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No. 9/2010 (March 1, 2010)
Wireless HDMI.
Gefen company has launched a new device on the market, which allows wireless transmission of uncompressed HDMI 1.3 audio/video at resolutions of up to 1080p / 60 Hz with 8-channel digital audio.An important feature of the device is application of the 60 GHz band, providing a very wide spectrum needed for transmission of uncompressed data, as well as eliminating any interference with access points, cellular phones etc. A disadvantage is small range - less than 10 m (without walls or ceilings). Is it worth to pay $999?
The largest companies that manufacture televisions (Hitachi, Panasonic, Toshiba) are developing their proprietary wireless chips operating in the 60 GHz band and providing data rates of 1.5 Gb/s (at this speed the transfer of an entire CD takes about 5 seconds). LG has introduced a TV set with built-in receiver that allows for wireless connection with four sources of HD content.
HDMI interface allows transmission of uncompressed digital data representing high-definition digital video and audio, via a single dedicated cable. It allows to interconnect compatible DVD or Blu-ray players/writers, game consoles, computers, monitors, televisions. The interface is the successor of analog (e.g. S-Video, SCART, VGA) and digital (DVI) interfaces used in older equipment.
With the growing number of multimedia devices in the home, there are increased needs for interconnections. The largest transfers can be achieved using fiber optic cables, but it is still a cable connection. In many cases, the most convenient solution seems to be application of wireless technology.
With the growing number of multimedia devices in the home, there are increased needs for interconnections. The largest transfers can be achieved using fiber optic cables, but it is still a cable connection. In many cases, the most convenient solution seems to be application of wireless technology.
Winter problems with satellite signal reception.
Snow accumulated on the dish and/or LNB may degrade or even prevent satellite signal reception. In the case visible in the photo on the left, the signal level decreased by 50%.If the problem occurs frequently, especially in mountain areas, it is good to learn from the experience of the Nordic countries and use a special cover on the LNB.
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Plexiglas shield used in the Nordic countries is an effective protection against snow
- receive terrestrial radio (FM) and TV programs,
- receive satellite broadcasts from 2 satellites (8 outlets),
- monitor chosen areas with 4 analog CCTV cameras and record the video on DVR,
- use home LAN/WLAN wirelessly connected to the Internet (desktop PCs and laptops, netbooks etc).
Home antenna system integrated with LAN/WLAN and CCTV
The terrestrial antennas should be chosen according to local reception conditions.
Some specific examples are presented in the article Selection of Terrestrial TV Antennas.
The CCTV system employs two indoor (M10737) and two outdoor (M11240) cameras. They ensure monitoring of the areas in front of the building (entrance gate, driveway), behind the building (rear entrance, garden), and inside the building (entrances to the staircase and living room). Such positioning provides possibility of monitoring and recording any events around the property as well as in sensitive places in the building (in case of burglary etc).
The home LAN/WLAN is wirelessly connected to the Internet via the N2941 access point cooperating with the A712427 outdoor antenna. Connection of multiple computers (including laptops etc.) with the use of one external IP address is possible thanks to the router with integrated access point (N2950). The system enables the users to connect other network devices: print-server, NAS, TV with DLNA function etc.
The integration of the system consists in:
- using the TVs to watch images from the CCTV cameras
- using the computers to:
- view images from the cameras,
- play back CCTV recordings,
- independently archive CCTV material,
- manage the whole system,
- view the material recorded due to various events (recordings triggered by alarms, e.g. door opening sensor, motion detection, etc.),
- providing access to the CCTV images over the Internet (for authorized users).
How to increase satellite signal strength?
The problem with too low levels of satellite signals is rather rare in individual installations - adequate size and alignment of the dish, and LNB skew adjustment - usually provide fully satisfactory results. The problem rather occurs in SMATV systems with long cables (100 m or more), with passive components that additionally lower signal levels.Most multiswitches available on the market, among them TERRA and SIGNAL multiswitches, have active satellite paths with maximum output levels about 95 dBuV. However, in the case of a very long cable these signal levels may not be sufficient. This problem can be solved by using the R85101 or R904075 amplifier, directly connected to the output of the multiswitch.
Sat Line Amplifier TERRA SA-001 R85101 is ideal for typical multiswitch systems - it is powered (via the subscriber outlet) from the satellite receiver. Its gain is about 20 dB, maximum output level 104 dBuV. Thanks to small size it is possible to locate even several such amplifiers by the multiswitch, in the same box/cabinet etc.
The apartment amplifier ALCAD Al-414 R904075 can amplify satellite signals up to 25 dB, with 12 dB gain adjustment. In addition, the device has terrestrial TV/FM amplifier (gain adjustable from -3 dB to 12 dB) and 4 outputs, so that it can feed up to 4 outlets (one satellite receiver can only be used, connected to any of the outputs; the terrestrial signals can be used independently at all 4 outlets). The amplifier requires 230 VAC power supply.
Please note that none of the amplifiers improves signal quality (e.g. BER), but they only raise signal levels. Generally, satellite signals are characterized by lower S/N ratios than terrestrial signals. Each active component of the path (amplifier) introduces additional noise, so in the case of any satellite system the basic rules include use of a dish of sufficient size and precise alignment of the dish and LNB/s.
Insulation stripper HT-332 - blade gap adjustment - a movie.
The HT-332 E8003 insulation stripper is used for preparing the ends of RG58, RG59, RG6, TRISET, Tri-Lan and many other coaxial cables. It is a very useful tool for installers that connect lots of plugs to coaxial cables.The stripper is equipped with two blades with adjustable distance (with the help of the included wrench). The length of the stripped sheath can be set to 4, 6, 8, or 12 mm. The video shows how to do it.
