Japan began test broadcasts of satellite television programmes in 4K, as major firms including Sony and Sharp bet on the super high-definition technology to rescue their embattled TV units. A consortium of major broadcasters, TV manufacturers and communications firms rolled out the test across the country of 128 million, a move that comes with Tokyo's backing as it looks to boost the competitiveness of the world's number three economy. The technology has four times the resolution of standard high-definition televisions, but high prices have so far limited commercial sales of 4K-equipped televisions. (continue....)
MBMS (Multimedia Broadcast/Multicast Service)
MBMS (Multimedia Broadcast/Multicast Service) is an IP datacast (IPDC) type of service that can be offered via existing GSM and UMTS cellular networks. The infrastructure gives the possibility to use an up- link channel for the interactions between the service and the user. This is not a straightforward issue in usual broadcast networks, as for example conventional digital television is only a one-way (unicast) system. MBMS has been standardized in various groups of 3GPP (Third Generation Partnership Project), and the first phase standards are to be finalized for UMTS release 6. The service seems to be rather attractive, as quite a lot of operators, equipment manufacturers and other representatives have participated in the standardization work. It can consequently be assumed that there will be several services offered via MBMS in the near future. MBMS is a solution for transferring light video and audio clips, although real streaming is also possible via the system. For heavy duty streaming in a wide area for a large, concentrated audience there are more suitable solutions such as DVB-H (Digital Video Broadcast, Handheld) which is an extension to terrestrial digital television. Nevertheless, MBMS is a suitable method also for mass communications.
Bluetooth wireless technology (IEEE 802.15.1) is a short-range communications technology originally intended to replace the cables connecting portable and/or fixed devices while maintaining high levels of security. The key features of Bluetooth technology are threefold: robustness, low power, and low cost. Bluetooth has been designed in a uniform way. This way it enables a wide range of devices to connect and communicate with each other by using the Bluetooth wireless communication protocol. The Bluetooth technology has achieved global acceptance in such a way that any Bluetooth-enabled electronic device, almost everywhere in the world, is able to connect to other Bluetooth-enabled devices in its proximity. Bluetooth-enabled electronic devices connect and communicate wirelessly through short-range, ad hoc networks known as piconets. Each device can simultaneously communicate with up to seven other devices within a single piconet. Each device can also belong to several piconets simultaneously. Piconets are established dynamically and automatically as Bluetooth-enabled devices enter and leave radio proximity. One of the main strengths of the Bluetooth wireless technology is the ability to handle data and voice transmissions simultaneously. This enables users to use a hands-free headset for voice calls, printing, fax capabilities, synchronizing PDA’s, laptops, and mobile phone applications to name a few. An important aspect of this thesis is about the scalability of Bluetooth broadcasting. Since scalability can sometimes be a rather vague concept, we give a short explanation of the term. An important aspect of software products is how they are able to cope with growth. For example, how does the system handle an increase in users or data traffic? This property of a software system is usually referred to as scalability. A more detailed specification of the concept is given by André Bondi, who defines it as follows: ‘Scalability is a desirable attribute of a network, system, or process. The concept connotes the ability of a system to accommodate an increasing number of elements or objects, to process growing volumes of work gracefully, and/or to be susceptible to enlargement.’ Whenever a system meets these requirements we can say that thesystem scales. In this thesis scalability comes down to the question if the system is capable of dealing with large groups of users equipped with Bluetooth enabled devices capable of receiving simple text messages.
Digital Audio Broadcasting
Digital audio broadcasting, DAB, is the most fundamental advancement in radio technology since that introduction of FM stereo radio. It gives listeners interference - free reception of CD quality sound, easy to use radios, and the potential for wider listening choice through many additional stations and services. DAB is a reliable multi service digital broadcasting system for reception by mobile, portable and fixed receivers with a simple, non-directional antenna. It can be operated at any frequency from 30 MHz to 36Hz for mobile reception (higher for fixed reception) and may be used on terrestrial, satellite, hybrid (satellite with complementary terrestrial) and cable broadcast networks. DAB system is a rugged, high spectrum and power efficient sound and data broadcasting system. It uses advanced digital audio compression techniques (MPEG 1 Audio layer II and MPEG 2 Audio Layer II) to achieve a spectrum efficiency equivalent to or higher than that of conventional FM radio. The efficiency of use of spectrum is increased by a special feature called Single. Frequency Network (SFN). A broadcast network can be extended virtually without limit a operating all transmitters on the same radio frequency.