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No. 38/2011 (Nov. 21, 2011)
The standard has been implemented and China attempts to make a true great leap forward.
October 26 is probably the most important day of this year for the global telecommunications. Then, at ITU Telecom World in Geneva, there were announced the world's first certified G-PON devices. Gigabit-capable Passive Optical Network (G-PON or GPON) is one of the most popular optical architectures for applications in telecommunications.The compliance with the standard was confirmed for the products from 7 manufacturers: Alcatel-Lucent, Broadlight, Cambridge Industries Group, Huawei, PMC-Sierra, PT Inovacao and Tecom. They have passed the Broadband Forum G-PON ONU Certification Program and conform with Broadband Forum TR-156 and ITU-T OMCI G.984.4/G.988 requirements.
Introducing a certification system for GPON network components, ITU (International Telecommunication Union) concluded standardization process which started in 2008. The standardization of networks and devices will allow rapid spread of this already very popular technology. Interoperable equipment will give service providers greater opportunities to expand their high speed broadband services cost-effectively.
What does it mean in practice?
During this event, Mr.Wei Leping said on behalf of China Telecom that by 2015 his country intends to connect 250 million fiber-optic lines to the residents, mainly based on GPON.
If the project was transferred to Europe, it would mean optical connectivity for practically all households, from Portugal to the Urals. It would be a telecommunications revolution actually driving the European economy forward to the 21st century!
The enthusiasm of the Chinese can be tempered by large-scale deployment problems, however they make a really good start - on November 10, 2011, Alcatel has signed a contract with China Unicom to supply equipment for the construction of 6 million GPON lines. Where is the rest of the world?
During this event, Mr.Wei Leping said on behalf of China Telecom that by 2015 his country intends to connect 250 million fiber-optic lines to the residents, mainly based on GPON.
If the project was transferred to Europe, it would mean optical connectivity for practically all households, from Portugal to the Urals. It would be a telecommunications revolution actually driving the European economy forward to the 21st century!
The enthusiasm of the Chinese can be tempered by large-scale deployment problems, however they make a really good start - on November 10, 2011, Alcatel has signed a contract with China Unicom to supply equipment for the construction of 6 million GPON lines. Where is the rest of the world?
PON (Passive Optical Network) is currently the most popular last mile fiber-optic solution. Its gigabit version (GPON) may implement a number of transmission rates, but currently the typical bandwidth is 2.488 Gbit/s (downstream) /1.244 Gbit/s (upstream).
PON uses a point-to-multipoint architecture for delivering Triple-Play services (television, Internet, telephony) via a single optical fiber. The optical distribution network is passive, i.e. any active devices (requiring power supply) are needed only at the service provider's central office and end users' locations (in other words - at the edge nodes of the network). This is a huge advantage that allows to build a transmission channel with a length of about 20 km, powered only on the operator and subscriber sides. The distribution of the signals between them is done using only passive components - optical fibers and splitters.
A PON network consists of:
PON uses a point-to-multipoint architecture for delivering Triple-Play services (television, Internet, telephony) via a single optical fiber. The optical distribution network is passive, i.e. any active devices (requiring power supply) are needed only at the service provider's central office and end users' locations (in other words - at the edge nodes of the network). This is a huge advantage that allows to build a transmission channel with a length of about 20 km, powered only on the operator and subscriber sides. The distribution of the signals between them is done using only passive components - optical fibers and splitters.
A PON network consists of:
- distribution device (access node): OLT (Optical Line Termination),
- termination units in local distribution node: ONU (Optical Network Units),
- if the optical fiber connection is directly run to the customers' premises/homes (FTTH)
they are equipped with ONT (Optical Network Termination).
Because of the large extent of the area to be monitored, the DVRs had to be located in two places. One of the DVRs should record images from 12 fixed and 4 PTZ outdoor cameras. The DVR in the second location was to be connected with 8 fixed outdoor cameras, 4 PTZ cameras, and 4 vandal proof cameras.
In order to implement the proposed project, the system has been based on two SIGNAL DL-8316 M78316 DVRs, able to record in each channel 4CIF images at 25 fps. They both are connected to the LAN. After forwarding the appropriate ports on the TP-Link TL-WR941ND N3251 router, the Internet connectivity allows for password-protected access to the monitoring system from any computer or smartphone.
