The Research And Realization Of Android Radio Subsystem

Android is a smart phone platform developed by Google, it supports multi-functions such communication, multimedia processing, GPS navigation, Wifi connection, sensor etc. With the development of mobile Internet, QQ, MSN, Twitter and other applications based on data connection has become one of the important communication means besides voice calls and SMS. A wide range of baseband modules are used at present and complete communication can not be easily carried out on all of them, that's the meaning this thesis research and implement the Android telephone subsystem.Based on the analysis of mobile phone communication and Android radio subsystem, this thesis brings out a solution which can implement the complete communication on baseband modules with a single physical interface, the solution has the following characteristics:1) By adding a GSM0710 multiplexing layer, voice calls, SMS and other services based on AT commands and GPRS/EDGE Internet access business can work in parallel without affecting the original structure of Android radio subsystem.2) By adding baseband module sleep wake-up control in the multiplexing layer, system power consumption is reduced.3) Has universal significance on baseband modules with a single physical interface which support GSM0710 protocol.In accordance with the transplant development model of Android smart phone, this thesis builds a development platform and implements Android radio subsystem on this development platform. The development platform building includes selection of IC chips, design of hardware, software migration of Blob boot code, Linux 2.6.29 kernel and Android 2.2 file system, driver development and Android hardware abstraction layer implementation for relevant hardware modules. The implementation of Android radio subsystem includes drivers development for baseband module, sleep wake-up mechanism for Android radio subsystem, design of GSM0710 multiplexing layer, development and analysis of Radio Interface Layer based on the GSM0710 multiplexing layer, implementation of calls, SMS, GPRS/EDGE Internet access and other major communication, software debugging and improvement of baseband module. This thesis tests the basic functions of Android radio subsystem, analyzes the baseband power consumption. It is proved that the solution for baseband with a single physical interface is feasible. At last summarizes the work done and to be done.