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

Google computers will heat homes.

Google has announced the modification of one of its data center in Hamina, Finland. The server room will be powered by renewable energy, and the surplus heat generated by the computers will be used to heat nearby buildings. The energy obtained in this way will account for as much as 80% of the local district heating network's annual heating requirements. The center in Finland is already 97% powered by carbon-free energy.

Tests have shown that servers providing computing power for artificial intelligence algorithms generate huge amounts of heat. The amount of heat generated by training the GPT-3 model from OpenAI would be enough to heat nearly five massive greenhouses that could produce up to a million tomatoes a year. Construction work on the new server room is expected to be completed by December 2025.

IP surveillance system using a bispectral camera.

A bispectral camera, is a solution that combines the advantages of traditional video surveillance. It allows identification of people during the day or night with the use of additional lighting and thermal imaging. A thermal imager does not need additional illumination to work properly. Any object with a temperature above absolute zero (0 K = −273.15°C) emits infrared rays. A thermal imaging camera allows you to see the temperature distribution on the surface of this body and thus detect people and animals without additional lighting at night and in difficult weather conditions. After connecting the bispectral camera to the DVR, the image from the visible light sensor and the thermal imager can be added to two separate channels. In addition, it is possible to do a fusion (overlay) of the images and consequently get a thermal image of better quality. The camera supports also the VCA image analytics that can be used to implement perimeter protection.

Below, an example of a monitoring system with the use of bispectral camera is presented. The system has been built with two DS-2CD2043G2-I K03207 cameras and a DS-2TD2628-3/QA K04987 bispectral camera. The video from the cameras is recorded on the DS-7608NXI-K1 K22069 DVR. The recordings are stored on a 2 TB M89270 WD drive. Access to the system from the external network is provided by the Mercusys AC12G N2933 router.

Cameras with a thermal imager are an excellent solution for monitoring areas with the required high detection efficiency, while lacking any illumination. The model described here has a human detection range of up to 150 m and up to 28 m in the case of perimetric VCA protection operation. Perimetric functions, such as virtual line or zone intruder detection, can be used when monitoring entry into a specific area. In the case of homes and estates, this could be trespassing in an unauthorized area. Thermal imaging cameras can also be used in other areas, such as monitoring fish ponds, landfills and warehouses, or detecting fires.

Dead zone in the ULTIMODE OR-20 OTDR.

Dead zone in the OTDR is created when measuring any reflectance, or reflective, event. In a fiber optic system, such events are usually connections. This zone is located behind the connector and includes a section of the fiber where the OTDR will not be able to record any events (other connectors, splices, bends, etc.).

Also, the connector of the reflectometer (OTDR) generates a dead zone. The size of this zone depends primarily on the width of the measurement pulse, the condition and cleanliness of the connector in the OTDR and the connector plugged into it (both should always be clean). Manufacturers, when declaring the size of dead zones for their devices, always specify them for the shortest measurement pulse. This is, of course, the most favorable case – the zones will then be the smallest.

The size of the dead zone of the Ultimode OR-20 L5830 OTDR is 3 m (event dead zone, i.e. one in which the OTDR will not recognize another event of reflectance nature, such as connectors) and 12 m (attenuation dead zone, i.e. one in which the OTDR will not recognize and measure an event of purely attenuation nature, such as splice). In the case of an event dead zone, the mere recognition of a subsequent event is not the same as measuring its parameters. It can be roughly assumed that, in order for a subsequent connector to be measured, it must be outside the attenuation dead zone.

The following reflectograms were generated with an OTDR L5830 by increasing the width of the measurement pulse from 5 ns to 1 μs. A wider pulse increases the dynamics of the OTDR, making it possible to measure longer optical fibers. It can be perfectly seen that, as the width of the measurement pulse increases, the noise of the reflectogram is reduced. The consequence, however, is an increase in the width of the initial peak. This width corresponds to the initial dead zone.

The size of the dead zone immediately downstream of the measuring device does not necessarily correspond 100% to the dead zone generated by any connector occurring further along the line. This one can depend on the distance of the connector from the OTDR and, most importantly, its reflectance – connectors that are more reflective can generate larger dead zones. Dirt on the connectors or their poor mutual alignment will have an even greater negative effect.

Care should be taken when configuring the OTDR. You should use the shortest possible pulses, but still provide the right level of dynamic range for the specific situation. The launch fibre is also important. It allows you to eliminate the dead zone behind the OTDR, and this makes it possible to measure the parameters of the first connector in the system. As can be seen from the above reflectograms, the length of such a fibre, especially when measuring the shortest lines, could be 20 m, but the production of launch fibers no shorter than 150 m has been accepted as a certain standard. It is also worth remembering that by taking a measurement from the other side of the fiber, the installer has the opportunity to see the events that occurred in the dead zones during the first measurement.

Intelligent image analysis in Sunell devices.

Similar to intelligent motion detection, the intelligent image analysis features of Sunell cameras are based on deep learning algorithms, enabling accurate recognition of people and vehicles. This in turn significantly reduces false alarms caused by irrelevant objects. Recordings can be quickly filtered to find objects of interest.

The following detection functions are available:

• trespassing
• crossing a line
• crossing two lines
• walking
• driving against the traffic

and the people counting function after crossing a virtual line.

TERRA LWO102 4F31 LNB with optical output.

In the case of a fiber optic bus, the size of the facility in which the system is implemented is irrelevant. The signal can be transmitted over hundreds of meters or even tens of kilometers without regeneration. For large buildings, this will greatly simplify the backbone of the system. A conventional system, based on copper wires, allows the signal to be transmitted in the trunk line for several tens of meters. This distance can be increased through the use of amplifiers, although this too has some limitations (as well as implementation and operating costs).

The innovative TERRA equipment for TV/SAT systems in multi-family buildings using fiber optic cable and PON (Passive Optical Network) technology is an excellent alternative to typical systems based only on coaxial cables. PON is a technique that uses only passive infrastructure (fiber optic cabling, optical splitters) at the transmitter (optical converter) – receiver section.

How to locate damage to a fiber optic cable? FTTH cables installed in multi-family buildings are frequently exposed to damage. This is due to the fact that they are usually run together (in a corridor, a cable duct) with other cables (twisted-pair cable, coaxial cable), among which fiber optic cable is the most vulnerable to damage. The problem with flat fiber optic cable used in FTTH systems is that it is resistant to crushing and stretching, while if the minimum bending radius is exceeded, the risk of fracture of the FRP rods inside significantly increases, and this in turn leads to excessive bending and even fracture of the optical fibers...>>>more