[Project Background] This client operates a regional distribution center for a major automotive parts supplier in East China. The warehouse covers nearly 10,000 square meters and is equipped with over 40 backpack-style and forklift-style AGVs. These AGVs are centrally controlled by a WMS (Warehouse Management System) and a central dispatch system to perform high-frequency parts receiving and shipping operations.
[Real-World Engineering Challenges] During the project's trial operation, AGVs frequently experienced "unexpected emergency stops (stalling)," requiring manual on-site resets, which severely slowed down overall outbound efficiency. After on-site packet capture and testing by the integrator and network engineers, mechanical and software faults were ruled out, and the root cause was confirmed to be communication timeouts caused by a poor wireless roaming mechanism:
Disconnections caused by sticky client behavior: The warehouse is filled with high-density metal shelving, which severely blocks Wi-Fi signals. The standard wireless modules originally equipped on AGVs suffer from "roaming stickiness"—even if an AGV has entered a new AP coverage area, as long as the old AP still emits a faint signal, the onboard module will stubbornly "lock onto" the old AP and refuse to switch.
Passive safety mechanism triggered: When an AGV stubbornly remains connected to an old access point, causing the signal to weaken to the limit, packet loss or high latency lasting 1 to 2 seconds may occur. If the AGV controller does not receive a "heartbeat packet" from the central dispatch system within 500 milliseconds, the underlying safety mechanism will determine that communication has been lost, triggering an emergency stop and causing the vehicle to come to a halt.
[Rayin Solutions] To address this typical warehouse environment characterized by high mobility and significant signal obstruction, Rayin implemented an end-to-end industrial wireless network upgrade for this project:
Vehicle-side Modification (On-board Client Optimization): Remove the existing commercial-grade network cards and install Ruiying Technology industrial-grade wireless client terminals in the control cabinet of each AGV. These terminals feature a deeply optimized active roaming algorithm, and engineers can precisely set the "roaming threshold (Roaming RSSI)" to -65dBm in the backend. When the signal falls below this threshold, the onboard module will proactively and forcibly establish a connection with the AP with the strongest signal ahead, completely eliminating "roaming stickiness."
B Basic Network Reconstruction (AC+AP Architecture): RuiYing Technology's industrial-grade dual-band wireless APs were redeployed throughout the ceiling area. A wireless controller (AC) was used to perform global channel optimization and automatic power adjustment, reducing co-channel interference and ensuring proper overlap coverage between adjacent channels.
[Actual Client Returns]
Seamless roaming, no more downtime: After the upgrade, extreme shuttle tests were conducted on-site. While the AGV moved at high speed across the entire facility and traversed multiple AP coverage zones, handover times were consistently maintained within 30–50 milliseconds. During movement, the packet loss rate in ping tests dropped below 0.1%, completely eliminating the phenomenon of abnormal emergency stops in AGVs caused by network latency.
B Successful Project Delivery and Acceptance: The throughput efficiency of the entire warehousing and logistics system has returned to its designed theoretical peak. The integrator successfully completed the final project delivery and acceptance, and the rate of service requests caused by network issues has dropped to zero.
