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No. 29/2014 (Sept. 22, 2014)
How many kilobits per second is needed to transfer ... thoughts?
Communication between two people who use the same language is an obvious thing. One says or writes something, and the partner understands the meaning. However, the dream of some people is a direct transfer of their thoughts to others without speaking or writing. Is it possible that the brain of one person contacts the brain of another? An international team of neuroscientists and roboticists proved that it is possible, even over a distance of 8000 km.The experience consisted in sending information from a person who was in India to a person in France, using only brain activity. The signal was sent via the Internet. A team of Alvaro Pascual-Leone assumed that the "transmitted" words would be "hola" and "ciao". To "capture" them, they used an electroencephalograph (EEG) recording weak electrical signals occurring at different points of the scalp, and transcranial magnetic stimulation devices (TMS) to "express" them on the other sides. TMS is a noninvasive method that causes depolarization and hyperpolarization of neurons. It is based on electromagnetic induction - a rapidly changing magnetic field induces weak electric currents in some parts of the brain.
A diagram illustrating the idea of brain-to-brain communication
There were four participants directly involved in the experiment: the "sender", connected to EEG monitoring equipment acting as an interface between the brain and a computer, and three people connected to TMS devices acting as bridges between other computers and their brains. Using EEG, the words "hola" and "ciao" were "translated" to binary code and and then sent to recipients using ordinary e-mails. On the other side, the messages were received by the other computers and provided to TMS devices stimulating the brains of the recipients who experienced visual disturbances (flashes of light in their peripheral vision) allowing them to interpret the messages.
The man on the right, about 8000 km away, "reads" the thoughts of the one on the left
It is clear that due to the early stage of the research, complicated method and high costs, this type of experiments can currently be carried out only in scientific laboratories. However, with improved and cheaper solutions, this form of communication can prove to be a breakthrough for millions of people with disorders that make them unable to communicate in the traditional manner. Such a technology is also interesting for military applications - armed forces would certainly be glad to use direct transmission of thoughts ...
The end is near.
September 28 is the last day we accept entries to the Engagingly about Antennas - 13th DIPOL's Summer Holiday Contest 2014. So far, we have received many interesting pictures. The main prizes will be awarded by photographer and designer from Krakow, Mr. Pawel Zechenter. We invite you to browse your own archives and send a unique photo on the subject of antennas. The rules of the contest are available here.Some of this year's entries:
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"Koko-channel" Michal Gawryluk | Rainbow amplitude Jakub Lukasik | Antenna connecting people Sylwia Duraj |
DVB-T programming in cable TV.
Cable TV operators that include into CATV programming the range of channels available from terrestrial DVB-T transmitters, usually use one of two ways mentioned below.In the first one, the digital DVB-T channels are converted into digital DVB-C equivalents. This method is more popular, because the all the programming can be distributed in DVB-C standard within the whole frequency range normally used in CATV networks.
In the second method, the DVB-T channels are distributed within a CATV network without changing the original standard. This may be beneficial for subscribers who would normally use individual antennas mounted on balconies or by windows. Usually, for a low price they can receive the DVB-T channels via the CATV outlets instead.
Using the second method, the operator cannot use S channels, because most DVB-T receivers do not search DVB-T in the S band. Usually, all the DVB-T channels are shifted into the VHF band. This forces the change of the width of DVB-T multiplexes broadcast in the UHF band (8 MHz) to 7 MHz bandwidth obligatory in the VHF band.
COFDM-COFDM (DVB-T) Trans-Modulator TERRA ttx311 R81714
TERRA company provides a solution allowing for processing of TV channels, based on MMH-3000 headend. The processing is performed by TTX-311 R81714 modules. In addition to changing the original RF channel, the TTX-311 module demultiplexes the entire DVB-T stream, so that it is possible to modify the output content, in particular to change the channel width of a multiplex redistributed in the VHF band (BIII). However, such a change limits the capacity of the new multiplex - usually it is necessary to remove one channel from the original multiplex.
Home automation for everyone.
Exta Free is a popular in Europe, low-cost home automation system for remote control of electrical appliances and lighting. Its greatest advantages include reliability and simplicity. The user can start from a single pair of devices, a remote control (transmitter) and actuator (receiver), and later add new components, including central unit (server) to get control of the home system from smartphones.Ready-to-use kits for typical applications are ideal for novice users:
 | F5010 | 2-channel wireless remote control and 1-channel receiver/relay for comfortable control of lighting, heating etc. |
 | F5011 | 2-channel wireless remote control and 1-channel radio dimmer |
 | F5012 | 2-channel wireless remote control and roller blinds controller |
 | F5013 | 4-channel wireless remote control and 2-channel receiver/relay for comfortable control of lighting, heating etc. |
 | F5014 | 2-channel wireless remote control and 1-channel receiver with bistable relay for comfortable control of lighting and any electrical devices |
 | F5019 | remotely controlled power outlet and wireless remote control for switching on/off any electrical appliances |
It often happens that one wants to control lights from a different place than it has been designed. Generally, it is rather troublesome to move a light switch from one area of a room to another. Such a task is connected with running an additional wire from the current switch to a new switch and some redecorating work. Using Exta Free system components, it is enough to install them in existing junction boxes and control the lights by suitable remote controls.
IP video surveillance system with fiber optic cabling - equipment selection.
The following diagram shows a proposal for the implementation of a video monitoring system composed of seven outdoor IP cameras deployed in an industrial plant. The installation of this type of systems based on fiber optic cabling requires some knowledge and experience.
