Time: Apr.29, 2021
Location: JD QiXian Supermarket (WANKELI Shop)
Requests: Calling signal and 4G data signal of whole China Netcom
JD QiXian Supermarket (WANKELI Shop) is located in the podium building and the basement 1 floor of "WANKELI-ZHEN" residential area, near the exit of Antuoshan metro station in Futian District, Shenzhen. As “WANKELI-ZHEN” is newly built, the signal coverage from signal operators is not arranged, but the opening time of supermarket (Apr.30) is imminent.
According to the drawings and field surveys, it is found that there are two parts of JD QiXian Supermarket. One part is the distribution area in the ground floor with around 300sqm, and the other part is supermarket working , warehousing and office area in the basement 1st floor, with an area of 2300sqm.
Distribution area in the ground floor
After field surveys, we found that the distribution area on the ground floor is close to the street and has a small area without any partitions or obstructions. The signals of the three networks here are all very good. Therefore, we don’t need to have mobile signal coverage for the distribution area.
However, because the supermarket is located in the center of basement 1st floor without any indoor signal distribution from signal operators, only very weak signal could be received in some specific area, calling signal unclear and no 4G signal.
Except the freezer, not matter for shopping or working, 2G/3G/4G signal needs to be fully covered in a supermarket, , especially in the office and checkout.
Scheme
the wiring of indoor signal distribution as below：
1, Outdoor antenna is installed on the exterior wall of distribution area to receive good signal resource.
2, Optical fiber full netcom repeater (MU) is installed on the interior wall of distribution area.
3, Wiring a 200-meter optical fiber cable to connect MU in distribution area of the ground floor to the repeater (RU) in machine room of basement 1st floor.
4, distributing channels from RU to connect 17 ceiling antennas to have fully coverage in B1.
The green areas above is the office area and checkout area.
Topology designed as follows：
The signal strength tested near the exterior wall as follows,
China Mobile 4G TDD-LTE1900MHz, signal strength -85dBm
China Telecom 4G FDD-LTE2100MHz, signal strength -81dBm
China Unicom 4G FDD-LTD1800MHz, signal strength -84dBm
Based on the signal strength tested, we would use our five-band optical fiber MU-RU full netcom devices. Because of the location of the supermarket, over 150-meter distance from distribution area in the ground floor, a MU-RU connection solution with optical fiber cable could effectively reduce cable loss, and could double-amplified to have better performance.
Device Introduction
UDAS Introduction
UDAS: Ultra Wide Band Distributed Antenna System, also called optical fiber distribution system. Its main feature is to connect Main Unit (MU) and Remote Unit (RU) with optical fiber cable, which could meet the demands of long-distance signal transmission. The signal transmission in optical fiber cable is 20-120km (single band signal) or 2-5km (multi bands signal).‘
multiplexer
optical module
Power supply module
Minitor module
Main Unit (MU)
Remote Unit (RU)
Working principle diagram
System topology diagram
UDAS could have a better performance to solve the signal attenuation problem in transmission, which is applied to large area signal coverage. The double-amplified signal by MU and RU could effectively ensure the amplification of weak signal and ensure all devices with full output power, which makes coverage bigger and performance better.
With a double-amplification, the system gain could be up to 85dBm. Full output power of RU could be 27dBm, which allows it to connect with 15-20 indoor antennas to cover 3000-5000sqm.
Construction and installation
Panel Antenna is adopted as outdoor antenna, installed on the exterior wall of distribution area in the ground floor.
Main Unit (MU) is installed on the interior wall of distribution area in the ground floor, and the Remote Unit (RU) is installed in the machine room in the basement 1st floor.
To ensure the use on opening time of the supermarket, it only took 2.5 days to complete all equipment’s installation and complete the whole indoor antennas distribution. Besides, all our cables are wired in the cable trays, which won us high praise from the property and supermarket.
Project effect
After the construction and installation, we tested the signal strength that the 5 bands frequency could achieve very good performance. Below it is the device working value for 5 bands:
The output power could also achieve very good performance. Excellent calling signal and 4G data signal could be tested in every corner of the supermarket. Signal strength tested as follows:
China Mobile 4G signal strength -75dBm to -90dBm
China Telecom 4G signal strength -80dBm to -95dBm
China Unicom 4G signal strength -85dBm to -95dBm
JD QiXian Supermarket also had a self test, that’s to ask the all shop staff test messages, call, surf the internet at the same time to see if the performance could meet their demands. After the verification, they are very satisfied with our scheme!
It took less than 10 days to finish the project after we received the project. We used the best solution and the fastest construction efficiency to meet clients demands of supermarket signal coverage.
This project is a typical signal coverage solution for supermarket.
Shenzhen ATNJ Communication Technology Co., Ltd
Apr.30, 2021
