#package GSM::SMS::PDU
# decode a SMSSubmit message (experimental!)
sub SMSSubmit_decode {
        my ($self, $data) = @_;
        my @msg = split //, $data;
        
        # Get service center
        my $sca = $self->getServiceCenterAddress(\@msg);

        # Get PDU type
        my $pdu = $self->getoctet(\@msg);

        # message ref
        my $mref = $self->getoctet(\@msg);

        # destination address
        my $da = $self->getOriginatingAddress(\@msg);

        #  protocol identifier
        my $pi = $self->getoctet(\@msg);

        # data scheme
        my $ds = $self->getoctet(\@msg);

        # vp
        my $vp = $self->getoctet(\@msg);

        # length
        my $dl = $self->getoctet(\@msg);

        my $udh;
        my $payload;

        # print join "|", @msg;
        # print "\n";

        if ($pdu=~/51/) {
                # we have a user data header
                my $udhl = hex($msg[0].$msg[1]);
        
                # print "udhl ($msg[0]): $udhl\n";

                $udh = $self->getoctet(\@msg, $udhl+1); 
                $payload = join("", @msg);
        } else {
                $payload = $self->decode_7bit( join("", @msg), 160 );
        }       

         # print "da : $da\n";
         # print "pdu type : $pdu\n";
         # print "data scheme : $ds\n";
         # print "length : $dl\n";      
         # print "udh : $udh\n";
         # print "pay : $payload\n";    

        return ($da, $pdu, $ds, $udh, $payload);
}