Bidirectional LiFi Attocell Access Point Slicing Scheme

LiFi attocell access networks will be deployed everywhere to support diverse applications and service provisioning to various end-users. The LiFi infrastructure providers will need to offer LiFi access points (APs) resources as a service. This, however, requires a research challenge to be solved to dynamically and effectively allocate resources among service providers (SPs) while guaranteeing performance isolation among them and their respective users. This paper introduces an autonomic resource slicing (virtualization) scheme, which realizes autonomic management and configuration of virtual APs, in a LiFi attocell access network, based on SPs and their users service requirements. The developed scheme comprises of traffic analysis and classification, a local AP controller, downlink and uplink slice resources manager, traffic measurement, and information collection modules. It also contains a hybrid medium access protocol and an extended token bucket fair queueing algorithm to support uplink access virtualization and spectrum slicing. The proposed resource slicing scheme collects and analyzes the traffic statistics of the different applications supported on the slices defined in each LiFi AP and distributes the available resources fairly and proportionally among them. It uses a control algorithm to adjust the minimum contention window of user devices to achieve the target throughput and ensure airtime fairness among SPs and their users. The developed scheme has been extensively evaluated using OMNeT++. The obtained results show various resource slicing capabilities to support differentiated services and performance isolation

Design and Analysis of Free-space Optical Communications Systems for Next Generation Short-range Wireless Networks

This dissertation focuses on indoor free-space optical communications systems for use in short range wireless networks. We propose that current radio frequency wireless links be augmented or replaced with optical frequency links due to overcrowding in the radio frequency spectrum. Optical frequencies contain hundreds of terahertz of unregulated bandwidth and offer a physical layer of protection due to the inherently line-of-sight nature of near infrared light. We first present a hybrid optical and radio frequency link based on inexpensive LEDs in which a downlink is established optically, while the uplink is routed through preexisting radio frequency channels. Second, an all optical dual channel laser-based communication system is implemented consisting of a medium bandwidth wide-angle optical femtocell and a high-speed line-of-sight optical attocell. This approach balances the diverse needs of end users by providing links optimized for both mobility and bandwidth. Lastly, we demonstrate a high-power vertical cavity surface emitting laser (VCSEL) array transmitter for use in optical femtocells. A complimentary design for a distributed current laser driver is also presented

AI/ML assisted Li-Fi communication systems for the future 6G communication systems

