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

Galileo is already tested!

On December 1, 2012, the testing ground station located in the heart of the Ardennes forest in Belgium received the first test signal from the FM3 satellite put into orbit in the process of forming the European navigation system, Galileo. FM3 and FM4 satellites were sent into orbit in October and joined two satellites launched a year earlier. Galileo global navigation satellite system (GNSS) will be an alternative to the American GPS (Global Positioning System) and Russian GLONASS GNSS. It should be more accurate, and above all, independent from military forces.

The first signal was transmitted by the satellite in band E1 (1559-1591 MHz), also used by GPS. Then, the satellite transmitted signals in the other bands that are to be ultimately used by the Galileo system, E5 (1164-1215 MHz) and E6 (1260-1300 MHz). According to the schedule, subsequent satellites will be launched and tested in the beginning of 2013. The system should become functional by the end of 2014, with 14-18 orbiting satellites.

The advantage of the Galileo system will also be the interoperability with GPS and GLONASS, two other global satellite navigation systems, as well as with other, non-navigation systems. The integration with GSM/UMTS/LTE infrastructure could revolutionize the telecommunications market by offering new services. The simultaneous use of Galileo and GPS will significantly increase the availability of satellite navigation signals in highly urbanized areas (coverage up to 95% of the areas compared with the current 50%). Wider bandwidth and higher power of Galileo transmitters in relation to GPS circuitry will allow the use of satellite navigation in buildings and some tunnels.

The differences between universal and distribution optical fiber cables.

Novice installers may have problems with choosing which type of the cable will be optimal for a particular application. Let's focus on the single- and multi-mode cables with 8 fibers, which register the highest sales figures:

Universal cable (left) and distribution cable (right)
1. Optical fiber
2. Gel inside the central tube
3. Central tube
4. Aramid yarn
5. LSZH jacket

Universal Ultimode cables can be used in indoor and outdoor applications. The fibers are contained in central gel-filled tube. The gel in the tube is a kind of protective coating for optical fibers, which absorbs mechanical stresses and protects against environmental factors.

The universal cables are mainly intended for horizontal connections in buildings and outside buildings. Due to the small size and flexibility, the cables are ideal for installation in cable ducts. They are used in modern FTTH and FTTB systems, in server rooms, between buildings. Because of the gel-filled structure, the vertical cable runs of the cables installed in buildings should not be longer (higher) than 30 meters.

Distribution Ultimode cables belong to the "Minibreakout" category intended for applications in buildings. The fibers in tight buffers are contained in one sheath. Individual fibers are comfortably accessible, which makes it easier to install optical connectors, to make splices etc. The aramid yarn is designed to protect fibers from mechanical damage. The jacket (sheath) is made of low smoke zero halogen flame retardant poly-olefin (LSZH). Indoor distribution cables from ULTIMODE IDC series are gel-free fiber optic cables intended for horizontal and vertical connections in buildings.

In search for the best DVB-T antenna...

In general, digital terrestrial television can be received with the use of identical antennas as analog TV (taking into account the same bands/channels). So, digital multiplexes can usually be received both by broadband "grid" antennas and directional assemblies. However, especially in areas with "duplicate" signals from different transmitters, the safest solution is to use directional antennas directed towards the "main" transmitters. The large half-power beam of broadband antennas (ca 45 degrees) may cause interferences that will decrease the signal quality and reliability of reception.

UHF antennas from the "Tri Digit" series: A2660, A2665, A2670, A2675, feature gain values at the level identical to the best directional multi-element antennas. The indisputable advantage of the series is high resistance to environmental stresses such as wind or rain, due to compact dimensions and increased rigidity.

Dipol 44/21-69 Tri Digit with LNA-177 A2675 amplifier
- the most universal antenna for reception of DVB-T

Stable reception depends on many factors, not only on the distance from the transmitter and its power. The installer/user must also take into account the terrain profile, the height the transmitting antenna is placed at, the gain of the receiving antenna, sensitivity of the tuner/receiver. More information on this subject can be found in the article How to select an antenna for digital TV (DVB-T).

CCTV systems with video/audio/data transmission via UTP cable.

