1xRTT stands for "1 Times Radio Transmission Technology." It is a mobile data standard that allows for packet-switched data transmission over CDMA (Code Division Multiple Access) networks. Introduced in the early 2000s, 1xRTT enables users to access the internet and send data at speeds up to 144 kbps, which was a significant improvement over earlier technologies. This technology is often considered a precursor to more advanced standards like EV-DO (Evolution Data Optimized). While 1xRTT has largely been replaced by faster technologies, it played a crucial role in the evolution of mobile data services, helping to pave the way for the modern mobile internet experience.