CDPD vs CMDA vs GSM vs GPRS vs EDGE

CDPD :


Cellular Digital Packet Data

• Packet-based network.
• Optimal bandwidth of 19.2 Kbps.
• Run in the same spectrum as the AMPS networks.

CDMA :

Code Division Multiple Access

• Either packet based or circuit based.
• CDMA1 :  Uses circuit switch data, that runs at 14.4 Kbps, and acts as a dial-up connection.
• CDMA2000 : packet based, and has a maximum of 144 Kbps, and delivers 50-120kbps in real world usage.

GSM :

Global System Mobile Communication

• Circuit-based network.
• The user must make a dial-up connection to access the network.
• Optimal bandwidth of 14.4 Kbps.
• Provides voice service through digital network.
• SIM card (Subscriber Identity Module card) stores phone number, connection information, and may store an address book. 
• This allows a user to switch devices without needing to contact the service provider.

GPRS :

General Packet Radio Service

• Packet-based wireless communication service.
• Extends the GSM network that allows for advanced data services.
• Data rates from 56 up to 114 Kbps and continuous connection to the Internet for mobile phone and computer users, but delivers in the 30-50 Kbps in real world usage.
• Advantage over GSM is that one can use the device as the modem or as an Web-Browser.

EDGE :

Enhanced Data for Global Evolution

• An extension to the GSM / GPRS networks.
• 3 times faster than GPRS.
• Download speed extends about 300 Kpbs.