Developers guide

Psion Teklogix Mobile Devices SDK Developers Guide 191
WIRELESS WIDE-AREA NETWORKING 22
22.1 Wireless Wide-Area Networking (WWAN)..............................193
22.2 PsionTeklogix Computers Supporting WWAN............................193
22.3 Supported WWAN Modems......................................193
22.3.1 Multiplexing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .194
22.3.2 Virtual Serial Port.......................................194
22.3.2.1 Using The Virtual Serial Port............................194
22.3.2.2 Configuration ....................................194
22.3.2.3 AT Commands....................................195
22.3.2.4 Entering AT Commands in Windows CE......................195
22.3.3 Dial-up Data Connections...................................196
22.3.3.1 Dial-up Data in GSM Networks...........................196
22.3.3.2 Dial-up Data in UMTS Networks..........................197
22.3.3.3 Dial-up Data in CDMA Networks..........................197
22.3.3.4 Dial-up Data in iDEN Networks...........................197
22.3.4 Packet Data..........................................197
22.3.5 Summary Of Modem Differences ..............................198
22.3.6 GSM Power Driver......................................198
22.4 Initializing WWAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .199
22.4.1 Checking The Initialization Status Of The WWAN Driver. . . . . . . . . . . . . . . . . .199
22.4.2 WWAN Driver Status Flags..................................199
22.4.3 Initializing The WWAN Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .201
22.5 Closing WWAN.............................................205
22.6 Connecting To The Internet.......................................205
22.6.1 Windows CE 5.0 Connection.................................206
22.6.2 Windows Mobile 5.0 And Windows Mobile 6 Connection . . . . . . . . . . . . . . . . .209
22.6.3 The DbGprs.csv File.....................................209
22.6.4 Checking Packet Data Status.................................210
22.6.5 Roaming............................................210
22.6.6 Connecting Manually to A WWAN Network ........................210
22.6.7 Selecting An Access Point Name (APN)...........................211
22.6.8 Connecting To A VPN....................................211
22.7 Access Flags...............................................212
22.7.1 Controlling The Interaction With The Control Panel. . . . . . . . . . . . . . . . . . . . .213
22.8 RSSI (Received Signal Strength Indicator)...............................213
22.9 WWAN API Elements.........................................214
22.10 Using SMS (Short Message Service).................................215
22.10.1 SMS API Elements.....................................215
22.11 WWAN Supplementary Services...................................216
22.11.1 Voice Service States.....................................217
22.12 Voice Calls On A WWAN.......................................217