1、附录 An Analysis and Comparison of Open and Closed Mobile Platforms Android vs. iPhone 1. Introduction In recent years, the popularity of smart phone kept going up. More and more smart phones are sold anda lot of people are embracing them. Smart phones brought great convenience to users, as well creat
2、ed opportunities for smart phone researchers. Thats to say, the wide spread of smart phones benefited both sides. At the same time, developing of smart phone OS becomes one of the smartest industry. To be a smart phone OS, the system should: 1. Provide services like a PC. 2. Work with a GPU for bett
3、er visual effects. 3. Allow the user to surf on Internet freely. And apparently, therere also some weaknesses:1.Limited battery. 2. Poor CPU performance against PC CPU. 3. Small storage. 4. The use of RAM may leads to loss of data when the phone runs out of battery Now the 2 giants of smart phone OS
4、 are Android and iPhone OS. On one side, Android is based on Linux kernel and Dalvik virtual machine, and it is open sourced. The upper layer of Android is Java based,allowing developers to develop Android applications with Google SDK and sell their software in Android Market. On the other side, iPh
5、one OS, which bases on Unix kernel and Darwin model but is closed sourced,evolves from Mac OS X and is the default OS of iPhone, iPod Touch and iPad. Objective C based software can run in iPhone OS, and just like Android, you can develop your own iPhone applications and upload them onto Apples App S
6、tore for sale . By comparing the latest Android and iPhone OS, Android 2.2 Froyo and iOS 4, we can take a glimpse at the main feature of open and closed smart phone OSs. While the 2 OSs are designed in rather different mentality and functionality, its a little early to tell which one is better. 2. S
7、mart Phone OS 2.1. Android The system architecture of Android consists of 5 layers, which are Linux Kernel, Android Runtime, Libraries, Application Framework and Applications, from bottom to top. Android provides core services like security, memory management, process management, network stack and d
8、rivers, basing on Linux 2.6. Being the abstract layer between software and hardware, the layer of Linux Kernel hides the implementing details of hardware and provides integrated services for upper layer. Dalvik virtual machine and Java core libraries are included in the layer of Android Runtime, pro
9、viding most functions in Java core libraries. The layer of Libraries contains a class of C/C+ libraries for Android components. Those libraries are integrated by the layer of Application Framework and then provided to developers. The layer of Application Framework provides all kinds of modules for p
10、rogram initialization to simplify the use of components, allowing developers do whatever they want and provide services for other softwares, under the limitation of security, of course. Mainstream applications are located in the layer of Application, including e-mail, SMS, calendar, Google map, Web
11、browser and contacts. Users interact directly with this layer12 . The latest version of Android, Android 2.2 Froyo, puts on some new features. They are: 1. Support Flash 10.1, enables user to watch flash on the phone. 2. V8 JavaScript engine in web browser leads to faster Internet data transportation. 3. Big advance in network sharing. You can use the phone as a 3G NIC,or convert 3G signal to Wi-Fi. 4. Automatically software update. 5. Softwares can be setup in SD card to extend file storages.
