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

Multimode fibers - development or regression?

IBM broke the speed record for data transmission over a multimode fiber. Thus, it proved that the technology being considered by many as obsolete can still be successful in the market.

Thanks to modern solutions, the research team was able to achieve data transfer rate of 64 Gbps in both directions. The data transmission at such speed was possible over a distance of 57 meters. It's not much, but multimode fibers have never been used for long-distance transmissions, but they rather connect neighboring buildings and are widely used for internal links between servers, offices, apartments etc. IBM has shown that the structural cabling based on multimode fibers can still be used in modern communication systems and there is no rational need to change the cabling.

From the technical side, the new speed record is not a result of a great revolution, but is achieved through the improvement of the existing technologies. The source of light was Vertical Cavity Surface Emitting Laser (VCSEL), invented in the 70s of the twentieth century, and successfully used today for gigabit transmissions in single-mode optical fibers. The key to the success was the integrated circuit managing the data exchange, BiCMOS8HP VCSEL . It uses sophisticated algorithms that simultaneously control the sensitivity of the receiver and the speed of the transmitter. The processor controls VCSEL created at Chalmers University of Technology in Sweden, made ​​with silicon-germanium (SiGe) and a chipset developed at the IBM research center. The idea of the algorithms for optimum signal transmission was taken from the conventional copper networks. As a result, the researches could achieve the 64 Gbps transfer, much higher than the previous record with VCSELs, 44 Gbps. It was enough to transfer the method used for electrical signals to photonics.

It is difficult to assess whether this achievement will significantly increase the development of multimode networks or will only extend the life of the existing infrastructure.

Marking of optical fibers.

Fiber-optic communication lines are typically used at very large distances. The proper identification of individual lines is a necessary condition for the maintenance of the network. All the cables, running next to each other, have to be individually labelled. At any administration point in a cabling infrastructure, accurate labels are essential. They identify pair modularity and tell technicians where the other end of the cable is terminated.

Tag for fiber optic cables L5562

An example of labels for optical cables and links is the information tag L5562. The plate is made of durable plastic and has 6 holes for cable ties used for securing it to the cable(s). The plastic is resistant to severe weather conditions such as frost and moisture, typical for ducts in the ground. Thanks to small dimensions, the tag can be placed on any section of the cable, and the bright color makes it easy to find it. The use of tags is usually required by law and/or the investor. Cabling system administration, labeling and records are covered in ISO/IEC 14763-1.

Terra SatNet3.2 - new version of SMATV software, supporting at4xx amplifiers.

TERRA has published the new SatNet3.2 version of the software for designing multiswitch systems. This time the changes are considerable and, as announced before, include the support for the use of channel amplifiers at420 R82510 and at440 R82511. When a project incorporates the amplifiers, the frequency response for terrestrial path is limited to the frequency band from the lowest to the highest channel selected on the amplifier(s). The graph is continuous, but the utility checks the signal levels only for the selected channels.

Thanks to the introduced innovations, the user/designer does not have to worry about aligning all levels of DVB-T signals at the input of the system. The necessary thing is only to choose the layout of the system. The software selects passive components, takes into account the attenuation of cables, and calculates the optimum settings of multiswitches and amplifiers.

Video monitoring of a house.

A typical requirement for such a system is high image quality at a reasonable price. It should work round the clock and cover both the area around the house, as well as selected areas of ​​its interior. The main tasks of the monitoring is to minimize the risks of burglary, theft, vandalism (writing graffiti, dropping litter etc).

The cameras are powered from one point via UTP cables, the same that transmit video. It is possible by using video transmitter-receiver sets Etrix 1VAP M16659 (baluns with BNC connectors and DC-2.1/5.5 jacks). The video from the cameras is recorded by ULTIMAX 1204 (4CIF at 12 fps for each channel). The users can access the DVR resources via web browsers, Internet Explorer, Google Chrome, Firefox, or free IVMS software. In the case of mobile devices, the video can be viewed through smartphones and tablets with Android, Windows Mobile or iOS systems.
The signal from the SPOT out is split by the video signal multiplexer RV-1/2P M1707 into two paths. One of them is used by the monitor of the intercom system, and the other is connected to a TV with composite video input. This solution allows for simultaneous viewing of images on the intercom monitor and on the television screen.

Sunell SN-IPR54/14AKDN - easy-to-mount 2MP IP camera.

CCTV installers may have problems with hiding the cables going out from security cameras. Usually they have to use special boxes or plunge them directly into the wall, using for this purpose boring heads. In the case of Sunell SN-IPR54/14AKDN K1681 camera the increased effort is not needed, the manufacturer provides special bracket base.

View of the bracket base and template supplied with the Sunell SN-IPR54/14AKDN K1681 camera

The installer should only drill holes for screw anchors, according to the enclosed template. The bracket base mounted on the wall will encompass the cables and connectors, in the space between the camera bracket and the wall. The bracket with three-axis control system allows the installer to quickly and easily direct the camera towards the desired coverage area.

Compact IP Camera Sunell SN-IPR54/14AKDN (2MP/FullHD, Sony Exmor, ONVIF) K1681

Which wireless router for speeds above 60 Mbps?

With the development of broadband access techniques, the speeds offered by ISPs continuously increase. Today, the max download rates often reach 30 Mbps, 60 Mbps or even 120 Mbps.

To make use of the high bandwidths in home wireless networks it is necessary to use wireless routers equipped with the appropriate access points. The still popular devices operating in the 802.11b/g standard (theoretically up to 54 Mbps) are capable of achieving real transfers up to the level of 23-24 Mbps. This is not optimal solution for faster Internet connections. They will be supported more effectively by 802.11n devices, from the simplest 150 Mbps implementations with single antennas (real transfers up to 60 Mbps) to the highly-efficient MIMO devices with theoretical limit of 300 Mbps (real transfers up to 120 Mbps).

It is worth mentioning that the efficiency of a router equipped with wireless AP depends also on the number of antennas, type and clock speed of the CPU, the amount of internal memory.

The table below presents some wireless routers with built-in APs designed for high-speed communication.

April 7, 2014 - tomorrow starts Securex 2014 trade fair 2014. At our booth No. 5 in pavilion 8A, you can see mobile PROTECT DVRs with one, two or four channels, cooperating with SD cards or 2.5" HDD. We will also present the family of ULTIPOWER PoE switches.
More about our offer presented on the international trade fair you can read here.

Which UPS to choose? When choosing an uninterruptible power supply, it is important to take into account the output voltage waveform. Depending on the kind of a UPS, the waveform may be rectangular, simulated (approximated) sine wave, or pure sine wave. The waveform of the output voltage is important for the powered devices ... more

The waveforms of the output voltage generated by UPSes:
red - pure sine wave, blue - simulated sine wave, violet - square wave