The diffusion of 3G communication networks and mobile computing
together with the massive use of computer-based systems and applications
represent a strong motivation for ubiquitous access to such applications. An
example of a widely diffused application is email. We want to be able to
access our email from everywhere and through a wide range of media.
The purpose of this case study is to develop the UbiMail application,
which provides ubiquitous access to email though several media and
devices: HTML browsers running on PCs and connecting to the wired inter-
net, WML browsers running on high-end mobile phones and connecting
through the wireless internet, and text messages on GSM mobile phones and
connecting through the GSM network.
Focus: this application exemplifies the use of Java to develop simple web
applications and the use of multiple user interfaces.
Java features: Java Server Pages and Java Mail classes.
Used knowledge: the reader should be familiar with the basics of web
standards such as HTML and HTTP.
The UbiMail system should provide access to email via the most diffuse
types of devices that can connect to the internet, i.e. personal computers
and cell phones. It must adapt the presentation of email to the device
capabilities; for instance controlling the number of characters shown on a
The user should be able to switch from one to the other medium of access
seamlessly. For instance, reading the mail from a PC in the office and con-
tinuing to look at the email on a WAP (Wireless Access Protocol) phone
while out of the office.
The system must be able to access different types of mail servers, using
several kinds of mail access protocol such as POP3 (Post Office Protocol 3)
and IMAP (Internet Mail Access Protocol).
When such flexible devices as PCs and WAP phones are not available a
limited service must be available. It must be able to notify new messages by
means of GSM (Global System for Mobile Communications) SMS (Short