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Library for Decode/Encode SMS PDU

Eduard Gomolyako

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18 Oct 2012CPOL

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Library for decoding and encoding mobile short messages to/from SMS protocol data unit

Last Updates

You can find some community fixes mentioned on comments section on Project Home at Google Code[^].

Introduction

The smspdulib library is intended for more transparent interaction with SMS PDU. This thought over hierarchy of classes will allow you to create new classes for other types of short messages using the realized base functionality.

At present, the following types of short messages are supported: status report, SMS (with long (large) SMS parts support).

Hierarchy of Classes

Classes hierarchy

Sample Code

This example shows you how to decode PDU.

C#

SMSType smsType = SMSBase.GetSMSType(pduSource);
switch (smsType) {
    case SMSType.SMS:
        SMS sms = new SMS();
        SMS.Fetch(sms, ref pduSource);
        //Use instance of SMS class here
        break;
    case SMSType.StatusReport:
        SMSStatusReport statusReport = new SMSStatusReport();
        SMSStatusReport.Fetch(statusReport, ref pduSource);
        //Use instance of SMSStatusReport class here
        break;
}

This example show you how to encode SMS to PDU.

C#

SMS sms = new SMS();
sms.Direction = SMSDirection.Submited;
sms.PhoneNumber = &quot;+74951234567&quot;;
sms.ValidityPeriod = new TimeSpan(4, 0, 0, 0);
sms.Message = &quot;Me message here!&quot;;
string pduSource = sms.Compose(SMS.SMSEncoding.UCS2);

Useful Links

Updated

Updated Decode7bit method: Fixed some bugs (see comments)
PopDate method now doesn't recognize time zone because some phones send strange stuff

Please help me find more detailed specification of PDU format and TP-SCTS format.

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Written By

Eduard Gomolyako

Chief Technology Officer

Russian Federation

This member has not yet provided a Biography. Assume it's interesting and varied, and probably something to do with programming.

Comments and Discussions

Re: Encode PDU Fail

Eduard Gomolyako23-Jun-08 20:17

Eduard Gomolyako

23-Jun-08 20:17

Hi James,

I think this is a bug, but i have no time to figure out problem. I (and all other library users i think) will be very much appreciated for help.

Best, Ed.

Re: Encode PDU Fail

jamesng7424-Jun-08 15:39

24-Jun-08 15:39

Eduard, I think you forgot something
you defined a method only for SMSEncoding.UCS2.
you did not define a method for 7bits encoding.

public virtual string Compose(SMSEncoding messageEncoding)
        {
            .....
            .....

            byte[] messageBytes = null;

            switch (messageEncoding)
            {
                case SMSEncoding.UCS2:
                    messageBytes = EncodeUCS2(_message);
                    break;
                default:
                    messageBytes = new byte[0];
                    break;
            }

            ......
            ......            

            return encodedData.ToUpper();
        }

for SMSEncoding.UCS2 you used: Encoding.BigEndianUnicode.GetBytes

public static byte[] EncodeUCS2(string s)
{
    return Encoding.BigEndianUnicode.GetBytes(s);
}

I wanna help, but i dont know what Encoding should be used for SMSEncoding._7bit

Sorry,..

Re: Encode PDU Fail

Eduard Gomolyako24-Jun-08 20:57

Eduard Gomolyako

24-Jun-08 20:57

Oh yeap. Try to implement 7 bit encoding using an articles from "Useful links" section or find ready solution.

Sorry, but i have no time. Good luck.

Best, Ed.

Member 339753130-May-08 16:43

30-May-08 16:43

Hi Ed,

Now, i can encode sms to pdu

SMS mysms = new SMS();
mysms.Direction = SMSDirection.Submited;
mysms.PhoneNumber = "+6281212345678";
mysms.ValidityPeriod = new TimeSpan(5, 0, 0, 0);
mysms.Message = "Hello";
string pduTxt = mysms.Compose(SMS.SMSEncoding.UCS2);

How do i send sms ?

Eduard Gomolyako1-Jun-08 19:57

Eduard Gomolyako

1-Jun-08 19:57

Hi.

This library doesn't respond to sending or receiving requirements, only encode/decode functionality.
So, you can use SerialPort class to send and receive AT commands from your cell phone or use special sms protocol to sen messages via sms provider. For both methods you need encoding and decoding message to/from PDU format.

My best wishes.

Best, Ed.

how to handle USSD?

jamesng7416-Apr-08 18:42

16-Apr-08 18:42

i'm sorry,
i dont know this is a correct place to ask about USSD or not.
Does anyone know, how to handle USSD (Unstructured Supplementary Service Data)?

