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No. 9/2015 (March 2, 2015)
More about light... 0.2 Tbps!
Researchers at the University of Oxford informed about reaching a record speed of wireless data transmission using light. They managed to establish a bidirectional connection between light transmitters and receivers located 3 meters away, of aggregate bandwidth of 224 Gbps (light beam width of 60o, 6 x 37.4 Gbps), or 112 Gbps (light beam width of 36o, 3 x 37.4 Gbps). The researchers say that their study will help to develop an alternative to the WiFi standard. The latest version of this standard - 802.11ac - offers bandwidth of "only" 6-10 Gbps.
The concept of LiFi (Light Fidelity) technology
- data exchange via visible light
(source: purelifi.com)
- data exchange via visible light
(source: purelifi.com)
In opposite to "true" Li-Fi solutions, the light sources used in the experiment operated at a wavelength typical for lasers used in commercial optical networks (1550 nm, invisible infrared light). The system was composed of two transceivers - one being the point of connection to an external network, installed e.g. on the ceiling of the room, and a second, installed on a computer that (so far) had to be in a fixed position at the time of transmission. The both devices generated and received light beams similar to those of LCD projectors. The width of the beams determined how much information could be transmitted by such optical links just over the air.
Wireless communication using light as a carrier - Li-Fi (Light Fidelity) - was first presented in 2011 by Professor Harald Haas from the University of Edinburgh. Using one LED, he managed to get a throughput of 10 Mbps, sufficient for streaming an HD video to a computer. This year, a 3 Gbps speed was achieved by the Fraunhofer Heinrich Hertz Institute in Germany, and another research carried out by the Ultra Parallel Visible Light Communications project, a joint venture between the universities of Oxford, Cambridge, Edinburgh, St Andrews and Strathclyde, resulted in transmission speeds of 10 Gbps. Li-Fi will enable creation of high-speed telecommunications networks with properties similar to Wi-Fi solutions. It can be used in places where radio carriers are prohibited, undesirable, or unreliable, such as in operating rooms, on airplanes, in factories etc. In the latest issue of the DIPOL Weekly Review we have informed about "smart spaces" concept of the researches from Dartmouth College, which should help in the practical implementation of "light networks".
A SMATV system on one of housing developments in Krakow.
The market offers many types of multiswitches. When choosing the suitable equipment, the investor and installer should pay attention to its technical parameters and completeness. The completeness means both a variety of versions for different applications, a wide range of accessories, as well as technical support. Other significant factors are the experience and reputation of the manufacturer, guarantying high reliability backed by an extended warranty.GKJ SYSTEM company has lately implemented SMATV system for reception of DVB-S/S2 signals from Hotbird 13°E, terrestrial DVB-T broadcasts and FM radio stations, located on a housing development in Krakow. The designing of the system with one master antenna set has been performed with the use of free SatNet software.
Diagram of the multiswitch SMATV system in a 4-staircase building, made with the use of SatNet app
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The signals from the master antenna are run via five coaxial cables ("bus") to the SA-51 TERRA R70501 amplifier for 5-input multiswitches. Additionally, terrestrial signals are processed by digitally programmable multi-band amplifier WWK-951 R89861. The use of the amplifier allows for strengthening and equalizing the signals. The UHF 1 and UHF 2 inputs use five independent band filters (paths) with adjustable width. Each staircase has been equipped with installation box containing MV-516 R70716, MV-524 R70724 and MV-532 R70732 multiswitches. The 5-cable bus has been divided into sections by the SD-504 R70515 and SDQ-508 R70520 SAT/TV splitters. A professional finishing touch has been added by the use of reliable "Self-Install" F plugs Cabelcon E80410 and TV-Sat surge protectors Signal R48602 mounted at the inputs of the first active devices of the system (just after the LNB and antennas).
The elegant and functional RACK cabinets are designed for mounting devices having housings compatible with 19" rack standard (482.6 mm). The height of the devices and auxiliary equipment is standardized as the multiplies of one rack unit ("U" = 1.75" = 44.45 mm).
