DIPOL Weekly Review - TV and SAT TV, CCTV, WLAN

186 Gbps in a WAN circuit.

At the SuperComputing 2011 conference in Seattle (US), taking place in November last year, researches established a new world record for data transfer in a wide area network circuit. The data was transmitted over a distance of 212 km, between the computer center of the University of Victoria in Canada and Convention Center in Seattle, in both directions. The combined rate of 186 Gbps would allow the sending of 2,000,000 gigabytes per day, that is, for example, the contents of 100,000 Blu-ray discs!
The practical value of the project comes from the fact that similar transfers were obtained between Canada and other locations in the U.S., Brazil and South Korea, and all the connections were based on commercial fiber infrastructure, originally anticipated for transfers up to 100 Gbps.
The optical devices and special highly-efficient servers were provided by CANARIE (Quebec's Advanced Research and Innovation Network). The main partners of the project were the California Institute of Technology (Caltech), the University of Victoria, the University of Michigan, the European Center for Nuclear Research (CERN), Florida International University.

Intensive research on the acceleration of data transmission is carried out around the world. The record transfer rate under laboratory conditions is 109 Tbps (National Institute of Information and Communications Technology, with the use of seven-fiber optical cable). In the case of a single laser and typical optical fiber, the record is 26 Tbps over a distance of 50 km, obtained in the Karlsruhe Institute of Technology (KIT) in May 2011. Such a link has a capacity of transferring about 400 million simultaneous phone calls.
Very advanced works are conducted in China. The project called "973" is to commercially achieve 400 Gbps (in the first stage) and then 1Tbps.

The demand for higher transfer increases with the amount of data collected. The driving force is cloud computing technology and the need to exchange data between data centers belonging to companies such as Google, Amazon, and Facebook. High data transfer rate is also an important element of the work carried out in large university centers and CERN, hence their involvement in the project.

UTP or coaxial cable?

Transmission of analog video signals over twisted pair cables has become more popular than over traditional coaxial cables. CCTV installers choose this method for several reasons. Often the most important is the overall price of the cabling. Although the unit costs (1 m) of a cat. 5e UTP cable and coaxial cable are very similar, the latter can transmit only one baseband video signal, whereas UTP cable can carry up to four such signals, or provide power supply instead.

In general, balanced transmission lines are more resistant to electromagnetic interference. Using twisted-pair cables and active transformers, the maximum transmission distance can reach 2400 m, while a good quality coaxial cable can transmit baseband video signal over a distance up to 600 m.

Example configurations of Etrix devices.
The green arrows show the possible directions of the video signal flow (transmitter -> receiver)

Etrix transformers (baluns) allow for various configurations of transmission lines. Passive transformers can be combined with each other regardless of the number of channels (e.g. 4-channel transformer with four single transformers). The same applies to active transformers, however in this case it is necessary to distinguish between the transmitters and receivers and to adjust signal levels. Active transformers are dedicated for longer distances, from 400 to 2400 m (used for distances shorter than 400 m they may cause signal deterioration).

In practice, most solutions combine coaxial and twisted-pair wiring. The transmission of video signals from a camera group to the nearby "collection" point is performed via coaxial cables, and then all the signals are transmitted to the DVR via UTP cable(s).

DVB-T and analog TV in a modern MATV system.

The designer should meet three main requirements: the installation is to serve 5 apartment houses, distribute DVB-T signals from a local transmitter, subscribers with old televisions without MPEG-4 tuners (CRT TVs and plasma/LCD TVs equipped only with MPEG-2 tuners) are to receive the DVB-T broadcasts converted into analog TV channels.

The signal from the UHF antenna DIPOL Tri Digit 44/21-69 A2670 has been split into two paths, digital and analog. The digital circuit contains a dual channel DVB-T amplifier with AGC (Terra at420 R82510) and multiband amplifier Terra ma400 R82520. The analog path consists of Terra MMH-3000 headend with OFDM receivers / DSB modulators Terra RT-316 R81707 and MPEG2/H.264 TS decoders / DSB modulators Terra DM-316 R817121. The analog and digital signals are combined in the 2-way TV/FM splitter Signal R-2 R60102.

To ensure the highest quality signals (DVB-T channels can broadcast in HD resolution), the designer employed fiber optic connections to the buildings. There has been used professional and cost-effective solution based on TERRA equipment.

The whole system consists of three subnetworks:

Diagram of the MATV system for 5 apartment houses,
employing fiber optics and distributing both the original DVB-T multiplexes
as well as their channels, as trans-modulated analog signals

The composite signal is distributed to the four individual buildings via fiber optic cables (from the building with the signal processing unit). The output optical signal goes from the optical transmitter TERRA MOS-211B R81720B (output power of 8 dBm), and then is split into four optical lines terminated in each of the four building by the optical node Terra OD-120 R81724. The node converts the optical signal into RF electrical signals, with a maximum output level of 113 dBuV, which is sufficient for their further re-distribution in a passive network with forty or so outlets (without a need for additional amplifiers).
In the first building, the composite signal is not converted into optical form, and after amplification by the HA-126 R82303 amplifier it is directly distributed in the building (also to about 40 outlets).

