TechNews digests: Jan - Nov 2009

TechNews is a technology, news and analysis service aimed at anyone in the education sector keen to stay informed about technology developments, trends and issues. TechNews focuses on emerging technologies and other technology news. TechNews service : digests september 2004 till May 2010 Analysis pieces and News combined publish every 2 to 3 month

Enhancement of student learning in the lecture theatre by means of a radio frequency feedback system

The principal formal teaching mechanism of universities is the lecture - a cost efficient format where hundreds of students may be taught by a single lecturer. Lectures' learning outcome is less certain; the lecturer has little ability to appraise the nature of the audience's understanding. The introduction of an electronic communication path from students to the lecturer mitigates this disjuncture. This communication path has been introduced and was found to be extensively used during a series of lectures, with each student provided with a handset that is reliable, inexpensive and portable. Upon these handsets are buttons; the data is transmitted at radio frequencies to the lecturer, aggregated and displayed graphically for quick assimilation. It has been recognised that this communication path permits the direct measurement of student's educational behaviour without disturbing the lecture itself. Preliminary results indicating the value of this research methodology have been obtained. A significant correlation was identified between the percentage of questions during the lecture students answered correctly and their previous year's overall academic mark. A correlation was identified between the number of times students initiate communication with the lecturer and the number of questions during the lecture they answered correctly. Mixed evidence was found regarding a possible correlation between the evidence of satisfaction with their learning students provided using the system and the number of questions during the lecture they answered correctly. The introduction of an electronic communication path into lectures has proved to be an innovation deserving of further research and wider introduction into teaching practice

Energy efficient radio frequency system design for mobile WiMax applications. Modelling, optimisation and measurement of radio frequency power amplifier covering WiMax bandwidth based on the combination of class AB, class B, and C operations.

In today´s digital world, information and communication technology accounts for 3% and 2% of the global power consumption and CO2 emissions respectively. This alarming figure is on an upward trend, as future telecommunications systems and handsets will become even more power hungry since new services with higher bandwidth requirements emerge as part of the so called ¿future internet¿ paradigm. In addition, the mobile handset industry is tightly coupled to the consumer need for more sophisticated handsets with greater battery lifetime. If we cannot make any significant step to reducing the energy gap between the power hungry requirements of future handsets, and what battery technology can deliver, then market penetration for 4G handsets can be at risk. Therefore, energy conservation must be a design objective at the forefront of any system design from the network layer, to the physical and the microelectronic counterparts. In fact, the energy distribution of a handset device is dominated by the energy consumption of the RF hardware, and in particular the power amplifier design. Power amplifier design is a traditional topic that addresses the design challenge of how to obtain a trade-off between linearity and efficiency in order to avoid the introduction of signal distortion, whilst making best use of the available power resources for amplification. However, the present work goes beyond this by investigating a new line of amplifiers that address the green initiatives, namely green power amplifiers. This research work explores how to use the Doherty technique to promote efficiency enhancement and thus energy saving. Five different topologies of RF power amplifiers have been designed with custom-made signal splitters. The design core of the Doherty technique is based on the combination of a class B, class AB and a class C power amplifier working in synergy; which includes 90-degree 2-way power splitter at the input, quarter wavelength transformer at the output, and a new output power combiner. The frequency range for the amplifiers was designed to operate in the 3.4 - 3.6 GHz frequency band of Europe mobile WiMAX. The experimental results show that 30dBm output power can be achieved with 67% power added efficiency (PAE) for the user terminal, and 45dBm with 66% power added efficiency (PAE) for base stations which marks a 14% and 11% respective improvement over current stateof- the-art, while meeting the power output requirements for mobile WiMAX applications

MDSA, MULTI DECISION SCHEDULING ALGORITHM FOR UE ENERGY POWER SAVING ON MOBILE NETWORKS

Nowadays general different kind of recurrent network applications on mobile phones are like: news feed, podcast and e-mail which mostly run in the background and are a significant source of power consumption on battery limited mobile phones. Theory of scheduling such applications by prioritizing and evaluating step by step based on many conditions (or even parameters, timers) like radio network parameters, timeout values, coverage conditions or RSSI, switching between 2G and 3G on packet data, etc is our main focus on this paper. Cellular network providers typically try to control these timeout values, though some mobile devices use a technique called fast dormancy in order to reduce the time out duration which mostly results in huge power consumption for end user. The duration of this timeout, which ranges from a few seconds to ten seconds or more, is chosen to balance the cost of signaling for resource allocation to move a radio into active state (and the resulting latency and energy costs on the device) and the wasted resources due to maintaining a radio unnecessarily in active state. We also illustrate the significant energy savings that can be achieved via scheduling of recurrent mobile phone applications considering some network parameters, conditions and also user activity time (clock time) and phone battery condition as an add. These kinds of applications such as email syncing, facebook or photo uploads can defer communication, up to a point, without sacrificing service and user perception. Other applications such as on-demand streaming can prefetch content in anticipation of future need and this will not be considered for now on our study. The other very common service for mobile users is voice and by transmitting data when a call is active brings an extension on mobile phones battery life

The Economics of “Wireless Net Neutrality”

None.

