2.5G describes the state of wireless technology and capability usually associated with General Packet Radio Services (GPRS) - that is, between the second and third generations of wireless technology. The second generation or 2G-level of wireless is usually identified as Global System for Mobile (GSM) service and the third generation or 3G-level is usually identified as Universal Mobile Telecommunication Service (UMTS). Each generation provides a higher data rate and additional capabilities. There is also a fourth generation (4G) of technology in the planning and research stages.
GPRS offers data speeds at 28 kbps (and possibly higher) and is expected to be introduced in the 2001 through 2003 timeframe.