Η πανταχού παρούσα εξάπλωση της ασύρματης σύνδεσης κατά την τελευταία δεκαετία είχε ως αποτέλεσμα μια τεράστια αύξηση του όγκου της κίνησης και μια τεράστια ζήτηση, η οποία δημιούργησε μια αξιοσημείωτη πίεση στους πόρους του δικτύου που δεν μπορούν να διαχειριστούν εξαρχής λόγω της σπανιότητας του εύρους ζώνης. Επομένως; Η Optical Wireless Communication θεωρείται ως η αναδυόμενη λύση για τα τρέχοντα δίκτυα ραδιοφώνου, όπου λειτουργεί στην εκμετάλλευση του φωτός ως ασύρματος φορέας και έχει ταξινομηθεί ως φιλική προς το περιβάλλον τεχνολογία λόγω της βιωσιμότητας και του επιπέδου ασφάλειας. Το Light-Fidelity (LiFi) είναι το πιο πρόσφατο παράδειγμα της οπτικής ασύρματης επικοινωνίας όπου υπάρχουν νέα χαρακτηριστικά όπως π. Στο σύστημα έχουν εισαχθεί τεχνικές διαμόρφωσης πολλαπλών φορέων και τεχνολογίες πολλαπλής πρόσβασης. Αυτή η αναφορά παρουσιάζει τη διαδικασία σχεδιασμού ενός πομποδέκτη LiFi που χρησιμοποιεί το MATLAB. όπου όλα τα μέρη του συστήματος προσομοιώθηκαν για να μιμηθούν ένα σύστημα LiFi σε ένα εσωτερικό περιβάλλον που είναι ένα δωμάτιο με διαστάσεις 5 x 5 x 3 m. Ο πομποδέκτης έχει χαρακτηριστεί με χρήση οπτοηλεκτρονικών συσκευών περοβσκίτη λόγω της πολλά υποσχόμενης απόδοσής του όσον αφορά την εκπομπή φωτός και την ανίχνευση. Ωστόσο, έχει προκύψει σημαντικός όγκος θορύβου λόγω της φωτοανίχνευσης που έχει μετριαστεί με την εισαγωγή ενός ενισχυτή transimpedance μετά τον φωτοανιχνευτή και την εφαρμογή ενός μηχανισμού εκτίμησης καναλιών στην πλευρά του δέκτη. Τα ληφθέντα αποτελέσματα έδειξαν ότι το σχεδιασμένο σύστημα μπορεί να επιτύχει περίπου 3,5 Mbps με 25dB SNR και λιγότερο από 4x10^(-6) BER χρησιμοποιώντας 5 πομπούς με 1000 LED σε κάθε πομπό, χωρίς να λαμβάνεται υπόψη καμία εξωτερική πηγή θορύβου όπως ο θόρυβος περιβάλλοντος. Οι πιθανοί περιορισμοί για ένα τέτοιο σύστημα είναι οι προδιαγραφές των οπτοηλεκτρονικών συσκευών που περιλαμβάνουν, την επιφάνεια της συσκευής, το οπτικό πεδίο του φωτοανιχνευτή και τη γωνία μισής ισχύος του LED. Ωστόσο, τα συστήματα οπτικών ασύρματων επικοινωνιών είναι πιο ευέλικτα για βελτιστοποίηση και τα σχέδια μπορούν να τυποποιηθούν σύμφωνα με την ζητούμενη υπηρεσία και τη φύση του περιβάλλοντος λόγω της ποικιλίας των διαθέσιμων συσκευών με χαμηλό κόστος.The ubiquitous spread of the wireless connection during the last decade has resulted in a tremendous growth in the traffic volume and a huge demand, which created a remarkable pressure on the network’s resources that can’t be managed due to bandwidth scarcity in the first place. Therefore; Optical Wireless Communication is considered as the emerging solution for the current radio networks, where it works on exploiting light as a wireless carrier and it has been classified as eco-friendly technology due to its sustainability and safety level. Light-Fidelity (LiFi) is the most recent paradigm of the optical wireless communication where new features such as; multicarrier modulation techniques and multiple access technologies have been introduced to the system. This report presents the design process of a LiFi transceiver using MATLAB; where all system parts were simulated to imitate a LiFi system in an indoor environment which is a room with dimensions of 5 x 5 x 3m. The transceiver has been characterised using perovskite optoelectronic devices due to its promising performance in terms of light emission and detection. However, a considerable amount of noise has been resulted due to the photodetection that has been mitigated using inserting a transimpedance amplifier after the photodetector and implement a channel estimation mechanism at the receiver side. The obtained results have demonstrated that the designed system can achieve around 3.5Mbps with 25dB SNR and less then 4x10^(-6) BER using 5 transmitters with 1000 LED at each transmitter, without considering any external source of noise such as the ambient noise. The prospective limitations for such a system are the optoelectronic devices specs which include, the device’s surface area, the photodetector’s field of view, and the half power angle of the LED. However, the optical wireless communication systems are more flexible to be optimized and the designs can be standardized according to the requested service and the environment nature due to the variety of the available devices with low cost

WiFO: A hybrid communication network based on integrated free-space optical and WiFi femtocells

Developments in smart home technology and the Internet of Things have significantly increased the demand for high-speed indoor wireless links. Although the majority of the research conducted in this area is still focused on the efficient usage of radio frequency (RF) spectrum, free-space optical (FSO) networks have also been explored as an alternative due to their large bandwidth potentials and low interference. In this paper we present a hybrid FSO and WiFi system (WiFO) that seamlessly integrates optical femtocell architecture with high mobility WiFi networks. Each FSO femtocell in this indoor communication system is capable of transmitting and receiving data at a rate of 50 Mbps over a distance of up to three meters with a field-of-view of +/- 15 degrees, while still achieving a low bit error rate between 10(-6), and 10(-4). Reed-Solomon forward error correction codes were also applied to the data stream to further reduce the bit error rate to below 10(-7). Different than many other free-space optical communication network using static transceivers, mobility in our WiFO system is achieved through the integration of a WiFi channel in the network protocol. The WiFi channel provides a feedback mechanism and allows for seamless handoffs between FSO femtocells. Additionally, we have experimentally demonstrated the advantage of this WiFO architecture by comparing the throughput of our system with a standard WiFi link in a realistic scenario. Our investigation has shown that the WiFO system presented in this work offers a cost-effective and easy-to-implement approach to significantly increase the capacity of current WiFi networks

