DIPOL Weekly Review - TV and SAT TV, CCTV, WLAN

New concept of CeBIT - a success? This year's CeBIT in Hanover - the world's largest trade fair for IT and telecommunications - took place between 4th and 9th of March.
There were about 5900 companies (by 5 percent less than last year). For the first time in the history of the fair, China had the largest representation, surpassing in numbers the previous leader, Taiwan.
Among the notable absentees were Sony, Sharp, Philips, Lenovo, Dell and Nokia.
After several years of decrease of the number of exhibitors, the organizers decided to increase the number of conferences - to attract professionals, and shorten the event by one day - to cut the costs of exhibitors. But probably the main focus was to define the objectives of the exhibition.
Unfortunately the organization efforts didn't seem to refresh the event. They couldn't eliminate the feeling of deficiency, a want for new technologies and for an impulse to stop the decrease of investments in European telecommunications.
During the trade fair we could see a steady factor in European industry - expansion of red tape. The organizers, using subsidizing, invite national exhibitors that, instead of products, are showing travel brochures, and grassroots movements - promoting projects like Green IT.
In this situation the most interesting trends seen at the fair were network and mobile solutions for television - as an extension of offers of telecommunication operators. The solutions are based on technologies that improve data transfers, especially those of mobile telephony. The example is LTE technology presented by Sony Ericsson and T-Mobile.

LTE (Long Term Evolution) is the newest transmission system for mobile applications, developed according to the 3rd Generation Partnership Project (3GPP). The specification accepted in January, 2008, adopts theoretical limit of 326 Mbps (practical speeds reach 100 Mbps).

Our report from this year's event in the next issue.

Green IT on CeBIT

New amplifier from the SilverLine family - AWS-1036. The AWS-1036 B11587 amplifier has been designed for applications in individual and community antenna installations. The device has been equipped with one input (which may require to employ an antenna diplexer to combine the received channels), and four outputs with independent level controls.
It is especially suitable for signal distribution in community (MATV) and CATV systems (due to whole TV band). The independent level controls allow to equalize signals in outlets (or branches) in the case of different distances (compensation of attenuation of the cables).
The set includes regulated AC/DC adapter (output: 12V/250mA, 3.5mm jack). It is possible to power the amplifier through its "D" output, via coaxial cable, using RF/DC separator - AZS-03 C0397 (and the included power supply). It allows to mount the amplifier in the attic and power it from a place with access to the power line. When using a splitter - it has to pass DC voltage, like E2094.
SilverLine is a new generation of antenna amplifiers from AMS company. Modern design and circuitry, solid cast metal (ZnAl) housing, protecting it against external interferences - make the devices leading European products.
They are two-stage RF amplifiers with gain adjustment implemented after the first stage. This way the antenna signals are not attenuated at the input, which improves noise figure.

Requirements for input signals in multiswitch systems. In the case of large multiswitch installation there have to be used many amplification stages, which increases the noise figure of such system. It directly translates into increase of BER. BER values above 10^-4 (in the outlet) will prevent the user from receiving satellite broadcasts (the receiver will not be able to restore the original signal). To ensure reliable and high quality decoding, the BER values should be at least about 10^-8 (in LNB outputs). Signals with low BER are ensured by use of appropriate dishes, e.g. 110 cm - A9658. It is very wise to use large dishes - the whole multiswich system needs only one set of dishes, being a small part of the total costs, but deciding on the quality of the input (and output) signals.

LNB skew adjustment. When installing a satellite system it is important to set appropriate skew (or polarization) angle of the LNB. The angle depends on the satellite and geographical location of the site.
LNB rotational position ("skew") has to be set to the correct angle so that horizontal and vertical signals are received with equal strength. It optimizes the cross-polarization isolation between signals of vertical and horizontal polarizations, and has strong influence on quality of digital signal. The isolation should be better 20 dB.
More precise procedure requires to choose two transponders, one with V polarization, the second with H polarization. Measurements performed for both polarizations (with R10811 meter) will allow to set the skew of the LNB to reach equal BER values for both transponders. Without such a meter an amateur can roughly achieve the same using the signal strength meter function in the receiver.

