System for improving the efficiency of wireless networks

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2003.Includes bibliographical references (p. 30-31).Wireless data networks are widespread and growing quickly. As their use increases, many wireless networks are becoming congested. In addition, as wireless data capability moves into ever-smaller devices, power becomes a significant issue. This thesis presents a system that increases network bandwidth and decreases energy use without changing existing network hardware or protocols. We use specialized proxy servers to transparently modify the traffic sent over the mobile link such that the total energy used by the receiver is reduced and the effective bandwidth is increased. Our techniques include optimizing packet size, eliminating unnecessary traffic, and masking wireless packet losses. We design and implement two proxies--one for access points and one for mobile devices--which when used together, achieve up to a 20% decrease in energy and 38% increase in throughput.by Hans Robertson.M.Eng

Authoring design patterns for user & device dependant adaptive data presentation

In 2000 the iSign project started as a virtual web-based laboratory for students of study program electrical engineering. Continuous development in the last years led to a heterogeneous learning environment offering learning material, adaptive user settings and access to a simulation tool. Access is available via web and wireless devices such as PCs, Laptops, PDAs, smartphones and mobile phones. Our attempt to adapt the content to the user's needs and the currently used device led us to a XML based data structure. This report shows our research results about content adaptation based on XML data. The two main aspects for that process are: the device capabilities and the adaptation methods using XML data.University of Applied Sciences Offenburg, Germany Mobile Communications and Waves La

Iterative multiuser detection with integrated channel estimation for turbo coded DS-CDMA.

In present days the demand of high bandwidth and data rate in wireless communications is increasing rapidly to accommodate multimedia applications, including services such as wireless video and high-speed Internet access. In this thesis, we propose a receiver algorithm for mobile communications systems which apply CDMA (Code division multiple access) as multiple access technique. Multiuser Detection and turbo coding are the two most powerful techniques for enhancing the performance of future wireless services. The standardization of direct sequence CDMA (DS-CDMA) systems in the third generation of mobile communication system has raised the interest in exploiting the capabilities and capacity of this type of Technology. However the conventional DS-CDMA system has the major drawback of multiple Access Interference (MAI). The MAI is unavoidable because receivers deal with the information which is transmitted not by a single information source but by several uncoordinated and geographically separated sources. To overcome this problem MUD is a promising approach to increase capacity. (Abstract shortened by UMI.)Dept. of Electrical and Computer Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2005 .C465. Source: Masters Abstracts International, Volume: 45-01, page: 0404. Thesis (M.Sc.)--University of Windsor (Canada), 2005

