Related Work

MVP integrates two popular technologies in different domains to construct a whole new framework for building portals. In the following paragraphs, we will expound the related researches and development of these two domains: portals and mobile agents, and compare them with the design of MVP respectively.

5.1 Portal

Nowadays the number of Internet users is getting larger and larger, and each of them has his own desired services. For example, housewives might prefer shopping information while teenagers might prefer sports news and traveling information. As a result, some of the major portal vendors are gradually changing their authorizing strategies to satisfy the requirement of personalization of portals. The most well-known way to manage personalization issue is employing an idea of web components to make up a page. These kinds of web components are generally called Portlets.

In spite of the identical opinion and idea, portal vendors develop their respective Portlets. There is no open standard for these kinds of web components until Java Portlet Specification 1.0 was released from Java Community Process (JCP) on October 2003. But neither the standardized Java Portlet nor other kinds of vendor-specific Portlet design solves the problem thoroughly: they ignore the users of mobile devices.

Traditional portals always use various techniques which cannot be applied to mobile devices to fulfill many fancy styles and appearances. The users can only see the simplified versions or segmented pages of these portals on their mobile devices.

When it comes to the simplified versions, users often hang back for fear of the bad look-and-feel. In addition, they need to make themselves be accustomed to another user interface different from the original version. As for researches about segmenting web pages [10] [11] [12], the result is always poor because there is no common styles and strategies for page arrangement. On the other hand, though the portlet-based pages are suitable to rearranging for mobile devices, the portlet-based systems or frameworks other than MVP do not think over this issue (see Figure 1-2 in chapter 1).

MVP framework considers a page a set of Fragments, and it can rearrange the page according to the Fragment-based structure. Therefore the display for mobile devices is easy to be generated. Users will see that one Fragment is shown at a time, and they can choose whatever Fragment they want. Users can also configure that which Fragments are needed to be downloaded to mobile devices in advance.

Additionally, when using traditional portals, users will be bound to certain portals which offer certain services. They have to browse portal A for some services, and then get to portal B for others. MVP framework can aggregate all kinds of Fragments based on MVP from any portals throughout Internet by means of migrating the wanted Fragments to a single portal. In this way, users don’t have to be on the run browsing numbers of portals any longer.

Portlet-based portals also leave two problems:

1. Portlets that follows Java Portlet Specification may adopt Web Services for Remote Portlets (WSRP [13]) to communicate with remote portlets. But in this way, portals still cannot acquire remote portlets to execute them locally. Thus, if the remote portals or their network connections failed, the way WSRP provide to communicate with remote portlets will also fail.

2. Portlet-based portals generate pages consisting of several portlets. If one or several of the portlets fail to execute or consume too much time, the performance of generating a page will get worse because it has to wait for all portlets which forms the page.

Compared with traditional portlet-based portals, MVP framework can rearrange pages for mobile devices and gather fragments from all MVP-based portals. Moreover, all Fragments in a page can be designed as smart as possible, and then they can negotiate with each other automatically for performance issues.

5.2 Mobile Agent

MVP also proposes a good way to manage and use mobile agents. Other researches about user interfaces for managing mobile agents can be roughly divided into two parts:

1. Developing standalone and dedicated applications to manage agents [14].

However, such kind of applications need to be installed in some specific procedures, and are usually bound to certain platform. Thus, it is inflexible to use these dedicated applications.

2. Adopting web-based user interfaces to manage mobile agents for users’

conveniences [15]. For example, a fragment of HTML code or a Java Applet is mapped to a mobile agent to control it [16]. Users can use any kinds of client devices that have a browser to manage and control mobile agents. But it is still not flexible enough for users to access mobile agents when they want to control agents that are from other hosts. They cannot share their agents with others and make use of others’ agents.

Using MVP framework, users can easily employ others’ agents, as known as Fragments, and manage them in an efficient way. Mobile agents that travel around the network are seen as ships and then anchored to a portal based on MVP framework.

Agents will be automatically arranged to be displayed on the portal pages, and the users who use desktop computers or mobile devices can access the agents through the portal.

Chapter 6