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Qualcomm

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

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Qualcomm

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  1. Qualcomm CDMA Technology

  2. 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

  3. 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

  4. 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

  5. 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

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

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