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Qualcomm CDMA Technology. What is CDMA? Code Division Multiple Access –As opposed to TDMA...
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Transcript of Qualcomm CDMA Technology. What is CDMA? Code Division Multiple Access –As opposed to TDMA...
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