The procedure of LNB skew adjustment

ULTIMAX - CCTV recorder of the 3rd generation. After the launch of ULTIMAX series there is no problem with quality of video recording in 16-channel DVRs. All 16 channels can be recorded with full D1 resolution (704 x 576), at 25 fps, fulfilling highest requirements of modern CCTV systems.
ULTIMAX-716 M77160 uses, 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. It saves the bandwidth of the network and the disc space required for recording the data. The DVR also enables the operator to record up to 16 audio channels and to use bidirectional voice communication or one-way voice broadcasting (from the monitoring center/ remote location to a camera site).
ULTIMAX-716 M77160 has huge storage potential - after installing eight HDDs with 2000GB (2TB) capacity each, the total disc space amounts to 16 TB. It allows to create extensive archives.
The DVR is dedicated for monitoring of sports facilities (stadiums, sports halls), railway/bus stations, airports, military installations, banks, markets etc., and mass events.
ULTIMAX DVRs can be connected via IP networks to form a large system controlled from a remote surveillance center (up to 16 devices).
ULTIMAX-716 can get text/number strings through RS-232 or network port. The strings can be sent from devices such as ATM/cash machine, POS machine or others. DVR can paste the strings into the real time image and record. The same strings can be used as keys for searching the recorded files to play them back.

Distributed surveillance in IP CCTV systems. IP CCTV technology, based on Internet protocols, allows to build distributed monitoring systems, both as regards the number and deployment of monitored locations and the surveillance posts (monitoring centers). Configuration of such systems depends on the scale and purpose.
An economic solution may be based on one monitoring center that controls a number of locations. The software allows to integrate images from chosen areas on one or several monitors.
Different functionality is required in city monitoring systems. There are usually several public services that are interested in having access to the surveillance system (the police, municipal services, road maintenance etc). Appropriate configuration of access rights (to the images from the cameras, to PTZ control) allows to eliminate conflicts that could occur.
An example of the managing software for CCTV systems is Alnet Netstation K3208, K3216, K3232. This software is compatible with majority of IP devices manufactured by leading producers of IP CCTV equipment.

Appropriate configuration of access rights (to the images from the cameras, to PTZ control) allows to eliminate conflicts that could occur.

Integration of many monitoring locations into a surveillance system with one monitoring center allows to control a large area from one place

Why RTOS (Real Time Operating System)? Operating system is the core of every digital recording device. It determines the overall quality and stability of the device. In industrial applications of computers, operating system decides on the sequence and way of performing the tasks. For RTOS it is important to take into consideration the time factor - positive result of operations depends not only on the sequence, but also on the time of completion. The example is conversion and compression of analog video signals. Recording of the signals in digital form (with set parameters: resolution, frame rate, number of channels) is a priority and has to be performed in real time. Any delay will cause loss of video data (e.g. several video frames). Real-time algorithms enable the system to perform critical tasks in precisely defined periods of time. In practice - DVR will delay less important operations (e.g. playback of archives) to ensure proper recording of video even with the maximum quality requirements. DVRs that are not equipped with RTOS systems simply decrease recording parameters, e.g. frame rate, losing some information. An example of DVR based on RTOS is ULTIMAX-716 M77160.

For high throughput demands - TP-Link IEEE802.11n (draft 2.0). DIPOL included into the offer a new series of wireless access devices based on the newest IEEE802.11n standard (draft 2.0). An advantage of the WiFi series is increased speed of transmission, up to 300 Mbps, very useful for multimedia transmissions.
TP-Link has also introduced inventive QSS (Quick Secure Setup) technology that allows to protect the wireless network easily.
The series of IEEE802.11n devices is also supported by CCA (Clean Channel Assessment) procedures which enable the system to find the best channels for undisturbed transmission.
Buying wireless devices compliant to n standard it is worth to know that they are compatible with each other only since draft 2.0 specification.
The devices also support IEEE 802.11g and IEEE 802.11b standards.

GSM antennas with cables and SMA R/P connectors. There area available GSM antennas with SMA R/P plugs that directly fit into many types of GSM modems/cards (the last model - with SMA plug).

We have written about:

TV-Sat Surge Protector. Receiving devices have to be connected to antenna installations thus they are exposed to overvoltages induced in long cables. It doesn't have to be direct lightning stroke - the charges induced even by distant storms can damage sensitive electronic circuitry...
- archive DWR of Dec. 10, 2007

Cameras with Wide Dynamic Range (WDR) sensor. WDR cameras use the newest generation of sensors from the American company Pixim. Every pixel of the sensor is an independent analog to digital converter. So every element has individually set exposition time, depending on light intensity. It eliminates under- and over-exposed areas in the image...
- archive DWR of Dec. 17, 2007

The factors influencing maximum range of wireless network. The range depends on the features of the devices used and the environment...
- archive DWR of Oct. 8, 2007

Index of published issues.

DIPOL at Intertelecom 2008 - see our virtual stand