On the power-splitting relaying protocol for SWIPT with multiple UAVs in downlink NOMA-IoT networks

Unmanned aerial vehicle (UAV) communication and non-orthogonal multiple access (NOMA) are two promising technologies for wireless 5G networks and beyond. The UAVs can be used as flying base stations to form line-of-sight communication links to the Internet of things devices (IDs) and to enhance the performance of usual terrestrial cellular networks. Moreover, the UAVs can also be deployed as flying relay nodes for forwarding data from a base station (BS) to the IDs. On the other hand, non-orthogonal resource sharing for many concurrent users is exploited in NOMA, thus improving spectrum efficiency (SE) and supporting massive connections. The NOMA combined with energy harvesting (EH) in an amplify-and-forward (AF) with cooperative UAV systems is researched. Specifically, the UAVs act as rotary-wing relays to forward data from the BSs to two IDs. This paper focuses on the analysis of outage probabilities (OPs), system throughput, and energy efficiency (EE) for two IDs. Besides, we also do the asymptotic analysis of OPs at high signal-to-noise ratios (SNRs). Furthermore, this paper also inspects the impacts of the UAV-based relaying on the OP, system throughput, and EE of the proposed NOMA scheme. The derived asymptotic expansions show that the suggested model can enhance user fairness and the analytical results match the simulation results

Stochastic Geometry Based Performance Study in 5G Wireless Networks

As the complexity of modern cellular networks continuously increases along with the evolution of technologies and the quick explosion of mobile data traffic, conventional large scale system level simulations and analytical tools become either too complicated or less tractable and accurate. Therefore, novel analytical models are actively pursued. In recent years, stochastic geometry models have been recognized as powerful tools to analyze the key performance metrics of cellular networks. In this dissertation, stochastic geometry based analytical models are developed to analyze the performance of some key technologies proposed for 5G mobile networks. Particularly, Device-to-Device (D2D) communication, Non-orthogonal multiple access (NOMA), and ultra-dense networks (UDNs) are investigated and analyzed by stochastic geometry models, more specifically, Poisson Point Process (PPP) models. D2D communication enables direct communication between mobile users in proximity to each other bypassing base station (BS). Embedding D2D communication into existing cellular networks brings many benefits such as improving spectrum efficiency, decreasing power energy consumption, and enabling novel location-based services. However, these benefits may not be fully exploited if the co-channel interference among D2D users and cellular users is not properly tackled. In this dissertation, various frequency reuse and power control schemes are proposed, aiming at mitigating the interference between D2D users and conventional cellular users. The performance gain of proposed schemes is analyzed on a system modeled by a 2-tier PPP and validated by numerical simulations. NOMA is a promising radio access technology for 5G cellular networks. Different with widely applied orthogonal multiple access (OMA) such as orthogonal frequency division multiple access (OFDMA) and single carrier frequency division multiple access (SC-FDMA), NOMA allows multiple users to use the same frequency/time resource and offers many advantages such as improving spectral efficiency, enhancing connectivity, providing higher cell-edge throughput, and reducing transmission latency. Although some initial performance analysis has been done on NOMA with single cell scenario, the system level performance of NOMA in a multi-cell scenario is not investigated in existing work. In this dissertation, analytical frameworks are developed to evaluate the performance of a wireless network with NOMA on both downlink and uplink. Distinguished from existing publications on NOMA, the framework developed in this dissertation is the first one that takes inter-cell interference into consideration. UDN is another key technology for 5G wireless networks to achieve high capacity and coverage. Due to the existence of line-of-sight (LoS)/non-line-of-sight (NLoS) propagation and bounded path loss behavior in UDN networks, the tractability of the original PPP model diminishes when analyzing the performance of UDNs. Therefore, a dominant BS (base station)-based approximation model is developed in this dissertation. By applying reasonable mathematical approximations, the tractability of the PPP model is preserved and the closed form solution can be derived. The numerical results demonstrate that the developed analytical model is accurate in a wide range of network densities. The analysis conducted in this dissertation demonstrates that stochastic geometry models can serve as powerful tools to analyze the performance of 5G technologies in a dense wireless network deployment. The frameworks developed in this dissertation provide general yet powerful analytical tools that can be readily extended to facilitate other research in wireless networks

Development and testing of a portable GNSS network solution using the magellan propark3

