SignalNET - telecommunications and RF distribution systems in multi-dwelling units

Modern concepts of implementing integrated telecommunications and RF distribution systems in multifamily buildings

The latest regulations in Poland concerning signal distribution systems in multi-dwelling units and public buildings specify more precisely requirements for cabling systems being deployed in new buildings. The purpose of the requirements is to unify the provision of services for every user by allowing access to broadband Internet, television, telephony etc. - not restricted to one operator or technology.
Similar requirements are or will be compulsory in many countries, so that the investors must take them into consideration. Even if such regulations have not been passed yet, the fulfillment of the recommendations will make the buildings more attractive for the customers/residents.
The main requirements include:
1) installation of fiber-optic system consisting of optical distribution frame located in a technical room and cabling (at least two fibers provided to each apartment)
FTTH (Fiber-To-The-Home) technology greatly improves the quality of broadband services, in particular allows the users faster data transmission rates, especially important for streaming HD video; the medium is also much safer for the users' equipment - no surge voltages.
2) installation of RF system for reception and distribution of digital terrestrial television and radio (DVB-T, DAB), as well as digital satellite television from two satellite positions; the system should include coaxial cabling and installation components: splitters, taps, amplifiers, multiswitches, antenna set
The optimal solution is to combine both installations into one multiswitch system that, using one coaxial cable, provides all the signals to each apartment. Thanks to this solution, the residents are not forced to pay for services of cable TV operator - they can receive free DVB-T broadcasts, FTA and pay TV satellite channels.
A very important fact is that residents of buildings without multiswitch systems had to mount their own satellite dishes (in Poland about 50% TV viewers have been using satellite receivers) on balconies and facades of buildings, which spoiled the overall aesthetics of the buildings. People having apartments only on north and west sides of the buildings were deprived of access to satellite signals from Polish operators. Multiswitch systems eliminate such problems.

3) additional coaxial cable that can provide signals/services from a cable TV operator, or independent SAT TV and DVB-T signals.
4) structural cabling based on two UTP cables led to each apartment providing access to the Internet, intercom connectivity etc.
5) installation box located in each apartment near the entrance door, with terminations of all cables and additional equipment such as RF splitter, Ethernet switch etc. The services are then provided to outlets in the apartment.
6) separated technical room containing distribution frame and cross connection box allowing for connecting any subscriber to the infrastructure of any service provider operating in the area.
Some examples of modern telecommunications and RF distribution systems in multifamily buildings
Multistory residential building equipped with fiber-optic and multiswitch installations plus structural cabling
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Installations in a multistory residential building with 3 staircases. The technical room is located in the middle staircase, there are additional cabinets in the other staircases. Click on to download pdf version.
How to cable multifamily buildings - choosing the kind of cabling and installation components
Fiber-optic system
Requirements for the system:
  • the core of the system in any building is technical room containing distribution frame and cross connection box allowing for connecting any subscriber to the infrastructure of any service provider operating in the area
  • the fiber distribution frame connected with the service providers is linked to each subscriber outlet or fiber terminations via at least two single-mode fibers with minimum parameters given in the table:
attenuation at λ =1310..1625 nm ≤ 0.4 dB/km
attenuation at λ =1550 nm ≤ 0.25 dB/km
chromatic dispersion coefficient D ≤ 0.092 ps/nm2*km
nominal mode field diameter 8.6 to 9.5 μm
cut-off wavelength ≤  1260 nm
loss of 100 turns of fiber (60 mm in diameter, at 1625 nm) ≤ 0.1dB
The requirements are met by the cables below:
Code L7712 L7644 L7502
Name Ultimode-BS Ultimode-UNI Ultimode-IDC
Number of fibers
12, 24 4, 8 2, 4, 8
Applications ideal for multistory buildings indoor /
  • the system uses single-mode SC/APC connectors
L3552 L5756 L4222
PG-52S KeyQuick10  A-522S
pigtail (thermal splicing) SC/APC (mechanical splicing) adapter for installation boxes etc.
  • the attenuation of the optical link from the distribution frame to any outlet or fiber termination cannot exceed 1.2 dB (at 1310 nm and 1550 nm)
  • any places with cable terminations should have appropriate warning signs about hazards of invisible optical radiation
An example of practical implementation of fiber-optic system in a multistory building
Multistory residential building equipped with fiber-optic installation
Click on to download pdf version (2.5 MB)
In the example, the building has 5 floors with 3 apartments on each floor. According to the requirements specified above, the installation contains 30 fibers, with two terminations in each apartment.
