Weekly Review – TV and SAT TV, CCTV, WLAN

Will QUIC oust TCP? – New network protocol from Google.

QUIC (Quick UDP Internet Connections), a communication protocol developed by Google to speed up data exchange between devices on the Internet, has been accepted and officially published by the international Internet Engineering Task Force (IETF), an organization responsible for setting technical and organizational standards for the Internet. The publication by the IETF is the first step towards wide use of the protocol, which Google hopes for. It is even said that to replace the developed nearly 50 years ago, but extremely popular TCP.

QUIC is based on the UDP protocol, which is supposed to reduce the time needed to establish communication. The new protocol is better in every aspect and is in a way a hybrid of UDP and TCP protocols. An unquestionable advantage is the elimination of the effect of blocking an entire set of packets when only one of them is delayed (the basic TCP problem). There is also a solution allowing unacknowledged data transmission when a user has communicated with a server before.

As it is known, the whole Internet is based on communication between Internet clients and servers. It is done by sending requests and receiving replies using HTTP protocol. HTTP/3 is a breakthrough version of the hypertext transfer protocol using UDP, which is a departure from traditional HTTP. QUIC has been shown to work brilliantly with HTTP/3, which is undoubtedly the seed for widespread adoption of the new protocol in principle today.

Summer Photo Contest!

Only the next week, we are beginning to accept submissions for the anniversary edition of our contest. This year, in addition to photos, we are also accepting videos! We have arranged extremely attractive prizes, such as DJi Mini 2 drones and JBL Bluetooth speakers. You can learn more about the contest and the rules here.

Main prizes in the competition - DJI Mini 2 drones

How to measure the quality of images from a camera?

A common measure of camera image quality is its pixel density. Higher density means better image quality and better video surveillance capabilities. Camera image quality can be measured in pixels per object (e.g. person or face) or in pixels per meter of the observed frame height (px/m). The basic operational criteria in video surveillance of target observation are: detection, recognition and identification.

To easily check the pixel density, you can use the pixel calculator that is displayed in live video preview of Hikvision devices. It shows the width and height of the selected area in pixels. It can be used, for example, to verify the number of pixels per license plate or face of an emerging person.

Pixel calcuator - the selected area is marked green. The measurement is shown in a red frame.

The pixel calculator function is available, among others, in Hikvision EasyIP 3.0 cameras and in dedicated cameras for license plate identification.

Converting DVB-T2/HEVC signal to the DVB-T/H.264 standard.

In 2022, Poland plans to change the system of terrestrial television broadcasting from the DVB-T to DVB-T2 standard. Apparently, not all TV sets are suitable to work with the new system. Will we have to replace them to be able to watch TV? It is estimated that about 80 percent of TVs sold in the recent years support the DVB-T2/HEVC standard. If in doubt, check the user's manual or on the manufacturer's website whether your TV is compatible with the latest standard. What if we have a larger number of TVs in the system ( particularly in hotels and boarding houses) and they do not support the latest DVB-T2/HEVC standard, or they support DVB-T2, but cannot support H.265? The diagram below shows a sample system enabling conversion of DVB-T2/HEVC signal to the DVB-T/H.264 standard.

Signal from Dipol 28/5-12/21-60 DVB-T/T2 A2810 terrestrial TV antenna has been distributed via Signal R60106 passive R-6 splitter to 6 DVB-T2/HEVC decoders. Then each of the decoder HDMI outputs has been connected to TERRA mhi430 R81607 encoder. One mhi430 R81607 module allows conversion from 3 HDMI sources to three IP streams (TV programs), encoded in H.264 standard with individual multicast addresses. Two TERRA mhi430 R81607 encoders have been used to achieve that. Each of the outputs of the mhi430 R81607 encoder has been connected to the TP-LINK N29959 switch that supports IGMP Snooping version V3 needed for proper operation. In order to convert the IP standard back to DVB-T/H264, the mix440 R81611 transmodulator has been used, which makes up four adjacent DVB-T multiplexes (4 DVB-T MUXes, each with a maximum throughput of 31.66 Mbps).

Steel tapes and a banding tool – how to mount a distribution frame on a pole?

Since we have had a number of inquiries on how to use the E8581 banding tool, Dipol has prepared a video discussing this issue in the context of mounting a fibre optic distribution frame on a pole together with a cable storage rack. The following accessories are used in the video:

A video showing how to use the steel tape banding tool

If you have any further questions or concerns, please feel free to contact us at techniczny@dipol.com.pl. Check out also our Youtube channel with an extensive video library.

Different ways of adding tags to Hikvision IP video door stations.

