Effect of pedestrian movement on MIMO-OFDM channel capacity in an indoor environment

The rapid growth of mobile telephone use, satellite services, and now the wireless Internet and WLANs are generating tremendous changes in telecommunication and networking. As indoor wireless communications become more prevalent, modeling indoor radio wave propagation in populated environments is a topic of significant interest. Wireless MIMO communication exploits phenomena such as multipath propagation to increase data throughput and range, or reduce bit error rates, rather than attempting to eliminate effects of multipath propagation as traditional SISO communication systems seek to do. The MIMO approach can yield significant gains for both link and network capacities, with no additional transmitting power or bandwidth consumption when compared to conventional single-array diversity methods. When MIMO and OFDM systems are combined and deployed in a suitable rich scattering environment such as indoors, a significant capacity gain can be observed due to the assurance of multipath propagation. Channel variations can occur as a result of movement of personnel, industrial machinery, vehicles and other equipment moving within the indoor environment. The time-varying effects on the propagation channel in populated indoor environments depend on the different pedestrian traffic conditions and the particular type of environment considered. A systematic measurement campaign to study pedestrian movement effects in indoor MIMO-OFDM channels has not yet been fully undertaken. Measuring channel variations caused by the relative positioning of pedestrians is essential in the study of indoor MIMO-OFDM broadband wireless networks. Theoretically, due to high multipath scattering, an increase in MIMO-OFDM channel capacity is expected when pedestrians are present. However, measurements indicate that some reductions in channel capacity could be observed as the number of pedestrians approaches 10 due to a reduction in multipath conditions as more human bodies absorb the wireless signals. This dissertation presents a systematic characterization of the effects of pedestrians in indoor MIMO-OFDM channels. Measurement results, using the MIMO-OFDM channel sounder developed at the CSIRO ICT Centre, have been validated by a customized Geometric Optics-based ray tracing simulation. Based on measured and simulated MIMO-OFDM channel capacity and MIMO-OFDM capacity dynamic range, an improved deterministic model for MIMO-OFDM channels in indoor populated environments is presented. The model can be used for the design and analysis of future WLAN to be deployed in indoor environments. The results obtained show that, in both Fixed SNR and Fixed Tx for deterministic condition, the channel capacity dynamic range rose with the number of pedestrians as well as with the number of antenna combinations. In random scenarios with 10 pedestrians, an increment in channel capacity of up to 0.89 bits/sec/Hz in Fixed SNR and up to 1.52 bits/sec/Hz in Fixed Tx has been recorded compared to the one pedestrian scenario. In addition, from the results a maximum increase in average channel capacity of 49% has been measured while 4 antenna elements are used, compared with 2 antenna elements. The highest measured average capacity, 11.75 bits/sec/Hz, corresponds to the 4x4 array with 10 pedestrians moving randomly. Moreover, Additionally, the spread between the highest and lowest value of the the dynamic range is larger for Fixed Tx, predicted 5.5 bits/sec/Hz and measured 1.5 bits/sec/Hz, in comparison with Fixed SNR criteria, predicted 1.5 bits/sec/Hz and measured 0.7 bits/sec/Hz. This has been confirmed by both measurements and simulations ranging from 1 to 5, 7 and 10 pedestrians.

“Now I know their secrets” : Kineikonic texts in the literacy classroom

Kineikonic texts – sites of the moving image – are increasingly prevalent with the rise of digital television, Web 2.0 tools, broadband Internet, and sophisticated mobile technologies. Digital practices are changing the shape of the literacy curriculum, calling for new metalanguages to describe digital and multimodal texts. This paper combines multiliteracies and functional approaches to map conventional and new textual features of a popular kineikonic text – the claymation movie. Enlivened with data from an ethnically diverse, Year 6 classroom, the author outlines filmic conventions to enable teachers and students to analyse and design movies

Research adventures in Web 2.0 : encouraging collaborative local content creation through edgeX

The intersection of current arguments about the role of creative industries in economic development, online user-generated content, and the uptake of broadband in economically disadvantaged communities provides the content for this article. From 2006 to 2008 the authors carried out a research project in Ipswich, Queensland involving local creative practitioners and community groups in their development of edgeX, a Web-based platform for content uploads and social networking. The project aimed to explore issues of local identity and community building through online networking, as well as the possibilities for creating pathways from amateur to professional practice in the creative industries through the auspices of the Website. Set against the backdrop of a rapidly changing technological environment that has problematic implications for research projects aiming to build new online platforms, we present several case studies from the project to illustrate the challenges to participation experienced by people with limited access to, and literacy with, the Internet.