The technical room houses RACK cabinet R912012 with two fiber optic boxes ULTIMODE MT-524 L5124 with front panels L5541. The boxes can accommodate up to 48 SC/APC adapters L4222. The optical cables to the subscribers are distributed from the rear of the cabinet - they are welded with SC/APC L3552 pigtails placed inside the boxes.
The apartments are connected with the technical room via fibers of ULTIMODE BS easy access cables. The apartments on the first (ground) floor are connected by the fibers of the BS-12SM L7812 cable composed of 12 fibers, on the higher floors - of the BS-24SM L7824 cable composed of 24 fibers. On each floor, 6 fibers are extracted from the cable after cutting suitable window with special stripping tool L5911. The windows are protected by breakout units VQ-BU. Each pair of the fibers going to an apartment is protected by drop/distribution tube VC-TUB L7211.
In each apartment the fibers can be terminated in several ways, either in the case of using termination box or outlet. The best solution seems to be a small termination box housing the fibers terminated in a way that will not require the user to engage a professional service to splice them for the future use. It may be termination box ULTIMODE TB-02H L5302 containing spare lengths of the fibers, spliced with SC/APC L3552 pigtails terminated with L4222 adapters.
Multiswitch SMATV system
Requirements for the system:
  • coaxial cables at least of RG-6 category, with class A screening efficiency guaranteed by double shielding (aluminum foil and braid with minimum covering factor 77%), with copper central conductor of minimum 1mm diameter. Each apartment has to be equipped with two cables, one providing signals from the multiswitch (FM+DAB+ DVB-T+SAT), second also from the multiswitch or from a CATV operator.
RG-6 Dipolnet Triset-113
E1230 E1015
1.02 mm Cu
77% braid coverage
1.13 Cu
88% braid coverage
  • antenna set: FM 87.5-108 MHz, VHF/DAB 174-230 MHz, UHF 470-862 MHz, each with gain at least 14 dBi, satellite parabolic or offset dish(es) with diameter at least 1.2 m
Dipol 1RUZ PMB Dipol-4/DAB Dipol Tri-Digit
A0221 A0140 A2670
  • access to satellite broadcasts at least from 2 satellite positions, all components of the satellite system have to be compliant with A class of screening efficiency.
An example of practical implementation of SMATV system in a multistory building
Considering the number of outlets and their layout in a building, we can distinguish two main cases. In the case where the total number of outlets within a single subnet (usually encompassing apartments in one staircase) is relatively large (above 32), a good solution is to install multiswitches in boxes on each floor to provide the signals to the apartments on the floor.
The main advantages of this solution are limited number of the cables in shafts and division of the distributing network into small, independent subnetworks. This segmentation allows for virtually complete elimination of a massive breakdown of the system.
The photo above shows an example of the box with equipment for signal distribution on one floor. The SS-920 R70526 tap takes signals from the 9-cable "bus" going vertically from the bottom to the top of the building. The MSV-908 70858 multiswitch is connected with the tap through F-F E8242 adapters. Identical layout of the outputs of the tap and inputs of the multiswitch allows for these quick end elegant connections that take minimum amount of space in the installation box. This is a key issue when the boxes are located in limited space designed for such installations. Additionally, MSV multiswitches are powered via signal lines from SA-901 R70901 amplifier located on another floor - there is no need to provide a separate power cable to each box. The box in the photo is the TPR-21 R90562 (450x350x120 mm).
SMATV system in a multistory building
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The solution presented in the figure above, based on Terra MSV multiswitches and tap-off line concept (cable bus) is the most optimal one in terms of the number of components. Due to a small size of the subnetwork in the example (encompassing 15 apartments located in a single staircase of a 5-story building), all the apartments can be served by one multiswitch. The SMATV system distributes signals from two satellites (e.g. Hotbird and Astra) received by two dishes equipped with QUATRO Inverto Black Ultra A98266 LNBs, and a range of terrestrial signals, received by DVB-T antenna Dipol Tri-Digit A2670, VHF antenna Dipol-4/DAB A0140, and FM antenna Dipol 1RUZ PMB A0221.
