QualcommQualcommCDMA TechnologyCDMA Technology

What is CDMA?What is CDMA? Code Division Multiple AccessCode Division Multiple Access

– As opposed to TDMA (time-division)As opposed to TDMA (time-division) Strives to better utilize the radio spectrum Strives to better utilize the radio spectrum

by allowing multiple users to share the by allowing multiple users to share the same physical channel same physical channel

Originally created by military during WWII Originally created by military during WWII to make it harder for enemies to intercept to make it harder for enemies to intercept radio signalsradio signals

Qualcomm was first to commercialize the Qualcomm was first to commercialize the technologytechnology

GSM (TDMA) vs CDMAGSM (TDMA) vs CDMA GSM divides the channel in GSM divides the channel in

frequency and time-domain frequency and time-domain (narrowband)(narrowband)

CDMA uniquely encodes and CDMA uniquely encodes and transmits calls across entire transmits calls across entire spectrumspectrum– Spread Spectrum: can overlap Spread Spectrum: can overlap

multiple calls on the same channelmultiple calls on the same channel GSM operates on four frequencies GSM operates on four frequencies

– Switch to determine handoffSwitch to determine handoff CDMA doesn’t assign a specific CDMA doesn’t assign a specific

frequency to each user, all on frequency to each user, all on SAME frequencySAME frequency– Soft handoffSoft handoff

Why does it matter?Why does it matter? CDMA consistently provides better capacity CDMA consistently provides better capacity

for voice and data communicationfor voice and data communication Analogy: a room full of people trying to Analogy: a room full of people trying to

have one-on-one conversationshave one-on-one conversations– TDMA: Each couple takes turns saying one TDMA: Each couple takes turns saying one

sentencesentence– CDMA: All speak at the same time but in CDMA: All speak at the same time but in

different languagesdifferent languages CDMA has traditionally been faster than CDMA has traditionally been faster than

GSMGSM– Important for data transferImportant for data transfer– Pressure for others to stay competitivePressure for others to stay competitive

LawsuitsLawsuits

Qualcomm has the most patents on Qualcomm has the most patents on CDMACDMA

Ericsson, Nokia, Texas Instruments, Ericsson, Nokia, Texas Instruments, Broadcom…Broadcom…

NokiaNokia– Thought Qualcomm wasn’t selling their Thought Qualcomm wasn’t selling their

technology to enough of the markettechnology to enough of the market– Qualcomm then sued Nokia for using Qualcomm then sued Nokia for using

their technology in new versions of GSMtheir technology in new versions of GSM

Resolution?Resolution?

Most of the companies have multiple Most of the companies have multiple ongoing lawsuitsongoing lawsuits

Out of court settlements are being Out of court settlements are being used as bargaining toolsused as bargaining tools