How to install fiber optic cabling in a building?

Fiber optic distribution frames/boxes allow for easy organization of fiber optic cables, ensuring connection and re-connection of optical paths, as well as operational and control measurements.
The items also protect splices and splitters and ensure appropriate bending radius of the optical fibers, which protects them against micro-cracks. Additionally, they should allow for quick and easy access, maintenance and reconfiguration.

The ULTIMODE distribution box TB-08B L5408 provides a splice tray (for 12 splices) and the place for a MICRO optical splitter. Three PG cable bushes are designed for optical cables with external diameter of 7-12 mm. The detachable outer cover is held on by clips and can be protected against unauthorized access by seals.

View of the ULTIMODE TB-08B L5408 distribution box
(used in a system - the installed components are not included)

Description of the ULTIMODE TB-08B L5408 distribution box:

1 - space for for a MICRO splitter ( L3604, L3608 ), for its fixing and protecting.
2 - tray for fusion splices. It protects the splices and ensures correct bending radius of the fibers.
3 - place for spare lengths of optical fibers.
4 - spaces for inserting optical adapters (easy access and reconfiguration).
5 - cable locking element.

Remote access to DVR recordings.

An investor has decided to set up remote CCTV system covering distant farm buildings. The basic requirement was to access the recordings from his house located 800 meters away from the place of the installation.

Due to the distance and environment, the installer has chosen wireless solution based on access points TP-LINK TL-WA5210G N2350. The remote access point connects with the DVR Trend 250X16 M72516. The second AP has been installed at home and connected with the home workstation. The home computer runs CMS software allowing for monitoring live images from all cameras, viewing recordings, and control of the DVR functions. In certain places (such as passages) there have been set motion detection zones, activated at some times. Any case of detecting motion in such a zone is indicated on the computer.
The surveillance video is captured by sixteen high resolution cameras n-cam 710 M11276 (600 TVL, 0.01 lx). In addition to high image quality, the cameras have built-in IR illuminators and IP65-rated housings.

Diagram of the system with wireless access to the DVR

Using PoE for cameras without that feature.

Normally, Power over Ethernet can be used for cameras compatible with 802.3af standard. The standard allows for transmission both of data and power supply via the same UTP cable. The power is provided by a suitable power supply with short-circuit and overload protection, e.g. M1890.

The above diagram shows a solution for remote power supply via twisted pair cable for a camera without PoE function. The original power supply included with the camera can be plugged into a 230 VAC outlet in a different location using Power over Ethernet (PoE) adapter N9205. The set of two PoE adapters allows for powering LAN devices (with DC voltage up to 12V) through typical transmission cable (FTP/UTP etc.). Please note the voltage drop (about 0.1 to 0.2 V per meter).
More on powering cameras in CCTV systems can be read here.

Sharing ADSL connection with the use of a TP-LINK router.

It is one of the most popular ways to distribute Internet within the home, as most home users are connected to the Internet through ADSL lines (Asymmetric Digital Subscriber Line). The suitable wireless router is e.g. TD-W8960N N2904 with integrated ADSL/ADSL2/ADSL2+ modem, 4-port switch, and IEEE802.11b/g/n access point. Its WAN port (R11) should be connected directly to the phone line.

An example of a computer network based on ADSL connection in a single family home,
with distribution of the Internet connection via TP-LINK TD-W8960N N2904 wireless router

Worth reading:

Constellation diagram - the indicator of DVB-T signal quality. In the case of analog TV antenna systems the key parameter measured in addition to the levels of input signals (antenna) and output signals (subscriber outlets) is C/N (carrier to noise) ratio. This parameter, however, carries no information about phase noise, equally important in typical digital modulations. A professional installer who wants to know and analyze the sources of noise and interference in the reception/distribution network, should choose for this purpose the constellation diagram...

Portable PROTECT camera DVR for simple, cheap, and effective video monitoring. There are businesses, offices and various institutions that - due to economic, technical, or operational reasons - cannot install fully featured CCTV systems. We have also noticed an increased demand for compact DVRs integrated with cameras, suitable for applications in vehicles. In response to frequent questions of clients, DIPOL offers a new series of PROTECT products. The mobile PROTECT devices (for indoor applications) combine high resolution camera and DVR capable of recording high-definition video (720p) with MPEG-4 ( M70501) or H.264 ( M70701) compression, and audio. Such high-performance video recordings allow the users to easily recognize human faces, banknotes, details of road accidents etc. Their fixed lenses with very little distortion ensure very wide, 120-degree viewing angle. Each kit includes a suction cup with a handle (to be mounted on flat surfaces, such as glass, polished or enameled metal - at cash registers, in vehicles etc.) and 12-24 VDC / 5 VDC power supply with plug for cigarette lighter outlet...

PROTECT 701 M70701

Access Point modes (example: TP-LINK TL-WA500G N2941).

Typical Access Point supports the following operation modes:

The idea of Repeater mode

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