PERANCANGAN JARINGAN MOBILE WIMAX (IEEE 802.16E) UNTUK LAYANAN MOBILE BROADBAND INTERNET ACCESS

ABSTRAKSI: Worldwide Interoperability for Microwave Access (WiMAX) adalah salah satu pengembangan teknologi wireless untuk komunikasi data sebelumnya, yang memberikan layanan broadband dalam cakupan Metropolitan Area Network (MAN) dengan kecepatan akses yang tinggi. Teknologi WiMAX yang telah sesuai dengan standar yang dikeluarkan Institute of Electrical and Electronics Engineering (IEEE) 802.16, menggunakan dua model operasi, yaitu tetap (fixed) atau nomadik, dan mobile (pengguna yang berpindah-pindah tempat). Disamping memiliki kecepatan akses yang tinggi, teknologi WiMAX memiliki keistimewaan tersendiri dibanding dengan teknologi nirkabel berpita lebar atau broadband wireless access (BWA) sebelumnya. Sehingga dengan munculnya WiMAX diperkirakan banyak digunakan untuk BWA masa sekarang dan masa depan. Teknologi WiMAX yang telah dikembangkan baik fixed maupun mobile, tanpa harus LOS (Line Of Sight) ini menawarkan kemudahan akses internet bagi penggunanya. Dengan frekuensi operasi yang berkisar 2.5 GHz dan 3.5 GHz untuk pita frekuensi yang berlisensi, 5.8 GHZ untuk pita frekuensi bebas lisensi, WiMAX dapat menangani kecepatan data hingga 75 Mbps, juga dengan jarak jangkau mencapai 50 km (tergantung frekuensi yang digunakan). Atau dengan kata lain, WiMAX dapat diaplikasikan untuk koneksi broadband ‘last mile’ ataupun backhaul. Adapun pada Proyek Akhir ini dibahas mengenai perancangan jaringan mobile WiMAX untuk layanan akses internet dengan studi kasus Jakarta Pusat yang merupakan daerah urban. Perancangan ini diperkuat dengan data-data yang menentukan coverage layanan, kapasitas jaringan, permintaan trafik, dan dimensioning cell, serta tools untuk memudahkan dalam perhitungan trafik dan link budget. Sehingga hasil perancangan untuk wilayah Jakarta Pusat ini, dapat diprediksi trafik dan link budget yang dibutuhkan.Kata Kunci : jaringan mobile wimax, IEEE 802.16e, backhaul, dimensioning cell, link budgetABSTRACT: Worldwide Interoperability for Microwave Access (WiMAX) is one of the development of technology for wireless data communications before, which provides broadband coverage in the Metropolitan Area Network (MAN) with a high-speed access. WiMAX technology that has been in accordance with standards issued by the Institute of Electrical and Electronics Engineering (IEEE) 802.16, using the two operating model, which is fixed (fixed) or nomadik, and mobile (the user who moved the place). Besides having a high-speed access, WiMAX technology has a distinctive feature compared with the wireless technology broadband wireless access (BWA) previously. So with the emergence of WiMAX is widely used for the BWA and the future now. WiMAX technology has been developed that either fixed or mobile, without having to LOS (Line Of Sight) offers ease of access for internet users. With the operating frequency range of 2.5 GHz and 3.5 GHz for licensed frequency band, 5.8 GHZ frequency band for the free licenses, WiMAX can handle data speeds up to 75 Mbps, as well as the coverage distance reached 50 km (depending on frequency of use). Or in other words, can be applied to WiMAX broadband connection \u27last mile\u27 or backhaul. The End of this Project will be discussed about the design of mobile WiMAX network for internet access service with a case study the Central Jakarta which is representative urban area. This design with the data that determines the service coverage, network capacity, traffic demand, and cell dimensioning, as well as tools to facilitate in the calculation of traffic and link budget. Therefore, the results of the Central Jakarta for this region, can be predicted traffic and link budget required.Keyword: mobile wimax network, IEEE 802.16e, backhaul, dimensioning cell, link budge

CogCell: Cognitive Interplay between 60GHz Picocells and 2.4/5GHz Hotspots in the 5G Era

Rapid proliferation of wireless communication devices and the emergence of a variety of new applications have triggered investigations into next-generation mobile broadband systems, i.e., 5G. Legacy 2G--4G systems covering large areas were envisioned to serve both indoor and outdoor environments. However, in the 5G-era, 80\% of overall traffic is expected to be generated in indoors. Hence, the current approach of macro-cell mobile network, where there is no differentiation between indoors and outdoors, needs to be reconsidered. We envision 60\,GHz mmWave picocell architecture to support high-speed indoor and hotspot communications. We envisage the 5G indoor network as a combination of-, and interplay between, 2.4/5\,GHz having robust coverage and 60\,GHz links offering high datarate. This requires an intelligent coordination and cooperation. We propose 60\,GHz picocellular network architecture, called CogCell, leveraging the ubiquitous WiFi. We propose to use 60\,GHz for the data plane and 2.4/5GHz for the control plane. The hybrid network architecture considers an opportunistic fall-back to 2.4/5\,GHz in case of poor connectivity in the 60\,GHz domain. Further, to avoid the frequent re-beamforming in 60\,GHz directional links due to mobility, we propose a cognitive module -- a sensor-assisted intelligent beam switching procedure -- which reduces the communication overhead. We believe that the CogCell concept will help future indoor communications and possibly outdoor hotspots, where mobile stations and access points collaborate with each other to improve the user experience.Comment: 14 PAGES in IEEE Communications Magazine, Special issue on Emerging Applications, Services and Engineering for Cognitive Cellular Systems (EASE4CCS), July 201

