Energy economy in mobile devices is becoming an increasinglyimportant factor as the devices become more advancedand rich in features. A large part of the energy footprint of amobile device comes from the wireless communication module,and even more so as the amount of trac increases.In this paper we study the energy footprint of a mobilebroadband hardware module, and how it is aected by software,by performing systematic power consumption measurements.We show that there are several cases where thesoftware does not properly take into account the eect thatdata communication has on the power consumption. Thisopens up for potential energy savings by creating better applicationsthat are aware of the energy characteristics of thecommunication layer.

WiMax or the IEEE 802.16 standard is one of the most promising broadband wireless technologies nowadays. It is characterized by its high data rates, large coverage area, flexible design and QoS support. The standard defines two modes of operation: Point-to- Multi-Point (PMP) and the Mesh Mode. In the first mode, all nodes are connected directly to the base station and communication is not allowed amongst nodes. In the mesh mode, nodes are placed in an ad hoc manner communicating to neighbors and relaying the traffic of other nodes. The goal of this thesis is to design a partitioning scheme for the frame structure of the Mesh mode. Increasing the frame utilization would result in better support for QoS applications and optimized resource allocation, and thus revenue increase from the service provider’s perspective. The mesh frame is divided into control and data, which are further divided into centralized and distributed portions. We propose a novel and efficient scheme for partitioning the data subframe between the two schedulers. We use a Markovian model that studies the system behavior in the long run, and provides predictions based on analysis of previous window of frames. We further enhance the decision by tuning the partitioning through statistical analysis of smaller windows to accommodate demand changes. Our simulations show that the proposed scheme achieves high utilization under different network and traffic conditions and decreases the packet overflow. / Thesis (Master, Computing) -- Queen's University, 2008-10-02 18:41:36.551

ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, California / With the recent broadband upgrades to various cellular infrastructures and the myriad new emerging wireless broadband standards and services offered by carriers, it is often difficult to navigate this sea of technology. In deciding the best choice for broadband telemetry applications, one must look not only at the technology, but also at the economics, market timing, bandwidths, legacy issues, future expandability and coverage, security, protocols, and the requirements of the specific application. This paper reviews the technology roadmap of cellular providers keeping these issues in perspective as they apply to TCP/IP data for images, audio, video, and other broadband telemetry data using CDMA 1xRTT, EV-DO, and EV-DO Rev A systems as well as GSM GPRS/EDGE, UMTS/W-CDMA, HSDPA, and HSUPA networks. Lastly, issues seen by system integrators when using cellular channels for telemetry applications are examined, and a case is presented for overcoming many of these issues through the use of cellular routers.

This Thesis is an embodiment of some research work carried out towards achieving faster and more reliable handover techniques in a Mobile WiMAX (Worldwide Interoperability for Microwave Access) network. Handover, also called handoff, is the critical mechanism that allows an ongoing session in a cellular mobile network like WiMAX to be seamlessly maintained without any call drop as the Mobile Station (MS) moves out of the coverage area of one base station (BS) to that of another. Mobile WiMAX supports three different types of handover mechanisms, namely, the hard handover, the Fast Base Station Switching (FBSS) and the Micro-Diversity Handover (MDHO). Out of these, the hard handover is the default handover mechanism whereas the other two are the optional schemes. Also, FBSS and MDHO provide better performance in comparison to hard handover, when it comes to dealing with the high-speed multimedia applications. However, they require a complex architecture and are very expensive to implement. So, hard handover is the commonly used technique accepted by the mobile broadband wireless user community including Mobile WiMAX users. The existing Mobile WiMAX hard handover mechanism suffers from multiple shortcomings when it comes to providing fast and reliable handovers. These shortcomings include lengthy handover decision process, lengthy and unreliable procedure of selecting the next BS, i.e., the target BS (TBS) for handover, occurrence of frequent and unwanted handovers, long connection disruption times (CDT), wastage of channel resources, etc. Out of these, reducing the handover latency and improving the handover reliability are the two issues that our present work has focused on. While the process of selecting the TBS for handover adds to the overall delay in completing the process of handover, choosing a wrong TBS for handover increases the chance of further unwanted handovers to occur or even a call drop to occur. The latter greatly hampers the reliability of a handover. In order to contribute to the solution of the above two problems of slow handover and unreliable handover, this Thesis proposes and investigates three handover techniques, which have been called Handover Techniques 1, 2 and 3, respectively. Out of these three techniques, the first two are fully MS-controlled while the third one is a dominantly serving BS-controlled. In Handover Techniques 1 and 2, which share between them some amount of commonness of ideas, the MS not only itself determines the need for a handover but also self-tracks its own independent movement with respect to the location of the (static) neighboring BSs (NBS). N both these handover techniques, the MS performs distance estimation of the NBSs from the signal strength received from the NBSs. But they (the two handover techniques) employ different kinds of “lookahead” techniques to independently choose, as the TBS, that NBS to which the MS is most likely to come nearest in the future. Being MS-controlled, both Handover Technique 1 and Handover Technique 2 put minimal handover-related workload on their respective SBSs who thus remain free to offer services to many more MSs. This interesting capability of the two handover techniques can increase the scalability of the WiMAX network considerably. In Handover Technique 3, which is a BS-controlled one with some assistance received from the MS, the SBS employs three different criteria or parameters to select the TBS. The first criterion, a novel one, is the orientation matching between the MS’s direction of motion and the geolocation of each NBS. The other two criteria are the current load of each NBS (the load provides an indication of a BS’s current QoS capabilities) and the signal strength received by the MS from each NBS. The BS assigns scores to each NBS against each of the three independent parameters and selects the TBS, which obtains the highest weighted average score among the NBSs. All three handover techniques are validated using simulation methods. While Handover Techniques 1 and 2 are simulated using Qualnet network simulator, for Handover Technique 3, we had to design, with barest minimum capability, our own simulation environment, using Python. Results of simulation showed that for Handover Techniques 1 and 2, it is possible to achieve around 45% improvement (approx) in the overall handover time by using the two proposed handover techniques. The emphasis in the simulation of the Handover Technique 3 was on studying its reliability in producing correct handovers rather than how fast handovers are. Five different arbitrary pre-defined movement paths of the MS were studied. Results showed that with orientation matching or orientation matching together with signal strength, reliability was extremely good, provided the pre-defined paths were reasonably linear. But reliability fell considerably when relatively large loads were also considered along with orientation matching and signal strength. Finally, the comparison between the proposed handover techniques in this Thesis and few other similar techniques in Mobile WiMAX proposed by other researchers showed that our techniques are better in terms providing fast, reliable and intelligent handovers in Mobile WiMAX networks, with scalability being an added feature.

