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Multiplexer User's Guide
Siemens Cellular Engines
Version: 06
DocID: Mux_guide_v06
Users Guide
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Multiplexer User's Guide s Confidential / Released mo b i l e Document Name: Multiplexer User's Guide Version: 06 Date: June 30, 2004 DocId: Mux_guide_v06 Status: Confidential / Released General notes Product is deemed accepted by Recipient and is provided without interface to Recipients products. The documentation and/or Product are provided for testing, evaluation, integration and information purposes. The documentation and/or Product are provided
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Multiplexer User's Guide s Confidential / Released mo b i l e Contents 0 Document history..........................................................................................................5 1 Introduction ...................................................................................................................6 1.1 Supported products and related documents..........................................................7 1.2 References ...........................................
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Multiplexer User's Guide s Confidential / Released mo b i l e 5 Multiplexer protocol version control.........................................................................33 5.1 Introduction..........................................................................................................33 5.2 Multiplexer protocol versions ...............................................................................34 5.3 Implementing version control...........................................
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Multiplexer User's Guide s Confidential / Released mo b i l e 0 Document history This chapter reports modifications and improvements over previous versions of this document. Preceding document: Multiplexer User's Guide Version 05 New document: Multiplexer User's Guide Version 06 Chapter What is new 1.1 Added further supported products. 3.1.1 Added note about closing Multiplexer. 3.1.2 Added note about maximum frame size N1. 4.2.4 Second byte for frame size greater than 127
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Multiplexer User's Guide s Confidential / Released mo b i l e 1 Introduction Siemens GSM engines support the basic option of the multiplexer according to the ETSI TS 101 369, GSM 07.10 Multiplexer Protocol. This allows a mobile to run a triple session over a serial link interface. Outside the GSM engine, on the application side of the serial interface, another multiplexer must be integrated in order to demultiplex the signal and distribute it on the three virtual channels. The external
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Multiplexer User's Guide s Confidential / Released mo b i l e 1.1 Supported products and related documents Supported products • AC43 • AC45 • MC35i • MC35i Terminal • MC39i • MC45 • MC46 • MC388 • MC5x • TC35i • TC35i Terminal • TC45 • XT55 Related documents [1] Hardware Interface Description supplied with your GSM engine [2] AT Command-Set supplied with your GSM engine [3] Release Notes supplied with your GSM engine [4] Remote-SAT User's Guide [5] Multiplexer Driver
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Multiplexer User's Guide s Confidential / Released mo b i l e 1.3 Term and abbreviations Abbreviation Description CSD Circuit Switched Data CTS Clear to Send DCD Data Carrier Detect DLCI Data Link Control Identifier DSB Developer Support Box DSR Data Set Ready DTR Data Terminal Ready FC Flow Control FFC Flat Flex Cable GPRS General Packet Radio Service GSM Global System of Mobile Communication IEI Information Element Identifier IP Internet Protocol MO Mobile originated MP
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Multiplexer User's Guide s Confidential / Released mo b i l e 2 Multiplexer protocol an overview 2.1 Product concept and architecture The multiplexer mode enables one serial interface to transmit data to three different custo- mer applications. This is achieved by providing three virtual channels using a multiplexer (Mux). This is especially advantageous when a fax/data/GPRS call is ongoing. Using the multiplexer features, e.g. controlling the module or using the SMS service can be
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Multiplexer User's Guide s Confidential / Released mo b i l e 2.2 Virtual channels and AT commands Please note that a cellular engine designed for multiplex operation does not include three different devices. Only one single air interface (RF part) is available. As mentioned before the multiplexer enables one serial interface to run three sessions simultaneously. All incoming or outgoing calls are connected to the device. Channel 1 supports the full range of functions, which is ava
