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

The first 5G network with national coverage.

Everyone can now connect to the 5G network all over South Korea. This latest generation of wireless data transmission system is offered by three largest telecommunications companies in the country: SK Telecom, KT and LG Uplus. The start of the service has been synchronized with the launch of Samsung Galaxy S10 5G, the first South Korean smartphone that supports 5G.

5G network is the successor to 4G, and its biggest advantage is the high data transmission speed (downloading up to 20 Gbps, downloading up to 10 Gbps sending, but the first implementations are able to reach slightly lower speeds, up to several Gbps). Not without significance is a short transmission delay (depending on a solution, 1 or 5 ms) and resistance to performance drops associated with a large number of simultaneously connected users.

The transition to the new technology involves the necessity of installing new base stations (it is known that SK Telekom has launched 35,000 stations), and the cost of such an operation is estimated at hundreds of millions of dollars. In the country known for its high technical level, a fast wireless network is a condition for further development, which is why the adaptation of customers and the resulting reimbursement of expenses should be quick. The largest South Korean operator predicts that by the end of this year, a million subscribers will join its 5G network. A large part of connections will be used by autonomous devices. The high network capacity and low latency are key to the development of modern applications such as autonomous cars and IoT devices. The same applies to solutions related to artificial intelligence and virtual reality, provided as network services.

DIPOL is now also in Gdansk.

The DIPOL's sales network has been expanded by new point in Gdańsk, in the Trakt Świętego Wojciecha 3 street. Dipol 57 is a specialist wholesaler for installers of antenna systems, LAN/WLAN networks, and CCTV systems. The wholesale store provides the full range of products offered by DIPOL, along with technical and training support, as well as design consultations. Regular customers get attractive discounts. We invite you from Monday to Friday between 8:00 and 16:00 CET.

Since April 2019, the products offered by DIPOL are available in 11 authorized wholesale stores in Poland

Measurements of Modulation Error Ratio (MER) of DVB-T signals.

From practical point of view, MER carries information on the level and type of noise that interferes with the digital signal (phase noise, amplitude noise etc.). MER can be treated as a measure of the distance of the received signal to "digital cliff" effect (a sudden jump from a normal reception to a complete lack of content). Without knowing this parameter, the antenna installer cannot guarantee stable reception in adverse weather conditions or other situations when the signal can fluctuate (e.g. interfered by a passing truck). The recommended and minimum values of MER required for proper reception depend on the modulation technique. In the case of 64-QAM modulation, they are 31 dB and 26 dB respectively.

The Signal R10514 DVB-T/T2 meter can measure the MER parameter

To truly understand the importance of measuring the MER parameter, there is the need to explain the phenomenon of so-called digital cliff. In the case of a digital signal, the boundary between an ideal image quality and loss of reception is very sharp. In DVB-T, similarly to other digital broadcasting, we have to cope with this effect. The operation on the boundary is the reason that the picture appears to freeze up or show up like a mosaic. The recommended MER above 31 dB provides a large safety margin, practically eliminating the risk of accidental interruptions caused by various interference factors.

Monitoring of an apartment building based on Hikvision EasyIP 2.0plus cameras.

The following figure shows a concept of a video monitoring system covering a building, based on a Hikvision NVR and IP cameras from the EasyIP 2.0plus series. The outside area around the building is monitored by eight DS-2CD2043G0-I K17635 compact cameras with 4 MP resolution and 2.8 mm lens with 98° viewing angle. Inside the building there are four ceiling cameras DS-2CD2123G0-I K17321 with 2 MP resolution, equipped with 2.8 mm lenses with 114° viewing angle. Both models of the cameras have IR illuminators with range up to 30 m made in EXIR technology ensuring even lighting of the scene at night. The layout of the cameras allows for good identification of any potential vandals who might destroy the facade of the building.
The cameras are powered and connected to the NVR via the N29986 16-port PoE switch. The cameras of the EasyIP 2.0plus series support H265+, H.265, H.264+, H.264 video compression. With the use of two 3 TB hard drives, e.g. M89285, along with H.265 video compression and continuous recording mode at 25 fps for each camera, the data retention time is 15 days.