Re: how to handle USSD?

Eduard Gomolyako16-Apr-08 20:57

Eduard Gomolyako

16-Apr-08 20:57

I have not appropriate hardware for testing, but have some knowledges. Please, try to describe what is your problem.

You plan to work with USSD through cell phone or network SMS protocol?

Best, Ed.

Re: how to handle USSD?

jamesng7417-Apr-08 22:03

17-Apr-08 22:03

i plan to create an application to work with USSD through cell phone (siemens c55).

For example,
My GSM provider, provide a USSD tools to transfer voucher between customers. than, i want to transfer a voucher to my friend.

below is current process (manually):
1. from my cell phone, i dial a USSD number such as: *123#
2. then my phone display a USSD message. i.e "input phone number"
3. i click button "answer"
4. my cell phone display a text box:
5. input my number: +1233453455
6. then click OK
... etc

How to create a program like that?

Thanks for reply.

Re: how to handle USSD?

Eduard Gomolyako18-Apr-08 1:09

Eduard Gomolyako

18-Apr-08 1:09

Okay. First of all you need to establish connection between application and phone. In my case, i pair phone with computer via bluetooth service and setup serial port connection. In "phone and modem options" in control panel I've see port COM21. When I connect phone via usb cable I've see COM6 port at "phone and modem options".

I wrote simple program that send "AT" command to phone and phone replies "AT" to me using SerialPort .net 2.0 class. With default settings: bit-rate and so on.

When you'll achieve same result, I'll continue my tutorial.

Best, Ed.

Re: how to handle USSD?

jamesng7418-Apr-08 15:48

18-Apr-08 15:48

OK,
i've several cellphones (Nokia N73, siemens c77, etc),
but for this purpose, i used Siemens C55.
my Siemens c55 do not have a bluetoth facility.
But, I could establish connection between PC and my Siemens C55 via USB Cable using COM8. And i tried using Hyper terminal, and send AT command "AT" to my cell phone like following:

AT
OK

AT+CMGI
SIEMENS

AT+CMGM
C55

Since my siemens C55 do not have bluetooth facility,
Should i used my Nokia n73 for this purpose?

Thank you for the reply.

Re: how to handle USSD?

Eduard Gomolyako18-Apr-08 20:15

Eduard Gomolyako

18-Apr-08 20:15

No. If you don't need phone mobility you can use your siemenes device as well.

Write simple console program using SerialPort class.

//using System.IO;<br />
<br />
SerialPort port = new SerialPort("COM8");<br />
<br />
port.DataReceived += new SerialPortEventHander(delegate(object sender, SomeArgs sa) {<br />
    string recievedData = port.ReadToEnd();<br />
});<br />
<br />
port.WriteLine("ATD*100#;");

In your case you've interesting in AT+CUSD command (page 97 in document below).

AT Command Set.

Best, Ed.

Re: how to handle USSD?

jamesng7420-Apr-08 16:34

20-Apr-08 16:34

Thank you verry much Eduard ! Big Grin | :-D

Big Grin | :-D

Re: how to handle USSD?

Eduard Gomolyako20-Apr-08 22:00

Eduard Gomolyako

20-Apr-08 22:00

Welcome, James Smile | :)

Smile | :)

Best, Ed.

MAZHAR ALI SHAIKH17-Mar-08 9:50

MAZHAR ALI SHAIKH

17-Mar-08 9:50

Hello Sir,
I am making a project in SMS Application,please do suggest me what should i study first before taking up this project and also tell me the hierarchy of steps to develop this project .
Thanks
Mazhar

ESTAN11-Apr-08 14:28

11-Apr-08 14:28

Believe me, developing the sms encoding consumes a lot of time. I had to do it also for my company, for this I can't publish the whole code,but i can help if needed.

There are tools available online to convert this project to vb.net.
Doing so, you probably still need to change some small glitches that may have appeared during the conversion, but at least you will learn the proces of the encode/decode.

So in small words, understand how the encoding goes...

http://labs.developerfusion.co.uk/convert/csharp-to-vb.aspx[^]

MAZHAR ALI SHAIKH17-Mar-08 9:49

MAZHAR ALI SHAIKH

17-Mar-08 9:49

Hello Sir,
I am a project in SMS Application,please do suggest me what should i study first before taking up this project.
Thanks
Mazhar

MAZHAR ALI SHAIKH16-Mar-08 10:41

MAZHAR ALI SHAIKH

16-Mar-08 10:41

Hello,
Is this code available in VB.NET bcoz i am making a project of SMS Application in VB.NET.

