private static string DecodeAddress(byte[] pduData, int start, out int elementLength)
{
int length = pduData[start];
int coding = pduData[start + 1];
int digitStart = start + 2;
StringBuilder builder = new StringBuilder();
/* 1 byte digit count, 1 byte numbering scheme plus the number of nibbles/2 */
elementLength = 1 + 1 + (length + 1) / 2;
switch (coding & 0x7F)
{
case 0x50:
/* alphanumeric */
string message = GSM7Bit.Decode(pduData, digitStart, ((length * 4) / 7), 0);
builder.Append(message);
break;
default:
char[] characters = new[] { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '*', '#', 'a', 'b', 'c', ' ', };
for (int digit = 0; digit < length; digit++)
{
long bcd = (pduData[digitStart + digit / 2] >> (4 * (digit % 2))) & 0x0F;
builder.Append(characters[bcd]);
}
break;
}
return(builder.ToString());
}
private static string DecodeGSM7Bit(byte[] pduData, int start, int skipBytes, int charCount)
{
try
{
return(GSM7Bit.Decode(pduData, start, charCount, (skipBytes * 8 + 6) / 7));
}
catch (Exception e)
{
return("(DecodeGSM7Bit failed)");
}
}
public bool Handle(byte[] data)
{
int lpd = (data[0] >> 5) & 3;
int seq = data[0] & 0x0f;
if (lpd != 1 || data.Length < 23)
{
return(false);
}
if (Sequence != seq)
{
Sequence = 0;
return(false);
}
Array.Copy(data, 1, CBCBuffer, seq * 22, 22);
Sequence++;
/* final packet */
if (Sequence >= 4)
{
bool emergency = ((CBCBuffer[0] >> 5) & 0x01) == 1;
bool popup = ((CBCBuffer[0] >> 4) & 0x01) == 1;
int messageCode = (((CBCBuffer[0] << 8) | CBCBuffer[1]) >> 4) & 0xFF;
int updateNr = CBCBuffer[1] & 0xF;
int messageIdent = (CBCBuffer[2] << 8) | CBCBuffer[3];
int dataCoding = CBCBuffer[4];
int pageParam = CBCBuffer[5];
Array.Copy(CBCBuffer, 6, CBMessage, 0, CBMessage.Length);
if (ShowCBMessages)
{
StatusMessage = "Cell Broadcast: ";
if (emergency)
{
StatusMessage += "[Emergency] ";
}
if (popup)
{
StatusMessage += "[Popup] ";
}
StatusMessage += "[Channel " + messageIdent + "] ";
StatusMessage += "[Update " + updateNr + "] ";
StatusMessage += "[Code " + messageCode + "] ";
StatusMessage += "[Coding 0x" + String.Format("{0:X2}", dataCoding) + "] ";
StatusMessage += "[Page 0x" + String.Format("{0:X2}", pageParam) + "] ";
StatusMessage += Environment.NewLine;
StatusMessage += " '" + GSM7Bit.Decode(CBMessage) + "'" + Environment.NewLine;
}
else
{
StatusMessage = null;
}
Sequence = 0;
}
return(true);
}