This research focuses on developing a framework for Worldwide Interoperability for Microwave Access (WiMax) technology adoption by Small and Medium Enterprises (SMEs) in the Kingdom of Saudi Arabia (KSA). WiMax has emerged as a technology to overcome the limitations of traditional and existing broadband technologies and support a great number of organisations and consumers/citizens in providing a higher speed over substantial distances i.e. in areas that are difficult for wired infrastructure to reach. Despite all the interest in the types of broadband adoption as demonstrated by SMEs in several countries, there seems to be slow progress and lack of information supporting the decision making process for WiMax technology adoption by SMEs specifically in the context of KSA. This may illustrate that SMEs adopt WiMax technology solutions at a slower pace and make them characterised as laggards in terms of new technologies adoption. This research takes into consideration this literature gap and makes a step forward and investigates on WiMax technology adoption by SMEs in KSA with an organisational cultural view, vendors’ commercialisation strategies and government policies by analysing the normative literature related to this research. The data collection of this study was carried out in two phases including quantitative and qualitative approaches. The first phase of the research provided results indicated that, the Saudi SMEs who participated in this research are strongly dominated by clan culture and adhocracy culture. These cultures also have a positive impact on the Internet technologies adoption such as WiMax by SMEs. It is found that, the combination of clan and adhocracy cultures in Saudi SMEs is making them more likely to adopt latest Internet technologies. In the second phase, the results showed a wide difference in views among SMEs, WiMax vendors and government agencies involved in WiMax technology diffusion to SMEs in Saudi Arabia. Although WiMax technology started as an innovation that has the potential to be disruptive and could replace the widely diffused fixed wire line Internet connection, the research findings showed an interesting deviation from this path. In particular, the WiMax technology market analysis in Saudi Arabia highlighted the vendors’ tendency to treat WiMax technology as a sustaining innovation. Research findings also indicated that, the Saudi government provided funds for Information and Communications Technology‘s diffusion in the country. However, the level of awareness displayed by SMEs is persistently low. Knowledge deployment, mobilisation, innovation directive and subsidy have been emphasised by SMEs as the most important government interventions that might have an impact on WiMax adoption by them. Finally, further important issues have been uncovered by the research such as taxation, experience exchange, herd culture/bandwagon, consumer right protection and customer service in relation to the adoption of WiMax by SMEs. The perceived future prospect of these additional issues has been considered as an influence on adoption of WiMax technology by SMEs. The findings of this research can be useful to guide analysts and researchers in determining critical aspects of the complex issues involved in technologies adoption, and lead to suggestions for further valid research.