Video streams from five 1.3 MP Hikvision K1763 cameras are transmitted via outdoor UTP cable E1410 to Ultipower N29983 PoE switch that also provides power for the cameras. Other two cameras ( K1764 ), located at large distance from the rest, are locally connected to the Ultipower N29980 switch. This second, distant switch is connected with the first one via a single-mode optical link that includes Ethernet media converter L1301 and two SFP modules, L1415 and L1416. The video streams are recorded by an NVR connected to the N29983 switch (the devices are located in the security post). Additionally, the surveillance data is provided via a multimode optical link to the corporate local network (over a distance of 350 meters). The link uses two L1402 SFP modules that have been installed in the N29983 and N29958 switches.
The most important guidelines that should be followed:
- fiber optic cabling - if the network and video monitoring system is built from scratch, basically it does not matter what type of fiber is selected. However, multimode fibers can be used over distances up to 2 km, and in the case of longer links it is necessary to employ single-mode cables that can also be used for shorter transmission lines. For the shorter links, the decisive factor may be the cost of active devices needed for the single-mode or multimode optical fibers;
- media converters - the basic criteria for the selection should be the maximum data transfer rate - 100 Mbps or 1 Gbps, and the type of the dedicated fiber (multimode or single-mode). Video surveillance systems with a greater number of megapixel cameras will require the application of Gigabit devices. An important feature is also the kind of the connectors. And the maximum transmission distance is important in the case of dispersed locations - the offered devices can be used for transmissions over maximum distances of 550 m, 2 km, 20 km and 40 km.
- SFP modules - should be carefully selected for compatibility with the switches or media converters. The basic rules are the same as in the case of media converters (data transfer rate, type of fiber, connectors, maximum transmission distance), however, choosing specific modules the installer should take into account three important issues:
- if the SFP port of a switch or media converter is marked as "Gigabit", "GbE", "1000 Mb/s", "1 Gbps" etc, the only choice should be a gigabit SFP module, otherwise there can be compatibility problems; when the SFP port is marked "10/100/1000 Mb/s" etc, the choice is broader, according to the needs;
- the installer should pay attention to the wavelengths at which the SFP modules operate, and use pairs of complementary devices; a typical mistake is an attempt to communicate devices (Tx/Rx) operating at 850/850 nm or 1310/1310 nm, or the same WDM modules, e.g. 1310/1550 nm on the both sides of the link. Each pair must consist of complementary devices, i.e. the wavelength of the transmitter of the first device has to be the same as the reception wavelength of the second device;
- despite the same standard, it happens that SFP modules from some manufactures have compatibility problems with switches from other producers. Ultimode SFP modules are compatible with Ultipower and TP-LINK switches.
How to calculate the storage capacity of hard disks in CCTV systems?
The user usually determines how long the recorded video data should be stored in the system. Based on this information and parameters of the system, the installer should calculate the required capacity and number of hard drives that have to be installed in the DVR(s). Aside from the retention time, the total capacity depends on the number of cameras (channels), recording intensity (the average ratio of the recording time to the total operation time), frame rate, video resolution, and compression method used in each channel, and additional parameters, such as recording quality, bitrate. Hikvision company provides Disk Calculator (15 MB) that simplifies the calculations.
A screenshot from the Disk Calculator utility
Based on the provided parameters listed above, the application calculates the required capacity of the hard disk(s), or, when the disk space is given, the recording time. In addition to manual data entry, it is possible to find DVRs in the local network and download the necessary parameters automatically. Another option is the import of a special file generated by the iVMS software (110 MB).
Sunell cameras in park in Chorzow.
The walkers in Silesian Park in Chorzow can enjoy the latest work of Julita Wojcik, a Polish artist. This six meter high "mosquito" named "Dron" has been well received by the majority of the audience. This exhibit is to symbolize the control of the artist over her work and its loss to the viewer. On the sculpture there has been installed vandal-proof camera Sunell K1691, to provide the video to a large screen nearby.
To prevent vandalism, the "mosquito" is additionally monitored
by another Sunell camera - the compact model K1681
by another Sunell camera - the compact model K1681
The video from the camera located on the sculpture is transmitted by the N24113 access point to a streaming server. With this solution, the image from the camera is displayed in a special module on the www.parkslaski.pl website. The users can "take" pictures and publish them on social networks.
View from the K1691 camera placed on the sculpture
 | Dome IP Camera Sunell SN-IPR54/14ALDN K1697 is equipped with Sony Exmor 1/2.8" image sensor with a resolution of 1920x1080 pixels and sensitivity of 0.1 lx. It means that every part of the scene is much more closely monitored, even in low-light conditions. Additionally, the built-in varifocal lens (3.3-12mm @ F1.2) allows for precise adjustment of the field of view. The metal vandal-proof housing with IP66 rating protects the camera from vandalism acts, as well as from adverse weather conditions and dust. | |
 | Wireless Access Point RouterBoard SXTG 5HPACD N24118 is a complete device of the Customer Premises Equipment (CPE) category, compliant with 802.11ac standard. It operates in 5 GHz band using MIMO 2x2 technology, has double-polarization antenna with 16 dBi gain and separation between the polarizations of 35 dB. The RouterBoard SXTG 5HPACD access points usually operate as client stations and can also be used to build point-to-point links. | |
 | Installation Box for Signal HD-200 Camera M5722 hides and protects cable connections, balun etc. | |
Worth reading
Struggle with attenuation in optical networks. The phenomenon of signal attenuation is the basic problem of the transmission of information over long distances. In the case of fiber-optic networks, an additional attenuation can be caused by factors such as inadequate precision of splices or too small bending radius. However, it happens that the attenuation of a link is too high, despite observing the basic rules... more
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A dirty ferrule end face (on the left) and the face cleaned with the NC-001 tool.
Improper cleaning of ferrule end faces may cause permanent scratches.
Improper cleaning of ferrule end faces may cause permanent scratches.
Engagingly about Antennas - 13th DIPOL's Summer Holiday Contest 2014
