Terra multiswitch system - from design to implementation

Shared antenna systems (usually called SMATV systems - Satellite Master Antenna TV) are typically mounted in apartment buildings (condominiums), usually managed by housing cooperatives or property management companies. In each case the owner or manager of the facility should ensure trouble-free operation of the antenna system providing access to terrestrial (DVB-T, FM/DAB) and satellite (DVB-S/S2) broadcasts.

This article concisely presents the process of designing and implementing a multiswitch system in one of multifamily buildings in Krakow - from specification of requirements for the project to the completion and operation of the system.

The lack of the list of requirements that should be known before any investment is often the source of many problems in the next stages of the implementation. Sometimes it is caused by a lack of the basic knowledge of antenna systems among developers, which is the reason that the final shape of the installation in multi-family buildings, and even entire housing developments must be decided by the installation company.

In many countries the minimum requirements are defined by local law. In Europe, the residents should usually have access to digital terrestrial TV (DVB-T), analog FM radio, DAB radio, cable TV services, and often to satellite broadcasts from one or two satellite positions (Hotbird and Astra).

In the case of the described system, there were the following assumptions and requirements:

The market offers many types of multiswitches. When choosing the suitable equipment, the investor and installer should pay attention to its technical parameters and completeness. The completeness means both a variety of versions for different applications, a wide range of accessories, as well as technical support. Other significant factors are the experience and reputation of the manufacturer, guarantying high reliability backed by an extended warranty.

Terra equipment for multiswitch systems ensures:

Implementation of SMATV system in a multifamily building should be guided by the design taking into account information such as the number and layout of the outlets, which usually determines the topology of the system and selection of multiswitches, splitters and taps, and the parameters of the distribution network: levels of input signals, gain of amplifiers, attenuation of cables and passive components of the system. The designing process consists in selecting the elements of the system and adjusting their parameters so that the output signals are compliant with current standards and recommendations.

Below we present the design of the system for the building (see the assumptions and requirements above), created with the use of SatNet software. The system in the residential building in Krakow has been based on TERRA multiswitches of MV-5XX series. The signal lines are split for the subnetwork in each staircase with the use of 5-path SAT/TV splitters and SAT/TV taps with appropriate attenuation levels.

Download the design (*.STN).

The master antenna consists of directional UHF antenna Dipol 44/21-69 Tri Digit A2670 with gain of 16.8 dBi, FM antenna Dipol 1RUZ B A0210, DAB antenna (BIII) A0140, 100 cm satellite dish TRIAX 100 TD A9645 with QUATRO LNB Inverto BLACK Ultra A98266. All the components are mounted on 3-meter steel mast E903830, which has been attached to the wall of an exhaust stack with the use of wall bracket OMP-50L40 E8552.

View of the components in the installation box located in the upper part of the middle staircase

The signals from the master antenna are run via five Triset-113 PE E1017_100 cables to the set of amplifiers placed in metal box TPR-7 R90561 (500x500x200 mm) mounted in the upper part of the middle staircase. SA-51 TERRA R70501 amplifier for 5-input multiswitches equalizes SAT IF signals (four polarization-band pairs) and provides power to active components of the system (LNB, multiswitches). DVB-T signals are processed by four-channel TV amplifier Terra at440 R82511, a highly selective tunable RF amplifier capable of filtering, amplifying and equalizing four digital multiplexes broadcast in the UHF band. The paths are equipped with automatic gain control (AGC) ensuring high and stable output levels of the DVB-T signals. FM/DAB signals are amplified by FM/VHF/UHF amplifier ma400 R82520. The both amplifiers of the terrestrial signals are powered from the DR-60-12 R82532 power supply and placed on DIN rail. All the active devices at the input of the system are grounded and protected against overvoltages by TV-Sat surge protectors Signal R48602.

All the terrestrial signals enter the Terr. TV input of the SA-51 amplifier. The output terrestrial and satellite signals from the amplifier are led through five coaxial lines to another TPR-7 R90561 box located in the basement of the building. The ends of the lines are marked with colors compliant with appropriate markings on the inputs of splitters, taps and the MV-524 R70724 multiswitches. The die-cast metal housings of the devices ensure high screening efficiency and great resistance to RFI. The 5-cable bus is extended to the rest of the staircases by 5XX taps with suitable attenuation levels and enters the inputs of the MV-524 R70724 multiswitches.

View of the equipment extending the 5-cable bus to other staircases.
The devices are located in the basement in the middle staircase,
with the multiswitch distributing signals to apartments located in this staircase.

The picture above shows the SD-520 R70518 tap extending the 5-cable bus, MV-524 R70724 multiswitch distributing signals to 24 outlets located within the middle staircase, and SD-504 R70517 splitter for extending the bus in both directions, to the rest of the staicases. All the components are placed in another TPR-7 R90561 box.

The inside of the installation box located in the second staircase

The bus is extended in the second and fourth staircases with the use of SD-515 R70517 taps. The MV-524 R70724 multiswitch located together with the tap in each of the staicases provides signals to outlets located there. The components in these staicases are also mounted in placed in TPR-7 R90561 boxes.

The signals from the antenna sets are carried to the system components located in the building by Triset-113 PE E1017_100 cables, with PE jacket resistant to UV radiation. In order to ensure comprehensive protection of the SMATV system against lightning surges, the lines from antennas are connected via TV-Sat surge protectors SIGNAL R48602. The indoor distribution system uses Triset-113 E1015_500 cable, with white PVC sheath. There have been also used "Self-install" compression F-connectors Cabelcon E80410.

The actual signal quality and levels were measured with Digiair PRO R10510 (DVB-T meter) and Satlook Micro HD R10740 (DVB-S/S2 meter).