Code Division Multiple Access

Code Division Multiple Access

« Back to Glossary Index
Visit Us
Follow Me

Code Division Multiple Access (CDMA) is a digital cellular technology that uses spread spectrum techniques to allow multiple users to share the same frequency band simultaneously. Each call or data session is assigned a unique code, and all users are transmitted over the same frequency. The uniqueness of the codes allows the receivers to distinguish between different calls.

CDMA is characterized by:

  1. High Capacity: Allows many users to share the same frequencies without cross-interference.
  2. Flexibility: Can easily add more users.
  3. Good Performance in Weak Signal Conditions: CDMA has excellent coverage characteristics, making it ideal for use in areas with weak signals.
  4. Security: Since calls are encoded, they’re inherently more secure from casual eavesdropping.

CDMA is a key technology behind many 3G networks. The most common form of CDMA is the IS-95 standard, also known as “cdmaOne,” and its 3G evolution, CDMA2000.

CDMA contrasts with GSM (Global System for Mobile Communications), another cellular technology used for mobile communication. Both have their own sets of advantages. For example, GSM phones use a SIM card, allowing users to easily switch phones by swapping the card. On the other hand, CDMA phones require that the phone’s hardware be specifically programmed for the user.

As of my knowledge cutoff in September 2021, most cellular networks are transitioning away from CDMA and GSM, moving toward 4G LTE (Long-Term Evolution) and 5G technologies. LTE and 5G use an entirely different technology called OFDMA (Orthogonal Frequency Division Multiple Access), which offers better spectral efficiency, latency, and flexibility than the older CDMA and GSM.

You may also like...