The cabling consists of 11 coaxial cables Triset-113 E1015 going from the roof to the technical room containing all active devices. In the case of a higher building or when the distance from the antenna set to the technical room is longer than 25-30 meters, it is recommended to install additional installation box with amplifiers, located close to the antennas (in the attic or on the highest floor). In the presented solution, all the cables to the subscribers run from the room. Because of large number of cables going in parallel, they should have very good screening efficiency, like TRISET-113 E1015.
More on topologies and solutions of multiswitch systems can be found in the excerpt of another article, Example diagrams of multiswitch systems
The technical room contains:
  • set of amplifiers for terrestrial signals: DVB-T, FM, DAB (two channel amplifiers Terra at420 R82510 and broadband amplifier Terra ma400 R82520). The combined output signal is distributed via the multiswitch system;
  • amplifier for 9-input multiswitches SA-901 Terra R70901, amplifying TV SAT and terrestrial TV signals and powering via signal lines all MSV multiswitches;
  • TV/SAT tap Terra SS-920 R70526 extending 9-cable systems (2x4 SAT + Terr. TV) into two subnetworks;
  • 9/16 multiswitch TERRA MSV-916 R70866 with 9 inputs with signal level adjustment and 16 outputs with diversification of signal levels to compensate the differences in attenuation of various lengths of cables that have to be used in the installation.
The highly reliable Terra devices are covered by a 4-year warranty.
Designing of SMATV systems - Terra SatNet software
Selecting the equipment for a multiswitch system, the designer has to take into account the attenuation in all paths, to ensure proper signal levels in every subscriber outlet. The figure below shows a part of the project of the previously introduced system, made ​​with the use of free Terra SatNet utility.
A part of a multiswitch system designed with Terra SatNet utility
Click on to enlarge
Key features of Terra SatNet utility:
  • designing complete systems for reception of terrestrial and satellite broadcasts
  • taking into account individual parameters of all devices and cables
  • taking cable parameters from provided table or entering specific values
  • taking into account cable lengths
  • declaring the signal levels at the input of the system (from LNB and DVB-T antenna)
  • calculating loss of DVB-T and SAT signals at various frequencies in the whole frequency range
  • possibility of manual adjustment of automatically preselected gain levels of multiswitches
  • automatic choice of passive components (splitters, taps)
  • signaling the correct signal levels in all devices and outlets
  • printing the final designs
The diagrams that we have prepared with SatNet software (.dwg files), everyone can use for practical implementations of systems based on Terra devices.
Structural cabling (LAN, intercom)
Requirements for the system:
  • telecommunications box in each apartment has to be connected with the technical room at least with two UTP cables, Cat 5e or higher
Name NETSET UTP cat. 5e
Code E1408
Standards IEC 61156-6 (2000)
ISO/IEC 11801 (2000) TIA/EIA-568-A (1995)
PN/EN 50173 (1999)
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  • the transmission paths have to be compliant with class D (IP multicast)
  • one of the links is to be used by a provider of telecommunications services, the second for the implementation of intercom system, doorbell etc.
Implementation of LAN in a multistory building
An example of LAN in a multistory building
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Telecommunications box in each apartment is connected via two UTP cables NETSET E1408 with the technical room that is the connection point with telecommunications networks. One of the cables can be used, for example, by door entry system. The cables in the apartment boxes can be terminated e.g. with two-port patch panels, for easy connection with the cabling installed inside the apartments.
The cables from the apartments go down through the shaft and enter the technical room with 24-port (CAT5 RJ45) patch panels R9120316. This way the service providers can easily connect their switches installed in the room to the building network.
CATV network
Requirements for the system:
  • one of the coaxial cables brought to the telecommunications box in each apartment may be used for the provision of services by a cable TV operator
  • the cabling does not belong to a cable TV network - users can choose any service provider operating in the area
  • parameters of the coaxial cable are at least at the same level as in the case of SMATV system
Due to the fact that CATV networks utilize the coaxial cables for providing Internet services and use the 5-65 MHz band as the return channel, the cables should have an increased shielding effectiveness in that band, like Triset-PROFI E1010 with screening efficiency better than 110 dB (30-1000 MHz) - class A++.
Implementation of CATV network in a multistory building
An example of CATV distribution in a multistory building
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