gsm-cdma

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gsm cdma presentaion

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GSM & CDMA:

GSM & CDMA A comparison

GSM:

GSM Time Division Multiple Access Based Technology 200kHz bandwidth per carrier Deployed in reuse pattern 3/9, 4/12, 7/21 Available operating frequency 900, 1800, 1900 MHz Using SIM Card

CDMA:

CDMA Code Division Multiple Access Based Technology 1.25 MHz bandwidth per carrier Reuse factor 1 Available operating frequency 450, 800, 1900 MHz Using RUIM Card

CDMA:

CDMA Inherently superior receive sensitivity (approx. -121 dB) Tradeoff between Capacity, Coverage and Quality Soft/Softer hand-off (make before break): Precise power control algoriths minimize interference Multiple diversities: Receive Spatial Diversity trough two receive antennas Path diversity trough rake receivers Frequency diversity trough spread spectrum Time diversity trough interleaving

GSM:

GSM Fixed coverage Receive sensitivity improvement (approx. -108dB), relies on external solutions (masthead pre-amplifier, high power amplifier) Hard hand-off (break before make)

Summary:

Summary CDMA, compared with GSM (TDMA) technology, provide : better spectrum efficiency (more capacity) better coverage (less sites required) better voice quality better data capability better forward compatibility (same spectrum can be reused)