Add:9F, Dongguan Building, Jiangnan Ave 4288, Binjiang District, Hangzhou
Indoor distribution system source selection
Indoor distribution system source selection should be a comprehensive trade-off of system capacity, frequency resources, expected revenue, input costs, expected results and other factors can be determined.
The system capacity directly determines the network quality of the indoor distribution system. If the capacity is too small, it will directly lead to a series of serious problems such as channel blockage in the coverage area, drastic increase of call loss rate, connection difficulty, call drop seriousness and so on. Too much capacity can cause excessive cost and resource waste, so it is important to configure the capacity of a reasonable indoor distribution system. The following provides experience in engineering design:
The average traffic per busy hour: 0.02Erl
User call loss rate: 2%
Repeaters coverage area traffic does not exceed its donor base station traffic volume of 40%
When the coverage area of the repeater exceeds 40% of the traffic volume of its donor base station, the macro cell or microcell base station should be changed to be the source of the signal.
Signal distribution system
Signal distribution system is mainly composed of signal splitters / combiners, power distribution devices, feeders, indoor antennas and other components. The signals of base stations or repeaters are uniformly covered in every corner of the room. As shown below:
The way the signal is distributed
(1) RF passive distribution system
Passive system consists of points / combiner, splitter, coupler, feeder, antenna. Passive systems have no active devices with low failure rates, high reliability, little maintenance, and easy scalability. However, the loss caused by the signal transmitted in the feeder and each device can not be compensated, so the coverage is greatly affected by the output power of the source. When the source output power is large, the passive system can be applied to large-scale indoor coverage projects such as large office buildings, shopping malls, convention centers, etc. When the source power is small, the passive system should only cover small areas such as small basement, Supermarket and so on. As shown below:
(2) RF active distribution system
Active system mainly by the trunk amplifier, splitter, coupler, feeder, antenna composition. Active devices in active systems can effectively compensate for signal loss in transmission, thereby extending the coverage, less affected by the output power of the signal source. Active systems are widely used in a variety of large and medium-sized indoor coverage systems engineering. As shown below:
(3) Optical fiber distribution
Optical fiber distribution system is the use of optical fiber as the transmission medium, covering the client (main unit, interface unit), remote coverage unit, antenna, optical splitter / combiner components. Due to the small fiber loss, suitable for long-distance transmission, the system is widely used in large-scale office buildings, hotels, underground tunnels, residential buildings and other indoor coverage system. As shown below:
(4) leaked cable distribution
The signal source transmits the signal through the leaky cable and creates a surface current on the outer conductor through a series of openings in the outer conductor of the cable to create an electromagnetic field in the cross-section of the cable opening which corresponds to a series of antennae emitting signals And receiving effect. It is suitable for tunnels, subways, promenades and other terrain. As shown below:
Comparison of several signal distribution methods:
Determine the indoor distribution system source access methods and signal distribution that is completed indoor distribution system networking solutions.
CenRF Communications Limited
Add：9F, Dongguan Building, Jiangnan Ave 4288, Binjiang District, Hangzhou
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