'

==========================================================

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                    SMS,EMS Decoder

'

                      2005-2-20

'

1.Description

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   This class decode a SMS or EMS PDU code to a certain

'

class. You can use it in your software to read SMSs and 

'

EMSs. All of this is done under GSM 03.40. I tested it

'

on my SIEMENS M55 and NOKIA 8xxx and it works well.

'

2.Useage 

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   If you know what type of PDU code, you can create a 

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new instance of class like DIM s as SMS(myPDUCode)

'

When instance is created, you read its public variable 

'

to get what you want.

'

   When TP_DCS=0, PDU code is coded from 7bit 

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charactor (see GSM 03.38), use shared function 

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Deocde7Bit to decode it.

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   When TP_DCS=8, PDU code is coded from Unicode

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charactor (see GSM 03.38), use shared funtion

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DecodeUnicode to decode it.

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3.Bugs

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   So far in my tests I found none.

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4.When you use it

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   You can freely use it or modify it in your program,

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but when you find bugs or improved it please publish it

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or send one copy to me. Thanks

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5.About me

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   I am writting a program which can list folders and 

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files in SIEMENS M55 mobile phone. It can also read

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and send SMS,EMS. Some documents are hard to find on

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internet, but I keep on my mind to study it and finally

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I found it is full of interests.

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    I like freedom, so'I exchange my ideas with all of 

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the world. It is so happy that you can use my classes!

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   In the end, sorry for my poor english.

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6.Contact me

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   Email:hesicong@mail.sc.cninfo.net

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   QQ:38288890

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   Homepage:http://dream-world.nease.net (Chinese)

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   Thanks for using it!

'

                       ----By HESICONG

'

'

Revision:

'

   2004-10-29:

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       Fix bug in decode "@" charactor.

'

       Add functions in "decode 7 bit code to english" region

'

   2005-2-20:

'

       Final version released. Fixed minor bugs. 

Imports

 System.text

Namespace SMS

Namespace SMS

    Namespace DecoderNamespace Decoder

        Public MustInherit Class SMSBaseClass SMSBase

            'Note all of following various with TP_ can be found in GSM 03.40

            Public SCAddressLength As Byte  'Service Center Address length

            Public SCAddressType As Byte    'Service Center Type[See GSM 03.40]

            Public SCAddressValue As String 'Service Center nuber

            Public FirstOctet As Byte       'See GSM 03.40

            Public TP_PID As Byte

            Public TP_DCS As Byte

            Public TP_UDL As Byte

            Public TP_UD As String

            Public Text As String

            Public Type As SMSType

            Public UserData As String

            Public Enum SMSTypeEnum SMSType

                SMS_RECEIVED = 0

                SMS_STATUS_REPORT = 2

                SMS_SUBMIT = 1

                EMS_RECEIVED = 64 'It is "Reserved" on my phone??

                EMS_SUBMIT = 65

            End Enum

            Public MustOverride Sub GetOrignalData()Sub GetOrignalData(ByVal PDUCode As String)

            'Get a byte from PDU string

            Shared Function GetByte()Function GetByte(ByRef PDUCode As String) As Byte

                Dim r As Byte = Val("&H" + Mid(PDUCode, 1, 2))

                PDUCode = Mid(PDUCode, 3)

                Return r

            End Function

            'Get a string of certain length

            Shared Function GetString()Function GetString(ByRef PDUCode As String, ByVal Length As Integer) As String

                Dim r As String = Mid(PDUCode, 1, Length)

                PDUCode = Mid(PDUCode, Length + 1)

                Return r

            End Function

            'Get date from SCTS format

            Shared Function GetDate()Function GetDate(ByRef SCTS As String) As Date

                Dim year, month, day, hour, minute, second, timezone As Integer

                year = Val(Swap(GetString(SCTS, 2))) + 2000

                month = Val(Swap(GetString(SCTS, 2)))

                day = Val(Swap(GetString(SCTS, 2)))

                hour = Val(Swap(GetString(SCTS, 2)))

                minute = Val(Swap(GetString(SCTS, 2)))

                second = Val(Swap(GetString(SCTS, 2)))

                timezone = Val(Swap(GetString(SCTS, 2)))

                Dim result As New Date(year, month, day, hour, minute, second)

