No. 27/2009 (Aug.31, 2009)
A great stride in IP CCTV - IP video standard.
In June this year, ONVIF member Merit Lilin released the world's first ONVIF conformant product - speed dome IP CCTV camera.Lack of a universal standard in IP CCTV has been hindering installations and limiting expansion of the new technology.
One of the basic differences between CCTV systems based on analog cameras cooperating with DVRs and IP CCTV systems - is that the former systems can be composed of various cameras and digital video recorders (coming from different manufacturers). This is possible due to the fact that European countries use identical video standard - PAL (Americans and Japanese - NTSC).
The latter systems (IP) have to be carefully implemented, using dedicated software for certain family of products - usually from one manufacturer. Equipment from several manufactures requires purchasing software compatible with all devices.
In order to establish an internationally recognized standard of digital video in IP CCTV systems, two competing organizations emerged: ONVIF (Open Network Video Interface Forum) and PSIA (Physical Security Interoperability Alliance). They have gathered all leading manufacturers of this kind of equipment and software. The aims are the same - introduction of standards that will allow to use any components from any manufacturer, without a need of reconfiguring the system.
Monument to Olympics - where is the tower?
Collserola Tower was erected to serve the Olympics in 1992. Implementation of the project was entrusted to the brilliant British architect Sir Norman Foster.Tower construction started in March 1990. The main element of the structure is reinforced concrete core with a diameter of 450 cm. It is 205 meters high and its foundations reach a depth of 5 meters. At the top there is an 83 meter steel structure with transmitting antennas. It has a cone shape and is held vertically by ropes of 56 mm diameter.
At the height of 135 meters there is an observation platform. In good weather the visitors can enjoy beautiful views in a radius of 70 kilometers.
The official opening took place on June 27, 1992. The Olympic Games were held in this city shortly afterward.
Which is the city? You can find the answer at the end of this issue.
Monument to Olympics - where is the tower? The answer at the end of this issue.
Photos by Wojciech Kocot
Unicable technology.
The Unicable standard was introduced to the market by SES Astra over 3 years ago, but there not many publications on this subject so far. It seems a little strange, as the technology has a big potential.Satellite installations in one-family homes often require to use several cables. This is not a problem when the designer and building company have prepared spare conduits. If not, drilling and hammering walls in existing houses is a nuisance for the inhabitants.
Unicable helps those who are planning to upgrade an existing installation up to 4 outlets (up to 4 single-tuner receivers), or want to replace a single-tuner receiver/s for increasingly more more popular PVR receiver/s (Personal Video Recorder) with 2 tuners (each of them requires additional cable from the LNB).
Unicable helps those who are planning to upgrade an existing installation up to 4 outlets (up to 4 single-tuner receivers), or want to replace a single-tuner receiver/s for increasingly more more popular PVR receiver/s (Personal Video Recorder) with 2 tuners (each of them requires additional cable from the LNB).
How does it work?
Unicable LNB can receive four signals of different frequencies from different bands/polarizations. The signals are amplified by a low-noise RF amplifier. All the signals are shifted to L band and then enter special multiplexer (a kind of multiswitch) and Single Cable Router (SCR). SCR selects the transponder desired by the receiver (user) and shifts it into one of four channels in IF band (channel 1 - 1680 MHz, channel 2 - 1420 MHz, channel 3 - 2040 MHz, channel 4 - 1210 MHz). The signals are combined using RF filters and can be sent via one coaxial cable. The LNB is controlled by Micro Controller Unit (MCU). The receivers are connected to the LNB via dedicated splitters supplied with the LNB.
Diagram of Unicable LNB
Due to special splitters the individual receivers receive programs from one channel, but enable the user to select any of the transponders.
Transmission of signals in Unicable technology
Manufacturers of satellite receivers continuously expand their offers by new models of Unicable receivers. New firmware often supports this standard. Currently DIPOL offers the receiver Ferguson FX 7900 UCI PVR Ready A99361 which is compatible with Unicable technology.
As mentioned, this type of installation requires to use suitable LNB. The Unicable Quad Inverto LNB (A98259) is additionally equipped with 3 splitters that allow to distribute signals up to four outlets. We recommend well-tried Signal outlets: R694100 or R694140 (with return channel).