Untangling the Net : The Scope of Content Caught By Mandatory Internet Filtering

The following report considers a number of key challenges the Australian Federal Government faces in designing the regulatory framework and the reach of its planned mandatory internet filter. Previous reports on the mandatory filtering scheme have concentrated on the filtering technologies, their efficacy, their cost and their likely impact on the broadband environment. This report focuses on the scope and the nature of content that is likely to be caught by the proposed filter and on identifying associated public policy implications.

Communication and control : case studies in Australian telecommuting

This paper discusses the results of in-depth semi-structured interviews with 39 telecommuters from 12 Australian organisations. The paper serves two broad aims: firstly, it identifies current trends in telecommuting and offers a perspective on Australian developments. Secondly, it provides a focus on significant communication aspects of the Australian telecommuting experience. Findings are that the majority of interviewees reported overall satisfaction with telecommuting as an important contributor to their improved work and lifestyle outcomes. Overall, telecommuters appear to cope with communication aspects of their work environments. They also were not overreliant on advanced communications media when telecommuting. Difficulties as reported by telecommuter interviewees included: perceived discomfort over lack of management support for their telecommuting; reduced levels of interpersonal communication suggesting the likely need to adopt a ‘media mix’ approach to servicing their communication needs; problems of information access; and telecommuters’ reported levels of difficulty with their uses of some computer and communication technologies. Problems relating to telecommuters’ perceived professional and social isolation, were also identified. Finally, the paper underscores where organisational communication theorists and practitioners need to more energetically embrace the concepts of virtual work and telecommuting

If Big Brother comes to a venue near you! Employee surveillance issues and the communication professional

Todoy's monogers-drowing on the expertise of their IT professiono/s-

Designing for engagement towards healthier lifestyles through food image sharing : the case of I8DAT

This paper introduces the underlying design concepts of I8DAT, a food image sharing application that has been developed as part of a three-year research project – Eat, Cook, Grow: Ubiquitous Technology for Sustainable Food Culture in the City (http://www.urbaninformatics .net/projects/food) – exploring urban food practices to engage people in healthier, more environmentally and socially sustainable eating, cooking, and growing food in their everyday lives. The key aim of the project is to produce actionable knowledge, which is then applied to create and test several accessible, user-centred interactive design solutions that motivate user-engagement through playful and social means rather than authoritative information distribution. Through the design and implementation processes we envisage to integrate these design interventions to create a sustainable food network that is both technical and socio-cultural in nature (technosocial). Our primary research locale is Brisbane, Australia, with additional work carried out in three reference cities with divergent geographic, socio-cultural, and technological backgrounds: Seoul, South Korea, for its global leadership in ubiquitous technology, broadband access, and high population density; Lincoln, UK, for the regional and peri-urban dimension it provides, and Portland, Oregon, US, for its international standing as a hub of the sustainable food movement.