19" RACK adapter for ULTIMODE media converters.
The ULTIMODE L5215 adapter has been designed to house and power up to 14 ULTIMODE media converters. The housing is fully compliant to 19" RACK standard. Due to double power supply (redundancy) and forced ventilation (fans), the adapter ensures trouble-free continuous work of the media converters.The 14 slots allow to mount any ULTIMODE media converters, which greatly facilitates the construction and management of FTTH (Fiber to the Home), FTTB (Fiber to the Building) or FTTC (Fiber to the Curb) network.
Distinguishing features:
- suitable for 19-inch RACK mounting
- 14 slots for media converters
- equipped with two power supplies (redundant)
- Plug and Play
- forced ventilation (fans)
Example application of the rack adapter for ULTIMODE media converters
Redundant power supplies are a reliable solution for applications that require continuous operation. Each of the power supplies can be replaced without interrupting operation of the media converters (power sharing). Damage to the power supply is indicated by the LED located on the panel and by an audible alarm. Each slot is equipped with individual power connector, so any media converter can be changed without interrupting operation of the rest of the system.
1. Factors related to the devices used:
- output power (it has been decided by the manufacturer),
- cable attenuation (depends on the cable and its length),
- gain of the antennas (given by the manufacturer),
- sensitivity of the devices (given by the manufacturer).
2. External factors:
- attenuation between antennas (can be estimated basing on FSL model);
- interferences from other devices (can't be predicted - some additional margin of safety needs to be provided to compensate these interferences),
- influence of physical barriers (walls, floors, trees etc.)
In the case of unlicensed spectrum, the maximum radiated power is governed by the law. In the EU, the maximum value of EIRP that can be radiated without a special license is 100 mW (20 dBm) in 2.4 GHz band, and 1 W (30 dBm) in 5.47 - 5.725 GHz band.
The 2.4 GHz band consists of 13 channels, from which only three are fully independent from one another. It means that only maximum three WLAN networks can work in a particular area. In the case of 5 GHz band there are 12 independent channels and the same maximum number of wireless links in a given area. Because in practice the interferencess from other antennas are perceptible at distances 3 times longer than their operating range, it is important that they should transmit signals in the desired direction only. The more urbanized area, the more radio channels are occupied. In such environments, point-to-point links are much more reliable then point-to-multipoint topology. The difference lies in the antennas used. In the former case, the antennas can have very narrow half-power angles, so the signals coming from other directions are very poorly received. In the case of sector or omnidirectional antennas, the signals come from many directions, which reduces the available transmission capacity. The condition of best performance of the link is mutual visibility between the antennas.
The 2.4 GHz band consists of 13 channels, from which only three are fully independent from one another. It means that only maximum three WLAN networks can work in a particular area. In the case of 5 GHz band there are 12 independent channels and the same maximum number of wireless links in a given area. Because in practice the interferencess from other antennas are perceptible at distances 3 times longer than their operating range, it is important that they should transmit signals in the desired direction only. The more urbanized area, the more radio channels are occupied. In such environments, point-to-point links are much more reliable then point-to-multipoint topology. The difference lies in the antennas used. In the former case, the antennas can have very narrow half-power angles, so the signals coming from other directions are very poorly received. In the case of sector or omnidirectional antennas, the signals come from many directions, which reduces the available transmission capacity. The condition of best performance of the link is mutual visibility between the antennas.
Large CCTV system in Massasoit Community College.
Massasoit Community College, located on the east coast of the United States, is one of the largest schools in the Massachusetts community college system. Because of the need to enhance security of over 7000 students and 300 staff members, a decision was made to install an advanced video surveillance system.
The Massasoit Community College library
The installation company had to face several challenges. The main - the fact that the system was to cover the college's two sites, the 100-acre Brockton Campus and the 18-acre Canton complex in the Blue Hills area south of Boston.
The requirements of the investor also included high quality of the recorded video which would allow to identify human faces and car license numbers (outside the buildings). Additionally, due to the nature of the monitored facility, the recordings had to be kept at least for one month.
There have been employed the latest solutions used in advanced monitoring systems. The local nodes of the system (buildings) are equipped with HIKVISION DVRs. Depending on the number of camera points, there are used 8-channel M76080, M78080 or 16-channel M76160, M78160 models. Each of them has the ability to record video in D1 resolution. The most advanced versions allow to record video in D1 resolution at 25 fps (each channel).
The advanced models allow to store the video surveillance data on 8 SATA HDDs, each of 2 TB capacity (total capacity: 16 TB). Optimum use of disk space is provided by the possibility of triggering the recording of a given channel by motion detection in the field of view of the camera. The video is compressed with the use of AVC (H.264) algorithms, which allows to save disk space and reduce network bandwidth for data transmission. Each DVR is connected to the Internet.
Block diagram of the video surveillance system
All video data is available in the security center. The video streams from IP cameras are recorded on servers. The local police also have access to the data.
This extensive monitoring system is operating without any complaints. The college authorities are satisfied with the investment.
Several computers and one printer - print server TP-Link TL-PS310U.
Multifunction Peripheral (MFP) &Storage Server TP-LINK TL-PS310U N3312 is designed to share USB devices throughout home or office network (SOHO applications). It allows to use one printer or other USB device by a number of users.TL-PS310U can cooperate with:
- printer
- MFP (multifunction printer/peripheral)
- scanner
- external hard drive
- memory card (using additional card reader)
- flash drive
- loudspeakers
- web camera
Application diagrams:
Basic application of TP-LINK TL-PS310U N3312
Advanced application of TP-LINK TL-PS310U N3312
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