Development of Wireless Network Scripting Language System

• Main Authors: WU, YU-CHIN, 巫有欽
• Other Authors: HSU, CHING-CHI
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/96328673989363887549

碩士 === 國立臺灣大學 === 資訊工程學研究所 === 89 === The ubiquity of mobile communication system integrated with rich contents of the Internet is an important trend in the recent years. However, limitations of the mobile communication devices obstruct the applicability of the HTML/HTTP architecture in the Internet. According to that, WAP Forum proposed the WAP architecture to meet the need of the mobile Internet. WML is the contents of network resources in WAP architecture whereas WMLScript is the client-side web scripting language in the WAP architecture for promoting the interactivity of WML documents. WMLScript is based on ECMAScript and is modified to agree with the characteristics of wireless network. The main modification is that a WMLScript file will be compiled down to bytecode by a WMLScript compiler in a WAP gateway before it is transmitted to wireless network such that the need of network bandwidth can be reduced. In the client side, a WMLScript interpreter plays the role of interpreting the bytecode and executing it. In this paper we discusses the designing issues of WMLScript interpreter and its solutions, involving how to design the data structure to save memory, how to design replacement strategy of the cache to reduce the need of requesting bytecode from the server and proposing a state diagram of WMLScript interpreter to demonstrate its execution process. Furthermore, we implement WMLScript interpreter on a mobile phone and Palm. Through the implementation we can figure out what problems will occur while porting WMLScript interpreter between different platforms and how to solve these problems. Besides, in this paper we propose a mechanism for WMLScript compiler about how to design the mapping table between the libraries and its binary codes such that we can dynamically add new function in WMLScript libraries and every device can possess some specific libraries. In this way WMLScript will become more flexible.