                Return result

            End Function

            'Swap two bit

            Shared Function Swap()Function Swap(ByRef TwoBitStr As String) As String

                Dim c() As Char = TwoBitStr.ToCharArray

                Dim t As Char

                t = c(0)

                c(0) = c(1)

                c(1) = t

                Return (c(0) + c(1)).ToString

            End Function

            'Get phone address

            Shared Function GetAddress()Function GetAddress(ByRef Address As String) As String

                Dim tmpChar As Char() = Address.ToCharArray

                Dim i As Integer, result As String

                For i = 0 To tmpChar.GetUpperBound(0) Step 2

                    result += Swap(tmpChar(i) + tmpChar(i + 1))

                Next

                If InStr(result, "F") Then result = Mid(result, 1, result.Length - 1)

                Return result

            End Function

            Shared Function GetSMSType()Function GetSMSType(ByVal PDUCode As String) As SMSBase.SMSType

                'Get first october

                Dim FirstOctet As Byte

                Dim L As Integer = SMSBase.GetByte(PDUCode)

                SMSBase.GetByte(PDUCode)

                SMSBase.GetString(PDUCode, (L - 1) * 2)

                FirstOctet = SMSBase.GetByte(PDUCode)

                '[Chinese]取得特征码

                '[Chinese]取得基本码 最后两个bit + 是否有header作为标记

                'Get base code. Use last 2 bit and whether there's a header as remark

                Dim t1 As Integer = FirstOctet And 3 '00000011

                Dim t2 As Integer = FirstOctet And 64 '01000000

                '[Chinese]特别处理

                If t1 = 3 And t2 = 64 Then Return SMSBase.SMSType.EMS_SUBMIT

                Return t1 + t2

            End Function

            'Deoce a unicode string

            Shared Function DecodeUnicode()Function DecodeUnicode(ByVal strUnicode As String) As String

                Dim Code As String

                Dim i, j As Integer

                Dim c() As String       'temp

                ReDim c(strUnicode.Length / 4)     '2 Byte a Unicode char

                For j = 0 To strUnicode.Length \ 4 - 1

                    Dim d() As Char = strUnicode.ToCharArray(j * 4, 4)

                    c(j) = "&H" & CType(d, String)

                    c(j) = ChrW(Val(c(j)))

                    Code += c(j)

                Next

                Return Code

            End Function

'Deocde 7Bit to english#Region "'Deocde 7Bit to english"

            '2004-10-29:Region added

            'Fixed decode "@" charactor

            'I use a new method, it is easily to understand but look much longer than before.

            Shared Function InvertHexString()Function InvertHexString(ByVal HexString As String) As String

                'For example:

                '123456

                '===>

                '563412

                Dim Result As New StringBuilder

                Dim i As Integer

                For i = HexString.Length - 2 To 0 Step -2

                    Result.Append(HexString.Substring(i, 2))

                Next

                Return Result.ToString

            End Function

            Shared Function ByteToBinary()Function ByteToBinary(ByVal Dec As Byte) As String

                Dim Result As String

                Dim Temp As Byte = Dec

                Do

                    Result = (Temp Mod 2) & Result

                    If Temp = 1 Or Temp = 0 Then Exit Do

                    Temp = Temp \ 2

                Loop

                Result = Result.PadLeft(8, "0")

                Return Result

            End Function

            Shared Function BinaryToInt()Function BinaryToInt(ByVal Binary As String) As Integer

                Dim Result As Integer

                Dim i As Integer

                For i = 0 To Binary.Length - 1

                    Result = Result + Val(Binary.Substring(Binary.Length - i - 1, 1)) * 2 ^ i

                Next

                Return Result

            End Function

            Shared Function Decode7Bit()Function Decode7Bit(ByVal str7BitCode As String, ByVal charCount As Integer) As String

                Dim Inv7BitCode As String = InvertHexString(str7BitCode)

                Dim Binary As String

                Dim Result As String

                Dim i As Integer

                For i = 0 To Inv7BitCode.Length - 1 Step 2

                    Binary += ByteToBinary(Val("&H" & Inv7BitCode.Substring(i, 2)))

                Next

                Dim Temp As Integer

                For i = 1 To charCount

                    Temp = BinaryToInt(Binary.Substring(Binary.Length - i * 7, 7))

                    'There is a problem:

                    '"@" charactor is decoded to binary "0000000", but its Ascii Code is 64!!

