Time: May.10 to May.11, 2019
Address: Investment Center Mansion,Pingshan District, Shenzhen City
Requirements: AMR signal coverage (AMR: automatic meter reading)
Investment Center Mansion is located in Pingshan Street, Shenzhen, and it’s close to be finished. Power equipment systems were installed on the negative second floor of the five buildings. Since the area is a newly developed building, signal operators' equipment and signals have not been well covered in the area, and there is no signal in the underground parking lot.
The five areas on the negative second floor are power equipment, and the meter reading communication uses China Mobile 4G communication modules, so we need to cover the mobile 4G signals in the five areas in the figure below.
1． Signal Survey
In the area of the first and second floors on the ground floor of the building, the mobile 4G signals detected are all in the 1900Mhz band. The signal RSRP strength is around -90, which can meet the acquisition strength of the source.
2．Device Scheme
1、Device
Only mobile 4G is needed, and the 1900M band can meet the demand. Therefore, in this customer application scenario, a single mobile 4G F band is used, and the 1900M signal amplifier can be enhanced. This time, a high-power mobile 4G device is used, with a gain of 80dB and a power output of 27dBm.
2、Wiring Construction
Because the power rooms of the five buildings are on the negative second floor, and the distance between each building is very far away, we use a device to transmit signal to each Therefore, a device is used under each building to push multiple ceiling antennas into several rooms for signal coverage.
There are 2-4 power distribution rooms below each building, and the splitters and couplers used in the middle are slightly different. But regardless of the increase or decrease of 1-2 ceiling antennas, the measured output can meet the coverage needs.
3．Construction
50-12 cable is used as outdoor cable, which is introduced from the first and second-floor terraces to the negative second-floor power distribution room through the distribution room well. In the cable tray of the power distribution room, 50-3 feeders, power splitters and couplers are used to match the ceiling antenna of each room.
4．Testing
After the construction is completed, the mobile 4G signals of the five regional power distribution rooms have reached full grid, and the signal strength is high quality, between -60dB to -77dB.
The working value of the equipment is also very good, and it is in the same range as the value calculated by the evaluation.
Exact data tests were performed on 5 room areas, and the entire room was well covered, and the customer passed the acceptance test of the Electricity Bureau on May 13.
Conclusion:
For AMR signal coverage in the underground parking lot, the exact frequency and the signal operator are required before the scheme. It is very easy to solve and achieve the effect by measuring the length and loss of the feeder line in the construction and scheme.