. Also, despite existing research contributions, transparency is yet to be incorporated into the software engineering practice, and the promise it holds remains unfulfilled. Although there is evidence of increasing stakeholders’ demand for software and process transparency, the realization of such demand is yet to be fully witnessed within the software engineering practice. There is a need to uncover transparency and how it has so far been conceptualized, operationalized, and challenges faced. We applied a systematic literature review method in search of articles published between January 2006 and March 2022. This study reports a systematic review of the explicit conceptualization and application of transparency in 18 articles out of a total of 162 selected for review. Our study found that transparency remains an under-researched non-functional quality requirement concept, especially as it impacts information and software systems development. Of the 18 articles reviewed, only three studies representing 16.67% conceptualized transparency in software development and focused on the transparency of software artifacts. The remaining 83.33% of studies conceptualized transparency in information systems, focusing on general information and fully functional information systems. Transparency is yet to be fully explored from a theoretical gathering point of view and as a non-functional indicator of software quality hence its slow adoption and incorporation into mainstream software practice. Apart from providing a catalog of transparency factors that stakeholders can use to evaluate transparency achievement, the paper proposed a roadmap to enhance transparency implementation and also provides future research directions.

Effective and efficient public service delivery like healthcare services are very important in today's society, especially in the rural areas. People in rural areas are expected to have access to public facilities at all times. However, these services are not always available when they are needed. This paper discusses the problems faced by rural areas of Mafikeng in South Africa (SA) when public and basic healthcare facilities like medical ambulance transports are needed during emergency situation. The challenges ranges from poor communication, poor road network and unstructured address to non-arrival of ambulances leading loss of lives that are preventable. This paper designed and implemented a system prototype using mobile application technologies to offer cost-effective services to patients during emergencies. It is intended to reduce long queues in hospitals and long waiting periods for an ambulance via location-based services. By using this application, lives in the rural areas can be made easier and loss of lives prevented by providing timely response from the appropriate healthcare providers during emergencies.

Drink-driving and over-speeding of vehicles are the major causes of injuries and deaths on the road globally and South Africa (SA) is not an exception. Different systems which are currently used in detecting high alcohol concentration in drivers' breath and detecting vehicles that exceeds stipulated speed limit are not effective, efficient and poses health risks to traffic personnel. In an attempt to provide effective solutions to these challenges, this paper proposed a smart transportation system for real-time detection of drinkdriving and over-speeding on the roads using technology of vehicular networks. The objective is to allow for early intervention by traffic personnel aim at saving lives before actual accident occurred. We designed a theoretical framework of the system and implemented an application prototype which is web-based for use by traffic personnel to monitor the detection of traffic offenders in the capacity of drink-driving and overspeeding. We presented and discussed the operation of the system as well as the functionalities it offers. Additionally, we utilized the application to simulate the actual system and based on its working, we found that the system is feasible and can accomplish the tasks of road safety more effective than the existing approaches.

Low-Power Wide-Area Network (LPWAN) is a wireless WAN technology that connects low-powered and low-bandwidth devices with low bit rates atop Long Ranges (LoRa). It is characterized by improved scalability, wide area coverage, and low power consumption, which are beneficial to resource-constrained devices on the Internet of Things (IoT) for effective communication and security. Security in Long-Range Wide-Area Networks (LoRaWAN) widely employs Advanced Encryption Standard (AES) 128-bit symmetric encryption as the accepted security standard for a key generation that secures communication and entities. However, designing an efficient key manifestation and management model is still a challenge as different designs are based on different research objectives. To date, there is no global and well-accepted LoRaWAN security model for all applications. Thus, there is a need to continually improve the LoRaWAN security model. This paper, therefore, performed an in-depth analysis of some existing LoRaWAN key security models to identify security challenges affecting these security models and assess the strengths and weaknesses of the proposed solutions. The goal is to improve some of the existing LoRaWAN security models by analysing and bringing together several challenges that affect them. Several relevant studies were collected and analysed; the analysis shows that though there are few research works in this area, several existing LoRaWAN security models are not immune to attacks. Symmetry encryption is found to be the most used approach to manage key security due to its less computational operations. Moreover, it is possible to improve existing key security models in LPWAN with consideration of the resource constrained. Again, trusted third parties for key management were also widely used to defend against possible attacks and minimize operational complexities. We, therefore, recommend the design of lightweight and less complex LPWAN security models to sustain the lifespan of LPWAN devices.