Development and Integration of a Rapid Deployment Portable Land Mobile Unit for Emergency Communications

El disseny i integració d'una unitat de comunicacions mòbil per a situacions d'emergència englobada al projecte ABSOLUTE.[ANGLÈS] This thesis describes the design and implementation process of a portable land communications unit with a satellite backhauling link for emergency communications as part of the ABSOLUTE project. The ABSOLUTE project aim is to design rapidly deployable future network architecture capable of providing Broadband services and connectivity for large coverage areas affected by unexpected events or natural disasters where the terrestrial communication infrastructure is unavailable. The portable land communications unit is a system packed into a rugged suitcase and is a battery-powered device with several hours of operating autonomy. The communication systems that it has to provide within the ABSOLUTE project, are the following: mobile telephony and data over UMTS, mobile telephony and data over LTE, professional mobile radio over TETRA, Wireless LAN over IEEE 802.11, data collection from a Wireless Sensor Network, remote communications over a ka-band satellite link. Given the requirements and the specifications of the system, it has been designed starting from the state-of-the-art study and the selection of the hardware components and the main communication devices to the software needed to manage the communications and finishing with the implementation of part of these components for the first version of the system functional demonstration. The design process has been marked by the need to minimize the integrated devices’ power consumption with the aim to reduce the overall power consumption as well as the size and weight. That is why some proposals and studies to improve the system are presented although they have not been implemented for the first version they will be present in future versions.[CASTELLÀ] Esta tesis describe el proceso de diseño e implementación de una unidad portátil de comunicaciones terrestre con una conexión satélite para comunicaciones de emergencia englobada dentro del proyecto ABSOLUTE. El proyecto ABSOLUTE tiene como objetivo diseñar una futura arquitectura de red de despliegue rápido que pueda proporcionar servicios de banda ancha i conectividad a grandes áreas afectadas por eventos inesperados o desastres naturales i donde la infraestructura de comunicaciones terrestre haya quedado afectada. La unidad portátil de comunicaciones terrestre es un sistema de comunicaciones empaquetado en una maleta robusta i alimentado por baterías con varias horas de autonomía. Los sistemas de comunicaciones que ésta ha de proporcionar para el proyecto ABSOLUTE son: telefonía móvil y datos sobre UMTS, telefonía móvil y datos sobre LTE, radio móvil sobre TETRA, Wireless LAN IEEE 802.11, recogida de datos de una Wireless Sensor Network y comunicaciones remotas sobre un link por satélite en la banda ka. Dados los requisitos y las especificaciones del dispositivo, éste ha sido diseñado partiendo del estudio del estado del arte y de la elección de los elementos hardware y los dispositivos de comunicaciones necesarios, continuando por el software encargado de gestionar les comunicaciones y finalizando con la implementación de parte de estos elementos para la realización de la primera demostración funcional del dispositivo. El proceso de diseño ha estado marcado por la necesidad de minimizar el consumo de potencia de los dispositivos que lo integran con el objetivo de maximizar el tiempo de operatividad del conjunto así como reducir les dimensiones y el peso del mismo. Es por eso que se presentan propuestas i estudios de mejora del sistema que no han sido implementados para la primera versión pero que lo estarán en versiones futuras.[CATALÀ] Aquesta tesi descriu el procés de disseny i implementació d’una unitat portàtil de comunicacions terrestre amb connexió satèl·lit per a comunicacions d’emergència englobada dintre del projecte ABSOLUTE. El projecte ABSOLUTE té com a objectiu dissenyar una arquitectura de xarxa futurista de desplegament ràpid que pugui proporcionar serveis de banda ampla i connectivitat a grans àrees afectades per esdeveniments inesperats o desastres naturals i a on la infraestructura de comunicacions terrestre hagi quedat afectada. La unitat portàtil de comunicacions terrestre és un sistema de comunicacions empaquetat en una maleta robusta i alimentat per bateries amb vàries hores d’autonomia. Els sistemes de comunicació que aquestamaleta ha de proporcionar per al projecte ABSOLUTE són: telefonia mòbil i dades sobre UMTS, telefonia mòbil i dades sobre LTE, radio mòbil sobre TETRA, Wireless LAN IEEE 802.11, recollida de dades d’una Wireless Sensor Network i comunicacions remotes sobre un link per satèl·lit operant a la banda ka. Donats els requisits i les especificacions del dispositiu aquest ha estat dissenyat, començant per l’estudi de l’estat de l’art i l’elecció dels elements hardware i dispositius de comunicacions necessaris, continuant pel software encarregat de gestionar les comunicacions i finalitzant amb la implementació de part d’aquests elements per realitzar la primera demostració funcional del dispositiu. El procés de disseny ha estat marcat per la necessitat de minimitzar el consum de potència dels dispositius que l’integrenamb l’objectiu de maximitzar el temps d’operativitat del conjunt així com reduir les dimensions i el pes del mateix. És per això que es presenten propostes i estudis de millora del sistema que no han estat implementades per a la primera versió però que ho estaran en versions futures