From margins to mainstream : how screen and creative industries developed in the Northern Rivers region of NSW : 2000–2010

This thesis explores the proposition that growth and development in the screen and creative industries is not confined to the major capital cities. Lifestyle considerations, combined with advances in digital technology, convergence and greater access to broadband are altering requirements for geographic location, and creative workers are being drawn away from the big metropolises to certain regional areas. Regional screen industry enclaves are emerging outside of London, in the Highlands and Islands of Scotland, in Nova Scotia in Canada and in New Zealand. In the Australian context, the proposition is tested in an area regarded as a ‘special case’ in creative industry expansion: the Northern Rivers region of NSW. A key feature of the ‘specialness’ of this region is the large number of experienced, credited producers who live and operate their businesses within the region. The development of screen and creative industries in the Northern Rivers over the decade 2000 – 2010 has implications for regional regeneration and offers new insights into the rapidly changing screen industry landscape. This development also has implications for creative industry discourse, especially the dominance of the urban in creative industries thought. The research is pioneering in a number of ways. Building on the work conducted for my Masters thesis in 2000, a second study was conducted during the research phase, adapting creative industries theory and mapping methods, which have been largely city and nation-centric, and applying them to a regional context. The study adopted an action research approach as an industry development strategy for screen industries, while at the same time developing fine-grained ground up methods for collecting primary quantitative data on the size and scope of the creative industries. In accordance with the action research framework, the researcher also acted in the dual roles of industry activist and screen industry producer in the region. The central focus of the research has been both to document and contribute to the growth and development of screen and creative industries over the past decade in the Northern Rivers region. These interventions, along with policy developments at both a local and national level, and broader global shifts, have had the effect of repositioning the sector from a marginal one to a priority area considered integral to the future economic and cultural life of the region. The research includes a detailed mapping study undertaken in 2005 with comparisons to an earlier 2000 study and to ABS data for 2001 and 2006 to reveal growth trends. It also includes two case studies of projects that developed from idea to production and completion in the region during the decade in question. The studies reveal the drivers, impediments and policy implications for sustaining the development of screen industries in a regional area. A major finding of the research was the large and increasing number of experienced producers who operate within the region and the leadership role they play in driving the development of the emerging local industry. The two case studies demonstrate the impact of policy decisions on local screen industry producers and their enterprises. A brief overview of research in other regional areas is presented, including two international examples, and what they reveal about regional regeneration. Implications are drawn for creative industries discourse and regional development policy challenges for the future.

Urban informatics for rural knowledge economies

This position paper provides an overview of a proposed study that seeks to design and develop tools, methods and applications of urban informatics to promote an innovation culture and knowledge economy in regional Queensland. The National Broadband Network has the potential to leapfrog regional Queensland to join the knowledge economy, but effective applications and content strategies are required. The Edge is the Queensland Government’s Digital Culture Centre to engage young people in the technology/culture nexus. This position paper provides an overview of a proposed study that will set up Living Labs at The Edge and in a new precinct in rural Queensland (Goondiwindi) as sites to trial strategies and applications that engage people in entrepreneurial thinking, sustainability initiatives, and new creative practices across the urban and rural boundaries.

Rethinking regulatory design : The Australian National Classification Scheme review

This paper considers issues of methodological innovation in communication, media and cultural studies, that arise out of the extent to which we now live in a media environment characterised by an digital media abundance, the convergence of media platforms, content and services, and the globalisation of media content through ubiquitous computing and high-speed broadband networks. These developments have also entailed a shift in the producer-consumer relationships that characterised the 20th century mass communications paradigm, with the rapid proliferation of user-created content, accelerated innovation, the growing empowerment of media users themselves, and the blurring of distinctions between public and private, as well as age-based distinctions in terms of what media can be accessed by whom and for what purpose. It considers these issues through a case study of the Australian Law Reform Commission's National Classification Scheme Review.

Creative suburbia : rethinking urban cultural policy – the Australian case

This article considers the question of whether creative workers demonstrate a preference for inner cities or suburbs, drawing upon research findings from the ‘Creative Suburbia’ project undertaken by a team of Australian researchers over 2008–2010 in selected suburban areas of Brisbane and Melbourne. Locating this question in wider debates about the relationship of the suburbs to the city, as well as the development of new suburban forms such as master-planned communities, the article finds that the number of creative industries workers located in the suburbs is significant, and those creative workforce members living and working in suburban areas are generally happy with this experience, locating in the suburbs out of personal choice rather than economic necessity. This runs counter to the received wisdom on creative cities, which emphasize cultural amenity in inner city areas as a primary driver of location decisions for the ‘creative class’. The article draws out some implications of the findings for urban cultural policy, arguing that the focus on developing inner urban cultural amenity has been overplayed, and that more attention should be given to how to better enable distributed knowledge systems through high-speed broadband infrastructure.

