(WLAN /W-lan/, or "LAWN" /lorn/, sometimes "WiLAN" /wi-lan/) A communication system that transmits and receives data using modulated electromagnetic waves, implemented as an extension to, or as an alternative for, a wired LAN. WLANs are typically found within a small client node-dense locale (e.g. a campus or office building), or anywhere a traditional network cannot be deployed for logistical reasons. Benefits include user mobility in the coverage area, speed and simplicity of physical setup, and scalability. Being a military spin-off, WLANs also provide security features such as encryption, frequency hopping, and firewalls. Some of these are intrinsic to the protocol, making WLANs at least as secure as wired networks, and usually more so. The drawbacks are high initial cost (mostly hardware), limited range, possibility of mutual interference, amd the need to security-enable clients.