No abstract

iMobile is a proxy-based platform that addresses the research issues in building mobile services, iMobile acts as a message gateway that allows mobile devices using various protocols on different access networks to relay messages to each other. It also allows these clients to access intemet services, corporate databases, and to control various networked devices, iMobile implements three key abstractions: dev/et, infolet, and applet. A devlet is a driver attached to the proxy that receives and sends messages through a particular protocol for mobile devices. An infolet hosted on iMobile uses an access method to provide an abstract view of an information space. An applet implements service or application logic by processing information from various infolets. The core of iMobile, the let engine, implements the basic framework for maintaining applets, devlets and infolets, supports user and device profiles for personalization and transcoding, and invokes proper applets and infolets to answer requests from a devlet. The iMobile architecture allows new access devices and protocols to be added to its framework without changes in the service logic, iMobile effectively provides a personal agent on the network that enables a user to have mobile access to the vast information and services available on the various wireless and wirehne networks, without being limited by where the user is or what device or communication or protocol is available.

An experimental study on the radio characteristics of a 3G WCDMA system in a Taiwan suburban environment was conducted. This paper presents the results of handover behaviors. The examinations and performance evaluation are based on the measured E b /I 0 , mobile system transmitting power, bit-error-rate and frame-error-rate statistic distributions with respect to the time variations, which corresponds to different measurement locations, under individual and independent but appropriate design of experiment procedures. The corresponding radio characteristics are analyzed and evaluated according to the measured data.