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No. 24/2018 (June 11, 2018)
Will light make semiconductor computers a million times faster?
Researchers at the University of Michigan in the United States have shown how infrared laser pulses can shift electrons between two different states in a thin semiconductor layer. The described phenomenon may result in the creation of a new generation of computers that will be a million times faster than those currently used. A new computing technique that uses laser light pulses to create the basic calculation unit, called a bit, can switch between state "1" and "0" up to million times billion per second (106 x 109, i.e. 1015). The researchers used a pulsed infrared laser, interacting with a honeycomb-shaped lattice made of tungsten and selenium, allowing a silicon chip to change the state from "1" to "0" as in a normal computer processor, but one million times faster.
The researchers say that this structure can also be used in the case of quantum computations, in the world ruled by qubits (quantum bits). In a classic computer, one bit can store one of two values, two bits - four values, etc. The basic unit of quantum information is quantum bit. A qubit can simultaneously take the value 0 and 1, and an infinite number of states between 0 and 1, which is called a superposition. Only when checking the value of the qubit, it takes one of two basic states, 0 or 1.
It seems that this is a small difference, however, the qubit located in the superposition state could be used to perform many calculations simultaneously. This should allow quantum computers to perform calculations much faster than conventional machines can.
The experiment conducted by the scientists can open the door to ultra-fast computing technology, which can be used, for example, in the implementation of artificial intelligence algorithms, weather forecasting, and drug design and testing.
The DIPOL Summer Photo Competition has just started!
We look forward for your pictures! As every year, we are waiting for interesting, unconventional, artistic photos, with antennas of all shapes and sizes. More info on the contest and awards you can find on the contest site.
How to limit the data retention period in Hikvision monitoring systems?
To follow the guidelines for the protection of personal data, the amount and period of personal data that are recorded should be limited to a reasonable minimum. In video monitoring systems, there is no easy way to estimate the demand for disk space, because the amount of data generated and recorded depends on many factors independent of the recording device, e.g. the character of the scene, light conditions etc.The best way is to limit the parameter in the menu of the DVR/NVR. All Hikvision DVRs/NVRs have the option of specifying the data retention time in days. This setting (Expired Time) defines after how many days the recordings will be deleted. If the value is set to 0, then the files will be stored permanently. The user should take into account the capacity of HDD disk(s) - if the available space ends, the function will not protect the older recordings from overwriting.
View of the Advanced window with the Expired Time setting
SatNet 4.0.1 - designing fiber-optic SMATV systems.
The ability to transmit television signals over long distances without the need to regenerate them is one of the most important advantages of fiber optic systems. In the case of a fiber-optic trunk, the various sizes of facilities in which the signals are to be distributed do not cause technical problems. The signals can be easily transmitted both over hundreds of meters and tens of kilometers without a need for additional equipment. This significantly simplifies the deployment of signal distribution systems in large buildings. The newest version of SatNet 4 application has been extended with elements of TERRA fiber-optic solutions. Below, we show an example of an SMATV system combining fiber-optic and copper elements, designed with the use of the SatNet 4 software.
A combined fiber-optic and copper TERRA multiswitch system (click on to see the whole figure). The satellite and terrestrial TV signals are provided via coaxial cables to the OT501W A9872 optical transmitter. This way, instead of a typical 5-cable multiswitch bus, all the signal are transmitted via one single-mode optical fiber. This solution can be used in large facilities, where the distances between signal distribution points are more than several dozen meters or if we want to protect multiswitches and subscriber devices against the effects of overvoltages caused by atmospheric discharges. The OR501W A9877 optical receivers perform the reverse conversion of the optical signals into RF form. The RF signals are further distributed in the facility by the MV-924L R70824 multiswitches and coaxial cables.
Optical components of the TERRA system:
- TV Optical Transmitter TERRA OT501W A9872 - is used for transmission of television signals via optical medium. It converts input satellite signals from a quatro LNB, and DTT (DVB-T) and radio (DAB and FM) signals (the terrestrial signals have to be combined by a triplexer) from a set of terrestrial antennas. The built-in WDM multiplexer transmits the two groups of signals separately, in the II transmission window (1310 nm) and III transmission window (1550 nm), which guarantees exceptional quality of the transmission. Each input of the transmitter is equipped with automatic gain control (AGC) ensuring signal stability (compensation of signal level fluctuation associated with changing weather conditions - rain, heavy clouds etc.). Consequently, the output optical signal has a constant modulation depth.
- Optical Receiver TERRA OR501W A9877 - converts optical signal coming via passive optical network from the OT501W transmitter into electrical signals. These are SAT IF signals and terrestrial DVB-T, DAB and FM broadcasts. The device has 5 outputs, 4 of them providing the four pairs (VL–HL–VH–HH) of SAT IF signals (like typical QUATRO LNB) and terrestrial broadcasts. This "virtual QUATRO LNB" should be connected to a multiswitch or a group of multiswitches with a suitable number of outputs, depending on the number of subscriber outlets.
