RIL Design And Implementation Of Android Dual Sim Dual Standby Mobile Phone

With today's rapid development of information technology in the world, mobile communications technology has been integrated into people's lives. People demand more and more high standard mobile phone. Many users have multiple phones to replace the SIM card to meet their communications needs. Therefore, there is an urgent need for multi-mode mobile phone which can carry more than one SIM card.In August 2004, China Unicom and Qualcomm jointly launched the "World Wind" dual-mode handset, which makes China the first time to go in front of the world. But it is entirely built on the top of two chipsets simple sum, not a real sense of the dual-mode handsets. Through continuous development, there has been a kind of dual cards dual standby mobile phone that only running a system and use only one set of baseband. Google Android is an open source Linux-based mobile terminal platform which is released in 2007 by the Open Mobile Alliance. Since its inception, there have been a lot of operators, equipment manufacturers, developers join in the Android camp. Through the cooperation and constant innovation, there have been a large number of new products based on Android. Of course, this must include the Android-based dual card dual standby mobile phone.This paper's main task is based on the MSM7x27 Android Qualcomm dual card dual standby platform. MSM7x27 platform uses a common baseband and RF system to achieve the dual card dual standby. In this paper, to understand the premise of software and hardware of MSM7x27 platform, I studied the dual card dual standby RIL implementation and deeply studied the Android-based call control process. In order to facilitate the OEM extension functions of RIL, I added an OEMRILHook functional module in RIL. Finally, as the basis of independent functional module developed an upper layer application:dual-mode network automatic switching, and through this application on the phone validate the correctness and stability of RIL and OEMRILHook modules.Above all, Android Dual Sim Dual Standby mobile phone, not only meets the growing communication needs of people, but also meets people on the smart phone operating system. The OEMRILHook module shortens OEMs'development cycle of the RIL, and reduces the development effort; the development of OEMRILHook-based application:dual-mode network automatic switching, realizes GSM and CDMA network's automatic switching, and makes the dual-mode phone has a better user experience.