                    'Don't know what to do with it,maybe it is a bug!

                    If Temp = 0 Then Temp = 64

                    Result = Result + ChrW(Temp)

                Next

                Return (Result)

            End Function

#End Region

        End Class

        Public Class SMS_RECEIVEDClass SMS_RECEIVED

            Inherits SMSBase

            Public SrcAddressLength As Byte

            Public SrcAddressType As Byte

            Public SrcAddressValue As String

            Public TP_SCTS As Date

            Sub New()Sub New(ByVal PDUCode As String)

                Type = SMSBase.SMSType.SMS_RECEIVED

                GetOrignalData(PDUCode)

            End Sub

            Public Overrides Sub GetOrignalData()Sub GetOrignalData(ByVal PDUCode As String)

                SCAddressLength = GetByte(PDUCode)

                SCAddressType = GetByte(PDUCode)

                SCAddressValue = GetAddress((GetString(PDUCode, (SCAddressLength - 1) * 2)))

                FirstOctet = GetByte(PDUCode)

                SrcAddressLength = GetByte(PDUCode)

                SrcAddressType = GetByte(PDUCode)

                SrcAddressLength += SrcAddressLength Mod 2

                SrcAddressValue = GetAddress((GetString(PDUCode, SrcAddressLength)))

                TP_PID = GetByte(PDUCode)

                TP_DCS = GetByte(PDUCode)

                TP_SCTS = GetDate(GetString(PDUCode, 14))

                TP_UDL = GetByte(PDUCode)

                TP_UD = GetString(PDUCode, TP_UDL * 2)

            End Sub

        End Class

        Public Class SMS_SUBMITClass SMS_SUBMIT

            Inherits SMSBase

            Public TP_MR As Byte

            Public DesAddressLength As Byte

            Public DesAddressType As Byte

            Public DesAddressValue As String

            Public TP_VP As Byte

            Sub New()Sub New(ByVal PDUCode As String)

                Type = SMSBase.SMSType.SMS_SUBMIT

                GetOrignalData(PDUCode)

            End Sub

            Public Overrides Sub GetOrignalData()Sub GetOrignalData(ByVal PDUCode As String)

                SCAddressLength = GetByte(PDUCode)

                SCAddressType = GetByte(PDUCode)

                SCAddressValue = GetAddress((GetString(PDUCode, (SCAddressLength - 1) * 2)))

                FirstOctet = GetByte(PDUCode)

                TP_MR = GetByte(PDUCode)

                DesAddressLength = GetByte(PDUCode)

                DesAddressType = GetByte(PDUCode)

                DesAddressLength += DesAddressLength Mod 2

                DesAddressValue = GetAddress((GetString(PDUCode, DesAddressLength)))

                TP_PID = GetByte(PDUCode)

                TP_DCS = GetByte(PDUCode)

                TP_VP = GetByte(PDUCode)

                TP_UDL = GetByte(PDUCode)

                TP_UD = GetString(PDUCode, TP_UDL * 2)

            End Sub

        End Class

        Public Class EMS_RECEIVEDClass EMS_RECEIVED

            Inherits SMS_RECEIVED

            Public Structure InfoElemStructure InfoElem       'See document "How to create EMS"

                Public Identifier As Byte

                Public Length As Byte

                Public Data As String

            End Structure

            Public TP_UDHL As Byte

            Public IE() As InfoElem

            Sub New()Sub New(ByVal PDUCode As String)

                MyBase.New(PDUCode)

            End Sub

            Public Overrides Sub GetOrignalData()Sub GetOrignalData(ByVal PDUCode As String)

                SCAddressLength = GetByte(PDUCode)

                SCAddressType = GetByte(PDUCode)

                SCAddressValue = GetAddress(GetString(PDUCode, (SCAddressLength - 1) * 2))

                FirstOctet = GetByte(PDUCode)

                SrcAddressLength = GetByte(PDUCode)

                SrcAddressType = GetByte(PDUCode)

                SrcAddressLength += SrcAddressLength Mod 2

                SrcAddressValue = GetAddress((GetString(PDUCode, SrcAddressLength)))

