Media of the people: broadcasting community media in Australia

Provides an overview of Australia\u27s community media sector, looking at its origins and composition and the problems it faces in light of the tasks it performs and the lack of resources available to it to deliver a media which is ‘of the people’ in terms of aims, objectives and production. Introduction The term community media refers to radio, television and print services. Any or all of those forms of community media tend to emerge when communities are denied a voice for their views. In many countries they have provided a rallying point for protest and demands for rights. In post-apartheid South Africa, for example, community radio stations have emerged in an attempt to promote democracy as well as freedom of expression and diversity of broadcast content and ownership previously been denied in that country. It would be drawing a long bow to equate the situation which led to the establishment of community radio in South Africa with that of Australia. Nevertheless it is possible to consider that the Australian community broadcasting sector, which emerged in the 1970s, represented the demands of groups who felt that they were denied the opportunity to express their opinions or listen to alternative sources of entertainment. These groups ranged from those who felt marginalised to those who were beginning to feel that traditional media sources were not acting in the interests of the people. They even included groups who just wanted to hear music that was different from that broadcast on commercial stations. In seeking to deliver such alternatives, broadcast community media has done much to enhance Australian cultural diversity. It does much also to furnish ordinary Australians with an opportunity to contribute to debate on social and political issues. Indeed, researcher Michael Meadows and his colleagues argue that community broadcasting in Australia empowers audiences ‘to re-engage in the processes of democracy at the grass roots’ level creating social coherence through diversity’. Community broadcasting can be seen therefore as an alternative medium to public service and commercial media. As such, it occupies ‘an important space in citizen participation’ and is an important, though neglected, media sector. This paper provides an overview of the sector, looking at its origins and composition and the problems it faces in light of the tasks it performs and the lack of resources available to it to deliver a media which is ‘of the people’ in terms of aims, objectives and production

Toward Reliable Contention-aware Data Dissemination in Multi-hop Cognitive Radio Ad Hoc Networks

This paper introduces a new channel selection strategy for reliable contentionaware data dissemination in multi-hop cognitive radio network. The key challenge here is to select channels providing a good tradeoff between connectivity and contention. In other words, channels with good opportunities for communication due to (1) low primary radio nodes (PRs) activities, and (2) limited contention of cognitive ratio nodes (CRs) acceding that channel, have to be selected. Thus, by dynamically exploring residual resources on channels and by monitoring the number of CRs on a particular channel, SURF allows building a connected network with limited contention where reliable communication can take place. Through simulations, we study the performance of SURF when compared with three other related approaches. Simulation results confirm that our approach is effective in selecting the best channels for efficient and reliable multi-hop data dissemination

Back to the Future: The Emergence of Contrasting European and US Approaches to Digital Radio

Digital radio has been in development for over 25 years and yet is no nearer a point of successful adoption. This paper explores the emergence of contrasting European and American approaches to digital radio. The most established of these, Eureka-147 or Digital Audio Broadcasting (DAB), which originated in Europe, is contrasted with the so-called IBOC or /HD Radio approach, as alternative collective conceptualizations of how technology can bridge contemporary broadcasting practice to an ̳imagined‘ digital future. Drawing on the concept of ̳symptomatic technology‘ (Williams 1974), DAB‘s origins in European R&D policy of the 1980s and its affinity with established European broadcasting practice is characterised as a distinct technological vision for how the frontiers for radio broadcasting could be expanded within the European political and cultural landscape of the time. DAB‘s attempt to map a global solution for digital radio, combining satellite and terrestrial broadcast strategies, met with significant US opposition which subsequently supported the development of the alternative ̳in-band, on-channel‘ approach. While neither solution is guaranteed long term success, their importance lies in the mobilization of the relevant national and international policy frameworks for the construction of radio‘s future. Paying close attention to the discourses of technology inherent in these approaches and drawing on relevant contemporary engineering and technical descriptions, this analysis seeks to complement social shaping of technology studies (Mackay and Gillespie 1992) by focussing on the promotional efforts designed to support a particular technology‘s adoption

Energy-Efficient NOMA Enabled Heterogeneous Cloud Radio Access Networks

Heterogeneous cloud radio access networks (H-CRANs) are envisioned to be promising in the fifth generation (5G) wireless networks. H-CRANs enable users to enjoy diverse services with high energy efficiency, high spectral efficiency, and low-cost operation, which are achieved by using cloud computing and virtualization techniques. However, H-CRANs face many technical challenges due to massive user connectivity, increasingly severe spectrum scarcity and energy-constrained devices. These challenges may significantly decrease the quality of service of users if not properly tackled. Non-orthogonal multiple access (NOMA) schemes exploit non-orthogonal resources to provide services for multiple users and are receiving increasing attention for their potential of improving spectral and energy efficiency in 5G networks. In this article a framework for energy-efficient NOMA H-CRANs is presented. The enabling technologies for NOMA H-CRANs are surveyed. Challenges to implement these technologies and open issues are discussed. This article also presents the performance evaluation on energy efficiency of H-CRANs with NOMA.Comment: This work has been accepted by IEEE Network. Pages 18, Figure

Multiuser MIMO-OFDM for Next-Generation Wireless Systems

This overview portrays the 40-year evolution of orthogonal frequency division multiplexing (OFDM) research. The amelioration of powerful multicarrier OFDM arrangements with multiple-input multiple-output (MIMO) systems has numerous benefits, which are detailed in this treatise. We continue by highlighting the limitations of conventional detection and channel estimation techniques designed for multiuser MIMO OFDM systems in the so-called rank-deficient scenarios, where the number of users supported or the number of transmit antennas employed exceeds the number of receiver antennas. This is often encountered in practice, unless we limit the number of users granted access in the base station’s or radio port’s coverage area. Following a historical perspective on the associated design problems and their state-of-the-art solutions, the second half of this treatise details a range of classic multiuser detectors (MUDs) designed for MIMO-OFDM systems and characterizes their achievable performance. A further section aims for identifying novel cutting-edge genetic algorithm (GA)-aided detector solutions, which have found numerous applications in wireless communications in recent years. In an effort to stimulate the cross pollination of ideas across the machine learning, optimization, signal processing, and wireless communications research communities, we will review the broadly applicable principles of various GA-assisted optimization techniques, which were recently proposed also for employment inmultiuser MIMO OFDM. In order to stimulate new research, we demonstrate that the family of GA-aided MUDs is capable of achieving a near-optimum performance at the cost of a significantly lower computational complexity than that imposed by their optimum maximum-likelihood (ML) MUD aided counterparts. The paper is concluded by outlining a range of future research options that may find their way into next-generation wireless systems