Send SMS in android programmatically

I am using below code for sending sms in background for multiple peoples(Contacts) at a time. It is working for smaller text but however it not working for text which has more than 160 characters. I am getting GENERIC FAILURE.

public class SendSMS {

    private int mMessageSentParts;
    private int mMessageSentTotalParts;
    private int mMessageSentCount;
    private String message;
    private String[] array;
    private Context mContext;

    public SendSMS(Context context,String array[]) {
        // TODO Auto-generated constructor stub
        this.mContext = context;
        this.array = array;
        System.out.println("array length :::: "+array.length);
        message = mContext.getResources().getString(R.string.siri);
//      message="siri";
        startSendMessages();
    }

    private void startSendMessages() {

        registerBroadCastReceivers();

        mMessageSentCount = 0;
        sendSMS(array[mMessageSentCount].toString(), message);
    }

    private void sendNextMessage() {
        if (thereAreSmsToSend()) {
            sendSMS(array[mMessageSentCount].toString(), message);
        } else {
            Toast.makeText(mContext, "All SMS have been sent",
                    Toast.LENGTH_SHORT).show();
        }
    }

    private boolean thereAreSmsToSend() {
        return mMessageSentCount < array.length;
    }

    private void sendSMS(final String phoneNumber, String message) {
        String SENT = "SMS_SENT";
        String DELIVERED = "SMS_DELIVERED";

        SmsManager sms = SmsManager.getDefault();
        ArrayList<String> parts = sms.divideMessage(message);
        mMessageSentTotalParts = parts.size();

        Log.i("Message Count", "Message Count: " + mMessageSentTotalParts);

        ArrayList<PendingIntent> deliveryIntents = new ArrayList<PendingIntent>();
        ArrayList<PendingIntent> sentIntents = new ArrayList<PendingIntent>();

        PendingIntent sentPI = PendingIntent.getBroadcast(mContext, 0, new Intent(
                SENT), 0);
        PendingIntent deliveredPI = PendingIntent.getBroadcast(mContext, 0,
                new Intent(DELIVERED), 0);

        for (int j = 0; j < mMessageSentTotalParts; j++) {
            sentIntents.add(sentPI);
            deliveryIntents.add(deliveredPI);
        }

        mMessageSentParts = 0;
        sms.sendMultipartTextMessage(phoneNumber, null, parts, sentIntents,
                deliveryIntents);
    }

    private void registerBroadCastReceivers() {
        String SENT = "SMS_SENT";
        String DELIVERED = "SMS_DELIVERED";

        mContext.getApplicationContext().registerReceiver(new BroadcastReceiver() {
            @Override
            public void onReceive(Context arg0, Intent arg1) {
                switch (getResultCode()) {
                case Activity.RESULT_OK:

                    mMessageSentParts++;
                    if (mMessageSentParts == mMessageSentTotalParts) {
                        mMessageSentCount++;
                        sendNextMessage();
                    }

                    Toast.makeText(mContext, "SMS sent", Toast.LENGTH_SHORT)
                            .show();
                    break;
                case SmsManager.RESULT_ERROR_GENERIC_FAILURE:
                    Toast.makeText(mContext, "Generic failure",
                            Toast.LENGTH_SHORT).show();
                    break;
                case SmsManager.RESULT_ERROR_NO_SERVICE:
                    Toast.makeText(mContext, "No service", Toast.LENGTH_SHORT)
                            .show();
                    break;
                case SmsManager.RESULT_ERROR_NULL_PDU:
                    Toast.makeText(mContext, "Null PDU", Toast.LENGTH_SHORT)
                            .show();
                    break;
                case SmsManager.RESULT_ERROR_RADIO_OFF:
                    Toast.makeText(mContext, "Radio off", Toast.LENGTH_SHORT)
                            .show();
                    break;
                }
            }
        }, new IntentFilter(SENT));

        mContext.getApplicationContext().registerReceiver(new BroadcastReceiver() {
            @Override
            public void onReceive(Context arg0, Intent arg1) {
                switch (getResultCode()) {

                case Activity.RESULT_OK:
                    Toast.makeText(mContext, "SMS delivered",
                            Toast.LENGTH_SHORT).show();
                    break;
                case Activity.RESULT_CANCELED:
                    Toast.makeText(mContext, "SMS not delivered",
                            Toast.LENGTH_SHORT).show();
                    break;
                }
            }
        }, new IntentFilter(DELIVERED));

    }
}

Can you please help me. Thank you guys.