Chapter 5 Compliance : Configuring FortiGate units for PCI DSS compliance : Wireless network security
  
Wireless network security
Scanning for rogue access points is the minimum requirement for wireless security. Even if your organization does not use wireless networking, PCI DSS requires you to verify periodically that wireless networking has not been introduced into the CDE.
If you use wireless networking, the wireless network is only within the PCI DSS scope if it can connect to the CDE.