Femtocell deployment; next generation in cellular systems

The final Bachelor’s Thesis that is shown below has such a final purpose of giving an overview of the inclusion of the so-called Femtocells (or Home Node B) in the current cellular systems. The main objective is to give a clear but simple idea about the concepts of Femtocells, as well as to explain the benefits and disadvantages of the mass uses of these services both for consumers and associated companies with this phenomenon. In this text it is also possible to find a brief review of wireless technologies throughout the history of telecommunications, as well as an introduction to the more current wireless technologies, with a special interest in the concept of cellular systems. In the last chapter a simple mathematical explanation of the key issue of interference between Femtocells and macrocellular networks is presented, with a brief argument about possible solutions

Context Sensor Data on Demand for Mobile Users Supported by XMPP

Tänapäeval võimaldavad tehnoloogilised edusammud kasutaja käitumise seiremeetodites automatiseerida teatud arvutusülesandeid, mis täidetakse kasutaja kavatsust prognoosides. Nutitelefonid rikastavad mobiilseid rakendusi prognoosiva käitumisega kasutatavuses, mis võimaldab käitumismustritega sammu pidada. Üldiselt on sellist käitumist võimalik saavutada nutitelefoni enda vahenditega, kasutades telefoni sisse ehitatud mikromehaanilisi seadmeid, mis võimaldavad keskkonda tajuda. Lisaks võivad mobiilsed rakendused kasutaja mobiilse kogemuse rikastamiseks lõigata kasu keskkonda integreeritud hajuslausteenustest, nagu näiteks ümbrustundlike mängude, kodu automatiseerimise tarkvara jms puhul. Ent mobiilikasutajatele suunatud lausteenuseid pakkuvatel elektroonilistel seadmetel, mis koguvad sensorite abi keskkonnast informatsiooni, on teatavad riistvaralised piirangud (arvutusjõudlus, mälu, salvestusmeedia, energiatarbimine jne). Seega, lausüsteemid ei ole võimelised nõudluse suurenemisel skaleeruma ega rakendama suurt arvutusjõudlust. Töö eesmärgiks on pakkuda lahendus ületamaks skaleeruvuse, andmete terviklikkuse säilitamise ja vähese arvutusjõudluse probleeme ning rikastada nutitelefoni rakendusi detailsete kasutajapõhiste andmetega. Eesmärgi saavutamiseks transporditakse sensoritelt kogutud informatsioon optimiseeritud XMPP protokolli abiga Arduino mikrokontrollerist pilvesüsteemi. Süsteemi ehitamiseks kasutatakse Arduino poolt pakutavat odavat riistvara, samas kui pilvesüsteemi usaldusväärset ja kõrge kättesaadavusega vahendeid kasutatakse mikrokontrollerist saadetud andmete salvestamiseks ja edaspidiseks töötlemiseks. Töö käigus testiti mikrokontrolleri energia nõudlust, kasutades 9V patareid, nii juhtme kui ka juhtmevaba liidesega. Tulemused tõestasid eeldustele vastupidiselt, et juhtmevaba süsteemi energia nõudlus on suurem. Lisaks testiti vabavara XMPP serveri jõudlust pilvesüsteemi keskkonnas ning tulemused näitasid, et XMPP võimaldab üheaegselt serveerida suure hulga kasutajaid

Characterization and Optimization of Resource Utilization for Cellular Networks.

Cellular data networks have experienced significant growth in the recent years particularly due to the emergence of smartphones. Despite its popularity, there remain two major challenges associated with cellular carriers and their customers: carriers operate under severe resource constraints, while many mobile applications are unaware of the cellular specific characteristics, leading to inefficient radio resource and handset energy utilization. My dissertation is dedicated to address both challenges, aiming at providing practical, effective, and efficient methods to monitor and to reduce the resource utilization and bandwidth consumption in cellular networks. Specifically, from carriers' perspective, we performed the first measurement study to understand the state-of-the-art of resource utilization for a commercial cellular network, and revealed that fundamental limitation of the current resource management policy is treating all traffic according to the same resource management policy globally configured for all users. On mobile applications' side, we developed a novel data analysis framework called ARO (mobile Application Resource Optimizer), the first tool that exposes the interaction between mobile applications and the radio resource management policy, to reveal inefficient resource usage due to a lack of transparency in the lower-layer protocol behavior. ARO revealed that many popular applications built by professional developers have significant resource utilization inefficiencies that are previously unknown. Motivated by the observations from both sides, we further proposed a novel resource management framework that enables the cooperation between handsets and the network to allow adaptive resource release, therefore better balancing the key tradeoffs in cellular networks. We also investigated the problem of reducing the bandwidth consumption in cellular networks by performing the first network-wide study of HTTP caching on smartphones due to its popularity. Our findings suggest that for web caching, there exists a huge gap between the protocol specification and the protocol implementation on today's mobile devices, leading to significant amount of redundant network traffic.PHDComputer Science and EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/94024/1/fengqian_1.pd