Qualcomm CDMA Technology

What is CDMA?  Code Division Multiple Access –As opposed to TDMA (time-division)  Strives to better utilize the radio spectrum by allowing multiple users to share the same physical channel  Originally created by military during WWII to make it harder for enemies to intercept radio signals  Qualcomm was first to commercialize the technology

GSM (TDMA) vs CDMA  GSM divides the channel in frequency and time-domain (narrowband)  CDMA uniquely encodes and transmits calls across entire spectrum –Spread Spectrum: can overlap multiple calls on the same channel  GSM operates on four frequencies –Switch to determine handoff  CDMA doesn’t assign a specific frequency to each user, all on SAME frequency –Soft handoff

Why does it matter?  CDMA consistently provides better capacity for voice and data communication  Analogy: a room full of people trying to have one-on-one conversations –TDMA: Each couple takes turns saying one sentence –CDMA: All speak at the same time but in different languages  CDMA has traditionally been faster than GSM –Important for data transfer –Pressure for others to stay competitive

Lawsuits  Qualcomm has the most patents on CDMA  Ericsson, Nokia, Texas Instruments, Broadcom…  Nokia –Thought Qualcomm wasn’t selling their technology to enough of the market –Qualcomm then sued Nokia for using their technology in new versions of GSM

Resolution?  Most of the companies have multiple ongoing lawsuits  Out of court settlements are being used as bargaining tools