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Wi-Fi as WAN

RansNet routers support two Wi-Fi operating modes: AP mode, where the device acts as a wireless access point serving wireless clients, and STA (Station) mode, also known as Wi-Fi as WAN. In STA mode, the device connects to an existing upstream Wi-Fi network as a wireless client, using that connection as a WAN uplink — in the same role as a wired Ethernet or cellular interface.

Wi-Fi as WAN is suited for deployments where a wired broadband connection is unavailable or not yet provisioned — for example, connecting to a building's shared Wi-Fi, using a mobile hotspot as a temporary backhaul, or bridging connectivity across a site during installation.

For AP mode configuration, see Wi-Fi Access Point.

Radio Interfaces

RansNet branch devices expose two Wi-Fi radio interfaces:

Interface Radio Band Typical Use
ath0 2.4 GHz Longer range; better wall penetration; suitable when the upstream AP is further away
ath1 5 GHz Higher throughput; less interference; preferred where signal quality is good

In STA mode, the selected radio interface (ath0 or ath1) becomes the WAN-facing wireless client interface and can be configured with IP addressing, route metrics, and link tracking — just like any other WAN interface type.

GUI Configuration

Navigate to Device Settings → Network → Wi-Fi.

Wi-Fi as WAN — Mode Selection

Under Operating Mode, select STA Mode. This switches the radio from access point mode to wireless client (station) mode.

Configure the connection to the upstream Wi-Fi network:

Field Description
SSID The network name of the upstream Wi-Fi network to connect to
Security / Encryption Encryption method used by the upstream AP (e.g., WPA2-PSK)
Pre-Shared Key (PSK) The Wi-Fi passphrase for the upstream network
IP Address Set to DHCP to receive an address from the upstream router, or Static to assign a fixed IP

Note

The SSID and PSK must exactly match the upstream AP's configuration, including case sensitivity. A mismatch will prevent association.

Once STA mode is active, the resulting ath0 or ath1 interface is available as a WAN interface. Navigate to Device Settings → Network → Interfaces to configure IP addressing, route metric, and link tracking for this interface, alongside any other WAN uplinks.

Tip

To use Wi-Fi as WAN as a secondary or failover uplink, assign it a higher Route Metric than the primary WAN interface. Multi-WAN will automatically route traffic via Wi-Fi if the primary link fails.

CLI Configuration

Connect to a 5 GHz upstream network (DHCP)

interface ath1
  ip address dhcp
  enable
!
interface wifi 1
  ssid HomeBroadband
    encryption WPA2-PSK key Letmein99
    client station
    enable

Key points:

  • interface ath1 configures the 5 GHz radio interface; use ath0 for 2.4 GHz
  • interface wifi 1 references the same radio by index — wifi 0 for 2.4 GHz, wifi 1 for 5 GHz
  • client station sets the radio to STA (client) mode
  • encryption WPA2-PSK key <passphrase> sets the Wi-Fi authentication credentials
  • Replace ip address dhcp with a static address if the upstream network requires a fixed IP

Connect to a 2.4 GHz network with a static IP

interface ath0
  ip address 192.168.1.50/24
  enable
!
interface wifi 0
  ssid OfficeWifi
    encryption WPA2-PSK key MySecretKey
    client station
    enable
!
ip default-gateway 192.168.1.1

Verification

show interface ath1

Example output:

================================================================================
  Interface : ath1
================================================================================

  Network Information
  ----------------------------------------
  Admin State            : UP
  Link State             : UP
  MTU                    : 1500 bytes
  IPv4 Address           : 192.168.1.100/24

  Wi-Fi Station
  ----------------------------------------
  SSID                   : HomeBroadband
  Signal                 : -55 dBm (good)
  TX Rate                : 433 Mbps

  Physical Information
  ----------------------------------------
  Link Detected          : yes

================================================================================

Confirm that Link State is UP and the SSID matches the upstream network. A signal level of -70 dBm or better is recommended for stable WAN operation.

Wi-Fi as Backup to 5G

Use Case

5G networks offer significant benefits for industrial automation, autonomous vehicles, and modern AR/VR applications. However, 5G coverage in indoor environments remains inconsistent, while Wi-Fi is widely available and reliable indoors. This creates a common scenario where a device relies on 5G for primary backhaul, but needs a fallback to Wi-Fi when 5G signal is unavailable or degraded.

Using Wi-Fi as WAN as a backup to 5G provides two advantages:

  1. Indoor coverage — Wi-Fi bridges the gap when 5G signal is poor indoors
  2. Provider resilience — Wi-Fi typically connects to a different network provider than cellular, reducing the risk of correlated outages

Architecture

Wi-Fi as WAN — 5G Backup

The device maintains two independent WAN links:

  • Primary: 5G (wwan0) with route metric 10 (preferred)
  • Backup: Wi-Fi (ath0) with route metric 20 (secondary)

The router automatically shifts traffic to Wi-Fi when 5G link becomes unavailable or unreachable. For more advanced failover scenarios, see WAN Failover Configuration.

Configuration Example

interface ath0
  enable
  route-metric 20
  ip address dhcp
!
interface wwan0
  enable
  route-metric 10
  apn providerapn
  nr-mode NR5G
!
interface wifi 0
  country SG
  ssid mbox_wifiaswan
    encryption WPA1/WPA2-PSK key Letmein99
    client station
    enable

Key settings:

  • route-metric 10 on wwan0 — 5G is preferred (lowest metric = highest priority)
  • route-metric 20 on ath0 — Wi-Fi is secondary (higher metric = lower priority)
  • ip address dhcp — Both interfaces request IP from their respective upstream networks

Verification

Verify both links are active and metrics are correctly set:

show ip route | include 0.0.0.0

Expected output:

K>* 0.0.0.0/0 [20/0] via 192.168.1.1, ath0, weight 1, 00:05:12
K>* 0.0.0.0/0 [10/0] via 100.67.24.1, wwan0, weight 1, 00:02:34

The 5G default route (wwan0) has metric 10 (selected as primary), and the Wi-Fi default route (ath0) has metric 20 (backup). When 5G fails, the kernel automatically activates the Wi-Fi route.

Inbound Access and Transparent Failover

When 5G and Wi-Fi failover occurs, the device's public IP address may change (each WAN link has a different ISP-assigned IP). If you have inbound access (e.g., through port forwarding), clients connecting to the old IP will lose connectivity.

To provide seamless failover for inbound access, overlay an SD-WAN VPN tunnel on top of both WAN links. Applications then route through the VPN overlay (stable endpoint) rather than directly through the WAN underlay. The router handles failover transparently: the VPN tunnel remains up, only the underlying WAN path changes. From the application's perspective, there is no failover — the connection is uninterrupted.

See Dual-Hub SD-WAN for a complete example of multi-WAN with VPN overlay resilience.