In the wireless world, a gateway is an access point with additional software capabilities such as providing NAT and DHCP. Gateways may also provide VPN support, roaming, firewalls, various levels of security, etc.
General Packet Radio Service. A radio technology used in GSM networks that transmits digital data packets, much like Internet protocols do, for both voice and data without the need of a dedicated circuit for always-on access to data. This allows for more efficient communication and faster data rates. (See 3G, GSM).
Global Positioning System. A system that uses satellites, receivers and software to allow users to determine their precise geographic position. (See War driving).
Groupe Speciale Mobile, or Global System for Mobile Communications. A 2G digital standard for cellular phone communications adopted by many countries around the world. Its frequency bands range from 900-1800MHz. (See 3G, GPRS).