IS95cdmaOne

IS-95, commonly marketed as cdmaOne, is a second-generation (2G) cellular technology that uses code-division multiple access (CDMA) as its air interface. It was developed by Qualcomm and standardized by the Telecommunications Industry Association as Interim Standard 95 (IS-95) during the 1990s. IS-95 networks encode voice and data by spreading signals with unique pseudorandom codes, allowing many users to share the same radio channel. The standard employs a direct-sequence CDMA scheme with a chip rate of 1.2288 megachips per second and uses Walsh codes to multiplex users and channels. A key feature is closed-loop power control, which mitigates interference and enables soft handoff between cells, improving call quality and capacity.

The original IS-95 release supported digital voice and circuit-switched data with relatively low data rates. Subsequent revisions, notably IS-95A and IS-95B, added higher data rates and enhanced packet-data capabilities, paving the way for mobile data services and later evolutions. In marketing, the technology was branded cdmaOne by operators and manufacturers in many markets, particularly in North America.

Technically, IS-95 laid the groundwork for the CDMA2000 family. As networks evolved toward 3G, IS-95-based systems were extended with IS-2000 specifications and later complemented by higher-speed data standards such as 1xRTT and EV-DO. In many regions, IS-95/cdmaOne networks were gradually superseded by newer technologies, including GSM/GPRS/EDGE and, later, LTE, but the CDMA-based lineage remains a core part of mobile standards history.