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, APN
Where CID is the context ID number
PDP_TYPE identifies the protocol that you
intend to use
APN is the Access Point Name that you wish to
connect to remotely
AT+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
Request Radio Resources
Open up your service
the APN
AT+CGACT=1,1
AT+CGATT=1 response is AT+CGDREG=1
AT+CGDATA=1 opens a TCP/IP link to
TCP/IP carried by RF
Local
Link to
TCP/IP
peer
Radio Resources
Embedded
App in ME
A typical embedded APP for FTP using OPEN-AT
AT+WIPCFG=1
Start IP stack
AT+WIPBR=1,6
Open GPRS bearer
AT+WIPBR=2,6,11,"....."
APN name
AT+WIPBR=2,6,0,"..."
APN Username
AT+WIPBR=2,6,1,"..."
APN Password
AT+WIPBR=4,6,0
Start GPRS bearer
AT+WIPCREATE=4,1,"...","...","..." Create FTP session, fields are FTP
URL, FTP Usernam, FTP Password
AT+WIPFILE=4,1,2,"...",
Open a file for FTP upload with full pathname
AT+WIPCLOSE
Close down the FTP peer
AT+WIPBR=5,6
Stop GPRS bearer
AT+WIPBR=0,6
Close GPRS bearer
AT+WIPCFG=0
Stop IP stack
IP Address
Local
Global
Only has meaning in Has meaning in
this Network
World Wide Web
Dynamic
Assigned on a
temporary basis
Static
Assigned
Permanently
Mobile Phones
PDA's
GPRS/3G dongles
Via a Network
Address Translation
Table – ME's can
connect to the
WWW
Special Contract
only within a Virtual
Private Network
(VPN)
Special, and
expensive, contract
only