Re: Code in VB.Net

Eduard Gomolyako16-Mar-08 11:02

Eduard Gomolyako

16-Mar-08 11:02

You have forget question sign. No, this code doesn't available in VB .net.

Best, Ed.

How to implement Unicode SMS, multipart SMS and high capacity sending

William Ike8-Mar-08 21:45

8-Mar-08 21:45

If you don't have a lot of time it could be a good idea to use an SMS gateway,
such as the Ozeki SMS Sending and SMS
receiving Gateway, because it does a lot things that is very hard to
implement: character conversion to unicode SMS messages, GSM 7 bit, segmentation
and reassembly for multipart SMS messages with 8 bit reference numbering and 16
bit reference numbering, message delivered to network report,
message delivered to handset report, message delivery failed
report, etc. Not to talk about long term upgrade. If you do a system now with
a GSM modem, it might be possible that you will have to upgrade in the long term
to higher capcity IP SMS connection, such as SMPP
sms sending, UCP sms sending or
CIMD2 sms sending. Remember,
a GSM modem can only send 10 SMS meessages per minute, while an IP SMS connection
will allow you to send 3000 or more SMS messages per minute.

Nukumaar4-Jan-08 5:25

4-Jan-08 5:25

Hello.

Im trying to convert longer messages from PDU to Text,but it doesn´t work.
How can i do that?
Greets

Re: Long Messages?

Eduard Gomolyako8-Jan-08 9:20

Eduard Gomolyako

8-Jan-08 9:20

Hi, why it doesn't work? Any exceptions? Give me your PDU text, I'll try to figure out what the problem.

Best, Ed.

Re: Long Messages?

Nukumaar14-Jan-08 14:55

14-Jan-08 14:55

Im trying to parse a PDU (as a string) to Text.
It works,yes,but if the PDU-message is a longer one (not only a few words) it cant be decded correctly. The text then looks like: @@@@@@@a#eef####@@@ or something like that.

Im just using the SMSPDULib.dll and the code example,that is in your article.

You can email to sonja_hager138@hotmail.com

Re: Long Messages?

Eduard Gomolyako14-Jan-08 20:59

Eduard Gomolyako

14-Jan-08 20:59

Give me your PDU string and I'll try to figure out what the problem.

Best, Ed.

Re: Long Messages?

Nukumaar15-Jan-08 10:55

15-Jan-08 10:55

Im using SE W580i

This PDU can be decoded correctly:
05913476061211390B816067960850F50000FF11C7329A0E2287E7A0F9181DA6EBD33F

This one too:
059134760612040C9134766689005500007021926142624046553719E40ED3FD72767A8C06CDC76879392D06A5C76850B83E4683C8E932A82C9FD3CBA0797B0E42A7D1691768999ECF41E9311AC44E97C56510393D4603

But this can't:
059134760612513C0B816067960850F50000FFA0050003010302EA2074B94E2F83DA693AE81E96CFE9AEB0B82C0791C373507A4E07CDDF20F2FB6D66A5C768103A2C0691D36334889C2E83CE61B7BE0CD297D37450BD0D6AA7C76850585C9683D26334C85E96B7D3F339889C1EA341E4B0DB0DA2CBDF743DB9DC06D1DFF430DB1566CFDF2

Because the 2 shorter ones work,i think that the length is the problem!?

W580i gives me the first PDU in just one part,and the second one in two parts.Both work.
The third one is given in 3 parts.

I don't know whats the problem!?
Greets

Re: Long Messages?

Nukumaar17-Jan-08 15:13

17-Jan-08 15:13

for better reading,here are he 3 PDU strings:
1)
05913476061211390B816067960850F50
000FF11C7329A0E2287E7A0F9181DA6EBD33F

2)
059134760612040C91347666890055000070
21926142624046553719E40ED3FD72767A8C06
CDC76879392D06A5C76850B83E4683C8E932A82
C9FD3CBA0797B0E42A7D1691768999ECF41E931
1AC44E97C56510393D4603

3)
059134760612513C0B816067960850F50000FFA
0050003010302EA2074B94E2F83DA693AE81E96
CFE9AEB0B82C0791C373507A4E07CDDF20F2FB6D
66A5C768103A2C0691D36334889C2E83CE61B7BE0
CD297D37450BD0D6AA7C76850585C9683D26334C8
5E96B7D3F339889C1EA341E4B0DB0DA2CBDF743DB
9DC06D1DFF430DB1566CFDF2

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