GPRS /3G offers a Radio Connection between an ME and a GSM network.

GPRS /3G offers a Radio Connection between an ME and a GSM network.

Different services can operate over the RF link – so the connection needs to know the 'context'. This defines the service and the APN or Access Point Name

GPRS /3G offers a Radio Connection between an ME and a GSM network.

Different services can operate over the RF link – so the connection needs to know the 'context'. This defines the service and the APN or Access Point Name

AT+CGDCONT=CID, PDP_TYPE, APNWhere CID is the context ID numberPDP_TYPE identifies the protocol that you intend to useAPN is the Access Point Name that you wish to connect to remotelyAT+CGDCONT=1,”IP”,”orangeinternet”AT+CGDCONT=1,”IP”,”general.t-mobile.uk”AT+CGDCONT=1,”IP”,”internet”AT+CGDCONT=1,”IP”,”mobile.o2.co.uk”AT+CGDCONT=1,”IP”,”three.co.uk”

Activate the context AT+CGACT=1,1Request Radio Resources AT+CGATT=1 response is AT+CGDREG=1Open up your service AT+CGDATA=1 opens a TCP/IP link to

the APN

Radio Resources

TCP/IP carried by RF

Local Link to TCP/IP peer

Embedded App in ME

A typical embedded APP for FTP using OPEN-AT

AT+WIPCFG=1 Start IP stackAT+WIPBR=1,6 Open GPRS bearerAT+WIPBR=2,6,11,"....." APN nameAT+WIPBR=2,6,0,"..." APN UsernameAT+WIPBR=2,6,1,"..." APN PasswordAT+WIPBR=4,6,0 Start GPRS bearerAT+WIPCREATE=4,1,"...","...","..." Create FTP session, fields are FTP URL, FTP Usernam, FTP PasswordAT+WIPFILE=4,1,2,"...", Open a file for FTP upload with full pathnameAT+WIPCLOSE Close down the FTP peerAT+WIPBR=5,6 Stop GPRS bearerAT+WIPBR=0,6 Close GPRS bearerAT+WIPCFG=0 Stop IP stack

IP Address Local

Only has meaning in this Network

Global

Has meaning in World Wide Web

Dynamic

Assigned on a temporary basis

Mobile PhonesPDA'sGPRS/3G dongles

Via a Network Address Translation Table – ME's can connect to the WWW

Static

Assigned Permanently

Special Contract only within a Virtual Private Network (VPN)

Special, and expensive, contract only