With increasing development and expansion of Continuously Operating Reference Station (CORS)networks, globally and at home such as Sydnet, Global Navigation Satellite System users have greater options of utilizing reference station networks to receive correction data and undertake Real Time surveys without the need of supplying their own base station. A large majority of GNSS built today are equipped with built in mobile technology which utilize bidirectional communication including Internet based cellular connections. With increasing coverage of wireless internet, users will be able to utilize this technology in more places than they could ever before. The ProMark3 RTK GNSS receiver transmits correction data via a conventional 0.5 watt UHF radio. This allows a working range of up to 1.5km in open areas and 0.3 – 0.7km in urban built up areas. Unidirectional communication such as UHF also has its limitations including line of sight requirements, transmitter power, broadcasting antenna height limitations, reliability of the link and governmental restrictions such as licensing and operational limitations. Alternative options for receiving correction data are made available within the ProMark3’s onboard software, which include Networked Transmit of RTCM via Internet Protocol (NTRIP) and Direct Internet Protocol (DIP). These methods can extend that working range to 10km which is the recommended limit for RTK surveying. Built in wireless technology is not present in the ProMark3 however the user can still connect using a separate web enabled phone with Bluetooth technology. The advantage with this option is that the phone can be still used whilst you work, giving you even greater flexibility. This research project will explore the performance of the ProMark3 using Direct IP. Two different portable base reference stations to broadcast corrections will be designed. They include an office based and field based system. A rigorous testing regime will be conducted to explore the achievable range using Direct IP, the repeatability of position on an established baseline and the time taken to achieve a fixed solution at certain distances. The final part of this project will discuss the application of the technology to the surveying industry, particularly issues of reliability, cost and quality control. The use of CORS as an alternative to receiving correction data is improving work turn around time and field efficiencies, improving security as only one GPS is being utilized and offering survey firms the chance to experiment with this technology without a large expense upfront. The concept of a portable Direct IP station will allow users to operate privately run reference station networks from the office or the field. The benefit of a portable base station is that you can disassemble the base quickly and take it anywhere you decide to work. This will allow the operator and other users the chance to access data in areas not serviced by CORS and create opportunities for surveyors wanting to experiment with this alternate technology. The future may see an increasing amount of private CORS setup operating within existing government run networks, offering users even greater choice to access spatial data

Power consumption modeling in integrated optical-wireless access network

The access segments of both optical and wireless networks are well known for their domination over the network’s total power consumption. Therefore, the study on energy consumption particularly in integrated optical-wireless access networks is crucial as energy consumption issue is increasingly vital nowadays. Existing works to date largely addressed the physical characteristics of integrated devices and algorithms for layer 2 and layer 3, where the study in power consumption modeling was often ignored. Hence, this thesis focuses on developing a power consumption model for integrated optical-wireless access networks and investigates the energy efficiency of such networks. Gigabit Passive Optical Network (GPON) as the optical backhaul and Worldwide Interoperability Microwave Access (WiMAX) and Long-Term Evolution (LTE) with femtocell application for the wireless network are considered. First, the power consumption model of the integrated network involving Optical Line Terminal (OLT) and integration between Optical Network Unit (ONU) and Base Station (BS) known as Integrated ONU-BS (IOB) are developed. Then, the power consumption behavior of ONU under different traffic loads has been investigated to model the total power consumption of integrated access networks. An empirical approach has been proposed to characterize the power consumption of the ONU by using real GPON testbed and to develop the power consumption model of ONU based on experimental results. This is followed by the extensive analyses that have been conducted to investigate the impact of various parameters such as split ratio, Femtocell Base Station (FBS) cell range, broadcast factor, and modulation and coding scheme into the total network power consumption and energy efficiency. It has been observed that GPONLTE has the worst energy efficiency performance when compared to GPON-WiMAX, even though it offers the highest data rates. The study has been further extended by including energy saving aspects where sleep mode techniques have been applied (i.e. power shedding for the ONU and idle mode procedure for FBS) based on the user behavior from the traffic profile pattern in Cyberjaya municipal broadband access networks. The implementation of energy saving techniques have shown further significant improvement of 15% lower energy consumption for the integrated access network

