English to Chinese Tech/Engineering IT (Information Technology) wireless security

That's why WPA should be only the first line of defense in a wireless network. The next line of defense should be the use of virtual LANs, to segregate traffic and users from each other. This is the same principle as using subnets in a wired network. By confining users to specific VLANs, you can use access control policies to monitor wireless activity and {determine role-based access}, Kocher says, even if an unauthorized person gets past the WPA authentication step.
确定基于角色的访问？
感觉有些别扭。