RFID solutions allow to control not only certain zones or areas (e.g. border zone, airports), but also enable remote scanning of the embedded and dynamic data, get access to information on the people and their relocations, and can provide control authority (in the sense of access rights to certain zones etc.).
Many countries plan to introduce identity cards, passports and car registration plates with RFID tags. By the end of this year, China wants to issue for its citizens about a billion such identity cards. American passports issued after Oct. 6, 2006 are also equipped with RFID tags. The embedded data (including digital photograph) can be read even over a distance of 20m.
Civil liberties campaigners have criticized the test of anti-theft system based on tiny RFID chips at Tesco store in Cambridge. Anyone picking up Gillette Mach3 razor blades at the store triggered CCTV camera and had his or her picture taken. The second one was taken at the checkout, to compare the pictures of the customer.
Expansion of RFID technology. RFID (Radio Frequency IDentification) systems enable data to be transmitted by mobile devices, called tags, that are read by RFID readers. The data is then processed according to the needs of a particular application. There are used several typical frequency ranges: 125 - 134 kHz (LF), 13.56 MHz (HF), and the most popular - 865-952 MHz (UHF) and 2.4 GHz (microwave).
The application areas include transport, supply-chain management, identification of people and animals.
As mentioned, an RFID system consists of identifiers (tags), reader/s and managing (host) computer. There are used two kinds of tags: active and passive. The first ones have to be powered by a battery etc., the second - take the energy needed for operation directly from the reader (as the part of electromagnetic energy emitted by its antenna).
The pictures can be submitted from June 1st, 2008 to September 30, 2008.
The first prize - SAT HDTV receiver - Ferguson HF 8800 HD.
Rules of participation.
The pictures of 2007.
In smaller installations, an economical solution is use of TV channel converter R87205 which consists of demodulator and DSB modulator. DSB modulators require to use one-channel gap below the active channel.
The signal from receiving antenna has to be split into two paths. In one path we attenuate (filter) the stronger of the two adjacent channels, and process the second channel (in the channel converter), shifting it to another position. The new channel we combine with the stronger one (from the second path). Usually there is no need of additional filtering, the AWS-1036 B11686 amplifier is used for distribution of combined signals.
TV/Sat tap Terra SS-510 R70516 is used for connecting branches to the trunk line. Such a multiswitch trunk line, carrying signals from one Quatro LNB, consists of four coaxial cables. Additionally, the tap also distributes terrestrial TV signals. The tap is equipped with DC-transition switch that in "ON" position runs current through "H" paths to both branches. In "OFF" position it is possible only within one path.
The new series of 9-input Terra MSR-9XX multiswitches is dedicated both for home installations, as well as for multi-story buildings - as story devices. An important feature of these multiswitches is diversification of signal levels at different outputs, which enables the installer to compensate the losses in cables of different lengths that are unavoidable in such systems.
Additionally, the multiswitches have been equipped with correction of cable's characteristics, i.e. the signal level is increased adequately to the growth of cable's attenuation for higher frequencies.
It is a mistake to reconfigure network interface cards to the IP addresses embedded in the IP cameras. Every IP CCTV device should be equipped with dedicated software (usually on a CD-ROM) enabling the user to determine and change its IP address. This way the device can be adapted to the network.
These are usually proprietary programs included with the equipment - e.g. IQinVision provides IQ Finder, ACTi - IP Utility, PiXORD - IP Installer.
In simple systems the managing unit (computer, DVR) processes all the data, which may easily overload its processor. More advanced systems employ cameras that are capable of independent image processing that relieves the main processor of these basic operations.
Even the most advanced motion detection algorithms do not release the installer/operator from setting up some parameters experimentally. It is a matter of trying and error to minimize false alarms and ensure effective detection of real threats.
The most often adjusted parameter is sensitivity of motion detection, measured by the percentage of the pixels (in active area) that have to change to trigger the alarm. Other parameters include SAD (the Sum of Absolute Differences) - number of modified pixels, and motion vector.
- Measurement of power voltage.
- Indication of improper polarity of supplying voltage.
- Measurement of ripples.
- Measurement of video signal.
- PAL generator.
- Control of lens ZOOM.
- Control of lens FOCUS.
- Opening and closing diaphragm in lens with automatic aperture control.
- "grate" (black or black and white). The P1 grate pattern allows to estimate monitor's linearity or, in other words, deformation of imaging. The P2 grate pattern enables to assess the level of reflection, if it occurs. Reflection is caused by mismatch of a receiver (the load) and the transmission line, and usually is noticeable with longer transmission lines. On a screen it can be seen on the right side of the boundaries between light and dark objects (and vice versa).
- "vertical bars". Vertical bars with graded level of luminance allow to check and adjust proper levels of contrast and brightness in a monitor. All bars should be well distinguished. If some, mostly the outermost bars are seen as identical, it means that picture parameters are not suitably adjusted and need some correction. It is essential for proper observation of details in pictures from cameras.
- "white background" and "black background". They permit to assess number of damaged pixels, especially on LCD monitors.
- "gray background". Gray background is suitable for the above purpose, too, and may be used for testing the level of magnetization of color picture tubes. The magnetization may be caused by any close devices generating strong magnetic fields, like mains transformers, electromagnets, loudspeakers. The effect is seen as no great tinges, mainly near the outer edge of the screen. The device used for demagnetizing, or degaussing, the aperture mask and metal-bell portion of a color picture tube is external air-core electromagnet - degaussing coil. In most common situations, when the level of magnetization is not high, it is sufficient to use the inner degaussing circuit, mostly present in color monitors. The gray background is also suitable for finding such effects like "burnt" areas in the screen, produced by static pictures. Often it may be noticed e.g. in QUAD applications, where a dark cross comes into being in the center of the picture.
802.11n devices utilize MIMO technology - the use of multiple antennas at both the transmitter and receiver to improve communication performance. The devices may operate in several channels which multiplies their transmission capacities. The manufacturers like to boast about the maximum transmission speeds they offer, but also ensure that the minimum throughput is at least 100 Mbps (similar to Fast Ethernet). Such speed is satisfactory for effective wireless transmission of multimedia.
There are available "n" (draft 2.0) devices. TP-Link offers Access Point integrated with a router and switch - TL-WR841N N3251 and PCMCIA card - TL-WN910N N3231. They allow to transfer data up to 300 Mbps (raw data rates), being backwards compatible with 802.11b and 802.11g devices.
1997 (curr. marked as 802.11y)
1999 (hardware available since 2001)
Currently 2.4 GHz
Video surveillance system in Myslenice near Krakow. The murder of the owner of exchange office and his son, committed a year ago, shocked the residents of Myslenice. Several days after the assault they organized Silent March to protest against violence and these tragic, unnecessary deaths...
- archive DWR of Feb. 18, 2008
Is it really defective? - part 1. There are many cases when WLAN devices land in service center with a description like: "it doesn't work, no access to the device, cannot log in, doesn't ping, no LAN... etc". About 1/3 of the WLAN devices are in perfect working order, but they have been improperly configured...
- archive DWR of Feb. 4, 2008
ULTIMAX - the market leader in digital CCTV recording ULTIMAX is a series of 3rd generation digital video recorders, with implemented, so far the most efficient, H.264 compression. This type of deep compression is characterized by capability of providing good video quality at substantially lower bitrates than the previous standards...
Index of published issues.
CeBIT 2008 - new trends in telecommunications and IT. Reception of adjacent channels in large systems - channel...