Arad MN52H 250K mold Bluetooth Module Bi-directional Communication (MASTER/CENTRAL TO SLAVE/PERIPHERAL) Transmission Range Test

Introduction

This report presents the latest findings from the Arad Connectivity MN52H BLE (Bluetooth Low Energy) module's transmission range test series. Following the successful verification of the maximum communication distances for the 125K (Long Range) and 1M modes in previous phases, the current testing focuses specifically on validating the bidirectional transmission performance of the 250K PHY mode in an open-field environment.

The 250K mode plays a critical role in the Internet of Things (IoT) landscape, being commonly applied in smart home-related devices. Furthermore, it serves as the foundational physical layer mode adopted by key protocols such as Zigbee, Matter, and Thread when establishing wireless connections.

The primary objective of this test is to provide comprehensive performance data for the MN52H across all critical BLE physical layer modes. This complete dataset offers developers a practical and valuable reference for designing robust smart home and long-range communication applications.

1. Test Objectives

· Validate the effective communication range of the MN52H BLE module's bi-directional communication (MASTER/CENTRAL TO SLAVE/PERIPHERAL) in an open field environment.

· Compare the communication performance of different antenna types (CHIP / PCB / u.FL).

2. Test Date

    ✅ October 30, 2025

3. Test Environments

    ✅ Outdoor Environment: Open and unobstructed area.

4. Equipment Required

    ✅SLAVE/PERIPHERAL Device (Emitting Board):

l Test Modules (MN52H-C40, MN52H-P40, MN52H-U40)

    ✅MASTER/CENTRAL Device:

l Test Equipment (MN52H-U40)

    ✅Test Software: Arad Technology Test Firmware for Bluetooth Module.

    ✅Distance Measurement and Recording Tools: Google Map, Mobile GPS Positioning.

5. Test Parameters

6. Test Procedure

This procedure aims to measure the maximum transmission range of the MN52H Bluetooth module under various antenna configurations in standardized and repeatable conditions.

6.1 Test Preparation and Connection Establishment

1. Equipment Settings and Transmission Parameters:

l Ensure both the SLAVE/PERIPHERAL devices (MN52H-C40, MN52H-P40, MN52H-U40) and the MASTER/CENTRAL device (MN52H-U40) have their TX Power set to +8 dBm.

l Transmission Rate Confirmation: In 250K mode, the LED light flashes 5 times per second, transmitting 5 packets per second.

2. Starting Point Positioning: Fix the SLAVE device at the starting point, with the antenna 3 meters above ground level, ensuring all antenna directions face the planned movement path.

3. Connection Confirmation: The MASTER device establishes an effective connection with the SLAVE device at the starting point and performs bi-directional packet transmission. The packet reception status will be displayed and confirmed by the flashing LED on the module.

6.2 Distance Measurement and Data Recording

1. Incremental Testing: The MASTER device moves outwards along the Line-of-sight path in increments of 50 meters.

2. Halt and Monitoring: At each measured distance point, confirm the connection status of the MASTER device and continue moving outwards.

l Connection Quality Confirmation: Judge the connection status by observing the flashing LED. A solid off or irregularly flashing LED indicates packet loss.

l Continuous packet transmission and reception are defined as an effective connection.

3. Angle Influence Test: At the distance where the signal begins to attenuate, test the effect of different rotation angles of the SLAVE device antenna on the Packet Success Rate (PSR) to determine the signal radiation pattern and polarization effects of different antenna types.

4. Maximum Range Determination: Continue moving until the connection cannot be stably maintained (e.g., continuously low Packet Success Rate or complete connection interruption, at which point the LED will stop flashing). Use Google Map and GPS positioning tools to accurately record the disconnection distance and the environmental characteristics at the point of disconnection.

7. Test Results Summary

l Comparison of maximum range under different transmission orientations.

l Performance comparison table for each antenna model.

l Test device version and firmware information.

l Record of test anomalies (e.g., packet loss).

*******************************Antenna Axis Defined*******************************

8. Test Conclusions and Observations

A comparative analysis between the current 250K PHY mode data and the previously recorded 125K (Long Range) mode results reveal a high degree of consistency in the maximum achievable transmission distance, with both modes reliably maintaining a connection within the range of 2.2 km to 2.3 km. Furthermore, data recorded across various antenna orientations showed minimal variance. Critical observations confirmed that all signal link disconnections occurred in the vicinity of several large wind turbines within the test site. These structures are identified as significant physical obstructions, which prevented the establishment of a true Line-of-Sight (LoS) measurement scenario. Based on the environmental limitations noted above, it is concluded that the measured distance does not represent the ultimate limit of the Bluetooth transmission capability. The true maximum range of the MN52H module remains unquantified due to constraints imposed by the testing environment.

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