                TP_PID = GetByte(PDUCode)

                TP_DCS = GetByte(PDUCode)

                TP_SCTS = GetDate(GetString(PDUCode, 14))

                TP_UDL = GetByte(PDUCode)

                TP_UDHL = GetByte(PDUCode)

                IE = GetIE(GetString(PDUCode, TP_UDHL * 2))

                TP_UD = GetString(PDUCode, TP_UDL * 2)

            End Sub

            'Get Informat Elements 

            Shared Function GetIE()Function GetIE(ByVal IECode As String) As InfoElem()

                Dim tmp As String = IECode, t As Integer = 0

                Dim result() As InfoElem

                Do Until IECode = ""

                    ReDim Preserve result(t)

                    With result(t)

                        .Identifier = GetByte(IECode)

                        .Length = GetByte(IECode)

                        .Data = GetString(IECode, .Length * 2)

                    End With

                    t += 1

                Loop

                Return result

            End Function

        End Class

        Public Class EMS_SUBMITClass EMS_SUBMIT

            Inherits SMS_SUBMIT

            Sub New()Sub New(ByVal PDUCode As String)

                MyBase.New(PDUCode)

                Type = SMSBase.SMSType.EMS_SUBMIT

            End Sub

            Public TP_UDHL As Byte

            Public IE() As EMS_RECEIVED.InfoElem

            Public Overrides Sub GetOrignalData()Sub GetOrignalData(ByVal PDUCode As String)

                SCAddressLength = GetByte(PDUCode)

                SCAddressType = GetByte(PDUCode)

                SCAddressValue = GetAddress(GetString(PDUCode, (SCAddressLength - 1) * 2))

                FirstOctet = GetByte(PDUCode)

                TP_MR = GetByte(PDUCode)

                DesAddressLength = GetByte(PDUCode)

                DesAddressType = GetByte(PDUCode)

                DesAddressLength += DesAddressLength Mod 2

                DesAddressValue = GetAddress(GetString(PDUCode, DesAddressLength))

                TP_PID = GetByte(PDUCode)

                TP_DCS = GetByte(PDUCode)

                TP_VP = GetByte(PDUCode)

                TP_UDL = GetByte(PDUCode)

                TP_UDHL = GetByte(PDUCode)

                IE = EMS_RECEIVED.GetIE(GetString(PDUCode, TP_UDHL * 2))

                TP_UD = GetString(PDUCode, TP_UDL * 2)

            End Sub

        End Class

        Public Class SMS_STATUS_REPORTClass SMS_STATUS_REPORT

            Inherits SMS_RECEIVED

            Public TP_MR As Byte

            Public TP_DP As Date

            Public Status As EnumStatus

            Public Enum EnumStatusEnum EnumStatus

                Success = 0

                NotSend = 96

                NoResponseFromSME = 98

            End Enum

            Sub New()Sub New(ByVal PDUCode As String)

                MyBase.New(PDUCode)

                Type = SMSBase.SMSType.SMS_STATUS_REPORT

            End Sub

            Public Overrides Sub GetOrignalData()Sub GetOrignalData(ByVal PDUCode As String)

                SCAddressLength = GetByte(PDUCode)

                SCAddressType = GetByte(PDUCode)

                SCAddressValue = GetAddress(GetString(PDUCode, (SCAddressLength - 1) * 2))

                FirstOctet = GetByte(PDUCode)

                TP_MR = GetByte(PDUCode)

                SrcAddressLength = GetByte(PDUCode)

                SrcAddressType = GetByte(PDUCode)

                SrcAddressLength += SrcAddressLength Mod 2

                SrcAddressValue = GetAddress(GetString(PDUCode, SrcAddressLength))

                TP_SCTS = GetDate(GetString(PDUCode, 14))

                TP_DP = GetDate(GetString(PDUCode, 14))

                Status = GetByte(PDUCode)

                'Status report do not have content so I set it a zero length string

                TP_UD = ""

