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

No. 33/2022 (October 17, 2022)

Training artificial intelligence models on edge devices using a small amount of memory.

Microcontrollers, or miniature computers that can execute simple commands, are the basis of billions of devices: from the Internet of Things (IoT) to sensors used in cars. However, low-cost, low-power microcontrollers have very limited memory and no operating system. All of this makes it challenging to train artificial intelligence models on "edge devices" that operate independently of central computing resources. Training a machine learning model on a smart edge device enables it to adapt to new data and make better predictions. For example, training a model on a smart keyboard can enable it to continuously learn based on how the user types. However, the training process requires so much memory that it is usually carried out using powerful computers in the data center before the model is deployed on the device. This is more costly and raises privacy issues due to the need to transfer data to a central server.
To solve this problem, researchers at MIT and the MIT-IBM Watson AI Lab have developed a new technique that allows training on a device using less than a quarter of a megabyte of memory. Other training solutions for networked devices can use more than 500 megabytes of memory, far exceeding the 256-kilobyte capacity of most microcontrollers (there are 1024 kilobytes in one megabyte). The framework and smart algorithms that the researchers have developed reduce the amount of computation needed to train the model, making the process faster and more memory-efficient. This technique can be used to train a machine learning model on a microcontroller in minutes. It ensures privacy by storing data on the device, which can be particularly beneficial for sensitive data, such as in medical applications. It can also allow the model to be customized to the users' needs.
An example of how a computer vision model works to detect people in photos
A popular type of machine learning model is the neural network. These models, loosely based on the human brain, contain layers of interconnected nodes or neurons that process data to perform a task such as recognizing people in photos. The model must first be trained, which means showing it millions of examples so it can choose the correct solutions on its own. As the model learns, it increases or decreases the strength of the connections between neurons, which are called weights. The model can go through hundreds of updates as it learns, and intermediate activations must be stored during each round. Since there can be millions of weights and activations, training a model requires much more memory than running a pre-trained model.
The researchers tested their framework by training a computer vision model to detect people in pictures. After just 10 minutes of training, it learned to successfully perform the task. The optimization required only 157 kilobytes of memory to train the machine learning model on a microcontroller, while other techniques designed for lightweight training would still need 300 to 600 megabytes. With this method, the model could be trained more than 20 times faster. Now the researchers want to apply the technique to language models and different types of data, such as time series data. At the same time, they want to use what they have learned to reduce the size of larger models without losing accuracy.

Operation of CCTV cameras by the monitor of Hikvision IP video intercom system.

A camera built into the video intercom is usually unable to be aimed at the desired point, and its field of vision may be obscured by the caller. A solution to this may be the use of cameras from the existing surveillance system and adding them to the video intercom monitor. The integration is possible by adding:
  • Hikvision IP cameras to the video door monitor,
  • an IP camera from another manufacturer using ONVIF protocol (2nd generation monitors from firmware version v2.1.2),
  • any camera (HIKVISION, ONVIF) via HD-TVI/IP DVR.
Up to 16 IP cameras can be added to the monitor. It can decode images from cameras with a maximum resolution of 720p with H.264 compression set. It does not mean, however, that the monitor cannot be equipped with cameras of higher resolution. For example, if an 8 MP camera is added where the main stream is set to the maximum resolution and H.265 compression, and the auxiliary stream is set to 640 x 480 resolution with H.264 compression, the monitor will automatically decode the auxiliary stream. If the main stream was downgraded to 720p resolution and H.264 compression was enabled, the monitor would decode the main stream. Adding cameras is possible directly at the monitor level , or using the iVMS-4200 client application. To do this, go to the remote settings and then: Remote settings->Intercom->IP camera details.
An example of direct connection of the Hikvision IP camera
and the ONVIF protocol selected in the G74001 DS-KH6320-WTE1/EU monitor

SMATV system receiving TV signals from two DVB-T2 transmitters.

The main task of the installer was to perform a SMATV system to receive 5 DVB-T/DVB-T2 multiplexes from two transmitters: 4 multiplexes from a local 100 kW transmitter (a distance of 12 km), 1 multiplex from a 50 kW transmitter 50 km away, and then distribution of the signal in a TV installation of about 70 receivers. For this purpose, an antenna set consisting of two DIPOL SMART antennas was used: Horizon A2230, City A2010 and Terra PA420T R82516 channel amplifier.
DIPOL SMART HORIZON DVB-T2 DVB-T2 antennaDIPOL SMART CITY DVB-T2 DVB-T2 antennaPA420T FM+UHF+2xVHF/UHF TERRA channel amplifier with AGC – digitally programmable
Schematic diagram of the system
Due to the short distance of the reception site from the powerful transmitter, a DIPOL SMART CITY A2010 antenna operating in passive mode was used to receive channels from the no. 1 transmitter. The DIPOL SMART Horizon A2230 antenna operating in active mode was directed to the distant transmitter no. 2. The PA420T R82516 channel amplifier was connected to the antenna set configured in that way.
The TerrNet application was used to configure the amplifier. The levels of useful signals at the input of the amplifier were 60...80 dBuV (for the active mode of the SMART HORIZON antenna). Assuming signal attenuation of about 40 dB, when split between 70 receivers, the output level of the amplifier was set to 100 dBuV. The amplifier equalized power for all channels. The built-in AGC circuit stabilizes the output signal in case of input signal fluctuations.
You can read more about it here

Why use the outdoor twisted pair cable.

