> 1 | Introduction

> The multiplex mode according to the ETSI TS 101 369, GSM 07.10 Multiplexer Protocol enables one physical serial interface to be partitioned into three virtual channels. This allows you to take advantage of three simultaneous sessions running on one serial interface. For example, you can send or receive data on the first channel, while the other two channels are free to control the GSM/GPRS engine with AT commands.
> In order to properly communicate with the wireless modem, the application needs to support the Multiplexer Protocol and 3 virtual ports must be installed. For this purpose the ready-to-use multiplexer driver WinMux can be provided for Microsoft® Windows XP™ and Microsoft® Windows Vista™. The driver offers basic multiplexer functionality and serves as a reference implementation to aid developers and system integrators in designing, developing and testing customized multiplexer applications. As such, it has been tested by Siemens using a variety of applications and platforms, but naturally, even the most extensive test setup can never be adequate to cover all conceivable configurations.
> The Siemens AG does not guarantee any support regarding the integration of the driver into a customer’s application. However, the documentation as well as code binaries and source files can be provided and used for further development.
> This document1 describes how to integrate the WinMux driver into Windows XP and Windows Vista based GSM applications.

> 1
> The document is effective only if listed in the appropriate Release Notes as part of the technical documentation delivered with your Siemens wireless product.