The Internet of Things (IoT) is one of the most important emerging technologies, spanning a myriad of possible applications, especially with the increasing number and variety of connected devices. Several network simulation tools have been developed with widely varying focuses and used in many research fields. Thus, it is critical to simulate the work of such systems and applications before actual deployment. This paper explores the landscape of available IoT and wireless sensor networks (WSNs) simulators and compares their performance using the Low Power Wide Area Network (LPWAN) communication technology called LoRa (Long Range), which has recently gained a lot of interest. Using a systematic approach, we present a chronological survey of available IoT and WSNs simulation tools. With this, we categorized and content-analyzed published scientific papers in the IoT and WSNs simulation tools research domain by highlighting the simulation tools, study type, scope of study and performance measures of the studies. Next, we present an overview of LoRa/LoRaWAN technology by considering its architecture, transmission parameters, device classes and available simulation tools. Furthermore, we discussed three popular open-source simulation tools/frameworks, namely, NS-3, OMNeT++ (FLoRa) and LoRaSim, for the simulation of LoRa/LoRaWAN networks. Finally, we evaluate their performance in terms of Packet Delivery Ratio (PDR), CPU utilization, memory usage, execution time and the number of collisions.

The fifth-generation (5G) mobile network is the next paradigm shift in the revolutionary era of the wireless communication technologies that will break the backward compatibility of today’s communication systems. Visible Light Communication (VLC) and Light Fidelity (LiFi) technologies are among the potential candidates that are expected to be utilized in the future 5G networks due to their indoor energy-efficient communications. Realized by Light Emitting Diodes (LEDs), VLC and LiFi possesses a number of prominent features to meet the highly demanding requirements of ultrahigh-speed, massive Multiple-Input Multiple-Output (MIMO) device connectivity, ultra-low-latency, ultra-high reliable and low energy consumption for 5G networks. This paper provides an overview contributions of VLC and LiFi towards 5G networks. Furthermore, we explain how VLC and LiFi can successfully provide effective solutions for the emerging 5G networks.

Light Fidelity (LiFi) is a form of Visible Light Communication (VLC) that provides high-speed, bidirectional and fully networked wireless communication systems using low power Light Emitting Diodes (LEDs) light bulbs. As a reliable, license-free, high-speed and fully bi-directional wireless networked, LiFi is a potential technology to the Radio Frequency (RF) based systems and beyond mobile networks. As the spectrum utilized by Li-Fi does not overlap with that of used by the RF, a hybrid LiFi and wireless fidelity (WiFi) networks can provide high-speed data transmission that will improve the Quality of Service (QoS) and Quality Experience (Qoe) of the internet users. However, in such hybrid network systems, intermittent light-path blockages and user mobility may degrade the system throughput due to frequent handover among the networks. Different mechanisms to mitigate the frequent handover issue in hybrid LiFi and WiFi networks have been proposed in the literature. This paper provides an overview concept of hybrid handover in LiFi/WiFi networks. Furthermore, related works done in this field are also discussed. Finally, comparison between LiFi and WiFi technologies is also provided.

As the number of internet users continues to increase, the demand for more wireless frequency spectrum has grown significantly over the years. Given the limitations in Wireless Fidelity (WiFi) networks, it becomes evident that the current frequency allocation schemes cannot meet the needs of increasing higher data rate devices. Visible Light Communication (VLC) has emerged as one of the promising technologies to address the spectrum crunch and other anomalies associated with WiFi networks. VLC provide high-speed, secure and reliable data communication using Light Emitting Diode (LED). This paper reviews the various modulation schemes suitable for VLC networks. Furthermore, performance analysis of these schemes in terms of normalized power requirement, Signal to Noise Ratio (SNR), spectral efficiency, dimming factor and Bit Error Rate (BER) are discussed. Finally, applications of VLC are presented.

This paper presents a Hybrid Multipulse Amplitude and Position Modulation (H-MPAPM) scheme for Optical Wireless Communication (OWC) system. H-MPAPM is a combined version of the Pulse Amplitude Modulation (PAM) and Gradual Multipulse Pulse Position Modulation (Gradual MPPM) where the transmitted information is encoded in the amplitude and position of multiple optical pulses. The performance measures in terms of the number of bits-symbols per frame, power requirements and bandwidth-utilization efficiency for the proposed scheme are derived and compared with MPPM, Gradual MPPM and Multiple Pulse Amplitude and Position Modulation (MPAPM) schemes. It is shown that the proposed scheme allows more symbols and bits transmission per frame and achieves higher bandwidth-utilization efficiency than MPPM, Gradual MPPM and MPAPM. However, in terms of the power requirements, the MPPM and Gradual MPPM outperforms the proposed modulation scheme. Thus, the proposed scheme displays a significant improvement in terms of the transmitted symbols and the bandwidth-utilization efficiency.