Môj košík je prázdny



DIPOL Weekly Review - TV and SAT TV, CCTV, WLAN
No. 27/2007 (Aug 20, 2007)
Digital broadcasting in Europe. The concept of development of terrestrial digital TV in Europe is changing. Until quite recently, the basic European standard, nearly in all countries, was considered standard television (SDTV) broadcast as MPEG-2 stream. It meant, in a way, disregard for technological progress expressed in large scale of production of HD televisions with big screens. Lack of HDTV programs in Europe (terrestrial, satellite or cable) was the reason for limited interest shown by the public to the new TV sets (in the USA there is 4 times higher percentage of households equipped with HD-ready televisions).
Currently, growing number of European countries adopt MPEG-4 streaming as the binding standard, promoting development of HDTV technology. Among these countries there are Norway, Latvia, Estonia, Lithuania, Slovenia. The situation in the countries which have begun broadcasting in MPEG-2 is more complicated, but - for example - in the next year France runs free HD programs in MPEG-4. It means migration to that standard (MPEG-4), which has been used for some time yet (for paid Canal programs, so far broadcast as SDTV channels). Similar decision is expected in Great Britain. So haste makes waste - the countries that didn't start digital broadcasting may choose the latest technology, without MPEG-2 as a staging post.
Digital broadcasting will extend the offer of TV programs - how to defend oneself against a deluge of information?
Antennas in Shqiperia. The present-day state is being recognized as relic and legacy of ancient Kingdom of Illyria, that lasted from 1225-167 B.C.
Illirians had first lost their independence for Roman Empire, but in the sixth century A.D. they were eventually forced to submit to Slav tribes.
Present-day Shqiperia has ca. 3.5 million inhabitants, next 2 million are scattered all over the world.
The economy of the country is quickly growing - ca. 7% per annum. Due to the problems left over from the previous era - weak state structures - probably half of economy is running in the gray area. So the true numbers may even be higher.
Up to 1990, telecommunications in Shqiperia was at the lowest levels of development in the world. There were only 2 phone lines for every 100 inhabitants. Last years everyone could notice rapid development in this field - in 2004 there were operating 1.25 million of mobile phones, i.e. 35% of the population owned such a phone.
Even more impressive growth one can observe in TV infrastructure. There are available 4 national broadcasting networks (2 public and 2 commercial) and 62 local stations. Additionally, 3 satellite operators broadcast satellite packages, as well as there is available terrestrial digital TV.
Antennas in Shqiperia
Welcome to Shqip
The interest level in digital platforms in Poland. We show the results of the survey carried out among antenna installers in August 2007. Compared with the last year, the level is considerably higher, in contrast to FTA installations not offering new solutions, which seem to have reached market saturation.
For the first time we asked the interest in the new "n"platform, offering first HDTV broadcasts. It is close to the levels of the "older" Polsat and Cyfra, but still a little behind them. Taking into consideration a short period of time on the market, the launch of the platform is recognized as successful. But quick response of Cyfra (also introducing HDTV programs) and announcement of Polsat planning the same, allow the operators to defend their market positions.
The market is booming, similarly to the last year, especially in the number of installations in one-family and multi-family houses.

Survey on interest in digital satellite platforms in Poland
The interest level in digital platforms in Poland.
Indoor and outdoor cables. The cables used outdoors have to be equipped with UV-resistant and watertight sheath. These requirements are well fulfilled by polyethylene (PE) protective layer, especially with antioxidants like soot. That's the reason why the cables are usually black.
Unfortunately polyethylene is flammable, easily spreading fire. These cables are also less flexible, so not easy to use indoors. For indoor applications cables with PVC sheath should be used - they are usually white.
Coaxial Cable 75 ohm: TRISET-113 PE (gel-filled) [100m]
Quality outdoor cable: TRISET - 113PE E1017_100.
Coaxial Cable (75 ohm): TRISET-113 1.13/4.8/6.8 [100m]
Quality indoor cable coaxial cable: TRISET - 113 E1015_100.
DiSEqC - switching of satellite signals. The need for switching satellite signal from demanded converter (LNB) to the receiver is the reason for development of dedicated solutions. At the beginning there were used manually operated switches, then relays controlled by various methods (e.g. Tone Burst, control signal from Euroconnector). The diversity of the solutions required standardization - it has been supported by satellite operator Eutelsat - and resulted in DiSEqC standards. The development of the standards went from one-way to bidirectional protocols with recognition of the status of the controlled device (converters, multiswitches, positioners).
DiSEqC standards:
Mini DiSEqC (Tone Burst) - it is only tone generator ensuring two-position switching (notice: it is not Eutelsat standard),
DiSEqC 1... the systems allow one-way command transmission, from the receiver to the peripherals:
DiSEqC 1.0 - digital signal switching among up to 4 satellite sources (converters),
DiSEqC 1.1 - digital signal switching among up to 16 satellite converters,
DiSEqC 1.2 - digital signal switching among up to 16 satellite converters, and control of a motor drive system for positioning the dish. The control may be executed directly from the receiver, without additional device (there is used integrated controller/servo-motor).
DiSEqC 1.3 - in comparison with 1.2 it ensures more advanced control of motor drive system, but only usable with Staab (or compatible) positioners (notice: not Eutelsat standard);
DiSEqC 2... - the systems allow 2-way communication:
DiSEqC 2.0 - digital signal switching among up to 4 satellite sources, and control of a motor drive system for positioning the dish, with bi-directional communications (confirmation of commands' execution like on/off, polarization etc.),
DiSEqC 2.1 - as 2.0 up to 16 converters,
DiSEqC 2.2 - as 2.1, with advanced control of a motor drive system;
DiSEqC 3... systems feature previously listed capabilities, but additionally allow to use 1-cable solutions, e.g. "Unicable".
