Interactive TV provides, together with the stream of audio and video, special applications allowing for additional services. The most common are: paid video (VoD, PPV), information services, games, voting systems, e-mail, remote shopping.
By their nature, these additional services require a return channel. Interactive set-top-boxes may use for this purpose the traditional technologies to access the Internet, or - as in the case of DVB-RCT (Return Channel Terrestrial) terminals - can send the data wirelessly back to the DVB-T infrastructure supporting such an option.
arrange their programs, including TV schedules:
"My television, my programs, my schedule" - says the woman from the Alcatel's poster.
MHP is the middleware software enabling communication of interactive applications with the operating system of the set-top-box. The signal reaching the receiver is processed by the utility called Application Programming Interface (API). The concept of open system provides a lot of flexibility for equipment manufacturers and TV operators, both in the choice of applications and in the details of their implementation.
Despite the consensus on the importance of an open technology, there is more popular commercial solution - OpenTV - implemented in about 100 million set-top-boxes.
Lack of MHP equipment on the market hampered the launch of services. Interactive digital DVB-T receivers based on MHP standard are most popular in Italy, reaching 2 million. The popularity of these devices is the result of a controversial subsidy scheme. The purchase of a DVB-T receiver with interactive capabilities and access to the return channel has been subsidized by the state. The price reduction diminishes the difference between the MHP equipment and other, non-MHP receivers.
The equipment based on MHP is provided by a number of manufacturers including ADB, Philips, Strong, Humax. In Poland, MHP solutions have been implemented by the satellite "n" platform and some cable networks - Multimedia, INEA and Vectra.
The development of MHP promises a significant change of the trend in the near future. There are two directions - the first one is to simplify application development - in this field the main player is Sun Microsystems. The company has developed a new platform called JavaFX that facilitates application design. The second direction includes further universalization of the MHP, which results in rules of Globally Executable MHP (GEM). They will allow to use this platform in many promising areas, from Blu-ray technology to MHP-related OpenCable Application Platform (OCAP), being the basis for "tru2way" services available now in the US cable TV networks. It may significantly boost market expansion of this technology.
The beams have been joined with brass screws (without a single iron nail!). Due to the impact of antenna inductance, no ferromagnetic materials were used - the tower was originally built for medium-wave broadcast antenna. For over ten years now the tower is used for modern radio communications (mobile phones, radio taxi services etc).
Where is this tower? - The answer at the end of this issue.
Illuminated by eight spotlights, it fascinates everyone with its beauty.
(source: www.inzynierbudownictwa.pl)
The installation seen in the diagram below allows reception of any available terrestrial or satellite program in every outlet.
The MS-952/951 multiswitches (for two satellites) enable the designer/installer to build extensive SMATV systems with a hundred or so outlets. So large installations require to use additional amplifiers.There are available TERRA or Signal amplifiers (for two satellites - R694491). The amplifiers allow to adjust signals in terrestrial and satellite bands.
The channel amplifiers of ZG series allow to obtain the best possible parameters of terrestrial broadcasts.

The conditions that the system had to comply with included capability of precise monitoring of large areas and possibility of easy expansion in the future.
It has been decided to use IP ACTI cameras ACM-1311 K1117 equipped with IR illuminators. Their 1/3" SuperHAD CCD sensors ensure horizontal resolution of 420 TVL, enabling precise observation even at low light conditions. MPEG-4 SP compression allows economic transmission and recording of high-quality video data.
The system is managed by free ACTI NVR software (up to 64 channels). The 21 identical cameras are connected in a fixed wired network. The designed and implemented system has satisfied all the requirements of the investor.
The author got "Chameleon mug".
How to get the "Chameleon mug"?


The professional devices of ULTIAIR series are suitable not only for large service providers, but may also be used in small networks, with isolated client stations. Thanks to integration of the electronics and the antenna, the devices are highly efficient. These compact APs are easy to mount (PoE solution) and weather-resistant, ensuring long-term, maintenance-free operation.

The user (1) connects with AP (2) which enables Internet access. The switch allows to connect next computers to the network based on ULTIAIR.

On August 31, 1939, at 20:00 local time, the German radio station in Gleiwitz (since 1945: Gliwice, Poland) was attacked by seven SS troops in civilian clothes, who pretended to be Polish rebels. Their goal was to announce that Poland started the war with Germany, which would have exempted France and Britain from the obligation to provide military aid to Poland. The event is known as the Gleiwitz incident.
For visiting - please call in advance at +48 693 131 292.
Source: www.inzynierbudownictwa.pl and UNUSUAL TOWER (English version).
Thanks to Mr. Andrzej Jarczewski from the Gliwice Radio Station.
Antenna system measurements. Knowledge of signal parameters, among others: differences in levels of useful signals, signal levels in subscriber outlets, BER, level of noise and interferences allows to prepare optimal design and verify actual results...
- archive DWR of Nov. 19, 2007
Home and business Wi-Fi networks - applications of TP-LINK family. When we want to use wireless Internet connection we need device supporting WISP mode...
- Library
Gas/petrol stations - why they cannot be run without IP CCTV. Nowadays they are practically 100% self-service stations. That's why video surveillance system is indispensable - covering the gas/petrol pumps, cash desks, shopping area, car wash, compressor etc. The video has to be recorded and stored for some time...
- archive DWR of Feb. 18, 2008
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