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Jmtyra · 11-07-2005, 08:54 AM

from CNET:

Q: What exactly is the difference between CDMA and GSM, and how does that translate to real-world functionality?

A: You could write a book describing the technical differences between the two technologies, but I'll spare you the gritty details by describing how these variations may influence your mobile shopping decisions. In the most general sense, CDMA sends wireless signals in a series of unique codes, while GSM divides signals into a series of individual time slots (for more information, see the glossary in our quick guide to 3G). To you, that means a few things. CDMA networks tend to have more capacity so that more callers can use the network at one time, and they tend do a better job during handoffs, when your call is passed from one tower to another. CDMA also has more widespread coverage in the United States, especially when you count analog roaming, and offers more stateside high-speed data networks. Finally--and I know I'm opening a Pandora's box here--CDMA supporters, who are likely to be the most vociferous defenders, usually argue that their technology offers better call clarity. Keep in mind, though, that it's not necessarily a fact since individual call quality is a matter of opinion, and it depends on a multitude of factors that can be beyond your control.

On the other hand, GSM has its own advantages. GSM's advocates argue that because it is a newer technology (though it is based on the older TDMA networks), it's better equipped for the conversion to 3G. Also, GSM is more widely used than CDMA, with service available in more countries around the globe. CDMA is adding regions as time goes on, but if want a true world phone, GSM is your choice. GSM also uses a SIM card, so it's much easier to switch your phone number and your contacts between handsets. And speaking of phones, GSM phones usually require less battery power than CDMA, and at least in the United States, the GSM carriers (Cingular and T-Mobile) have a more varied selection of phones that include such higher-end features as Bluetooth than do CDMA providers Sprint and Verizon.

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Also, info on other wireless protocols:

PROTOCOL: 802.11a
MAIN USE: PC Networking
FREQUENCY: 5GHz
RANGE: 25-75ft inside/100ft Outside
SPEED: ~54Mbps
NOTES: Not backwardly compatible with 802.11b, 802.11g. Other 5GHz devices may disrupt connection

PROTOCOL: 802.11b
MAIN USE: PC/PPC Networking
FREQUENCY: 2.4GHz
RANGE: ~100ft inside/250 Outside
SPEED: ~11Mbps
NOTES: Other 2.4GHz devices may disrupt connection

PROTOCOL: 802.11g
MAIN USE: PC/PPC Networking
FREQUENCY: 2.4GHz
RANGE: ~100ft inside/250ft Outside
SPEED: ~54Mbps
NOTES: Other 2.4GHz devices may disrupt connection

PROTOCOL: Bluetooth
MAIN USE: Connecting Peripherals
FREQUENCY: 2.4GHz
RANGE: ~33ft
SPEED: ~720Kbps
NOTES: Other 2.4GHz devices may disrupt connection

PROTOCOL: EvDO (Evolution Data Only)
MAIN USE: Data for Digital Cell Phone Network
FREQUENCY: 800/1600CDMA, 900/1800GRPS
RANGE: Provider Coverage Area
SPEED: Expected 500kbps-800kbps, theoretical 2Mbps.
NOTES: -none-

PROTOCOL: GSM (Global System for Mobile Communications)
MAIN USE: Cell Phone Network
FREQUENCY: 900MHz/1,800MHz/1,900MHz
RANGE: Set by Provider
SPEED: Set by Provider
NOTES: Incompatible w/CDMA & TDMA networks

PROTOCOL: 3GSM (3rd Generation Global System for Mobile Communications)
MAIN USE: 3GSM Cell Networks
FREQUENCY: 1,920MHz to 1,980MHz/2,110-2,170MHz
RANGE: Set by Provider
SPEED: 2Mbps
NOTES: Incompatible w/CDMA networks

PROTOCOL: GPRS (General Packet Radio Service)
MAIN USE: Data for GSM phones
FREQUENCY: Set by Provider
RANGE: Set by Provider
SPEED: ~50Kbps
NOTES: Incompatible w/CDMA networks

PROTOCOL: CDMA (Code Division Multiple Access)
MAIN USE: Digital Cell Network
FREQUENCY: 800MHz/900MHz/1,700MHz/1,800MHz/1,900MHz
RANGE: Coverage Area
SPEED: 14.4Kbps/64Kbps
NOTES: Not compatible with GSM, TDMA networks

PROTOCOL: CDMA2000 (Code Division Multiple Access, Version 2000)
MAIN USE: Digital Cell Network
FREQUENCY: Any bandwidth selected by Provider
RANGE: Coverage area
SPEED: 144Kbps/4.8Mbps in the future
NOTES: Incompatible with GSM, TDMA networks

PROTOCOL: CDPD (Cellular Digital Packet Data)
MAIN USE: Analog Cell Data Ntwk
FREQUENCY: 800MHz, 1,900MHz
RANGE: Coverage area
SPEED: 19.2Kbps
NOTES:

PROTOCOL: TDMA (Time Division Multiple Access)
MAIN USE: Digital Cell Netowrk
FREQUENCY: 800MHz, 1,900MHz
RANGE: Coverage Area
SPEED: 64Kbps-120Kbps
NOTES: Not compatible with GSM, CDMA networks