As mentioned, this type of installation requires to use suitable LNB. The Unicable Quad Inverto LNB (A98259) is additionally equipped with 3 splitters that allow to distribute signals up to four outlets. We recommend well-tried Signal outlets: R694100 or R694140 (with return channel).
A complete image from analog camera consists of two fields. The matrix of the sensor is divided horizontally into even (2, 4, 6 ...) and odd (1, 3, 5 ...) lines. One complete frame is a composite of two scans - of even and odd lines. The number of scanning lines is compliant with TV norm (PAL: 625/560 - total/visible). At standard frame rate (PAL - 25 fps) the field scanning is performed 50 times per second. The resolution of the sensor is measured horizontally and depends mainly on its physical structure and electrical parameters.
Interlaced scanning
Image quality is directly connected with this parameter, especially the possibility of recognizing small details.
An example of analog camera of highest quality for a reasonable price is Sunell SN-468C M11202. It is equipped with top quality Sony CCD EX-View sensor capable of providing 540 lines.
The designer of a CCTV system should remember that the images from quality cameras have yet to be recorded without a loss of quality. On the market there are available many models of cheap DVRs capable of recording images with resolution of 352 x 288 pixels, about twice less than produced by the above-mentioned camera. ULTIMAX DVRs ensure preservation of original quality (they support resolution of 704 x 576 pixels).
An example of analog camera of highest quality for a reasonable price is Sunell SN-468C M11202. It is equipped with top quality Sony CCD EX-View sensor capable of providing 540 lines.
The designer of a CCTV system should remember that the images from quality cameras have yet to be recorded without a loss of quality. On the market there are available many models of cheap DVRs capable of recording images with resolution of 352 x 288 pixels, about twice less than produced by the above-mentioned camera. ULTIMAX DVRs ensure preservation of original quality (they support resolution of 704 x 576 pixels).
Video surveillance in Szczercow - quick apprehension of criminals.
Szczercow (town in Lodz region in central Poland) several months ago launched urban video surveillance system. The correctness of the decision to install the video monitoring system was confirmed by the horrific incident which took place on April 30, 2009. Four gangsters broke into property of a 79-year old woman, inhabitant of the town, who had traded gold jewelry. The injured women died in hospital.The most useful trace proved to be high quality recordings from the security cameras monitoring the area. Megapixel resolution of the recordings allowed to identify two men who had been observing the property and then broke into the premises. Thanks to the archive recordings the police were able to identify vehicle registration number of their car.
Szczercow is under surveillance of fifteen cameras which are deployed in the most vulnerable places, especially those for 24-hour monitoring. The cameras are installed in the vicinity of schools, market, and local government. The monitoring center is located in the municipal guard.
The system operates eleven IQinVision IP cameras with resolution of 3.1 Mpx - this is a resolution about 8 times greater than that of standard PAL camera. The megapixel cameras are equipped with wide-angle Tokina lenses M2235 (manually adjustable focal length from 4.5 to 13 mm).
We invite installation companies to describe implemented systems.
The authors get "Chameleon mugs".
How to get Chameleon mug"?
The authors get "Chameleon mugs".
How to get Chameleon mug"?
Compact wireless MPEG-4 IP camera PiXORD P405MW K1138.
DIPOL offers first megapixel wireless IP network camera. The P405MW K1138 camera is equipped with 1.3 Mpx sensor providing SXGA images (1280 x 1024) at refreshing rate up to 10 fps.The big advantage of the camera is a low price in relation to the phenomenal picture and sound quality. It can be used in LANs and WLANs (IEEE 802.11b/g, connected to any AP in infrastructure mode or to any computer in ad-hoc mode). Wireless network settings are available via Internet browser. The user gets list of active networks and can connect the camera to an open or protected network (with WEP or WPA-PSK encryption). WEP encryption can be performed in 64- or 128-bit mode, WPA-PSK can use AES or TKIP encoding. The device is equipped with SMA connector for the included dipole antenna.
- F-number (0.98);
- IR correction.
Lens brightness informs about how much of the light passes through the lens. It is calculated as the ratio of the lens effective aperture (D) and its focal length (f). In practice, lens brightness is expressed as an F number being the inverse (f/D) of the aperture ratio. "Bright" lenses have F-numbers lower than 1.4. The M2311 lens has F0.98.