To use twisted-pair cable for the transmission of analog video from the cameras plus audio and PTZ control signals, it is necessary to apply impedance transformers matching the impedance of unbalanced coaxial cables (75 Ω) to the impedance of balanced twisted pairs of UTP cable (100 Ω). Examples of such transformers are Etrix baluns.

The diagram below shows a typical application of the baluns.

A CCTV system using active video/audio/data baluns and UTP transmission medium

The video signals from the M11270, M11265 and M10775 cameras are transmitted via UTP cable over distance up to 2400 m with the use of active baluns M16744 and M16745. The video signal from the M1196 PTZ camera and sound from the M1912 microphone are sent by the M16742 and M16743 set. Additionally, the set conveys the control signal from the system control unit M77925. The video from the cameras is recorded by the Signal M76208 DVR.

Basic parameters of Etrix baluns:

Remote control of electrical devices.

IP watchdogs N3411 and N3412 allow remote power control of AC power outlets (via the LAN or Internet) - switching on/off the connected devices. The distinguishing feature is the fact that they can automatically monitor the connected network devices (the monitoring is based on PING function) - in the absence of a response the connected device is turned off or reset.

An application of the N3411 and N3412 watchdogs

The diagram above presents an application of the watchdogs that can be used not only for resetting network devices. For example, employing the N3411 watchdog and additional circuitry it is possible to remotely open and close the gate, whereas the two-channel watchdog N3412 can be used for opening / closing the barrier and turning on/off the light. In addition, the K1680 and K1660 cameras enable remote monitoring of the effects. The transmission of the IP signal over 2 km distance is performed with the use of TP-LINK L10222 media converters and universal fiber optic cable L7358.

What access point do I need?

When selecting an access point, make sure the device has the required functions and range of operation. A simple way to compare TP-LINK access points offered by DIPOL is to look at the table below:

Name	TL-WA901ND	TL-WA701ND	TL-WA5110G	TL-WA5210G
Code	N2944	N2942	N2945	N2350
Range of operation				*przy dod. antenie
Wi-Fi standards	802.11 n/g/b	802.11 n/g/b	802.11 g/b	802.11 g/b
Max data rate (Wi-Fi)	300 Mb/s	150Mb/s	54 Mb/s	54 Mb/s
Antenna(s)	3x 4 dBi	1x 4 dBi	1x 4 dBi	Dual 12 dBi
MIMO scheme	3T3R	-	-	-
Tx output power	<100 mW	<100 mW	<400 mW	<500 mW
WDS	YES	YES	YES	YES
PoE	YES	YES	YES	YES
QSS	YES	YES	-	-
AP mode	YES	YES		YES
AP Client mode	YES	YES	YES	YES
Bridge mode	YES	YES	YES	YES
Repeater mode	YES	YES	YES	YES
WMM (Wi-Fi Multimedia)	YES	YES
AP Client Router (WISP)			YES	YES
Security	WEP, WPA, WPA2, WPA-PSK, WPA2-PSK	WEP, WPA, WPA2, WPA-PSK, WPA2-PSK	WEP, WPA, WPA2, WPA-PSK, WPA2-PSK	WEP, WPA, WPA2, WPA-PSK, WPA2-PSK

You cannot do it quicker - Ultimode mechanical connectors. The biggest problem for technicians starting to install fiber optic systems is fiber connectivity. Compared to copper systems and depending on the technology used, the operations may require more sterile environment and special, often very expensive tools... more

The components of Ultimode FAST-02SC L5711 quick assembly connector

Amplification of DVB-T signals in MATV/SMATV systems. Shared antenna systems in multi-dwelling units, hotels, hospitals etc. with tens or hundreds of outlets should not use broadband amplifiers at their inputs i.e. just after the antenna array. It is recommended to use channel amplifiers allowing for equalization of the levels of the received channels (multiplexes)... more

An example set of channel amplifiers and modulators for MATV system

Remote access to analog CCTV systems. There are situations where the live CCTV images and recordings should be available from several locations at the same time, e.g. because the surveillance video has to be provided to the security staff, police and municipal police. With the use of Trend M72616 DVR, local access to the video can be provided by connecting the M3027 monitor with HDMI or VGA cable. The DVR can be controlled locally by the enclosed mouse... more

Components of a video monitoring system with remote access to the system resources