An Analysis and Comparison of Open and Closed Mobile Platforms

ESEP 2011:9-10 December 2011, Singapore

An Analysis and Comparison of Open and Closed Mobile

Platforms

Android vs. iPhone

Yinglu ZOUa,┤, Hao WU b, Jianxin HUANG a,b

a Information Engineering College, 7 JianXue Road, JinShui District, ZhengZhou,

450001, China

Abstract

With the release of Android 2.2 Froyo and iPhone 4, the war between open and closed mobile platforms tends to be fiercer. Being the representatives of the two parties, Froyo and iOS 4 are quite different at system framework, new feature, application market and integration model. According to the company spirits of Google and Apple, we do some analyses and comparisons of the above points, explain the differences of Android and iPhone from the shallower to the deeper, then conclude the characteristics of open and closed mobile platforms, aiming at providing an objective reference for researchers of mobile platforms, helping them see clearer into mobile industry. As a result, both Froyo and iOS 4 have their advantages and disadvantages, still they are far from being perfect, there's room for further improvement.

Keywords: Android; iPhone; Froyo; iOS 4; smart phone; mobile platform

1. Introduction

In recent years, the popularity of smart phone kept going up. More and more smart phones are sold and a lot of people are embracing them. Smart phones brought great convenience to users, as well created opportunities for smart phone researchers. That's 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 better visual effects. 3. Allow the user to surf on Internet freely. And apparently, there're 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 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, iPhone 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 Apple's 'App Store' for sale [1][2][3][4].

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, it's a little early to tell which one is better.

2. Smart 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 drives, 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, providing 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 program 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 browser and contacts. Users interact directly with this layer[1][2].

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 net work sharing. You can use the phone as a 3G NIC, or convent 3G signal to Wi-Fi. 4. Automatically software update. 5. Softwares can be setup in SD card to extend file storages.

2.2. iPhone

iPhone OS is consist of 4 abstract layers: Core OS, Core Service, Media and Cocoa Touch respectively.

Layers of Core OS and Core Service are designed in C language to handle core system services, enabling developers to perform file access, sockets calling and data handling. CFNetwork and SQLite are also parts of their 2 layers.

The layer of Media, according to its name, this layer is used to control video and audio, as well handle 2D and 3D images. The Open GL-ES Quratz part of the layer is coded with C language, while the part of Core-Audio and Core-Animation is Objective C based.

The layer of Cocoa Touch builds a basic framework for all kinds of programs in iPhone. Most programs run in Cocoa Touch layer, and it's surely Objective C based [3][4].

The latest iPhone OS is iOS 4. It includes the following new features: 1. Software classification. This feature enables user to place sorted softwares into different documents, making it clearer to manage. 2. Email integration. One account is for all e-mails from different providers. 3. iBook, originally from iPad, is built in iOS. 4. A brand new Apple Game Center makes iPhone a tremendous entertainment platform.

2.3. Android vs. iPhone

Being the top 2 smart phone OSs, we're sure that both Android and iPhone have their own advantages and disadvantages. Now let's take a look at each of them, and see what unique feature they have.

Android 2.2 Froyo fully support multitask, which means you can listen to music while writing blog. And iOS 4, officially announced to be 'multitasked', is in fact a play of concept. Only a few of softwares