Στόχος της εργασίας αυτής είναι η υλοποίηση ενός συστήματος WiMAX στο Matlab Simulink, σύμφωνα με το πρότυπο της IEEE 802.16-2004.Το σύστημα ενσωματώνει όλα τα υποχρεωτικά χαρακτηριστικά γνωρίσματα του φυσικού στρώματος OFDM 256-σημείων FFT. Η εργασία αυτή οργανώνεται σε πέντε κεφάλαια στα οποία γίνεται μια αναλυτική περιγραφή κάθε στοιχείου του συστήματος λαμβάνοντας κάθε φορά υπόψη τις προδιαγραφές του προτύπου αλλά και τις αντίστοιχες θεωρητικές πτυχές οι οποίες είναι απαραίτητες για να γίνουν αντιληπτές κάθε φορά όλες οι μέθοδοι και οι διαδικασίες που χρησιμοποιήθηκαν. Στο Κεφάλαιο 1 γίνεται μια αναδρομή στο πώς και για ποιό λόγο ξεκίνησε η ανάπτυξη του προτύπου IEEE 802.16 και περιγράφονται τα βασικά χαρακτηριστικά του. Ακόμη γίνεται μια σύγκριση μεταξύ του WiMAX και άλλων ασύρματων συστημάτων ευρείας πρόσβασης. Στο Κεφάλαιο 2 παρουσιάζονται οι βασικές παράμετροι που διέπουν την απόδοση του ασύρματου καναλιού ώστε να γίνουν αντιληπτοί οι περιορισμοί που αυτό εισάγει κατά τη διαδικασία της μετάδοσης. Επιπλέον αναλύεται η τεχνική διαμόρφωσης OFDM στην οποία βασίζεται το WiMAX και η οποία είναι κατάλληλη για περιπτώσεις ασύρματης μετάδοσης. Στο Κεφάλαιο 3 γίνεται μια εισαγωγή στις τεχνικές πολλαπλών κεραιών και κυρίως στην τεχνολογία ΜΙΜΟ. Η χρήση πολλαπλών κεραιών στον πομπό ή/και στον δέκτη σε μια επικοινωνιακή ζεύξη δημιουργεί μια καινούρια διάσταση στις ασύρματες επικοινωνίες βελτιώνοντας σημαντικά την απόδοση των συστημάτων. Ιδιαίτερο βάρος δίνεται στην περιγραφή της τεχνικής Alamouti η ο οποία και εφαρμόστηκε στην υλοποίηση του συστήματος. Στο Κεφάλαιο 4 παρουσιάζονται οι προδιαγραφές και τα τεχνικά χαρακτηριστικά του φυσικού στρώματος του προτύπου IEEE 802.16. Στο Κεφάλαιο 5 αναλύεται η υλοποίηση του συστήματος WiMAX(πομπός και δέκτης)η οποία πραγματοποιήθηκε στο Matlab Simulink. Παρουσιάζεται λεπτομερώς η σχεδίαση του κάθε μέρους του συστήματος και παρατίθενται τα αποτελέσματα των προσομοιώσεων τα οποία επιβεβαιώνουν την ορθότητα λειτουργίας του συστήματος που υλοποιήθηκε. / The purpose of this thesis is the implementation of a WiMAX system in Matlab Simulink, in compliance with the IEEE 802.16 standard. The system incorporates all the necessary features of the physical OFDM 256-FFT layer. The present topic is organized in five chapters, in which a detailed overview of every element of the system is given taking into account both the standard specifications and the corresponding theoretical aspects, which are necessary to understand all the different methods and processes that have been used. In Chapter 1 an overview is given explaining how and why IEEE 802.16 standard emerged and its main features are outlined. Moreover, a comparison is being made between WiMAX and other wireless broadband systems. Chapter 2 presents the main parameters that affect the performance of a wireless channel, so as to become clear the limitations that the channel itself inserts during the transmission process. Also, the OFDM modulation technique, in which WiMAX is based and it is appropriate for wireless transmission, is being analyzed. Chapter 3 introduces MIMO systems. The use of multiple antennas at the transmitter and/or at the receiver in a communication link opens a new dimension in reliable wireless communications, improving the performance of the system substantially. We are focusing on the Alamouti technique which was implemented in the system. Chapter 4 presents the specifications and the technical features of the IEEE 802.16 physical layer. Chapter 5 explores the implementation of the system (transmitter and receiver) that was made in Matlab Simulink. The design of each part of the system is being discussed in detail and the simulations results are given in order to provide proof for the right function of the implemented system.

This thesis presents an exploratory study into the development of digital societies and it examines public sector modernization and innovation from a technology management perspective. The study presents reasons why most city-wide or council-wide development of wireless broadband access networks currently end in failure or are unsustainable. It also suggests its links with wider problems of innovation management and the commercial failure of otherwise technically competent solutions It explores the modernisation of society, government, the underlying theories that influence it as well as the innovations triggered by its wake. The exercise reveals a myriad of innovations; firstly in the modernisation of the infrastructure of government and secondly in the development of societal infrastructure in the form of broadband networks.