Vehicular Dynamic Spectrum Access: Using Cognitive Radio for Automobile Networks

Vehicular Dynamic Spectrum Access (VDSA) combines the advantages of dynamic spectrum access to achieve higher spectrum efficiency and the special mobility pattern of vehicle fleets. This dissertation presents several noval contributions with respect to vehicular communications, especially vehicle-to-vehicle communications. Starting from a system engineering aspect, this dissertation will present several promising future directions for vehicle communications, taking into consideration both the theoretical and practical aspects of wireless communication deployment. This dissertation starts with presenting a feasibility analysis using queueing theory to model and estimate the performance of VDSA within a TV whitespace environment. The analytical tool uses spectrum measurement data and vehicle density to find upper bounds of several performance metrics for a VDSA scenario in TVWS. Then, a framework for optimizing VDSA via artificial intelligence and learning, as well as simulation testbeds that reflect realistic spectrum sharing scenarios between vehicle networks and heterogeneous wireless networks including wireless local area networks and wireless regional area networks. Detailed experimental results justify the testbed for emulating a mobile dynamic spectrum access environment composed of heterogeneous networks with four dimensional mutual interference. Vehicular cooperative communication is the other proposed technique that combines the cooperative communication technology and vehicle platooning, an emerging concept that is expected to both increase highway utilization and enhance both driver experience and safety. This dissertation will focus on the coexistence of multiple vehicle groups in shared spectrum, where intra-group cooperation and inter-group competition are investigated in the aspect of channel access. Finally, a testbed implementation VDSA is presented and a few applications are developed within a VDSA environment, demonstrating the feasibility and benefits of some features in a future transportation system

Wireless Network Design and Optimization: From Social Awareness to Security

abstract: A principal goal of this dissertation is to study wireless network design and optimization with the focus on two perspectives: 1) socially-aware mobile networking and computing; 2) security and privacy in wireless networking. Under this common theme, this dissertation can be broadly organized into three parts. The first part studies socially-aware mobile networking and computing. First, it studies random access control and power control under a social group utility maximization (SGUM) framework. The socially-aware Nash equilibria (SNEs) are derived and analyzed. Then, it studies mobile crowdsensing under an incentive mechanism that exploits social trust assisted reciprocity (STAR). The efficacy of the STAR mechanism is thoroughly investigated. Next, it studies mobile users' data usage behaviors under the impact of social services and the wireless operator's pricing. Based on a two-stage Stackelberg game formulation, the user demand equilibrium (UDE) is analyzed in Stage II and the optimal pricing strategy is developed in Stage I. Last, it studies opportunistic cooperative networking under an optimal stopping framework with two-level decision-making. For both cases with or without dedicated relays, the optimal relaying strategies are derived and analyzed. The second part studies radar sensor network coverage for physical security. First, it studies placement of bistatic radar (BR) sensor networks for barrier coverage. The optimality of line-based placement is analyzed, and the optimal placement of BRs on a line segment is characterized. Then, it studies the coverage of radar sensor networks that exploits the Doppler effect. Based on a Doppler coverage model, an efficient method is devised to characterize Doppler-covered regions and an algorithm is developed to find the minimum radar density required for Doppler coverage. The third part studies cyber security and privacy in socially-aware networking and computing. First, it studies random access control, cooperative jamming, and spectrum access under an extended SGUM framework that incorporates negative social ties. The SNEs are derived and analyzed. Then, it studies pseudonym change for personalized location privacy under the SGUM framework. The SNEs are analyzed and an efficient algorithm is developed to find an SNE with desirable properties.Dissertation/ThesisDoctoral Dissertation Electrical Engineering 201