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What Is Wi-Fi 7 Zero Roaming?
Wi-Fi 7 zero roaming is short for the zero-roaming distributed Wi-Fi 7 solution. This solution uses the zero-roaming AP (also called zero-roaming distributed AP, distributed AP, or DAP for short) + antenna unit (AU) architecture and adopts advanced same frequency network (ASFN) technology to eliminate roaming of STAs during movement, thereby avoiding packet loss and delay caused by roaming.
Wi-Fi 7 Zero Roaming vs. Wi-Fi 6 Zero Roaming
Huawei Wi-Fi 6 WLAN devices already support the zero-roaming distributed Wi-Fi solution before the zero-roaming distributed Wi-Fi 7 solution is launched.
Similarities
Wi-Fi 7 zero roaming and Wi-Fi 6 zero roaming both aim to solve the in-roaming packet loss and delay problems, providing a more stable wireless network experience. The two zero roaming modes also apply to similar scenarios, such as hospital wards and warehouses.
Differences
- Core devices and networking architecture: The core devices involved in Wi-Fi 6 zero roaming include DAPs, optical radio units (ORUs), and AUs. DAPs process only intranet data. Extranet data is processed by extranet APs connected to DAPs, and IoT data is processed by IoT base stations connected to DAPs. Wi-Fi 7 zero roaming does not involve ORUs. Instead, AUs are directly connected to zero-roaming APs. In addition, zero-roaming APs integrate extranet APs and therefore can simultaneously process intranet and extranet data (separately through two CPUs and physically isolated). In IoT convergence scenarios, zero-roaming APs can have IoT cards installed or IoT base stations connected.
- Technical implementation and zero-roaming range: Wi-Fi 6 zero roaming mainly relies on the distributed architecture, and zero roaming is supported only in the coverage area of a single AP, that is, a maximum of 64 AUs. Wi-Fi 7 zero roaming innovatively uses ASFN technology to achieve zero roaming between APs. Although a single AP can connect to a maximum of eight AUs, zero roaming between APs can be implemented, expanding the zero-roaming range.
Core Devices and Networking Architecture of Wi-Fi 7 Zero Roaming
- Zero-roaming AP: forwards data, processes radio signals, and manages AUs. Currently, Wi-Fi 7 zero-roaming APs can work only in Fit mode and are centrally managed and controlled by an AC. Each zero-roaming AP has two built-in CPUs, which can be connected to intranet and extranet switches in the upstream direction. A zero-roaming AP can also be connected to an IoT base station or have an IoT card installed, implementing converged deployment of three networks with physical data isolation.
- AU: directly connects to a zero-roaming AP to receive and transmit radio signals. An AU is essentially an antenna, which can be used without additional configurations after cables are connected. AUs are managed by zero-roaming APs. You can deliver commands to a zero-roaming AP on the AC to query the AU status, disable AUs, and rename AUs.
Core devices involved in Wi-Fi 7 zero roaming
Network ports on a Wi-Fi 7 zero-roaming AP
Converged Deployment and Isolation of the Intranet and Extranet
Intranet and extranet APs of a zero-roaming AP
- Physical isolation networking (intranet and extranet are physically isolated): A zero-roaming AP uses this networking mode by default. In this networking mode, the intranet and extranet uplink ports are connected to the intranet switch and extranet switch, respectively. The intranet and extranet data channels are physically isolated, improving classified information security protection.
- Standard networking: Zero-roaming APs support this networking mode in scenarios that do not strictly require physical isolation (for example, the scenario where both the intranet and extranet APs process intranet data or the scenario where the intranet and extranet are isolated using VLANs). In this networking mode, a zero-roaming AP, like a traditional AP, uses only one uplink port (intranet uplink port). After sending data to the intranet AP, the extranet AP reuses the physical uplink of the intranet AP. This simplifies network deployment.
- Backup networking: To enhance network reliability, zero-roaming APs also support the backup networking mode. In this networking mode, dual uplink ports of a zero-roaming AP are connected to the same switch. Uplink services of the intranet and extranet APs are forwarded through the intranet and extranet uplink ports, respectively. If either of the uplinks fails, only services forwarded through this uplink are interrupted, and services forwarded through the other uplink are not affected.
Three networking modes when the intranet and extranet are deployed in converged mode
Converged Deployment and Isolation of IoT and Wi-Fi Networks
- IoT base station/IoT card: processes IoT data. It can use its own antenna or reuse the AUs connected to the zero-roaming AP to receive and transmit signals. An IoT card is installed in the IoT card slot on the underside of a zero-roaming AP, and its uplink data is transmitted through the intranet uplink port of the zero-roaming AP. An IoT base station is externally connected to a zero-roaming AP, and its uplink data can be forwarded through the IoT WAN port, intranet uplink port, or extranet uplink port of the zero-roaming AP. When uplink data is forwarded through the IoT WAN port, an independent IoT switch needs to be deployed. The IoT data channel is physically isolated from the intranet and extranet data channels.
- IoT AU: You can replace a common AU with an IoT AU provided by a partner and use the IoT AU together with an IoT card or IoT base station to implement more IoT applications, such as room-level locating.
Converged deployment of IoT and Wi-Fi network (tri-network physical isolation networking as an example)
Core Wi-Fi 7 Zero Roaming Technologies
In the zero-roaming distributed Wi-Fi 7 solution, zero roaming is implemented for STAs within the coverage area of a single zero-roaming AP by using the zero-roaming AP + AU architecture and between multiple zero-roaming APs by using ASFN technology. (Only intranet APs support ASFN zero roaming.)
Zero-Roaming AP + AU Architecture
The implementation of Wi-Fi 7 zero roaming is similar to that of Wi-Fi 6 zero roaming. A zero-roaming AP and connected AUs together can be considered as one AP with multiple antennas. In the continuous coverage area of eight AUs connected to a zero-roaming AP, STAs are always associated with the same AP, without the need to switch channels or roam. This prevents packet loss and service interruption caused by roaming handovers.
Zero-roaming AP + AU architecture
ASFN Zero Roaming
On a traditional WLAN, a site is covered by multiple APs, and each AP uses a unique basic service set identifier (BSSID). To reduce co-channel interference, adjacent APs are usually deployed to operate on different channels in staggered mode. When a STA roams, it switches between different BSSIDs. During the roaming, the STA needs to disconnect from the original AP, request to reassociate with the new AP, and switch the operating channel. This process may easily increase the data communication latency and cause packet loss or even STA disconnection. As a result, the network fails to meet the low-latency service requirements and affects user experience.
In the ASFN solution, all APs have the same BSSID, operate on the same channel, and simultaneously send the same Beacon frames. This means STAs receive only one type of Beacon frames in each Beacon interval, and consider these APs as one logical virtual AP. When a STA moves, physical data transmission paths are switched between different APs, but the STA is always associated with the same virtual AP, without the need of reassociation or roaming. In this way, zero roaming is achieved.
Comparison between traditional roaming and ASFN zero roaming
Products Related to Wi-Fi 7 Zero Roaming
- Zero-roaming AP: AirEngine 6776-26HD
- AU: indoor 2.4 GHz & 5 GHz single-polarized omnidirectional antenna with the part number 27014400 (same model as the AU used in the zero-roaming distributed Wi-Fi 6 solution)
For more information about the solution and products, see AirEngine 6776-26HD: Quad-Radio Zero-Roaming Wi-Fi 7 AP.
- Author： Liu Jiayu
- Updated on： 2025-11-21
- Views： 461
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