High Performance Scheduling Mechanism for Mobile Computing Based on Self-Ranking Algorithm (SRA)

Introduction

Mobile computing and commerce are spreading rapidly, replacing or supplementing wired computing. Moreover, the wireless infrastructure upon which mobile computing is built may reshape the entire IT field. Therefore, it is fair to say that the mobile devices have a remarkable high profile in the most common communication devices nowadays. Individuals and organizations around the world are deeply interested in using wireless communication, because of its flexibility and its unexpected and fast development. The first solution to the need for mobile computing was to make computers small enough so that they could be easily carried. First, the laptop computer was invented; later, smaller and smaller computers, such as 3G, PDAs (personal digital assistants) and other handhelds, appeared. Portable computers, from laptops to PDAs and others are called mobile devices. In recent years a great development took place on the Internet and mobile technologies. Consequently, the next step will be merging these two technologies leading to the Wireless Internet. The Wireless Internet will be much more than just internet access from mobile devices; the Wireless Internet will be almost invisible, as people will use mobile services and applications directly. On the other hand these services and applications will be acting as our agents, conducting searches and communicating with other services and applications to satisfy our needs. Not only will the integration of mobile technology and the Internet paradigm reinforce the development of the new context-aware applications, but also it will sustain traditional features such as user preferences, device characteristics, properties of connectivity and the state of service and usage history. Furthermore, the context includes features strictly related to user mobility such as user’s current geospatial location (time and/or space). As direct use of existing Internet applications in a mobile environment is usually unsatisfactory; services and applications need to take into account the specific characteristics of mobile environments. The next section will introduce an overview of mobile devices as well as the present relation model between mobile devices and the grid.

Mobile Devices Development

The number of individuals and organizations relying on wireless devices is continually increasing. Figure 1 represents a statistical study of the current and the future increase in the sales of wireless equipments and the considerable growth in the sales of mobile phones.

Figure 1.

Worldwide wireless LAN equipment shipments (1000s of units) (Navrati Saxena 2005)

The mentioned table shows the rapid growth in the sales rates of wireless equipment, and they serve the purpose of being as a good metric of the flourishing future of the mobile computing. From 2001 to 2005, investments on mobile devices are expected to increase by 41% and reach $31 billion. In 2004, the laptops on the market reached 39.7 millions. On the other hand, not only did the number of mobile devices and wireless equipment increase, but also the computational power and the memory storage. As a result of such situation mobile computing and wireless Internet became a very important research area. This paper will approach it from the computational grid viewpoint.