Outdoor telecom cables usually have a sheath made of polyethylene (PE). This material is tougher and has greater mechanical strength than the polyvinyl chloride (PVC) used in indoor cables. What is also important, this material is much more resistant to UV rays, so the lifespan of outdoor cables exposed to sunlight is much longer compared to indoor cables operating under the same conditions.
The video below shows typical problem of using PVC-coated cable to connect an outdoor antenna with a router. The cable laid along the facade, exposed to high and low temperatures, as well as to sunlight and rain, cracks after several years at the latest. Afterwards, water gets inside, and after a short time, due to gravitational force, it "flows" down to the router. This may of course damage of the router itself and, in case of large accumulation of water in the area of the router, damage of other elements, such as furniture.
==Water leaking from the cable can be the result of using an indoor twisted-pair cable on the outside of the building. Installers mitigate the effects of cable breaks by creating loops that prevent water from flowing downward, but this is an ad hoc measure. It will be more reliable to combine these measures with the use of the right kind of cabling.===
DIPOL offers the following types of outdoor twisted pair cables:
  • NETSET U/UTP 5e cable gel-filled, black twisted pair, outdoor E1410_305
  • NETSET U/UTP PE 5e cable black twisted pair, outdoor E1412_305
  • NETSET BOX F/UTP 5e cable shielded twisted pair, E1517_305
  • NETSET F/UTP 5e outdoor PE cable, shielded, stranded E1519_500
  • NETSET U/UTP PE Category 6 cable, black, outdoor twisted pair E1610_305
CAT 5e UTP Cable: NETSET BOX U/UTP 5e <br />(outdoor - gel-filled, black) [305m]
NETSET U/UTP 5e gel-filled cable, black, outdoor twisted pair E1410_305

10 Gbps via one optical fiber.

Internet providers who build their networks over a larger area or partially rely on the infrastructure of larger operators are interested in optimal use of optical fibers. Here, the SFP modules, using one instead of two fibers for transmission, are of help.
Single mode modules SFP+ Ultimode 10 Gbps 20 km BiDi (WDM)
SFP+ Module: Ultimode 10Gbit/s BiDi (single-mode, 1270nm/1330nm, 20 km)
1270 / 1330 nm
SFP+ Module: Ultimode 10Gbit/s BiDi (single-mode, 1330nm/1270nm, 20 km)
1330 / 1270 nm
The speed of 10 Gbps has become a standard in backbone links even for smaller operators. The SFP+ Ultimode L1430 and L1432 modules make it possible to set up such a link using one single-mode fiber. The modules operate at wavelengths of 1270 nm and 1330 nm, i.e. the second transmission window, the safest in terms of any installation issues (poor splices, fiber bends, etc.).

New products offered by DIPOL

Switched-mode power supply 12V/300mA JACK 3.5 (+)
Switched-mode power supply 12V/300mA JACK 3,5 D0022 used to power antenna amplifiers via power separators C0397. This type of circuit is used when the amplifier (amplifier system) needs to be supplied with a current of 12 V and up to 300 mA. The standard D0012 power supply can only supply a current of 100 mA. The circuit with separator C0397 is also used in cases where the division of the RF/TV signal is supplied through splitters that do not pass DC voltage, and it is required to supply power to an amplifier placed on a mast or in an antenna box.

FM/TV House Amplifier: TERRA HA-216R65
The HA-216R65 TERRA R82216 house amplifier is a professional device used in SMATV and cable systems with return channel. The chip of the HA-216R65 amplifier at the penultimate gain stage is made of SiGe silicon-germanium nanostructures (silicon-germanium chip). Such a solution allows significant reduction of non-linear distortion, especially when it comes to second-order distortion. The final stage in the reciprocal circuit is made of gallium arsenide (GaAs).
LCD TV/Monitor bracket: SIGNAL KMA20-221 23
The KMA20-221 23"-42” SIGNAL E93312 adjustable wall bracket E93332 enables hanging a modern OLED/LCD monitor on a wall. Its load capacity is 25 kg. The wall mount allows easy adjustment of tilt in the range of-12o to +3o and horizontal rotation from -90o to 90o. The monitor distance from the wall is 65 to 200 mm.

Worth reading

How to power a camera and 12 V microphone using PoE? Numerous systems are faced with the problem of powering an IP camera via PoE from one UTP cable and another device requiring 12 VDC supply (e.g. an external microphone or an infrared illuminator). This can be done with any PoE (802.3af or PASSIVE) switch and using one output and the PoE Atte ASDC-12-124-HS M18953 stabilizer...>>>more
Powering the M1918 condenser microphone via PoE
SMART CITY DVB/T2 antenna with bypass up to 40 km from the transmitter