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

LiFi technology and the new global wireless communication standard IEEE 802.11bb.

On July 12, 2023, the IEEE organization published the 802.11bb (LiFi) standard, which adds to the 802.11 family of standards a wireless communications technique that uses light waves for transmission. In theory, such a solution makes it possible to increase the speed and reliability of communication and provide greater security compared to WiFi or 5G, since light is unable to penetrate walls. Among other things, the new standard defines specifications for the physical layer and architecture of systems dedicated to wireless communication using light waves.

In LiFi technology, data from a transmitting device is transmitted via flickering light using ordinary LEDs. Receivers detect the photons and convert them back into information. The flicker should not affect users because at frequencies above 60 Hz it is too fast for the human eye to perceive. LiFi signals can be 100 times faster than WiFi and reach speeds of up to 224 GBps.

The introduction of the standard is a critical step that allows cooperation between multiple vendors. For the first time, LiFi solutions can be used in the WiFi ecosystem, which is important for the development of new and innovative IoT applications. LiFi can replace cables with short-distance optical wireless links and connect numerous sensors and actuators to the Internet, which could create a mass market in the future. It is a matter of time before suppliers in the lighting and communications industries collaborate to implement this standard. LiFi, in combination with WiFi, will also enable improved communications for a variety of applications, from high-speed and secure Internet access in the home or office to augmented reality. LiFi allows for high-speed mobile connectivity in areas where the use of radio waves may be limited, such as classrooms, medicine and industry. pureLiFi has launched the Light Antenna ONE which, when used in a given device, allows LiFi technology to be used just like WiFi. Currently, the antenna can be ordered by manufacturers for use in their devices.

Signal's ST-5155 COMBO-type meter – HEVC 10 Bit decoder.

The proper alignment of a DVB-T2 terrestrial or DVB-S2X-S2/S satellite TV antenna, which has a key impact on the quality of the received signal, usually requires a professional meter. It is the installer, assembling the antenna set, taking and interpreting the measurement, who is able to accurately correct the antenna settings in order to achieve trouble-free reception of DVB-T2 or DVB-S2X-S2/S signals.

Introduced to DIPOL's offer is the Combo Meter ST-5155 R10155 that allows to measure DVB-S2X/S2/S (HD) satellite signal, DVB-T/T2 (HD) terrestrial TV signal in HEVC 10 Bit compression and DVB-C cable signal.

The 10-bit HEVC video codec is a high-performance video codec that uses 10 bits to represent the color of each pixel instead of the standard 8 bits. Such information provides more accurate color reproduction and image quality, but also requires more bandwidth. DVB-T2 digital terrestrial television provides for the use of 10-bit coding. The R10155 meter's embedded 10-bit HEVC video decoder allows viewing channels in both 8-bit and 10-bit HEVC standards.

The unquestionable advantage of the COMBO-type meter ST-5155 R10155 is the modern chipset and the built-in tuner that allows constant preview of the set channel. The monitoring of the tested channels and intuitive operation accelerate installation work. An unquestionable advantage of the device is a user-friendly menu, making easier the work of users without much experience in this field. In addition to that, an external HDMI output can feed the received channel to a TV/monitor screen via a cable.

WiFi networks in office buildings.

When designing a wireless network, you need to answer the question of whether it is to be a public network such as in the case of a network in a library or office, or a network closed to the employees of the office, institution or warehouse. This relates directly to determining the expected number of clients of the network.

If the network is to operate in an office building with a large number of walls, several floors, then the main problem is the impact of wall and ceiling attenuation on the radio signal level. For this reason, in order to cover the entire building it is necessary to deploy in it several dozen (and sometimes even dozens) access points.

One access point can usually serve about 50-60 users. This means that in most cases an office network designed on a dozen or more access points will offer huge redundancy in terms of theoretical capacity. However, note that if certain areas of the network are to be public, then in such a place the number of access points will be determined not only by the ability to cover the area, but primarily by the capacity. A large number of users gathering in one place may force the need to system more access points, even in smaller rooms.

A good device for building networks in such buildings is TP-LINK EAP610 N25690. The EAP610 is a flexible, easy to install and manage, and secure solution for wireless networks. It can be easily mounted to a wall or a ceiling. WlAN configuration and management are simplified through centralized software and web-based management (no need of a controller). Automatic bandwidth management and captive portal authentication make the EAP610 ideal for demanding environments such as campuses, hotels, shopping malls or offices. The device works on the 2.4 GHz and 5 GHz bands in the 802.11ax (WiFi 6) standard.

Best practices: use of color pigtails in fiber optic systems.

Fiber optic cable termination is typically accomplished by splicing pigtails to its fibers. Typical colors of pigtails, are yellow for single-mode pigtails (possibly white for G.675B3 fibers) and orange for multimode fibers (turquoise for OM3 fibers, purple for OM4 fibers).

The use of other colors – particularly for single-mode systems, is a good practice that improves the aesthetics of the workmanship and allows easier identification of individual fibers or fiber pairs in the case of duplex transmission.

The table below summarizes the available color pigtail kits with the most popular connectors: SC/UPC, SC/APC and LC/UPC. Each set contains 4 fibers, each in a different color. In total, the color range includes 12 items.

Diagram of video door entry system for one-family house with an additional IP camera.

When building a modern video intercom system you need to take into account that the video intercom can control the gate and entrance. An application installed on a smartphone can be used for this purpose. When installing a door station, the view from the built-in camera focuses on the caller. If the camera has a very wide viewing angle, it is possible to observe the area in front of the gate, but even if the door station covers such an area, it is usually insufficient.

An additional IP camera can be connected to the Hikvision IP video intercom system to cover the area of the entrance gate or the entrance gate and wicket. During or after answering the call, you can change the view from the main gate station to the additional IP camera and view the area in front of the gate. Thanks to remote operation via a smartphone, it is possible to open and verify remotely at any time, whether the entrance gate is open or closed.

The diagram of an IP video intercom system for a single-family house is shown below. The system is based on the one-subscriber IP Villa DS-KV8113-WME1(C) G73632 door station with a built-in camera and two relays for control of the gate and wicket. The DS-KH6320-WTE1 G74001 monitor equipped with Wi-Fi interface has been installed inside the building. The area at the gate can be viewed with the Hikvision DS-2CD2043G2-I K03207 IP camera. The Ultipower N299781 switch with 4 PoE ports (802.3af/at) is used to power the gateway station, monitor, and IP camera. The system is connected to the Internet via the Mercusys AC12G N2933 router. The wicket is controlled with the use of the Bira S12U G74220 electric door strike with steel keeper/latch with 4 mm adjustment range, suitable for 12 V AC or DC power supply. It is supplied with the 12 V DC M1820 power supply.

Signal T2-MINI DVB-T2 HEVC – ideal solution for hotels. At present, the most popular TV source used in most guesthouses and small hotels is DVB-T/T2 digital terrestrial TV. Reception of digital terrestrial TV does not require license agreements with broadcasters or re-broadcast fees. DIPOL offers an easy to implement and economically optimal solution to this problem. One of the interesting solutions are Signal T2-MINI A99313 DVB-T2 receivers dedicated for hotels...>>>more