A typical section of 19" RACK rail
(Source: Wikipedia)
(Source: Wikipedia)
RACK cabinets are ideal for installing headends, switches, computers, optical devices. They can also house devices that are not in standard 19" rack housings, for example multiswitches, RF amplifiers, modulators, DVRs, NVRs, servers. For this purpose, the user should buy one of the offered shelves.
Hanging RACK cabinets are ideal for smaller systems.
SIGNAL 19" Rack Cabinet (6U 600mm, hanging) R912017
Universal cable (left) and distribution cable (right)
| 1. Optical fiber 2. Gel inside the central tube 3. Central tube 4. Aramid yarn 5. LSZH jacket | |
Universal Ultimode cables can be used in indoor and outdoor applications. The fibers are contained in central gel-filled tube. The gel in the tube is a kind of protective coating for optical fibers, which absorbs mechanical stresses and protects against environmental factors.
Universal Cable ULTIMODE UNI-12MM-A (12x OM2) L73012
The universal cables are mainly intended for horizontal connections in buildings and outside buildings. Due to the small size and flexibility, the cables are ideal for installation in cable ducts. They are used in modern FTTH and FTTB systems, in server rooms, between buildings. Because of the gel-filled structure, the vertical cable runs of the cables installed in buildings should not be longer (higher) than 30 meters.
Distribution Ultimode cables belong to the "minibreakout" category intended for applications in buildings. The fibers in tight buffers are contained in one sheath. Individual fibers are comfortably accessible, which makes it easier to install optical connectors, to make splices etc. Indoor distribution cables from ULTIMODE IDC series are gel-free fiber optic cables intended for horizontal and vertical connections in buildings. Another category is the group of flat 2J and 4J cables.
Indoor Cable ULTIMODE ILB-2SM-A (2xG.657A1, limited bending radius) L7102
Network features of Sunell NVR.
The IP NVR Sunell K2508 has two network adapters, LAN1 and LAN2. With this solution, it is possible to separate the external network (LAN1) from the private network (LAN2) with the cameras. The network configuration options in the LAN1 include switching on DHCP client function, or setting the IP address, mask, gateway, and DNS servers manually. The configuration parameters in the LAN2 can be set only manually.Two LAN ports allow for the physical and logical division of the system into two separate networks, which protects the cameras from external network environment. The redundancy of Ethernet ports also increases the reliability of the system - if one interface fails, it is possible to reconfigure the NVR so that the system can operate with the second.
The use of two network adapters in SUNELL NVR.
The data from cameras are separated from data exchanged with NVR clients.
The data from cameras are separated from data exchanged with NVR clients.
UPnP protocol in Hikvision devices.
IP cameras, IP NVRs, and DVRs from Hikvision have been equipped with UPnP (Universal Plug-and-Play) protocol. It simplifies the configuration of the devices in IP networks.If a network has a router supporting UPnP, the attached Hikvision device will automatically configure and forward its ports used for the Internet connection: HTTP (80), RTSP (554), and SDK (8000).
The use of Auto Port Mapping Mode in a Hikvision IP camera
 | HD-TVI TURBO HD Camera Hikvision DS-2CE16D5T-IR M7558 - compact camera designed for use in CCTV systems based on HD-TVI DVRs. The camera provides 1080p video. With high sensitivity (0.01 lx) and built-in IR illuminator with range up to 20 m, the camera ensures high quality image in low light or even no-light conditions. | |
 | HD-TVI TURBO HD Camera Hikvision DS-2CE16D5T-IT3 M7569 - compact camera designed for use in CCTV systems based on HD-TVI DVRs. The camera provides 1080p video. The camera has the ability to control the OSD menu using the video signal cable. The control is possible via a compatible DVR, after selecting PTZ control in its menu and switching on the menu of the camera, with access to all configuration options. | |
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Worth reading
Microbending and macrobending in optical fibers. The optical fiber is a very delicate transmission medium from the mechanical point of view. During the installation of fiber optic systems, the installer has to follow specific rules, in particular, should avoid excessive bending and pulling of optical cables and fibers... more
Microbending and macrobending may have a significant effect on the signal attenuation in the fiber
Master connectors - the perfect choice