Schematic diagram of IP CCTV system based on Hikvision devices in an apartment building

The video streams from the cameras are recorded by 16-channel IP NVR DS-7616NI-K2 K22165. The images can be viewed locally and played back on the M3022 monitor. Additionally, after connecting the NVR to the Internet via the N3259 router, the access to the system is possible via Wi-Fi (within the range of the wireless router) and through the Internet (after forwarding ports or using cloud solution). The cabling is based on the E1408 cable.

Protecting wireless networks from lightning. (1)

Wireless access points, GSM amplifiers/repeaters etc. should be protected against the effects of lightning strokes. During thunderstorms, electronic devices are very vulnerable to damages. The risk of overvoltages caused by the lightning electromagnetic pulse is present even in distant spots, up to 1.5 km from the place where a lightning bolt strikes.

To protect e.g. the A6765 GSM repeater against the effects of lightning strikes, the installer should connect the A6815 TRANS-DATA RF surge protector between the outdoor antenna and the repeater. The lightning protector must be grounded via the clamp and low-impedance wire. To suppress overvoltages effectively, the protector should be connected to low-resistance grounding (below 4 ohm), by screwing or soldering. As the grounding, it is not allowed to use any lightning conductors/arresters or gas installation pipes!

RF surge protector TRANS-DATA 900-2500MHz A6815 used in Wi-Fi and GSM networks

Encrypted access to Hikvision devices.

When connecting to a CCTV device via a web browser, a device located in the local network could eavesdrop on the transmitted data, including login and password. This is called a "man-in-the-middle" attack. The secure mode provided by HTTPS protocol, which is an adaptation of the standard HTTP protocol for secure communication over a computer network, involves encryption by Transport Layer Security (TLS), effectively increasing the security level.

HTTPS protocol can be activated in the advanced network settings section. The user may create a self-signed certificate, or install a certificate signed by an accredited certification authority.

HTTPS connections must be activated in the network settings. The default communication port is 443. The self-signed certificate can be generated on the device, or the user can install a certificate signed by a certification authority (CA). In the case of the self-signed certificate, the browser will communicate connection through an untrusted site. In turn, the certificate signed by a certification organization is payable.

New economical RACK-mount ULTIMODE optical fiber distribution frames.

Termination of optical fiber cabling in RACK cabinets is an often used solution in optical networks. DIPOL offers new RACK distribution frames from budget line, allowing for termination up to 24 fibers. ULTIMODE RPU-324 L51320 is an 1U-high unit rovided with three front modules, each intended for eight SC simplex adapters (or LC duplex). Additional accessories can be bought separately: front panel L51321 with holes for eight SC duplex adapters, blank front panel L51322 protecting the frame against dust etc. The black version of the distribution frame is available as L51340.

Optical Fiber Distribution Frame ULTIMODE RPU-324 (24x SC simplex, GRAY) L51320

Distinguishing features of the new distribution frames:

Two satellites via four cables – Wide Band technology. Multiswitch SMATV systems with quatro LNBs receiving signals from two satellites (e.g. HotBird 13.0E and Astra 19.2E) have to use 8 coaxial cables (RG-6). A Wide Band LNB (e.g. A98222) has two outputs (H and V polarizations) and the distribution of signals from two satellites requires only four coaxial cables between the LNBs and the suitable multiswitch, reducing by half the number of the cables. With single local oscillators operating at 10.41 GHz, such LNBs provide much wider intermediate frequency band (290...2340 MHz) than conventional (legacy) LNBs... >>>more

An example of SMATV system distributing satellite channels in dSCR/Unicable technology,
along with amplified terrestrial broadcasts.

Signal surge protection boxes