Performance Enhancement Mechanism of IEEE 802.11AH Machine Communication System

As the Internet gets more populated and the number of devices increase dramatically, demanding connectivity anytime, anywhere and for everything, the urge for a novel concept is raised. Consequently, Internet of Things (IoT) is introduced to shed a light on the vision of the future Internet with tremendous amount of "things" interconnected to each other while utilizing various technologies for different applications. As a wide range of wireless technologies are developed and are extensively used worldwide, IEEE 802.11 working group for WLAN standards is developing a new amendment referred as IEEE 802.11AH targeting mainly the IoT based applications. The new amendment has inherited many characteristics from the legacy IEEE 802.11 while benefiting from new enhanced features defined specifically for IoT and Machine to Machine communications (M2M) systems. Ultimately, IEEE 802.11AH which has been defined to operate in sub-1 GHz band, is expected to support high number of simultaneous connections up to 6000 devices for a 1 km coverage range. This thesis implements some of the enhanced features for IEEE 802.11AH and conducts the corresponding evaluation based on a developed simulator. The aforementioned simulator has been compared to a Markov chain based analytical model, developed in this research. The results have shown that the developed system level simulator is following the results from the modeled network with high accuracy. The developed system level simulator has been used in performance evaluation of the IEEE 802.11AH main features like the restricted access window (RAW) and sectorization schemes in the case of single and multiple APs deployments scenarios. It is concluded that the implementation of these features, help to improve IEEE 802.11AH overall performance. The performance measures considered in this evaluation are throughput, energy efficiency and average delay in sending successful packets, respectively. Moreover, for resolving the coverage requirements there is a trade-off in using single AP or multi AP configuration. Implementing more APs results in more network capacity while causing additional interference to the network. The RAW and sectorization mechanisms can fortunately reduce this interference by minimizing the hidden node probability and mitigating against the overlapping BSS resulting problems

Performance Enhancement Mechanism of IEEE 802.11AH Machine Communication System

As the Internet gets more populated and the number of devices increase dramatically, demanding connectivity anytime, anywhere and for everything, the urge for a novel concept is raised. Consequently, Internet of Things (IoT) is introduced to shed a light on the vision of the future Internet with tremendous amount of "things" interconnected to each other while utilizing various technologies for different applications. As a wide range of wireless technologies are developed and are extensively used worldwide, IEEE 802.11 working group for WLAN standards is developing a new amendment referred as IEEE 802.11AH targeting mainly the IoT based applications. The new amendment has inherited many characteristics from the legacy IEEE 802.11 while benefiting from new enhanced features defined specifically for IoT and Machine to Machine communications (M2M) systems. Ultimately, IEEE 802.11AH which has been defined to operate in sub-1 GHz band, is expected to support high number of simultaneous connections up to 6000 devices for a 1 km coverage range. This thesis implements some of the enhanced features for IEEE 802.11AH and conducts the corresponding evaluation based on a developed simulator. The aforementioned simulator has been compared to a Markov chain based analytical model, developed in this research. The results have shown that the developed system level simulator is following the results from the modeled network with high accuracy. The developed system level simulator has been used in performance evaluation of the IEEE 802.11AH main features like the restricted access window (RAW) and sectorization schemes in the case of single and multiple APs deployments scenarios. It is concluded that the implementation of these features, help to improve IEEE 802.11AH overall performance. The performance measures considered in this evaluation are throughput, energy efficiency and average delay in sending successful packets, respectively. Moreover, for resolving the coverage requirements there is a trade-off in using single AP or multi AP configuration. Implementing more APs results in more network capacity while causing additional interference to the network. The RAW and sectorization mechanisms can fortunately reduce this interference by minimizing the hidden node probability and mitigating against the overlapping BSS resulting problems

Solutions for the electric potential and field distribution in cylindrical core-shell nanoparticles using the image charge method

This article considers the problem of finding the electrostatic potential that is given in terms of a scalar function called Green function in dielectric cylindrical nanoparticles with core-shell structure using the image charge method. By using this method that allows us to solve differential form of electric potential problem by the Green function, we investigate the distribution of the electric field in the configuration of a cylindrical nanoparticle surrounded by a continuum dielectric medium. By utilizing this well-known method, we obtain exact analytical formulas for the electrostatic potential and the electric field inside the shell, core and surrounding space of nanoparticle that can be applied to analysis of electromagnetic problems, electrostatic interactions in biomolecular simulations and also computer simulations of condensed-matter media

System-level analysis of IEEE 802.11ah technology for unsaturated MTC traffic

Enabling the Internet of Things, machine-type communications (MTC) is a next big thing in wireless innovation. In this work, we concentrate on the attractive benefits offered by the emerging IEEE 802.11ah technology to support a large number of MTC devices with extended communication ranges. We begin with a comprehensive overview of the novel features introduced by the latest IEEE 802.11ah specifications followed by the development of a powerful mathematical framework capturing the essential properties of a massive MTC deployment with unsaturated traffic patterns. Further, we compare our analytical findings for a characteristic MTC scenario against respective system-level simulations across a number of important performance indicators. Our analytical results provide adequate performance predictions even when simulations are challenged by the excessive computational complexity. In addition, we study the novel IEEE 802.11ah mechanisms offering improved support for massive device populations and conclude on their expected performance.acceptedVersionPeer reviewe