Place and Space: Community in the Internet Economy and What This Will Mean for Property

By 2020 Australia‟s National Digital Economy Strategy aims to increase household online participation and engage 12 per cent of all employees in teleworking arrangements. Achieving these goals is generally perceived as positive due to the reduced impact on the natural environment from less use of transport. However, this also will enable greater flexibility as to where people live and thus will impact upon the maintenance and formation of communities and on property use. This paper commences by clarifying what is Australia‟s internet economy before highlighting the impact of the internet on community formation and maintenance. The paper concludes by identifying what the achievement of these goals will mean for property use in the future.

Design and implementation of wideband baluns for Archimedean spiral antennas

The demand for high-speed data services for portable device has become a driving force for development of advanced broadband access technologies. Despite recent advances in broadband wireless technologies, there remain a number of critical issues to be resolved. One of the major concerns is the implementation of compact antennas that can operate in a wide frequency band. Spiral antenna has been used extensively for broadband applications due to its planar structure, wide bandwidth characteristics and circular polarisation. However, the practical implementation of spiral antennas is challenged by its high input characteristic impedance, relatively low gain and the need for balanced feeding structures. Further development of wideband balanced feeding structures for spiral antennas with matching impedance capabilities remain a need. This thesis proposes three wideband feeding systems for spiral antennas which are compatible with wideband array antenna geometries. First, a novel tapered geometry is proposed for a symmetric coplanar waveguide (CPW) to coplanar strip line (CPS) wideband balun. This balun can achieve the unbalanced to balanced transformation while matching the high input impedance of the antenna to a reference impedance of 50 . The discontinuity between CPW and CPS is accommodated by using a radial stub and bond wires. The bandwidth of the balun is improved by appropriately tapering the CPW line instead of using a stepped impedance transformer. Next, the tapered design is applied to an asymmetric CPW to propose a novel asymmetric CPW to CPS wideband balun. The use of asymmetric CPW does away with the discontinuities between CPW and CPS without having to use a radial stub or bond wires. Finally, a tapered microstrip line to parallel striplines balun is proposed. The balun consists of two sections. One section is the parallel striplines which are connected to the antenna, with the impedance of balanced line equal to the antenna input impedance. The other section consists of a microstrip line where the width of the ground plane is gradually reduced to eventually resemble a parallel stripline. The taper accomplishes the mode and impedance transformation. This balun has significantly improved bandwidth characteristics. Characteristics of proposed feeding structures are measured in a back-to-back configuration and compared to simulated results. The simulated and measured results show the tapered microstrip to parallel striplines balun to have more than three octaves of bandwidth. The tapered microstrip line to parallel striplines balun is integrated with a single Archimedean spiral antenna and with an array of spiral antennas. The performance of the integrated structures is simulated with the aid of electromagnetic simulation software, and results are compared to measurements. The back-to-back microstrip to parallel strip balun has a return loss of better than 10 dB over a wide bandwidth from 1.75 to 15 GHz. The performance of the microstrip to parallel strip balun was validated with the spiral antennas. The results show the balun to be an effective mean of feeding network with a low profile and wide bandwidth (2.5 to 15 GHz) for balanced spiral antennas.

Analysis of rural MUSA-MIMO-OFDM uplink channel capacity

Multi-user single antenna multiple-input multiple-output orthogonal frequency division multiplexing (MUSA-MIMO-OFDM) is a promising technology to improve the spectrum efficiency of fixed wireless broadband access systems in rural areas. This letter investigates the capacity of MUSA-MIMO-OFDM uplink channel by theoretical, simulation, and empirical approaches considering up to six users. We propose an empirical capacity formula suitable for rural areas. Characteristics of channel capacity temporal variations and their relationship with the wind speed, observed in a rural area, are also presented in this letter.