Glossary Categories: Telecom

1xRTT (CDMA2000 1x – Single Carrier Radio Transmission Technology): 1xRTT is a 2.5G wireless standard and the first CDMA2000 evolution, offering data speeds up to 144 Kbps — a significant leap from earlier CDMA systems. It was developed by Qualcomm and standardized by 3GPP2 around 1999–2000.

It was deployed widely by US carriers like Verizon and Sprint as a stepping stone before 3G, supporting basic mobile internet, text messaging, and low-bandwidth data services.

Key parameters include single carrier operation (1.25 MHz channel), up to 144 Kbps data speed, soft handoff support, and backward compatibility with IS-95 CDMA networks.

Advantages include improved spectral efficiency over 2G, low-cost upgrade from CDMA IS-95, extended battery life due to efficient coding, and wide coverage in suburban and rural areas. Limitations include low data speeds compared to modern standards, inability to support simultaneous voice and data, and obsolescence as 3G/4G became mainstream.

Qualcomm designed the core chipsets, while Nortel, Lucent, and Samsung built network infrastructure. Major operators included Verizon Wireless and Sprint PCS. 1xRTT networks have been largely decommissioned as carriers sunset 2G/2.5G to reallocate spectrum to LTE and 5G.