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

A new approach to privacy in consumer electronics cameras.

Intelligent devices using vision scanning of the environment, such as smart vacuum cleaners, electronic nannies, and drones, are increasingly being used and more readily seen in our homes and companies. These devices are often part of the "Internet of Things," or smart systems that connect to the Internet. By virtue of their access to the Internet, however, they can be vulnerable to hacking attacks, and thus some of the sensitive data such as the photos they take can end up online. In an effort to restore privacy, researchers at the Australian Robotics Center at the University of Sydney and the Center for Robotics (QCR) at Queensland University of Technology have developed a new approach to camera design in which visual information is processed and encrypted before it is digitized. This ensures that the images remain understandable only to the devices using them, and that they cannot be reconstructed in human-understandable form.

The innovation lies mainly in the fact that the researchers managed to split the image processing into an analog and a digital part. Until now, any image encoding or zone masking was done digitally and could be reversed relatively easily. The new approach allows image coding to be done already during the analog part of processing (the camera's analog system, right after the optical system), before the image is stored digitally. The distorted images can still be used by robots to accomplish their tasks, but they do not provide a comprehensive visual representation, which violates privacy. The researchers tried to break the security they had created, but were unable to reconstruct the images in any recognizable format. So they decided to give such an opportunity to the entire scientific community by challenging them to hack their method. The researchers' new approach can also be used to create devices that will work in places where privacy and security are important, such as warehouses, hospitals, factories, schools and airports. The researchers want to build a physical model of the camera in the future to demonstrate their solution in practice.

Pass-through RJ-45 connectors.

DIPOL offers EZ RJ-45 category 5e J2012_100 and category 6 J2013_100 connectors. Their hallmark is a loopthrough on individual wires that allows for a faster and more efficient termination. The plug should be crimped and the excess conductor cut off with the dedicated E7912 crimping tool.

Implementation of smart intrusion detection by Sunell NVRs.

Sunell DVRs (4, 8, 16 channels) have the ability to independently implement smart intrusion on 4 channels. This means that, on 4 selected channels, the DVR can independently perform image analysis for this analytics. Intrusion detection involves defining a detection zone, which, if exceeded, generates an alarm. Sunell DVRs are able to perform this function regardless of the brand of connected cameras, supporting both ONVIF-compliant and manufacturer-supported cameras.

Additionally, events can be filtered for the presence of people and/or vehicles, allowing users to focus on the correct alarm signals, improving the efficiency of monitoring and responding to potentially dangerous situations. This additional functionality is particularly useful for cameras that do not have such analysis by default. This allows the user to focus on the most relevant alarm signals, eliminating the problem of a large number of unnecessary alarms.

Measurements in fiber optic systems. Part 2.3 - transmission measurement - interpretation of measurement results.

Verification of the accuracy of a fiber optic system using a light source and optical power meter involves generating just one numerical value for the attenuation of the entire fiber optic path and comparing it with the expected value. When certifying a network, the expected value is specific to the application for which the link is being certified - for example, when certifying a network for a 10GBASE-LR application, i.e. a 10 Gbps Ethernet connection on single-mode fiber, the maximum attenuation of the fiber channel can be 6.2 dB for a wavelength of 1310 nm. Attenuation values for other applications can be found in documents describing the specific standard or in structured cabling standards ISO/IEC 11801, EN 50173. When the measured connection is not subject to certification, the maximum attenuation value is calculated by adding up the theoretical maximum attenuation values of all the elements included in the fiber optic path.

The problem with calculating the approximate typical attenuation of a given line arises from the lack of clearly defined attenuation standards for individual events such as splices and connectors. It may turn out that, according to one criterion, a line consisting of 2 connectors, 2 splices and 500 meters of fiber should attenuate no more than 2.3 dB, according to another 1.5 dB, and according to yet another 0.82 dB! Such divergent values have their source in various documents: structured cabling standards, company standards of large operators, international recommendations, manufacturers' standards defining attenuation classes of fiber optic connectors, product data sheets and information passed from mouth to mouth, which after some time become a kind of unscripted industry standard.

