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

A breakthrough in the field of optical transmission?

The Korean Institute of Science and Technology announced that a research team led by Dr. Yong Won Song from the Center for Optoelectronic Materials and Devices has made a quantum leap in increasing transmission speed using optical fiber.

Typical digital signal transmission in optical fiber is based on the amplitude modulation of the laser signal. To put it simply, when turned off, the laser corresponds to binary zero, and to binary 1 when turned on. The greater the laser's ability to switch from one state to another, the higher the transmission rates. Korean scientists increased the frequency more than 10,000 times, which looks to be not just a step, but even a leap into the world of ultra-fast transmission.

The scientists discovered the wavelength and intensity characteristics of laser radiation, which change over time, to be correlated. If the laser generator is added a resonator, the wavelength of the pulsed laser is periodically filtered, thereby changing the laser intensity change pattern. Graphene has the ability to absorb and eliminate weak light and to amplify its intensity by transmitting only strong light to the resonator. This allows for the change in laser intensity to be accurately controlled at a high speed, and thus the pulse repetition rate can be increased to a higher level. As a result, a repetition frequency of 57.8 GHz was achieved. The speed of data transmission and processing is expected to increase significantly by using this method of laser light processing.

DVB-S/S2 signal measurement – multiswitch system with Wide Band technology.

The use of quatro converters in multiswitch systems to receive programs from two satellite positions (HotBird 13.0E and Astra 19.2E) requires installation of 8 RG-6. coaxial cables. With the use of Wide Band A98222 LNBs, this number can be reduced to four. Unlike standard quatro LNBs, the Wide Band LNB has two signal outputs (H/V polarization). It is based on a single local 10.41 GHz oscillator providing excellent performance in the entire frequency range of 290...2340 MHz.

The Wideband LNB works with the dSCR SRM-522 (290...2340 MHz) TERRA R80522 multiswitch, which has 5 inputs: two pairs of SAT IF inputs (290...2340 MHz; V1, H1, V2, H2) enabling the satellite signal to be supplied from two Wide Band A98222 LNBs, and an terrestrial TV path (DVB-T/Radio signal). Each of the 2 outputs can work as a dSCR Out type output (enabling Unicable signal to be supplied to up to 16 receivers after using signal splitters) or Legacy Out (standard output, as in the Universal converter or standard multiswitches used to connect a satellite receiver).

The photo above shows the measurement of the satellite signal at the dSCR1 output of the SRM-522 R80522 multiswitch. The SRM-522 R80522 multiswitch is supplied with the signal from a satellite dish set to the HOTBIRD 13E satellite with an installed Wide Band A98222 converter. Each of the 2 multiswitch outputs can function as the dSCR Out/Unicable or Legacy output. Measurements were made using the dSCR/Unicable technology with the Signal WS-6980 R10837 meter for the 11508 V transponder (HOTBIRD 13E, DVB-S2, 8PSK, SR 27500, FEC 3/4). To do that, you need to change the LNB Type from Universal (Legacy signal measurement, fullband output) to SCR in the meter settings, and select one of the 4 available frequencies (user band): 1210 MHz, 1420 MHz, 1680 MHz, 2040 MHz. For SCR: UB1 = 1210 the signal obtained was PWR = 84 dBµV and MER = 13.6 dB. Such values ​​allow for a smooth reception of the satellite signal with a standard Legacy receiver or a receiver supporting the dSCR/Unicable technology. In addition to that, the PC102W R80561 programmer was connected to the dSCR2 output of the multiswitch to enable configuration and management of multiswitches based on the dSCR/Unicable system.

Batch software update in Hikvision devices.

Before installing a newly purchased monitoring system, it is recommended to update the equipment to the latest firmware versions. The devices can be updated individually, but it takes a lot of time, particularly when a more extensive system with, for example, 32 cameras is involved. For quick batch update of the same or the same hardware platform cameras, DVRs, etc., you can use the Batch Configuration software. To do this, after running the software with administrator privileges and adding all devices to it:

Batch update of 2 cameras belonging to the same hardware platform

What is the maximum PoC transmission range?

PoC, or Power over Coaxial, is a transmission system that allows HD-TVI video signal and power to be transferred through a common cable. Coaxial cables or a twisted pair (with an appropriate transformer) with a minimum of 5e category can be used for the transmission. To achieve a sufficient transmission range, quality cables are required, such as Tristet czy Netset. The maximum transmission distance is shown in the chart below:

Maximum PoC transmission distance

Pass-through RJ-45 connectors.

DIPOL now offers EZ RJ-45 (cat. 5e J2012_100 and 6 J2013_100) pass-through 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 E7911 crimping tool.

The plug ready for crimping

The plug has an elastic latch that prevents it from sliding out of the socket. Individual contacts have sharp, slightly spaced prongs, sticking directly into the insulation of individual wires, ensuring a reliable and durable connection.

The installer can be sure that the twisted pair cables are led to the front of the connector, which ensures the best contact of the relevant pins.

Transmission of DVB-T signals via optical fibers.

Most systems transmitting DVB-T signal via optical fibers use traditional optical transmitters and nodes, e.g. the mo418 R82522 transmitter and OD-005P R81760 receiver. The networks are composed of single-mode cables and passive optical splitters that enable distribution of the signal to different locations.

An alternative solution is based on the conversion of the DVB-T signal (from a master antenna or headend) to IP stream that is distributed via typical fiber optic network (active Ethernet network), and then converted back into DVB-T. The equipment used for the conversions:

The IP stream can be transmitted by optical fibers linking any Ethernet devices - media converters, switches with SFP modules, etc. The advantage of this solution is the possibility of transmission within both single-mode and multimode networks. The signal is split by traditional switches, so in most cases it is not necessary to modify the existing network.

Example of an MATV system (DVB-T) with fiber-optic transmission medium
(transmission of four digital multiplexes via optical link up to 20 km)

OTDR measurements: installers' doubts when measuring the optical path length. One of the more interesting advantages of a reflectometer is the ability to determine the length of the optical path or the distance from the person measuring the selected events (e.g. cable break). However, it happens that installers have doubts in the interpretation of the reflectometer indications, and even suggest its failure. The longer the optical fibers are measured, the greater the discrepancy between the distance measurement results and expectations may be...>>>more

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