Network connection type detection in Symbian Web Runtime
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Overview
Network connection* type detection is useful for widgets that make use of multimedia features such as big pictures. By detecting the network connection type, the widget can request content that is tailored for the available bandwidth from the server. For example, a smaller or more heavily compressed image could be returned if a 2G connection is used.
*Network connection refers to the connection that the widget is using. It is not always the same connection the phone uses. For example, a widget can use a WLAN connection in offline mode.
Solution
Network connection type can be obtained via the SystemInfo Service API (WRT 1.1). However, there is no single API that would provide a satisfactory end result. Two APIs must be used together: Network and Connectivity.
Network monitoring must be done in three steps:
1) First start monitoring the connection type with getNotification, using the criteria Connectivity ConnectionStatus. If your widget, some other widget, or the browser initiates a network connection, then this callback is called. It is also called if the phone is set to offline mode.
var serviceObj = device.getServiceObject("Service.SysInfo", "ISysInfo");
var connectionStatusCriteria = {
Entity : "Connectivity",
Key : "ConnectionStatus"
}
serviceObj.ISysInfo.GetNotification(connectionStatusCriteria, connectionStatusChanged);
2) Next, check the initial connection state with getInfo criteria Connectivity ConnectionStatus. In case there are no ongoing active connections (the widget will prompt IAP selection when accessing the network), the returned ConnectionList has a length of zero. Use ConnectionList.getNext(); to iterate over NetworkInfo objects.
serviceObj.ISysInfo.GetInfo(connectionStatusCriteria, connectionStatusChanged);
function connectionStatusChanged(transId, eventCode, result){
var nwMode = document.getElementById("nwMode");
if(result.ErrorCode == 0){
var connInfo;
//if wlan connection is made in offline mode, we get just conninfo object and not the list
if(result.ReturnValue.ConnectionList){
connInfo = result.ReturnValue.ConnectionList.getNext();
}else{
connInfo = result.ReturnValue;
}
if(connInfo != undefined ){
switch(connInfo.ConnectionType) {
case -1: nwMode.innerHTML ="Unknown"; break;
case 0: nwMode.innerHTML="Circuit Switched Data (CSD)";
rate(0);
break; // 9.6 kbit/s
case 1: nwMode.innerHTML="Wideband Code Division Multiple Access (WCDMA)";
rate(5);
break; //384 Kbps to 2 Mbps
case 2: nwMode.innerHTML="Local Area Network (LAN) [Emulator]";
rate(5);
break;
case 3: nwMode.innerHTML="Code Division Multiple Access (CDMA2000)";
rate(3);
break; //153 Kbps
case 4: nwMode.innerHTML="General Packet Radio Service (GPRS)";
rate(2);
break; //56-114 kbit/s.
case 5: nwMode.innerHTML="High Speed Circuit Switched Data (HSCSD)";
rate(1);
break; //up to 38.4 kbit/s
case 6: nwMode.innerHTML="Enhanced Data rates for Global Evolution (EDGE), Enhanced GPRS (EGPRS)";
rate(4);
break; //236.8 kbit/s
case 7: nwMode.innerHTML="Wireless Local Area Network (WLAN)";
rate(5);
break; //fast
case 8: nwMode.innerHTML="Bluetooth"; break;
case 9: nwMode.innerHTML="Virtual VPN"; break;
}
if(connInfo.ConnectionStatus == 0){
nwMode.innerHTML += " (disconnected)";
rate(-1);
}
}else{
nwMode.innerHTML="Widget is not yet connected to net";
}
}else{
writelog("Error connectionStatusChanged: "+ result.ErrorCode);
}
}
3) This step is a workaround for getNotification Connectivity ConnectionStatus. It does not fire if the access point stays the same but ConnectionType changes, for example from 3G to 2G. Therefore, one must listen to CurrentNetwork as well. Once the callback networkStatusChanged is called, check with getInfo Connectivity ConnectionStatus if it affects the widget connection.
var networkCriteria = {
Entity : "Network",
Key : "CurrentNetwork"
}
serviceObj.ISysInfo.GetNotification(networkCriteria, networkStatusChanged);
var oldNetworkMode = -1;
function networkStatusChanged(transId, eventCode, result){
if(result.ErrorCode == 0){
//only if network mode has changed
if(result.ReturnValue.NetworkMode != oldNetworkMode){
writelog("network mode changed from "+ oldNetworkMode+ " to " + result.ReturnValue.NetworkMode);
oldNetworkMode = result.ReturnValue.NetworkMode;
getInfo(connectionStatusCriteria, connectionStatusChanged);
}
}
}
For a complete example, see: ConType.zip
Where is the Connection Manager API? I need to access total MB, received MB, sent MB, upload speeds and download speeds for GPRS connections to show it in a widget on the homescreen.