Fixed Wireless Terminal (FWT) units differ from conventional mobile terminal units operating within cellular networks - such as GSM - in that a fixed wireless terminal or desk phone (FWP) will be limited to an almost permanent location with almost no roaming abilities.

WLL and FWTs are generic terms for radio based telecommunications technologies and the respective devices which can be implemented using a number of different wireless and radio technologies.

Wireless Local Loop service is segmented into a number of broad market and deployment groups. Services are split between Licensed - commonly used by Carriers and Telcos - and Unlicensed services more commonly deployed by home users and Wireless ISPs (WISPs).