            End Sub

        End Class

        Public Class PDUDecoderClass PDUDecoder

            Public Structure BaseInfoStructure BaseInfo

                Public SourceNumber As String

                Public DestinationNumber As String

                Public ReceivedDate As Date

                Public Text As String

                Public Type As SMS.Decoder.SMSBase.SMSType

                Public EMSTotolPiece As Integer

                Public EMSCurrentPiece As Integer

                Public StatusFromReport As SMS_STATUS_REPORT.EnumStatus

                Public DestinationReceivedDate

            End Structure

            Sub New()Sub New(ByVal PDUCode As String)

                Decode(PDUCode)

            End Sub

            Public Shared Function Decode()Function Decode(ByVal PDUCode As String) As BaseInfo

                Dim Result As BaseInfo

                Try

                    Dim s As Object

                    Dim T As SMSBase.SMSType = SMSBase.GetSMSType(PDUCode)

                    Result.Type = T

                    Select Case T

                        Case SMSBase.SMSType.EMS_RECEIVED

                            s = New EMS_RECEIVED(PDUCode)

                            Result.SourceNumber = s.SrcAddressValue

                            If s.SrcAddressType = &H91 Then Result.SourceNumber = "+" + Result.SourceNumber

                            Result.ReceivedDate = s.TP_SCTS

                            If Not (s.IE Is Nothing) Then

                                Dim Data As String = s.IE(0).Data

                                Result.EMSTotolPiece = CInt(Mid(Data, 5, 2))

                                Result.EMSCurrentPiece = CInt(Mid(Data, 7, 2))

                            End If

                        Case SMSBase.SMSType.SMS_RECEIVED

                            s = New SMS_RECEIVED(PDUCode)

                            Result.SourceNumber = s.SrcAddressValue

                            If s.SrcAddressType = &H91 Then Result.SourceNumber = "+" + Result.SourceNumber

                            Result.ReceivedDate = s.TP_SCTS

                        Case SMSBase.SMSType.EMS_SUBMIT

                            s = New EMS_SUBMIT(PDUCode)

                            Result.DestinationNumber = s.DesAddressValue

                            If s.DesAddressType = &H91 Then Result.DestinationNumber = "+" + Result.DestinationNumber

                            If Not (s.IE Is Nothing) Then

                                Dim Data As String = s.IE(0).Data

                                Result.EMSTotolPiece = CInt(Mid(Data, 5, 2))

                                Result.EMSCurrentPiece = CInt(Mid(Data, 7, 2))

                            End If

                        Case SMSBase.SMSType.SMS_SUBMIT

                            s = New SMS_SUBMIT(PDUCode)

                            Result.DestinationNumber = s.DesAddressValue

                            If s.DesAddressType = &H91 Then Result.DestinationNumber = "+" + Result.DestinationNumber

                        Case SMSBase.SMSType.SMS_STATUS_REPORT

                            s = New SMS_STATUS_REPORT(PDUCode)

                            Result.SourceNumber = s.SrcAddressValue

                            If s.SrcAddressType = &H91 Then Result.SourceNumber = "+" + Result.SourceNumber

                            Result.ReceivedDate = s.TP_SCTS

                            Result.DestinationReceivedDate = s.TP_DP()

                            Result.StatusFromReport = s.status

                        Case Else

                            Stop

                    End Select

                    '###########################

                    'Correct when s is SMS type, no TP_UDL is found.

                    'Note:Only EMS has the TP_UDHL and TP_UDH see 3GPP TS 23.040 V6.5.0 (2004-09)

                    '###########################

                    If s.tp_DCS = 0 Then

                        If T = SMSBase.SMSType.SMS_RECEIVED Or T = SMSBase.SMSType.SMS_STATUS_REPORT Or T = SMSBase.SMSType.SMS_SUBMIT Then

                            '#############################

                            'add a parameter

                            '############################

                            Result.Text = s.decode7bit(s.tp_UD, s.TP_UDL)

                        End If

                        If T = SMSBase.SMSType.EMS_RECEIVED Or T = SMSBase.SMSType.EMS_SUBMIT Then

                            Result.Text = s.decode7bit(s.tp_ud, s.tp_udl - 8 * (1 + s.tp_udhl) / 7)

                        End If

                    Else

                        Result.Text = s.DecodeUnicode(s.TP_UD)

                    End If

                Catch err As Exception

                    Result.Text = "PDU解码错误:" & PDUCode

                End Try

                Return Result

            End Function

        End Class

    End Namespace

End Namespace