CDMA2000 1x CDMA Protocol

CDMA2000 1X is a third-generation (3G) mobile telecommunications standard developed by Qualcomm in the late 1990s. It is part of the CDMA2000 family of standards, which evolved from the 2G CDMA technology, specifically IS-95 (cdmaOne). Here’s an overview of its history and key features:

History

  • Development: CDMA2000 1X was developed as an enhancement to the CDMA standard, aiming to provide higher data rates and improved voice capacity compared to its predecessor, IS-95.
  • Standardization: The standard was formalized by the Telecommunications Industry Association (TIA) and is part of the 3GPP2 standards.
  • Deployment: It has been widely deployed globally, particularly in regions where CDMA networks were already established. As of April 2014, there were 314 operators in 118 countries offering CDMA2000 1X and/or 1xEV-DO service.

Key Features

  • Radio Frequency (RF) Bandwidth: CDMA2000 1X operates on a 1.25 MHz-wide channel, which is the same bandwidth as IS-95. This allows for backward compatibility with older CDMA systems.
  • Capacity and Speed: It supports packet data speeds of up to 153 kbit/s, with real-world data transmission averaging 80–100 kbit/s in most commercial applications. The standard also supports circuit-switched voice services.
  • Technological Enhancements:
    • Orthogonal Code Channelization: This technique helps in user separation on the downlink, mitigating interference.
    • Fast Uplink Power Control: This feature reduces the near-far field effect, minimizing interference.
    • Rake Receivers: These receivers help in resolving multipath interference and supporting soft handoffs.
    • Soft Handoff: This feature allows seamless service by handing off users between base stations.
    • Single Frequency Reuse: This method increases overall network capacity by reusing the same frequency in different cells.
    • Downlink Slotted Paging: This feature extends the battery life of mobile devices by optimizing paging mechanisms.

Evolution

  • 1X Advanced: This is an evolution of CDMA2000 1X, which quadruples the capacity of today’s 1X networks. It also offers up to 70% more coverage, making it suitable for high revenue-earning data services or for increasing coverage.
  • 1xEV-DO: This is an all-IP 3G mobile telecommunications standard for wireless transmission of data. It provides higher data rates and is designed for broadband Internet access. The technology has gone through several revisions, including Revision A, which introduced enhanced capabilities like reduced latency and QoS support, and Revision B, which added multicarrier capabilities.

CDMA2000 1X has played a significant role in the evolution of wireless networks, providing a robust and efficient platform for both voice and data services. Its backward compatibility and continuous evolution have made it a reliable choice for many mobile operators worldwide.