The Screen Sharing System Based On The WIFI Heterogeneous Terminal

In recent years, with the rapid development of mobile Internet, with the maturity and popularity of smart mobile platform, smart phones have been one of the most important mobile terminals. Android operating system has absolutely dominated in mobile terminals, so more and more plentiful and personal applications are based on Android mobile phones.In an academic conference or a report, a speaker usually projects contents onto a large screen by his laptop, while attendees have to pay close attention to the screen in the whole time. If they are far away from the screen or in an inappropriate location, they probably can not see the contents. To ensure everyone would not miss any details because of locations, designing a system that could share PPT-screens between a laptop to laptops, a laptop to Android mobile phones has huge practical value.This paper designed a screen sharing system based on the WIFI heterogeneous terminal, it completed the single-to-multipoint transmission mode. The system was mainly divided into two parts of the sender and the receiver. The sender application ran on the Windows system laptop of a speaker, it mainly realized capturing, processing and sending of PPT images. While the receiver application ran on the Windows system laptop or the Android mobile phones of attendees, it mainly realized receiving, processing and showing of PPT images. The application running in Windows system was developed on VS2008 platform with C/C++language, while the application running in Android system was developed on Eclipse platform with Java language. In the meeting hall the sender and receiver were connected through WiFi network by switches and wireless routers, used UDP multicast protocol, and adopt the method of image packing as messages to solve the packets losing problem in LAN transmission.This paper mainly accomplished the following research:first it collected and organized the wireless transmission research based on Android from the market and universities, made clear the application scenarios of this system, sorted out the paper structure. Next this paper studied the related technology what the system needed, including TCP and UDP protocol, IP communication network, Winsock API, process and thread. Third it made a deep analysis in the Android system framework and application components, expounded Surface View and multi-touch technology. Fourth did demand analysis, designed general framework, refined technology module, completed the design of the sender and receiver. Finally chose the popular Windows laptops and Android mobile phones to test, including laptop’s brands like Lenovo, Toshiba, Samsung, Acer, Asus and phone’s brands such as MIUI, Lenovo, Huawei, Samsung, etc. By analyzing the test result, it verified the feasibility of the system. No matter between the laptops or from a laptop to Android mobile phones, system basically satisfied the real-time PPT images sharing by the single-to-multipoint module.