IR correction - in the case of typical lens different wave lengths (colors) are deflected by different angles. It is not so critical within visible light spectrum, but poses a problem in infrared range (night operation with IR lighting). Without correction, the focus set for visible light is not suitable for IR light. The specially designed aspherical optical components of the M2311 lens minimize this phenomenon and allow optimum operation both during the day and at night.
Summing up, the M2311 lens is ideal for cooperation with a camera supporting iris control and operating in difficult light conditions, including necessity of IR illumination.
The lens ensures automatic iris control, which adjusts the light intensity in changeable environments.
IR correction - in the case of typical lens different wave lengths (colors) are deflected by different angles. It is not so critical within visible light spectrum, but poses a problem in infrared range (night operation with IR lighting). Without correction, the focus set for visible light is not suitable for IR light. The specially designed aspherical optical components of the M2311 lens minimize this phenomenon and allow optimum operation both during the day and at night.
Summing up, the M2311 lens is ideal for cooperation with a camera supporting iris control and operating in difficult light conditions, including necessity of IR illumination.
The lens ensures automatic iris control, which adjusts the light intensity in changeable environments.
Physical layer - a few words on WiFi - part 2.
Documents from the 802.11 family describe the sublayer of transmission medium access control and physical layer. Even a superficial understanding of medium access technologies and types of physical layers will allow network designers and installers for more accurate selection of equipment and better design of the network.Physical layer
The IEEE 802.11 documents describe four physical layers:
- IR (Infra Red),
- FHSS (Frequency Hopping Spread Spectrum),
- DSSS (Direct Sequence Spread Spectrum),
- OFDM (Orthogonal Frequency Division Modulation).
FHSS, DSSS are listed in the original version of 802.11 and allow to transmit data in 2.4 GHz band at maximum rates of 2 Mb/s.
802.11b adopts improved DSSS, i.e. HR-DSSS, with throughput up to 11 Mb/s. The next development - 802.11g, compatible with 802.11b, employs both HR-DSSS and OFDM, providing data rates up to 54 Mb/s.
Both 802.11b and 802.11g standards have been developed for 2.4 GHz band. 802.11a standard concerns 5 GHz band and uses only OFDM, ensuring transmission speed up to 54 Mb/s.
802.11b adopts improved DSSS, i.e. HR-DSSS, with throughput up to 11 Mb/s. The next development - 802.11g, compatible with 802.11b, employs both HR-DSSS and OFDM, providing data rates up to 54 Mb/s.
Both 802.11b and 802.11g standards have been developed for 2.4 GHz band. 802.11a standard concerns 5 GHz band and uses only OFDM, ensuring transmission speed up to 54 Mb/s.
Physical layer consists of two sublayers: PMD (Physical Medium Dependent) and PLCP (Physical Layer Convergence Protocol). The first one depends on the transmission medium (IR, DSSS, FHSS, OFDM) and describes methods of transmitting and receiving data (encoding, modulation etc.) to get connectivity between two or more devices operating in the same channel. The second sublayer - PLCP - does not depend on transmission medium. It maps MPDUs (MAC Protocol Data Units) into units of PMD layer - PPDUs. The diagram illustrates the 802.11 model. The interfaces between MAC and LLC, MAC and PHY, PLCP and PMD - are marked as MAC-SAP, PHY-SAP, PMD-SAP respectively.
The task was undertaken by TELEAUDYT, the company dealing with construction and modernization of telecommunications systems and installation of IP video surveillance. | |
Measurements at the plant showed a very weak mobile signals inside the shop floor. By contrast, the signals outside the hall were much better and allowed smooth conversations via mobile phones.
Due to large space to cover, the proper choice was SIGNAL GSM-300 repeater (A6760) with two indoor GSM antennas (A6800).
Installation of the GSM repeater was divided into several steps:
- Step 1
Selection of the best place for an external antenna, so that it could receive decent GSM signals. Efforts were made to find suitable place in the middle part of the hall roof, not far from the place of installing the GSM repeater. The employed outdoor ATK 20/850-960 MHz A7028 antenna is equipped with appropriate connector fitting the GSM repeater interface.
- Step 2
Selection of places for installing indoor antennas. Each of them should cover with the amplified signals similar area.
- Step 3
Installation of the GSM repeater (inside the building), then connection of the cable from the external antenna.