11-07-2005, 08:54 AM	#9 (permalink)
Jmtyra Join Date: Nov 2005 Posts: 164 Thanks: 0 Thanked 0 Times in 0 Posts	Wireless Protocol(s) from CNET: Q: What exactly is the difference between CDMA and GSM, and how does that translate to real-world functionality? A: You could write a book describing the technical differences between the two technologies, but I'll spare you the gritty details by describing how these variations may influence your mobile shopping decisions. In the most general sense, CDMA sends wireless signals in a series of unique codes, while GSM divides signals into a series of individual time slots (for more information, see the glossary in our quick guide to 3G). To you, that means a few things. CDMA networks tend to have more capacity so that more callers can use the network at one time, and they tend do a better job during handoffs, when your call is passed from one tower to another. CDMA also has more widespread coverage in the United States, especially when you count analog roaming, and offers more stateside high-speed data networks. Finally--and I know I'm opening a Pandora's box here--CDMA supporters, who are likely to be the most vociferous defenders, usually argue that their technology offers better call clarity. Keep in mind, though, that it's not necessarily a fact since individual call quality is a matter of opinion, and it depends on a multitude of factors that can be beyond your control. On the other hand, GSM has its own advantages. GSM's advocates argue that because it is a newer technology (though it is based on the older TDMA networks), it's better equipped for the conversion to 3G. Also, GSM is more widely used than CDMA, with service available in more countries around the globe. CDMA is adding regions as time goes on, but if want a true world phone, GSM is your choice. GSM also uses a SIM card, so it's much easier to switch your phone number and your contacts between handsets. And speaking of phones, GSM phones usually require less battery power than CDMA, and at least in the United States, the GSM carriers (Cingular and T-Mobile) have a more varied selection of phones that include such higher-end features as Bluetooth than do CDMA providers Sprint and Verizon. -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Also, info on other wireless protocols: PROTOCOL: 802.11a MAIN USE: PC Networking FREQUENCY: 5GHz RANGE: 25-75ft inside/100ft Outside SPEED: ~54Mbps NOTES: Not backwardly compatible with 802.11b, 802.11g. Other 5GHz devices may disrupt connection PROTOCOL: 802.11b MAIN USE: PC/PPC Networking FREQUENCY: 2.4GHz RANGE: ~100ft inside/250 Outside SPEED: ~11Mbps NOTES: Other 2.4GHz devices may disrupt connection PROTOCOL: 802.11g MAIN USE: PC/PPC Networking FREQUENCY: 2.4GHz RANGE: ~100ft inside/250ft Outside SPEED: ~54Mbps NOTES: Other 2.4GHz devices may disrupt connection PROTOCOL: Bluetooth MAIN USE: Connecting Peripherals FREQUENCY: 2.4GHz RANGE: ~33ft SPEED: ~720Kbps NOTES: Other 2.4GHz devices may disrupt connection PROTOCOL: EvDO (Evolution Data Only) MAIN USE: Data for Digital Cell Phone Network FREQUENCY: 800/1600CDMA, 900/1800GRPS RANGE: Provider Coverage Area SPEED: Expected 500kbps-800kbps, theoretical 2Mbps. NOTES: -none- PROTOCOL: GSM (Global System for Mobile Communications) MAIN USE: Cell Phone Network FREQUENCY: 900MHz/1,800MHz/1,900MHz RANGE: Set by Provider SPEED: Set by Provider NOTES: Incompatible w/CDMA & TDMA networks PROTOCOL: 3GSM (3rd Generation Global System for Mobile Communications) MAIN USE: 3GSM Cell Networks FREQUENCY: 1,920MHz to 1,980MHz/2,110-2,170MHz RANGE: Set by Provider SPEED: 2Mbps NOTES: Incompatible w/CDMA networks PROTOCOL: GPRS (General Packet Radio Service) MAIN USE: Data for GSM phones FREQUENCY: Set by Provider RANGE: Set by Provider SPEED: ~50Kbps NOTES: Incompatible w/CDMA networks PROTOCOL: CDMA (Code Division Multiple Access) MAIN USE: Digital Cell Network FREQUENCY: 800MHz/900MHz/1,700MHz/1,800MHz/1,900MHz RANGE: Coverage Area SPEED: 14.4Kbps/64Kbps NOTES: Not compatible with GSM, TDMA networks PROTOCOL: CDMA2000 (Code Division Multiple Access, Version 2000) MAIN USE: Digital Cell Network FREQUENCY: Any bandwidth selected by Provider RANGE: Coverage area SPEED: 144Kbps/4.8Mbps in the future NOTES: Incompatible with GSM, TDMA networks PROTOCOL: CDPD (Cellular Digital Packet Data) MAIN USE: Analog Cell Data Ntwk FREQUENCY: 800MHz, 1,900MHz RANGE: Coverage area SPEED: 19.2Kbps NOTES: PROTOCOL: TDMA (Time Division Multiple Access) MAIN USE: Digital Cell Netowrk FREQUENCY: 800MHz, 1,900MHz RANGE: Coverage Area SPEED: 64Kbps-120Kbps NOTES: Not compatible with GSM, CDMA networks