- Optical Receiver TERRA OR501MW A9875 - converts optical signal coming via passive optical network from the OT501W transmitter into electrical signals. These are SAT IF signals and terrestrial DVB-T, DAB and FM broadcasts. The device has 4 outputs providing the complete satellite signals (like typical QUAD LNB) and terrestrial broadcasts.
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, 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 made of the E1408 cable.
Certified RACK cabinets.
Until recently, RACK cabinets have been used mainly in large telecommunications systems and server rooms. Currently, smaller RACK cabinets are used in majority of building installations and even in home systems. RACK cabinets are ideal for installing headends, switches, computers, optical devices, multiswitches, RF amplifiers, modulators, DVRs, NVRs.When choosing accessories for rack cabinets, the customer should pay attention to their compatibility with the specific models of the cabinets. Some components may be dedicated to other models, e.g. with greater depth or with a different way of mounting the accessory (e.g. a fan). DIPOL e-Store offers a simple mechanism that provides a list of compatible accessories for the selected RACK cabinet. The user should simply open the site with the required RACK, e.g. R912020, and then click on the "Add accessories" button in the right section.
Hanging RACK cabinets are ideal for building and home systems.
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Document confirming the compliance of the cabinet with general safety requirements contained in Chapter II
of the General Product Safety Directive (2001/95/EC) of 3 December 2001 and in the guidelines
of the EN 60950-1:2007 international standard, issued by KOMAG INSTITUTE OF MINING TECHNOLOGY
WDM (single-fiber) vs. duplex (two-fiber) links.
Installers can choose solutions based on Wave Division Multiplexing (WDM), which require only one fiber for bidirectional data transmission or those with two fibers (duplex). Choosing a solution, they usually take into consideration its cost and the number of fibers available in the cable. However, there is one more technical aspect associated with the use of one or two wavelengths.In the simplest form, WDM transmission uses two different wavelengths in one fiber (typically 1310 and 1550 nm, like in the case of the L11521 media converter). Duplex solutions use two fibers and only one wavelength (e.g. 1310 nm) in the both fibers. In each case, the characteristic feature of fiber optic transmission is the fact that different wavelengths are differently attenuated by the fiber optic fiber. This also applies to macrobending attenuation, i.e. the attenuation caused by bends exceeding 2 mm in diameter. Generally, fiber bends cause substantially higher attenuation for longer wavelengths.
A graph showing the dependence of the attenuation on the wavelength in the case of:
microbends (blue), macrobends with 20 mm (red) and 25 mm radius (green)
(The data come from studies of Cabelcon company)
microbends (blue), macrobends with 20 mm (red) and 25 mm radius (green)
(The data come from studies of Cabelcon company)
The graph shows that accidental fiber bending will result in different attenuation for different wavelengths - for example, a 20 mm bend does not cause significantly greater attenuation at the wavelength of 1310 nm, but in the case of the wavelength of 1550 nm, the attenuation of the bend will exceed 2 dB. Compared with normal attenuation of the fiber at the level of about 0.25 dB/km, the loss increase is gigantic.
In the case of systems using more than one wavelength, any installer should be aware of the above phenomenon. That is why it is generally recommended that measurements should be made for all wavelengths used in the installation.
 | Wireless router/modem TD-W9970 TP-Link N2903 has been designed for sharing Internet connection provided by Ethernet WAN (EWAN) or VDSL2/ADSL line. It has IEEE802.11n/b/g Access Point (transmission speed up to 300 Mbps at 2.4 GHz), Fast Ethernet switch, multifunctional USB port. The TD-W9970 device is the perfect choice for users who want to enjoy HD video streaming and online games. | |
 | HD-TVI TURBO HD 4.0 Camera Hikvision DS-2CE16H1T-AIT3Z M75772 has been designed for use in CCTV systems based on HD-TVI DVRs. The bullet camera provides high quality video with image resolution of 5 MP (can be optionally switched to 4 MP in the menu). The application of megapixel cameras with motozoom lenses allows for reduction of the number of camera points. Along with high sensitivity (0.01 lx) and built-in IR illuminator (Exir type ensuring even lighting) with range up to 40 m, the camera guarantees high quality video monitoring in low light or even no-light conditions. | |
 | Video Door Phone Hikvision DS-KIS202 G7381 is a 1-subscriber Hikvision video intercom system dedicated for single-family homes. It consists of 7" DS-KH2220 indoor station/monitor with a resolution of 800 x 600 px and DS-KB2411-IM gate/gantry/door station equipped with a color pinhole camera with a resolution of 720 x 576 px. The indoor monitor is made in TFT LCD technology and supports up to 2 door stations The monitor can cooperate with CCTV analog camera operating in CVBS standard and be used for displaying the video from the camera and the door station(s) and for control of the electric strike. | |
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