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Multiplexer User's Guide s Confidential / Released mo b i l e 3 Integrating multiplexer into the customer application When designing a multiplexer application, you can create your own sources or take advantage of the sources delivered upon request by Siemens. The Siemens sources are packed in a *.zip file which includes a driver for Windows 2000 and Windows XP. See [5] for a detailed description. 3.1 Characteristics After establishing the multiplexer mode according to the multiplexer
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Multiplexer User's Guide s Confidential / Released mo b i l e 3.1.3 Dependencies between multiplexer channels and restrictions of use When using the following functions, be aware of possible dependencies between the different channels. One way of avoiding problems may be to dedicate certain commands/features to one of the channels or to assure that the application avoids conflicts. • Call control: A voice call can be initiated, answered or ended on each channel. See AT commands like AT
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Multiplexer User's Guide s Confidential / Released mo b i l e 3.1.5 Timing conditions Switching on the multiplexer with AT+CMUX=0 causes a 5s timer to start. If the multiplexer control channel is not established within this time, the module returns to normal AT command mode without multiplexer. This prevents the module from being blocked if, for example, AT+CMUX=0 is sent from an application that does not support the multiplexer protocol. Fax is based on a protocol, which needs t
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Multiplexer User's Guide s Confidential / Released mo b i l e 3.2 Multiplexer control and signaling lines The following chapter covers all information you need to develop and set up a virtual driver. Differences and restrictions in comparison to the unframed module are pointed out. 3.2.1 Flow control Logical flow control The internal logical flow control (FC-BIT in MSC message, see Chapter 4.3.9) represents the existing flow control to the module. For example, if a data call is i
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Multiplexer User's Guide s Confidential / Released mo b i l e RTS/CTS on the logical channels The customer application needs to regulate the data flow according to the logical flow control. The implementation of the WinMux2k is a good example. It maps the 3 decoded channels to 3 serial interfaces as well as the logical flow control information (FC-BIT in MSC message) directly on the RTS/CTS-control lines. In this case CTS superposes the STOP information (data sending disabled) sent b
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Multiplexer User's Guide s Confidential / Released mo b i l e 3.2.2 Escape sequence When the multiplexer protocol is active only coded data is transmitted over the UART. The coding includes a header and a checksum. Therefore, the direct parsing of this sequence is not possible. An escape might be undetected because the decoded time relations may be disturbed. The following transmission path for the ESC signal has been implemented: • DTR is transported within the logical channel. To
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Multiplexer User's Guide s Confidential / Released mo b i l e 4 Structure of the multiplexer protocol 4.1 Introduction of the multiplexer protocol The supported multiplexer protocol conforms to the GSM 07.10 Multiplexer Protocol. The non-error recovery mode was implemented with the basic option. The frames have a start and a stop byte. A checksum is calculated to protect the transferred data. Frame repetition is not enabled. Data and fax calls are transferred in the logical channel
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Multiplexer User's Guide s Confidential / Released mo b i l e 4.2.1 Flag sequence A flag sequence is a specific bit pattern (usually 11111001; hexadecimal: 0xF9) used to mark the beginning and the end of a frame of data. Each frame begins and ends with a flag sequence. Only one flag sequence occurs between any two frames. If two successive flag sequences do occur, the frame is regarded as being empty and is discarded. The flag sequence is used for the synchronization of frames. 4
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Multiplexer User's Guide s Confidential / Released mo b i l e 4.2.3 Control field The control field contains control information to define the frame. Table 5: Coding of the control field Frame Type 1 2 3 4 5 6 7 8 SABM 1 1 1 1 P/F 1 0 0 (set asynchronous balanced mode) UA 1 1 0 0 P/F 1 1 0 (unnumbered acknowledgement) DM 1 1 1 1 P/F 0 0 0 (disconnected mode) DISC 1 1 0 0 P/F 0 1 0 (disconnect) UIH 1 1 1 1 P/F 1 1 1 (unnumbered information with header check) P/F: Poll/F
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Multiplexer User's Guide s Confidential / Released mo b i l e 4.2.4 Length indicator The length indicator specifies the length of the following information field. As the maximum frame size N1 is 98 bytes and cannot be changed the E/A bit is always 1. The setting E/A = 0 defined in GSM 07.10 for a frame size greater than 127 bytes is not supported. See also Chapter 3.1.2 for details on the maximum frame size. st 1 octet: Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7 Bit 8 E/A L1 L2 L3 L