6G wireless communications networks: a comprehensive survey

The commercial fifth-generation (5G) wireless communications networks have already been deployed with the aim of providing high data rates. However, the rapid growth in the number of smart devices and the emergence of the Internet of Everything (IoE) applications, which require an ultra-reliable and low-latency communication, will result in a substantial burden on the 5G wireless networks. As such, the data rate that could be supplied by 5G networks will unlikely sustain the enormous ongoing data traffic explosion. This has motivated research into continuing to advance the existing wireless networks toward the future generation of cellular systems, known as sixth generation (6G). Therefore, it is essential to provide a prospective vision of the 6G and the key enabling technologies for realizing future networks. To this end, this paper presents a comprehensive review/survey of the future evolution of 6G networks. Specifically, the objective of the paper is to provide a comprehensive review/survey about the key enabling technologies for 6G networks, which include a discussion about the main operation principles of each technology, envisioned potential applications, current state-of-the-art research, and the related technical challenges. Overall, this paper provides useful information for industries and academic researchers and discusses the potentials for opening up new research directions

New Waves of IoT Technologies Research – Transcending Intelligence and Senses at the Edge to Create Multi Experience Environments

The next wave of Internet of Things (IoT) and Industrial Internet of Things (IIoT) brings new technological developments that incorporate radical advances in Artificial Intelligence (AI), edge computing processing, new sensing capabilities, more security protection and autonomous functions accelerating progress towards the ability for IoT systems to self-develop, self-maintain and self-optimise. The emergence of hyper autonomous IoT applications with enhanced sensing, distributed intelligence, edge processing and connectivity, combined with human augmentation, has the potential to power the transformation and optimisation of industrial sectors and to change the innovation landscape. This chapter is reviewing the most recent advances in the next wave of the IoT by looking not only at the technology enabling the IoT but also at the platforms and smart data aspects that will bring intelligence, sustainability, dependability, autonomy, and will support human-centric solutions.acceptedVersio

Visible Light Communication (VLC)

Visible light communication (VLC) using light-emitting diodes (LEDs) or laser diodes (LDs) has been envisioned as one of the key enabling technologies for 6G and Internet of Things (IoT) systems, owing to its appealing advantages, including abundant and unregulated spectrum resources, no electromagnetic interference (EMI) radiation and high security. However, despite its many advantages, VLC faces several technical challenges, such as the limited bandwidth and severe nonlinearity of opto-electronic devices, link blockage and user mobility. Therefore, significant efforts are needed from the global VLC community to develop VLC technology further. This Special Issue, “Visible Light Communication (VLC)”, provides an opportunity for global researchers to share their new ideas and cutting-edge techniques to address the above-mentioned challenges. The 16 papers published in this Special Issue represent the fascinating progress of VLC in various contexts, including general indoor and underwater scenarios, and the emerging application of machine learning/artificial intelligence (ML/AI) techniques in VLC

Imaging Based Beam Steering for Optical Communication and Lidar Applications

Optical beam steering is a key component in any application that requires dynamic (i.e. realtime control) of beam propagation through free-space. Example applications include remote sensing, spectroscopy, laser machining, targeting, Lidar, optical wireless communications (OWC) and more. The pointing control requirements for many of these applications can be met by traditional mechanical steering techniques; however, these solutions tend to be bulky, slow, expensive, power hungry and prone to mechanical failures leading to short component lifetimes. Two emerging applications, Lidar imaging and OWC, truly need improved beam-steering capabilities to flourish and support the advancement of self-driving cars or relieve the congestion in radio-frequency wireless networks, respectively. We consider the novel requirements of these applications during development of a new beam-steering technology. We introduce imaging-based beam steering (IBBS) that uses an imaging transform between spatial and directional domains to implement a new method of electronic beam-steering. We introduce this concept while focusing on transmitters (Tx) for OWC but the pointing control mechanism is bi-directional supporting both transmit and receive functionality, even out of the same aperture; likewise, features that make this solution compelling for OWC are also great for Lidar imaging. In IBBS, an array of high-speed sources are positioned at the focal plane of a lens and the lens passively collects, collimates and steers the beam into a conjugate direction. Steering is accomplished by selecting which source to use for an OWC link. This gives a coarse, pixelated beam-steering control that is well-suited for short-range OWC such as indoor communications and we present a prototype bulb for this application. Notably, multiple sources can be utilized at once with each steered into its conjugate directions and this presents the first beam-steering technology that supports multiple beams out of a single aperture; this feature uniquely supports multiplexed communications and fast, high-resolution Lidar imaging