KIIT Digital Library: An open hypermedia Application

The massive use of Web technologies has spurred a new revolution in information storing and retrieving. It has always been an issue whether to incorporate hyperlinks embedded in a document or to store them separately in a link base. Research effort has been concentrated on the development of link services that enable hypermedia functionality to be integrate into the general computing environment and allow linking from all tools on the browser or desktop. KIIT digital library is such an application that focuses mainly on architecture and protocols of Open Hypermedia Systems (OHS), providing on-line document authoring, browsing, cataloguing, searching and updating features. The WWW needs fundamentally new frameworks and concepts to support new search and indexing functionality. This is because of the frequent use of digital archives and to maintain huge amount of database and documents. These digital materials range from electronic versions of books and journals offered by traditional publishers to manuscripts, photographs, maps, sound recordings and similar materials digitized from libraries' own special collections to new electronic scholarly and scientific databases developed through the collaboration of researchers, computer and information scientists, and librarians. Metadata in catalogue systems are an indispensable tool to find information and services in networks. Technological advances provide new opportunities to facilitate the process of collecting and maintaining metadata and to facilitate using catalogue systems. The overall objective is how to make best use of catalogue systems. Information systems such as the World Wide Web, Digital Libraries, inventories of satellite images and other repositories contain more data than ever before, are globally distributed, easy to use and, therefore, become accessible to huge, heterogeneous user groups. For KIIT Digital Library, we have used Resource Development Framework (RDF) and Dublin Core (DC) standards to incorporate metadata. Overall KIIT digital library provides electronic access to information in many different forms. Recent technological advances make the storage and transmission of digital information possible. This project is to design and implement a cataloguing system of the digital library system suitable for storage, indexing, and retrieving information and providing that information across the Internet. The goal is to allow users to quickly search indices to locate segments of interests and view and manipulate these segments on their remote computers

IP Flow Mobility support for Proxy Mobile IPv6 based networks

The ability of offloading selected IP data traffic from 3G to WLAN access networks is considered a key feature in the upcoming 3GPP specifications, being the main goal to alleviate data congestion in celular networks while delivering a positive user experience. Lately, the 3GPP has adopted solutions that enable mobility of IP-based wireless devices relocating mobility functions from the terminal to the network. To this end, the IETF has standardized Proxy Mobile IPv6 (PMIPv6), a protocol capable to hide often complex mobility procedures from the mobile devices. This thesis, in line with the mentioned offload requirement, further extends Proxy Mobile IPv6 to support dynamic IP flow mobility management across access wireless networks according to operator policies. In this work, we assess the feasibility of the proposed solution and provide an experimental analysis based on a prototype network setup, implementing the PMIPv6 protocol and the related enhancements for flow mobility support. *** La capacità di spostare flussi IP da una rete di accesso 3G ad una di tipo WLAN è considerata una caratteristica chiave nelle specifiche future di 3GPP, essendo il principale metodo per alleviare la congestione nelle reti cellulari mantenendo al contempo una ragionevole qualità percepita dall'utente. Recentemente, 3GPP ha adottato soluzioni di mobilità per dispositivi con accesso radio basato su IP, traslando le funzioni di supporto dal terminale alla rete, e, a questo scopo, IETF ha standardizzato Proxy Mobile IPv6 (PMIPv6), un protocollo studiato per nascondere le procedure di mobilità ai sistemi mobili. Questa tesi, in linea con la citata esigenza di spostare flussi IP, estende ulteriormente PMIPv6 per consentire il supporto alla mobilità di flussi tra diverse reti di accesso wireless, assecondando le regole e/o politiche definite da un operatore. In questo lavoro, ci proponiamo di asserire la fattibilità della soluzione proposta, fornendo un'analisi sperimentale di essa sulla base di un prototipo di rete che implementa il protocollo PMIPv6 e le relative migliorie per il supporto alla mobilità di flussiope

Rate Optimal design of a Wireless Backhaul Network using TV White Space

The penetration of wireless broadband services in remote areas has primarily been limited due to the lack of economic incentives that service providers encounter in sparsely populated areas. Besides, wireless backhaul links like satellite and microwave are either expensive or require strict line of sight communication making them unattractive. TV white space channels with their desirable radio propagation characteristics can provide an excellent alternative for engineering backhaul networks in areas that lack abundant infrastructure. Specifically, TV white space channels can provide "free wireless backhaul pipes" to transport aggregated traffic from broadband sources to fiber access points. In this paper, we investigate the feasibility of multi-hop wireless backhaul in the available white space channels by using noncontiguous Orthogonal Frequency Division Multiple Access (NC-OFDMA) transmissions between fixed backhaul towers. Specifically, we consider joint power control, scheduling and routing strategies to maximize the minimum rate across broadband towers in the network. Depending on the population density and traffic demands of the location under consideration, we discuss the suitable choice of cell size for the backhaul network. Using the example of available TV white space channels in Wichita, Kansas (a small city located in central USA), we provide illustrative numerical examples for designing such wireless backhaul network