我國的電信市場自1987年起開始逐漸邁向自由化，迄今已完成行動通信、衛星通信、固定通信等多項電信業務之開放，在2001年7月開放語音轉售業務(International Simple Release)及2002年2月完成第三代行動通信業務執照之釋出工作後，我國電信市場開放之程度已與國際電信市場發展趨勢同步。我國亦於2002年1月1日成為世界貿易組織(WTO)會員。 鑑於無線寬頻接取業務(Wireless Broadband Access Service)是全球積極研發的重點產業，我國政府為求與世界接軌，亦積極投入此一電信業務行列。國家通訊傳播委員會(NCC)為配合行政院所裁定推動的行動台灣產業政策，將政策轉化為法律，於2007年3月30日依據電信法第14條第6項之授權，發布「無線寬頻接取業務管理規則」，作為開放2.5-2.69GHz頻段提供無線寬頻接取服務之法規基礎。無線寬頻接取業務於2007年辦理執照競標，共發行6張分區特許執照，執照期限為6年。 本論文將檢視因配合政府產業政策所制定與第四代行動通訊系統有著密切關係的「無線寬頻接取業務管理規則」，是否符合我國電信法與其他國際組織所揭櫫的「技術中立」的基本精神與管制規範，以及因不合適的規範所造成在實務面上對法規與管制之影響。 關鍵字 ：無線寬頻接取、技術中立、電信法、國際標準規範。 / Liberalization of telecommunications market in Taiwan has been proceeded progressively since 1987. So far the restrictions on mobile communication, satellite communication, and fixed-network communication have all been relaxed. After the liberalization of ISR (International Simple Release) business in July 2001 and the release of the third generation mobile communication licenses in February 2002, Taiwan’s telecommunications market has become as open as all the other developed countries. In addition, Taiwan became a member of WTO on January 1st, 2002. In light of the importance of wireless broadband access services from a global perspective, Taiwan government has been actively devoting to the development of wireless broadband access to secure an early mover advantage. Given the fact that wireless broadband access is an integral part of Executive Yuan’s industry policy and the implementation demands appropriate regulations, National Communications Commission (NCC) released “Regulations on Wireless Broadband Access (WBA) Services” on March 30th, 2007 based on paragraph 6, article 14 of “Telecom Act”, which forms the legal framework for the release of 2.5-2.69GHz spectrums exclusively for the provisioning of wireless broadband access services. The licenses of wireless broadband access services were auctioned in 2007. The total number of licenses (regional) is six and the duration of permits is six years. As unbiased treatment is the core value, when international standard organizations are dealing with emerging technologies. This dissertation inspects the technical neutrality of “Regulations on WBA Services” which is induced by a government industry policy and highly relevant to the 4th generation mobile communication systems. The criteria includes the conformance of Telecom Act with the essence and standards of other international standard organizations as well as the impact on the implementation due to improper regulations from both the regulation and legal perspectives.

This thesis presents an exploratory study into the development of digital societies and it examines public sector modernization and innovation from a technology management perspective. The study presents reasons why most city-wide or council-wide development of wireless broadband access networks currently end in failure or are unsustainable. It also suggests its links with wider problems of innovation management and the commercial failure of otherwise technically competent solutions It explores the modernisation of society, government, the underlying theories that influence it as well as the innovations triggered by its wake. The exercise reveals a myriad of innovations; firstly in the modernisation of the infrastructure of government and secondly in the development of societal infrastructure in the form of broadband networks.

As wireless technologies evolve, novel innovations and concepts are required to dynamically and automatically alter various radio parameters in accordance with the radio environment. These innovations open the door for cognitive radio (CR), a new concept in telecommunications. CR makes its decisions using an inference engine, which can learn and adapt to changes in radio conditions. Fuzzy logic (FL) is the proposed decision-making algorithm for controlling the CR's inference engine. Fuzzy logic is well-suited for vague environments in which incomplete and heterogeneous information is present. In our proposed approach, FL is used to alter various radio parameters according to experience gained from different environmental conditions. FL requires a set of decision-making rules, which can vary according to radio conditions, but anomalies rise among these rules, causing degradation in the CR's performance. In such cases, the CR requires a method for eliminating such anomalies. In our model, we used a method based on the Dempster-Shafer (DS) theory of belief to accomplish this task. Through extensive simulation results and vast case studies, the use of the DS theory indeed improved the CR's decision-making capability. Using FL and the DS theory of belief is considered a vital module in the automation of various radio parameters for coping with the dynamic wireless environment. To demonstrate the FL inference engine, we propose a CR version of WiMAX, which we call CogMAX, to control different radio resources. Some of the physical parameters that can be altered for better results and performance are the physical layer parameters such as channel estimation technique, the number of subcarriers used for channel estimation, the modulation technique, and the code rate. / Ph. D.