- Step 4
Installation of two-way splitter A6812 and connection of internal antennas
Installation diagram
The measurements and tests performed after completion of the installation showed full coverage by GSM signals from all operators. The investor recognized the quality and efficiency of the installation. TELEAUDYT company will shortly install GSM repeaters in other buildings of the investor.
The list of installation components:
High quality connectors for reasonable price - certified up to 6 GHz!
DIPOL has launched RF connectors designed for operation up to 6 GHz, dedicated for installlation on Tri-Lan 240 and H-155 cables.The main parameters important for smooth RF signal transmission via cable connections include:
- Voltage standing wave ratio (VSWR) that determines how much energy of the incident signal is reflected back to the transmitter. Typical values should not exceed 1.5, which is equivalent to reflection of ca. 4% signal power. The new connectors have WFS = 1.3.;
- Impedance matching measured in decibels that decides how much of the signal power is transmitted by the connector-cable set. The greater its value, the better transmission quality. It should be not lower than 15 dB. In the case of using the connectors with Tri-Lan cable the value is at least 18 dB.
The connectors should be crimped with HT-106E E8000 tool.
The connectors of this series are used both in installations operating in 2.4 GHz and 5 GHz bands. This range of connectors fills the gap between cheap, low quality no-name products and very expensive ones from the top manufacturers.
There are available the following connectors:
There are available the following connectors:
--Comparison of DIPOL connectors with other brands---
Many tests showed that cheap no-name connectors do not ensure proper operation of transmission lines in 2.4 MHz and 5 GHz bands.
DS-101 E9660 shelf for holding home devices
like DVD player/recorder, sat receiver (click on to enlarge)
like DVD player/recorder, sat receiver (click on to enlarge)
Barcelona.
Barcelona, the capital of Catalonia, is the second largest city in Spain. It was founded by Phoenicians. Founded in antiquity (III century BC) as a Roman colony, it evolved as one of the most important merchant republics of the Mediterranean. Barcelona metropolitan area houses over 4 million inhabitants.Antennas in Spain - a DIPOL's photo report.
We have written about:
CCTV cables. The cables used in CCTV systems often have to be quite long, both in the case of video and power transmission. There is no big problem with long-distance video transmission. Our tests show that CAMSET 50 75-0.59/3.7 M6050 cable can transmit video up to 300-400 meters without perceptible loss of quality. ... Using Ohm's law - a camera of 245 mA consumption can be powered via CAMSET 50 M6050 cable over a distance of about 60 m. Using CAMSET 100 M6100 the distance doubles to about 120 m...
- archive DWR of Sept. 15, 2008
How to share a standard USB printer for all WLAN users? The wireless print server TP-LINK TL-WPS510U N3310 is ideal for use in offices and homes, eliminating the need of connecting cables from mobile computers to the printer. It also allows to print documents from many computers on one printer...
- archive DWR of Feb. 9, 2009
Prevention and diagnostics of problems with LAN cabling - Multifunctional Cable Tester N7058. NetWork Cable Tester N7058 with LCD display enables the user to verify proper installation of Ethernet cabling (CAT 5e, 6e) and telephone lines. The tester allows to check...
- archive DWR of March 2, 2009
Index of published issues
CCTV cables. The cables used in CCTV systems often have to be quite long, both in the case of video and power transmission. There is no big problem with long-distance video transmission. Our tests show that CAMSET 50 75-0.59/3.7 M6050 cable can transmit video up to 300-400 meters without perceptible loss of quality. ... Using Ohm's law - a camera of 245 mA consumption can be powered via CAMSET 50 M6050 cable over a distance of about 60 m. Using CAMSET 100 M6100 the distance doubles to about 120 m...
- archive DWR of Sept. 15, 2008
How to share a standard USB printer for all WLAN users? The wireless print server TP-LINK TL-WPS510U N3310 is ideal for use in offices and homes, eliminating the need of connecting cables from mobile computers to the printer. It also allows to print documents from many computers on one printer...
- archive DWR of Feb. 9, 2009
Prevention and diagnostics of problems with LAN cabling - Multifunctional Cable Tester N7058. NetWork Cable Tester N7058 with LCD display enables the user to verify proper installation of Ethernet cabling (CAT 5e, 6e) and telephone lines. The tester allows to check...
- archive DWR of March 2, 2009
Index of published issues