It is crucial, therefore, that the person performing the transmission measurement, in addition to the correct procedure for measuring and establishing the reference power, knows how to strictly define the criteria for evaluating its result - so that the determination of whether the system was done correctly or not is not subject to any interpretation.

The following lists the elements of the optical path to be analyzed when calculating the maximum attenuation of a single-mode fiber optic line. For each of them, acceptable attenuation values resulting from the application of various criteria are given, and the value that we feel, will be appropriate for analyzing the vast majority of fiber optic connections is indicated.

Thus, it can be seen that, depending on the criterion adopted, when estimating the maximum attenuation of a given connection, very different results can be obtained, which may result in the measurement result being correct for one and incorrect for the other. Taking into account the real attenuation, correctly executed elements of fiber optic systems, it will be more reasonable to make more restrictive assumptions. In reality, the measured values in the vast majority of cases will be significantly lower anyway. To sum up, the proposed values of attenuation of individual events to be taken for calculations are:

In the next issue of the Weekly review, we will include the last note in the series on transmission measurements. We will answer the question why it is important to perform measurements for 1310 nm and 1550 nm wavelengths and also how the result of both measurements can help determine possible causes of problems in the system.

Hotel TV.

A headend is a basic device or a group of devices dedicated to facilities and institutions where it is desirable to centrally manage the program offerings distributed in the TV system. In addition to the headend consisting of modules according to the installer choice (transmodulators, amplifiers, optical transmitters, IP streamers) for receiving and converting the TV signals, the system comprises also the antenna assembly (satellite antennas, terrestrial TV and FM antennas).

Headends distributing satellite programs converted to digital DVB-T COFDM format are still the most popular solution used in many hotels. Satellite channels can complement the DVB-T2 terrestrial TV program offer or be the only source of programming in the system.

The picture below shows a headend consisting of 4 TERRA tdx410c panels (the first 4 from the left) that allows conversion of DVB-S/S2 satellite signals from a single satellite transponder to the DVB-T COFDM standard. At the moment, the TERRA brand manufacturer has replaced the tdx410c modules with a new model tdx420c R81619, which can receive signals from 2 satellite transponders and create 2 DVB-T MUXes. Thus, 2 tdx-420c R81619 modules are enough to bring in satellite signals from 4 different satellite transponders.

The next 3 modules in the picture above, leaving aside the power supply, which is located in the central part of the system, are channel amplifiers from TERRA, enabling distribution of DVB-T2 signals in a system based on coaxial cable. The at440 amplifier (amplification of 4 DVB-T2 MUXes in the UHF band), the at420 amplifier (amplification of 2 MUXes in the UHF band), the at422 amplifier (amplification of 2 MUXes in the VHF band). In addition, the ma400 R82520 broadband amplifier enables the RF signal to be boosted to as much as 110 dBuV and split using passive splitters/taps to multiple receivers.

The ever-evolving DVB-T2 digital terrestrial television has forced manufacturers of TV equipment to look for new solutions. TERRA has decided to launch PA420T R82516 channel amplifier. One model of the PA420T R82516 amplifier is able to replace all the above channel amplifiers: at440, at420 and at422. The picture below shows the upgraded headend. The at440, at420 and at422 amplifier models have been replaced by the PA420T R82516 amplifier.

Optical-copper DVB-T2 and DVB-S/S2 system in a hotel complex. The owner of a large hotel complex has ordered a system for terrestrial television signals in the new DVB-T2 and satellite DVB-S/S2 standard. The installation was to cover 5 facilities. The TV system would distribute a signal in the new DVB-T2 standard from a local transmitter, as well as 15 FTA satellite programs in the form of a digital DVB-T signal. For this purpose, a solution on TERRA brand equipment was chosen...>>>more