The standards are back compatible, e.g. a DiSEqC 2.0 receiver can control DiSEqC 1.0 switches used in older installations, but a DiSEqC 1.0 receiver cannot control motorized features.
DiSEqC switches.
Aluminum Offset Satellite Dish: 90cm (A - E adjustment)TWIN Fullband LNB: Golden Interstar 0.2 dB Double Mount (for 2 LNBs)DiSEqC Switch: S. 166-A (TWIN + terrestrial TV) EMP-CENTAURISubscriber terminal outlet: Satel GAR-BG-DK-SAT (surface type)Subscriber terminal outlet: Satel GAR-BG-DK-SAT (surface type)
Practical use of DiSEqC switch - two twin converters and two receivers - a simple multi-user installation.
Factors determining selection of antennas. Proper selection of antennas is the basic problem of any individual or community antenna system. The main factors include:
  • Distance from the transmitter/transmitters
  • Number of the transmitters and their frequency bands
  • Angle distances among the transmitters
  • Output power of the transmitters
  • Directivity of transmitters' antennas
  • Polarizations of the transmitted signals
  • Obstacles on the line-of-sight between the transmitter/transmitters and the antenna/antennas
  • Kind of installation
  • Influence of interferences, including unwanted signals from other transmitters.
The article (in English) will be available soon: Factors determining selection of terrestrial TV antennas.
Compact camera with adjustable lens. Compact cameras are very popular in small CCTV installations (one-family houses, shops, small businesses). The user does not need to buy additional accessories (housings, lens). The cameras can be connected in a simple way to the existing antenna installation using an RF modulator.
An interesting solution is the camera VF-817 M11277.
It is an outdoor device, thanks to hermetic housing. A distinguish feature of the camera is the lens allowing manual adjustment of viewing angle (from 67 to 29 degrees), without a need for opening the housing. This adjustment is made with a knob placed under the cap, similar to the second adjustment (focus) - they both are in the rear part of the housing. Such solution allows quick correction of focal length and focus.
The camera ensures true colors during the day, and good results in the night - it switches then in B/W mode with IR illumination.
Compact Color Camera: V-CAM 315 IR
Adjustment of focal length in the M11277 camera.
MJPEG or MPEG-4 in IP CCTV cameras? Effective data compression is the only applicable method of limiting the video stream to the levels allowing transmission and recording, without substantial loss of resolution of the image.
There are many methods of such compression. The most popular are MJPEG and MPEG-4. The first one is popular with megapixel cameras, where the priority is the highest possible image quality, even at the expense of its smoothness. The second one is used for VGA, D1 resolutions, ensuring high compression levels with good quality and smoothness of the video.
IP Camera 5.0 Mpix: IQ755 (Day/Night, PoE, 4.5-13 mm Lens)
5.0 Mpix IP day/night POE camera equipped with 4.5-13mm lens - K1431
Lenses for megapixel cameras. In CCTV systems high resolution of the images becomes often the priority. The market offers a number of cameras with megapixel image sensors (1Mpix = 1000,000 pixels), which means at least twofold resolution in comparison to PAL standard (PAL: 704x576 = 405 504 pixels). Application of such a camera gives additional possibility of digital enlarging of the image, that will still feature good quality.
5 Mpix cameras offer 2592 x 1944 resolution (i.e 12.5 times more picture elements than in the PAL system, and even 2.5 times better results than in the case of full HD material).
High resolution of the image sensor means also adequate requirements for the lenses. Low quality of the important component of such a camera would spoil the overall quality of the set.
So there are available special megapixel lenses that should be used with the cameras. Their higher quality means reduction of geometric distortions, and, first of all, lower deformation of the light wave coming through the component lenses. The deformation is characterized by MTF parameter (modulation transfer function), and it affects sharpness of the images. Use of the special lenses allows to avoid trouble with enlarging blurred images, and ensures effective identification.
5 Mpix camera - K1431
Megapixel lens: 4-8mm F1.4 - M2233
Megapixel Lens: Computar H2Z0414C-MP (4.0 - 8.0 mm, F1.4)
1/2" 4.0 - 8.0mm F1.4 Mega-Pixel lens - M2233
New family of WLAN devices. There are available new devices of TP-Link using "eXtended Range" solutions - the technology of TP-LINK company that allows 2-3 larger range in 802.11b mode, and even 4-9 increase for 802.11g. Additionally, the employed Super G technology enables the user to reach even 108 Mbps transmission speed, still ensuring full compatibility with IEEE802.11b/g. The devices need only simple configuration and ensure easy management, as well as they feature modern design.
TL-WR642G N2953 consists of Access Point, broadband router (for xDSL or cable modem), and 4- port FastEthernet switch.
TL-WN620G N2923 enabling transmission speed up to 108 Mbps uses USB interface.
The wireless adapter TL-WN610G N2933 ensures transmission speed up to 108 Mbps and uses PCMCIA interface.
The wireless adapter TL-WN651G N2973 ensures transmission speed up to 108 Mbps and uses PCI interface.
Engagingly about Antennas - VI Summer 2007 Dipol Competition - first works.
Engagingly about Antennas - VI Summer 2007 DIPOL Competition
"Something new...discreetly" Tomasz Mlynarczyk
Coaxial Cable (75 ohm): TRISET-113 1.13/4.8/6.8 [100m]
Osoby so záujmom o týždenný informátor Informátora prosíme o zadanie e-mailu elektronickou poštou: