Television out of zeros and ones. Interview with Lukasz Bukowski, a specialist in the field of satellite TV.
Digitalization of TV - what does it mean for consumers ?
Digital television allows to extend the offer (increase the number of channels and improve their quality), widen the coverage, provide many so-called "smart solutions", such as interactivity. Thanks to digital technology, TV broadcasts become a type of telecommunications services. Triple Play packages (phone, TV and Internet) become a modern standard. Please note that we are only at the early stage of this technology, its real potential is still stuck in the minds of IT professionals who will prepare, in the coming years, intelligent video applications.
What about advancements in the implementation of digital television?
Internet TV has been directly introduced in digital formats, with the start of the era of video streaming. Internet television has been extending the capabilities of broadcasting throughout the world, as well as has created a new cultural phenomenon, that is YouTube. The catchphrase "YouTube - Broadcast Yourself" best describes the breakthrough which is the result of digitization, from a state monopoly to universal access, also including broadcasting. The "classic" broadcasting television in digital form has especially flourished in satellite technology, a smooth transition also takes place in the case of cable TV networks; the greatest problems are with terrestrial TV.
What are the problems with digital terrestrial television?
The ongoing EU action aiming at a wholesale switch to digital terrestrial broadcasting in Europe is still producing poor results. Several years ago there was a discussion on what is more important for the consumer: the number of available channels or their quality (resolutions). The decision-making bodies of the EU aimed at the introduction of digital TV of standard definition, as opposed to the U.S. and Asia. As a result of this decision, the leaders of the process (Spain, France, Germany) have found themselves in a difficult situation, because consumers demands and technology developments have resulted in the victory of HDTV - unfortunately they will have to replace the equipment.
Digital terrestrial television broadcasting systems in the world (source: wikipedia.org)
If everybody knows that the future belongs to HDTV, the introduction of DTT should go easier ...
Not necessarily. It is true that the broadcast technology is changing, including, among others, introduction of MPEG-4, more suitable for HDTV, but this is not a process of an avalanche. The broadcasters operating on the market are not in a hurry to change the technology because it generates costs and does not guarantee higher profits. What is worse, the released spectrum can be used by new competitors. On the other hand, consumers are not pushing enough, because they can get a variety of programs from satellites.
What could be a breakthrough accelerating the termination of analog terrestrial broadcasting?
So far, the greatest pressure for changing the technology is so-called "analog switch-off" date. 26 EU countries have decided to eliminate analog transmissions by the end of 2012. The exception is Poland, which will do it "not later than in 2015."
But the real acceleration can be caused by the growing popularity of the new equipment (HD televisions), demand for TV reception in mobile devices, interest in 3D imaging. Unfortunately, the current European standards do not keep pace with these developments in video technology.
What do you mean?
In the case of terrestrial broadcasting standards, currently the most modern one is the Chinese DMB-T / H (DTMB), much ahead of the European DVB-T2. The really prospective systems combine satellite and terrestrial broadcasting technologies. The example is CMMB - the Chinese equivalent of European DVB-SH. CMMB has a few million subscribers, while the European solution is still in a testing phase. A strong support in the form of production facilities have the Korean standards, T-DMB and S-DMB. MediaFLO, the American mobile standard enters the British market - it is an optimistic fact that, despite the preferences for own standards, an European country is open to other solutions.
And what about distribution of digital television to the home?
The antenna and cable installations in buildings will change. In the case of SMATV systems, the most prospective solutions are based on multiswitches. IPTV and cable TV networks will naturally migrate towards fiber-optic systems.
A sapper makes a mistake only once...
Installing antennas is a dangerous job (steep, slippery roofs etc). Sometimes the installers risk too much...
We invite you to take part in the "Engagingly about antennas"
contest. The works can be submitted from June 1st, however the pictures can be taken during any season of the year - just look for an interesting topic!
"Dish at any cost"
"You must do the job"
SMATV system within minutes - new functions of SatNet utility from TERRA. SatNet
program is gaining increasing popularity among installers designing extensive multiswitch systems.
The currently available version numbered as 2.1 brings two important innovations:
automatic calculation of settings of active devices (multiswitches, amplifiers), so that the signals in all outlets fulfill the requirements of the designer,
- navigation button for easy operation with larger projects.
Example design of a multiswitch system with 72 outlets, performed with the use of SatNet
The settings of active devices have been calculated automatically.
Automatic adjustment function allows to switch with one click the algorithm that tracks the levels of satellite and terrestrial signals in all paths, taking into account attenuation of the cables, and provides optimum gain and slope settings.
To date, the correction of all the settings had to be preceded by a thorough analysis of the whole network, and although the SatNet program was saving a great amount of time in designing the distribution network and carrying out power budget, only the current version is reducing the effort to an absolute minimum.
Correction of the characteristics of the cable by the SA-901 R70901
amplifier. The difference in signal levels in the whole band has been reduced from 10 dB to 5 dB.
Amplifier for 9-input multiswitches - Terra SA-901 R70901
- for larger multiswitch systems
The new version has also introduced new algorithms for calculation of attenuation of coaxial cables and its compensation.
Antenna outlets for PVR Twin receivers in multiswitch systems.
Twin receivers can receive two different satellite broadcasts, so they need two independent satellite signals connected via two cables (e.g. TRISET-113 E1015
outlet allows to feed two satellite signals. Its first input filters the composite signal from a multiswitch into SAT1, TV, and R signals. The another signal from the multiswitch is directly fed to the SAT2 output.
Application of the R694140
subscriber terminal outlet
The key issue in CCTV systems is resolution of the images. This parameter is directly determined by the resolution of the cameras. Megapixel cameras create new quality standards - their images can be digitally enlarged still meeting quality expectations. One-megapixel camera (1Mpx - 1,000,000 pixels) provides over twice the pixels than standard PAL camera (704 x 576 = 405 504 pixels). 5 Mpx cameras offer resolution of 2592 x 1944 pixels (12.5 times more pixels than PAL and 2.5 times more than HDTV images).
So high resolutions of the sensors require using adequate lenses. Low-quality lenses would spoil the resultant images.
For megapixel cameras there are used specially marked "megapixel" lenses. These high quality lenses exhibit substantially reduced geometric distortions and lower deformation of light waves passing through their optical lenses. The deformation is described by MTF parameter - Modulation Transfer Function. This parameter is essential for sharpness of the images, deciding on the identification capability of megapixel CCTV systems. Choosing a lens one has to take into consideration its exact specification for the specific group of megapixel cameras (e.g. up to 2 Mpx etc). Megapixel lenses
Tokina 3.3-8 mm 1.3 Mpix M2301
Tokina 4.5-13 mm 3.0 Mpix M2235
Monitoring of construction sites.
Everyday activity of the builders on a construction site is interesting both for the investor/developer and the building contractor.
The contractor, using IP CCTV, improves security (including health and safety), can document the course of work, supervise the sub-contractors, analyze possible stoppages. The investor/developer can monitor the pace of work, organization and commitment.
Because of temporary character of construction sites, the installations should be "mobile" at any phase of the undertaking. The cameras should be easily repositioned. It is provided by the use of wireless transmission, at distances up to ten or so kilometers. For the tasks there are employed sets of fixed, PTZ and megapixel IP cameras.
High-resolution images from the cameras (as well as sound and control signals) should be transmitted via high-capacity Wi-Fi access points. Ultiair - devices for wireless video transmission
Redbeam - cameras with professional IR illuminators for night observations.
Redbeam day/night cameras with IR illuminators - IC40 M1130
and IC35 M1131
- are equipped with Sony Super HAD sensors, known for their excellent image quality. The cameras have been integrated with IR illuminators based on LED matrices, with expected lifetime about 50000 hours. It means that they can work for over 10 years (12/24 cycle)! Throughout the whole period of operation, the illuminators maintain the same illumination parameters, as opposed to typical IR LEDs.
The IR illuminators installed next to the cameras (not integrated with their lenses) have the advantage over compact solutions that they do not overexpose objects appearing directly in front of the camera lenses. They do not create problems with snow, rain, insects etc. in close foreground.
camera can monitor areas over distances up to 40 m at the angle of 30o
. The M1130
camera has double illuminator with range up to 40 m and the half-power beam width of 45o
. The cameras are recommended to observe construction sites, parking lots, and other places requiring reliable monitoring in any weather and lighting conditions.
Can you find another such camera? - 550 TVL, SONY Super HAD II CCD, 2.8-12 mm lens.
High quality SONY Super HAD II sensor, 550 TVL, 0.01 lx, and a very attractive price - make CAM 508 camera (M10738) a market hit.
The camera comes with Korean built-in lens with adjustable focal length from 2.8 to 12 mm, which is very suitable to obtain the optimum field of view. The viewing angle can be changed from 87o
. The camera produces a natural-color rendition of the original scene and, thanks to a high resolution of the video (550 TVL), it is possible to distinguish fine details. The camera works very well in difficult lighting conditions - its high sensitivity ensures good color images without a "snow".
The camera can be mounted either on ceiling or wall and allows to hide the cables. It is dedicated for indoor applications.
CAM 508 M10738
is equipped with coaxial cable with a standard BNC connector (video) and power connector (2.1/5.5).
Can you find another such camera? - 550 TVL, SONY Super HAD II CCD, 2.8-12 mm lens M10738
Protection of WestEnd shopping center in Budapest - Hikvision/ULTIMAX DVRs.
WestEnd City Center is a shopping moll located at the Budapest West railway station. In addition to the functions of a commercial and entertainment center, it is a hub where intersect bus, subway, railway and streetcar routes. Every day, the gigantic center with an area of 186,000 m2
is visited by hundreds of thousands of shoppers and travelers.
WestEnd City Center in Budapest
To ensure the safety of so vast complex, the security staff must have an advanced video surveillance system, allowing for quick and effective assessment of threats.
The priority was to create a central monitoring system, coordinating the objectives of general surveillance with the protection of individual businesses. In addition, a significant factor influencing the selection of the CCTV equipment was ability to easily access the recordings - in the event of circumstances requiring use of archive material.
The monitoring center has been equipped with PCs, which are used by the operators for monitoring twelve 16-channel HIKVISION DVRs that are recording video from 192 fixed and PTZ cameras. The PTZ cameras patrol designated routes - in the case of a threat any of them can be manually controlled by the operator.
The DVRs record video with D1 (720 x 576) resolution at 25 fps. In places where such a high video quality does not play a significant role (observation of crowd behavior) the recorders allow to set lower parameters (CIF, QCIF, 2CIF). Some owners of the shops have decided to create privacy zones.
Each DVR has the ability to install up to 8 hard drives, each with capacity up to 2 TB, which ensures video footage from over 45 days (at maximum performance levels).
The owners of the center examined many offers of CCTV systems. HIKVISION proved to be the company providing the most robust and comprehensive solutions.
Remote power control and reset - IP power switch & watchdog.
The 9258HP N3410
IP power switch and watchdog allows remote power control of AC power outlets (via the Internet network) - switching on/off up to 4 devices. The IP power switch and watchdog has the ability to automatically monitor the connected network devices (monitoring based on PING function) - in the absence of a response the connected device is reset. The device can also perform cycles written in the Scheduler
- switching on, switching off, and reset (switching off and on).
IP Power Switch & Watchdog (4-ch) Aviosys 9258HP N3410
Distinguishing features of the N3410
- Configuration via web browser, telnet, or RS232;
- Control of up to 4 devices;
- Built-in web server and editor;
- Built-in multi-event scheduler (dates and times of switching on/off or reset of each connected device);
- Periodical switching off and on of a device (at a time of day, on a day of week, every several days);
- Automatic monitoring of the connected network devices, using PING function - in the absence of a response the device is turned off or reset;
- Support for HTTP CGI commands and Telnet commands;
- Action delay (switching on/off);
- Action alerts (alarms) - beep;
- Action alerts (alarms) - by e-mail;
- Configuration of startup default values (outputs on or off);
- Log memory;
- Hardware Watchdog;
- IP Blacklist capability to block unwanted IP addresses;
- 64-bit password protection;
- MAC address changer;
- DHCP client;
- PPPoE support;
- NTP client;
- DDNS support;
- Total output current (all four power sockets): 15 A / 110 VAC or 10 A / 240 VAC''; max load of a single output: 6 A;
- Supplying voltage: 90-240 VAC.
Typical applications of IP Power 9258HP N3410
- Switching on/off light, electrical devices;
- Opening gates, switching on/off cameras, IR illuminators etc.;
- Switching on/off various equipment for specified periods;
- Remote reconfiguration/rebooting of network equipment.
An example of application
In the example above, the device controls lighting, heating, blinds and sprinklers in the garden - from anywhere in the world, via the Internet. Similar solutions allow to manage and control any devices connected to the IP Power Switch and Watchdog. Also system administrators and network managers can securely monitor and control all their servers, routers, switches and other network devices.
We have written about: Megapixel surveillance technology in Hortpark, Singapore.
IP technology, more and more popular in video surveillance systems, has practically monopolized monitoring of dispersed locations, where it is impossible to build cable systems. An example can be extensive park or other open area. In Hortpark in Singapore such a system is based on wireless IP network and high resolution cameras. The cameras employed in the system - ACTi ACM-1231 (K1511)...
How to choose the components of a headend?
TERRA headend is used for redistribution of TV programs, received both from satellites and terrestrial transmitters. It can also distribute audio/video signals from CCTV cameras, computers, DVD players etc. The RF modulator of each module can operate on any channel from the whole 110-862 MHz band (channels S1-69). Therefore, the subscribes do not need any additional equipment - they can use regular TV sets. In the case of large distribution systems (above 100 outlets) as well as in hotels, boardinghouses etc., the headend is usually housed in a 19" RACK cabinet. The VSB modulators in the modules are capable of working on adjacent channels, with output levels up to 102 dBuV, which allows to connect approximately 60 outlets without using additional amplifiers... Building blocks of the network - SFP transceivers.
FTTH solutions should ensure flexibility for possible future changes, usually extensions of the system due to growing number of subscribers. In such situations the best hardware solutions are provided by media converters with SFP slots allowing to use a variety of SFP modules/transceivers. An example is the media converter ULTIMODE M-100G/SFP L1301
with SFP slot for optical modules compliant with IEEE 802.3z 1000Base-FX standard. In the case of expansion of the network - including topology change and even involving different power budget of the optical interconnection system - it is enough to replace the SFP module only, and not the entire device... Index of published issues