Tags can be added to Hikvision IP video door stations, depending on the model, in several ways, such as via a web browser, iVMS-4200 or a master card attached to the door station. IP Villa door stations have a built-in Mifare standard tag reader. A tag reader supporting the Mifare (13.56 MHz) or UNIQUE (125 kHz) standard can be connected to a DS-KD8003-IMEx modular door station (e.g. G73644).

1. Adding after logging in via the Internet browser (only for Villa DS-KV8X13-WME1, DS-KV6113-WME1 door stations).

After logging in to the door station via a web browser, go to the tab:

After pressing the Issue card button, put tags against the reader in the door station. Correct addition of each tag will be indicated with a single sound. Adding is complete after pressing the Issuing card completed button.

The process of starting and ending of the door station tagging

2. Using the iVMS-4200 by initializing a reader reading or entering a tag number.

By adding tags using the iVMS-4200 application, tags can be assigned to a user (max. 5 to one user) and manage them in a controlled manner in the future. After creating an organization and adding a user, go to the specific user settings and in the Credential -> Card tab add a card by pressing "+". A window will appear in which you can manually enter the tag number (if it is known) or, after indicating a registration station (specific gate station), begin reading of the applied tags. To do this, go to the Settings tab, select the card Reader option and select the door station to use to read the tags from the available list. After saving settings and returning to previous window, press the Read button and put the tag against the reader. The card will be read into iVMS-4200 application. Then return to the main program window and go to the Access Control->Autorization->Access Group tab, create a group and assign permissions and then, after selecting the group save all changes to the door station.

Note!If the Import to Group option is not checked when adding a door station to the iVMS-4200 application, it may not be available in the Credential->Card->Settings->Card Reader tab. A solution to this problem is to add the door station again with this tab checked or to import the Access Point for the door station in the Device Management -> Group tab.

3. Using the master card attached to the door station (Mifare readers only).

To add tags using the master card, begin the loading process by applying the card to the door station reader. Then, one by one apply the new cards or key ring tags. Finally, apply the the master card again to complete the registering process.

Yagi-Uda in theory.

Yagi-Uda, also known as Yagi, is one of the most popular antenna types. Despite a relatively simple design, it has a high gain, typically greater than 10 dBi. Such antennas can operate in the HF to UHF bands (3 MHz to 3 GHz), but often within a limited bandwidth around the center frequency of the Yagi antenna. The Yagi antenna was developed by Shintaro Uda in 1926 in Japan. The results of the work were published in Japanese. The design in English was first presented by prof. Yagi, who travelled to the United States contributing significantly to the spread of the developed antenna.

The basic geometry of a Yagi-Uda antenna is shown in the diagram below. The antenna has only a single active (driven) element, typically a half wave dipole or folded dipole. It means that only this member (W) of the structure is excited (fed/driven via a feed line from a generator). The rest of the components are parasitic elements (passive radiators) and they help to transmit the energy in a particular direction. The dipole is almost always the second element from the end (the left side in the diagram), with a length to make it resonant at the center frequency (in the presence of passive elements the optimal length of the dipole is somewhere between 0.45-0.48 of the wavelength).

Geometry of Yagi-Uda antennas

The element located behind the vibrator (figure above) is the reflector (R). Its length is slightly longer than that of the vibrator. Usually one reflector is used, since increasing their number does not significantly improve antenna parameters. The reflector lowers the relative level of the back lobe of the antenna's radiation pattern, thus reducing the amount of power radiated in the opposite direction while increasing the antenna's gain. The increased length of the reflector relative to the vibrator provides two benefits. First, the longer element provides more effective wave reflection, increasing the antenna gain. Furthermore, if the reflector is longer than the vibrator being in resonance, the impedance of the reflector is inductive (the voltage along the reflector precedes the current in phase). The opposite phenomenon occurs for directors (D) (passive elements placed to the right of the vibrator) which are shorter than the vibrator. Their impedance is capacitive (current precedes voltage). This impedance distribution of the elements provides phase progression along the antenna axis, which causes the antenna to radiate axially.

Yagi-Uda ATK-LOG ALP LTE MIMO 2x2 A7054_10 antenna set
for LTE reception, operating in the 800-3000 MHz range
in vertical and horizontal polarization

F MASTER connectors in TV/SAT systems. F-type connectors are used for making connections in coaxial cable systems with the impedance of 75 ohm. They are available in straight and angled versions. They are used in terrestrial, satellite, and cable TV systems, as well as in CCTV systems. The reliability of the connection, attenuation level, and impedance matching in the signal path depend on the design and quality of the connectors. Top quality MASTER crimped connectors guarantee long-term and failure-free operation even in the most harsh environment...>>>more

Animation of the MASTER crimped connector principle

Signal Fire AI-8/AI-8C/AI-9 - how to begin fusion splicing?