The most vulnerable points are monitored by top-class PH-33 M1196 PTZ cameras providing very detailed images within a large radius. Fixed observation points placed outdoors are equipped with Sunell SN-IRC5920AHLDN M11280 cameras. Thanks to powerful IR illuminator, high-sensitivity and the ability to manually adjust many parameters (BLC, AGC, white balance, noise reduction, and others), this model successfully operates in 20 locations with different characteristics. The v-cam 500 M10772 camera with the Sony's latest Effio E DSP has been chosen as the vandal-proof model.
One of the main requirements is the reliability of live monitoring. The live video from the both DVRs is supplied directly to the security room and management office. The system is fully controlled using K-01 M77925 consoles dedicated to the DVRs of the SIGNAL 83xx series. The control units fully implement the functions of the remote control and the front panel buttons of the devices. The consoles have been placed in two locations, but the one located in the main control room has a higher priority to avoid possible conflicts. However, each surveillance room has been equipped with two monitors, one for each DVR. This allows for monitoring the images from all 32 cameras or selection of any interesting one at the moment. The images are really "live", without any delay. Because the video and control signals are transmitted via a separate network, the monitoring system is independent of the existing computer system that uses different LAN subnet.
Video surveillance of large facilities, such as stadiums, railway stations, and video monitoring of cities, streets, squares etc. are the biggest tests for the CCTV equipment. In many cases, classic analog CCTV systems are the most efficient solutions. Affordability and ease of installation of the systems based on modern standalone DVRs are not the only advantages. From the user's point of view, the most important features include easy and ergonomic control of the system and high reliability - they are perfectly embedded in the SIGNAL DVRs.
How to mount antennas to a mast - part 1.
Many people interested in receiving DVB-T channels upgrade their antenna systems. Few of them, unfortunately including also professional installers, are aware of the fact that larger antenna arrays should be mounted on masts in the appropriate way, compliant with applicable standards. Although this subject is quite extensive and concerns mainly large antenna systems, it is worth to know the rules for proper installation of a next antenna on the mast attached to a wall or chimney...
Tri-Digit 44/21-69 A2670 - the most popular antenna for terrestrial TV
The conditions described in the international standard IEC 60728-11:2010 should be taken into account during the installation of antennas on the mast. It is important that the sum of bending moments caused by the antennas should not exceed the maximum allowable bending moment of the mast. The bending moment caused by an antenna can be calculated with a simple formula:
Bm = WL * d
where: Bm is the bending moment in [Nm], WL is the force caused by wind load on the antenna in [N] (Newtons),
d is the distance from the antenna anchor point to the antenna mount clamp in [m] (meters).
Example layout of antennas on a mast. It is worth mentioning that according to DIN EN 50083-1,
the distance between any adjacent antenna mount clamps should not be shorter than 1/6 of the mast length
the distance between any adjacent antenna mount clamps should not be shorter than 1/6 of the mast length
The following table shows the data and calculations for the example shown above:
The total bending moment from all the antennas is 659 Nm, well below the maximum allowable bending moment of the mast (1250 Nm). So, the above configuration can be safely used in almost any conditions.
The above calculations include wind loads on the individual antennas. More on this and other issues in the next edition of the Newsletter.
Extensive monitoring system with central management.
Video monitoring systems in small towns (up to 24 cameras) are often controlled by a single management center, located e.g. in the (municipal) police station. Such a system usually covers the market, railway/bus station, the areas near schools, and other most vulnerable places. So the signal transmission routes from the camera points to the center are usually quite long (often over 500 meters). If the investor decided to use a cable system, the best choice is application of fiber optic transmission medium. The cameras are connected to optical video converters changing analog video signals (from 1-16 cameras) to light signal in the allocated transmission window.The key benefits of optical signal transmission in CCTV systems:
- video transmission from up to 16 analog cameras by one optical fiber,
- transmission of PTZ signals from the monitoring center to the cameras through the same optical fiber,
- long transmission range without any delay or quality issues,
- no sensitivity to electromagnetic interference, lightning etc.
A video surveillance system covering a town center and school,
with a security room located e.g. in the municipal police station
1 - school, 2 - security center, 3 - town center
with a security room located e.g. in the municipal police station
1 - school, 2 - security center, 3 - town center
He chose a simple and relatively inexpensive solution to this problem shown in the diagram below. The video signals from the four v-cam 450 M10749 cameras are connected to four-channel modulator, Mixpol MDP-4S R95163. The modulator converts the baseband video signals into modulated RF signals (TV channels). The output RF signals from the modulator can be easily sent via the 75 ohm coaxial cable, and even combined with TV signals in antenna system and monitored on the ordinary television sets connected to antenna outlets. The DVR located at the end of the transmission line receives the video signals from the cameras after demodulation performed by two double AV demodulators R87204.
