Access to public broadcasting services across national digital delivery systems

Traditionally broadcasting and telecommunications have been regarded as completely separate sectors Broadcasting as a transmission system was inseparable from the broadcast content Alternatively, telecommunication networks were the sole providers of voice and basic data telephony services But as technology developed and both markets began to offer similar services, the regulatory dividing lines between Internet, broadcasting and telecommunications services have begun to blur Broadcasting as a transmission system is becoming detached from the broadcast content Even though these markets are technically converging the issue of access to content and the licensing of content providers over these new delivery platforms to carry their services remain unresolved The liberalisation of both markets may make a significant difference to the production o f content and the access of such programming content to pay-television and Free-to-Air viewers. The transmission of similar services over previously distinct delivery systems has been categonsed as convergence This term is generally considered as a suitable representation of the hazy combination of different broadcast and point-to-point services that were once considered the domain of the telecommunications incumbent Equally, the broadcast network was considered an indispensable part of the public broadcasting organisation in its provision of a single content service such as television programming Today, digital technology and the liberalisation of the cable and telecommunications networks have allowed multiple content service providers to offer many different services over several networks. Such technological convergence is delivering different services within each network In the past, the analogue broadcast relationship involved the content provider, network operator and customer Now, there are additional market players between the customer and the network operator called service providers who control different parts of the downstream and upstream dynamics This paper hopes to highlight the potential impact of telecommunication liberalisation on broadcasting as network operators begin to provide video and broadcast services while broadcast network operators transmit unicast and point-to-point services alongside their traditional broadcast service

An efficient multichannel wireless sensor networks MAC protocol based on IEEE 802.11 distributed co-ordinated function.

This research aimed to create new knowledge and pioneer a path in the area relating to future trends in the WSN, by resolving some of the issues at the MAC layer in Wireless Sensor Networks. This work introduced a Multi-channel Distributed Coordinated Function (MC-DCF) which takes advantage of multi-channel assignment. The backoff algorithm of the IEEE 802.11 distributed coordination function (DCF) was modified to invoke channel switching, based on threshold criteria in order to improve the overall throughput for wireless sensor networks. This work commenced by surveying different protocols: contention-based MAC protocols, transport layer protocols, cross-layered design and multichannel multi-radio assignments. A number of existing protocols were analysed, each attempting to resolve one or more problems faced by the current layers. The 802.15.4 performed very poorly at high data rate and at long range. Therefore 802.15.4 is not suitable for sensor multimedia or surveillance system with streaming data for future multichannel multi-radio systems. A survey on 802.11 DCF - which was designed mainly for wireless networks –supports and confirm that it has a power saving mechanism which is used to synchronise nodes. However it uses a random back-off mechanism that cannot provide deterministic upper bounds on channel access delay and as such cannot support real-time traffic. The weaknesses identified by surveying this protocol form the backbone of this thesis The overall aim for this thesis was to introduce multichannel with single radio as a new paradigm for IEEE 802.11 Distributed Coordinated Function (DCF) in wireless sensor networks (WSNs) that is used in a wide range of applications, from military application, environmental monitoring, medical care, smart buildings and other industry and to extend WSNs with multimedia capability which sense for instance sounds or motion, video sensor which capture video events of interest. Traditionally WSNs do not need high data rate and throughput, since events are normally captured periodically. With the paradigm shift in technology, multimedia streaming has become more demanding than data sensing applications as such the need for high data rate protocol for WSN which is an emerging technology in this area. The IEEE 802.11 can support data rates up to 54Mbps and 802.11 DCF was designed specifically for use in wireless networks. This thesis focused on designing an algorithm that applied multichannel to IEEE 802.11 DCF back-off algorithm to reduce the waiting time of a node and increase throughput when attempting to access the medium. Data collection in WSN tends to suffer from heavy congestion especially nodes nearer to the sink node. Therefore, this thesis proposes a contention based MAC protocol to address this problem from the inspiration of the 802.11 DCF backoff algorithm resulting from a comparison of IEEE 802.11 and IEEE 802.15.4 for Future Green Multichannel Multi-radio Wireless Sensor Networks

Convergence and next generation networks

Convergence and next generation networks and their potential impact on policies and regulations is the subject of this report, covering issues of competition in the new fibre environment, convergence of video, voice and data services, the rapid growth of new technologies, such as HDTV and mobile television, and the related demand for spectrum, as well as new possible "divides" between urban and rural areas created by the uneven development of high-speed fibre networks

A Misuse-Based Intrusion Detection System for ITU-T G.9959 Wireless Networks

Wireless Sensor Networks (WSNs) provide low-cost, low-power, and low-complexity systems tightly integrating control and communication. Protocols based on the ITU-T G.9959 recommendation specifying narrow-band sub-GHz communications have significant growth potential. The Z-Wave protocol is the most common implementation. Z-Wave developers are required to sign nondisclosure and confidentiality agreements, limiting the availability of tools to perform open source research. This work discovers vulnerabilities allowing the injection of rogue devices or hiding information in Z-Wave packets as a type of covert channel attack. Given existing vulnerabilities and exploitations, defensive countermeasures are needed. A Misuse-Based Intrusion Detection System (MBIDS) is engineered, capable of monitoring Z-Wave networks. Experiments are designed to test the detection accuracy of the system against attacks. Results from the experiments demonstrate the MBIDS accurately detects intrusions in a Z-Wave network with a mean misuse detection rate of 99%. Overall, this research contributes new Z-Wave exploitations and an MBIDS to detect rogue devices and packet injection attacks, enabling a more secure Z-Wave network