Diagram of the system allowing transmission of images from 4 analog CCTV cameras
through one coaxial cable. There is the possibility of live monitoring on regular TVs.
through one coaxial cable. There is the possibility of live monitoring on regular TVs.
Distributed IP video surveillance system with megapixel cameras.
Video monitoring systems in business chains (markets, gas/petrol stations etc.), at the local, national and international scales are becoming increasingly popular. Each of them allows for video surveillance of multiple chain locations from a single monitoring center. Economical and reliable systems can be implemented with the use of network video recorders NUUO K4108/ K4116 and Sunell megapixel IP cameras K1620, K1630, K1670, K1680.The architecture of the distributed system shown below enables local recording of the video streams from the cameras. It ensures the reliability and high quality of the video footage, independent from the Internet service. On the other hand, the connection to the Internet allows for remote monitoring, as well as searching, viewing and downloading the archive material on remote computer(s). The remote operations include modification of NVR settings (changing camera modes, the type and quality of recording etc.). The head office has current information on the number of customers during working hours, and after closing the business the operator can immediately assess the nature and scale of the threat (burglary, fire, or simply a false alarm).
The NUUO K4108/ K4116 NVRs are used in all kinds of maintenance-free systems. In this kind of small- and medium-size systems, the NVR can be connected to any node of IP network and provide service for a number of customers (clients) with hierarchical access rights. The NVRs locally archive the video streams from the connected cameras, whereas the remote access to these recordings is possible from every point of the network. To access the NVRs, the remote computers can use client software or Internet Explorer. The use of the web browser eliminates the need for additional applications, however the client software allows for multi-user operation.
Architecture of reliable distributed IP video surveillance system
Due to Linux OS, NUUO NVRs ensure stable operation and resistance to computer viruses that attack Windows(R) systems. The maintenance cost of NUUO NV-4080S is several times lower than a typical server, due to very low power consumption (approx. 30 W).
Wireless link with an intermediate point.
In many situations it is impossible to achieve a direct link between the locations that should be connected. However, lack of mutual visibility does not eliminate wireless technology. In most cases the solution is to create a relay node. The system is a combination of two point-to-point links, where the second begins at the point where the first ends.The links to the instruction manuals which show how to properly configure a point to point link (BRIDGE) are available on each of the catalog pages.
Example point-to-point configurations:
- N2300 ULTIAIR 419KC <=> ULTIAIR 319KC N2310
- N2301 ULTIAIR 423KC <=> ULTIAIR 323KC N2311
- N2301 ULTIAIR 423KC <=> ULTIAIR 423KC N2301
- N2301 ULTIAIR 423KC <=> ULTIAIR 419KC N2300
- N2301 ULTIAIR 423KC <=> ULTIAIR 319KC N2310
- N2300 ULTIAIR 419KC <=> ULTIAIR 323KC N2311
- N2310 ULTIAIR 319KC <=> ULTIAIR 319KC N2310
- N2311 ULTIAIR 323KC <=> ULTIAIR 323KC N2311
- N2311 ULTIAIR 323KC <=> ULTIAIR 319KC N2310
- N2314 ULTIAIR 319KC 150 Mb/s <=> ULTIAIR 319KC 150 Mb/s N2314
- N2315 ULTIAIR 323KC 150 Mb/s <=> ULTIAIR 323KC 150 Mb/s N2311
When choosing a pair of devices, the user should pay attention to:
- gain of the antennas - higher gain allows for a longer link,
- wireless standard - 802.11a (54 Mb/s) or 802.11n (150 Mb/s),
- Mikrotik license level - extension of point-to-point link to point-to-multipoint configuration requires level 4.
Example wireless link with an intermediate point, based on ULTIAIR devices
New products offered by DIPOL:
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Worth reading:
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Web smart TP-Link switches. This series of professional Gigabit Ethernet TP-Link switches, fully compliant with IEEE 802.3/802.3u/802.3ab/802.3 standards, is designed for middle and large corporate computer networks.
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TP-Link switches are equipped with powerful processors ensuring stable flow of data and setting port priority (static port priority as well as QoS, based on IEEE 802.1p). QoS enables administrators to prioritize network traffic. This process ensures smooth and free from interference VoIP and video conferencing...
