ABSTRACT
Global networking and mobile computing are two of the biggest trends in computing today. The popularity of the Internet is still growing, and Internet is now used for both private and commercial purposes. New networked applications are steadily emerging, and some of them put new demands on the underlying network. To meet such demands, the concept of tunable services has evolved. The basic idea with tunability is to provide mechanisms that can offer different service levels, which are expressed through welldefined parameters that are specified on the basis of need during operation. Bit rate, throughput, delay, and jitter are all examples of common performance parameters in packet networks. These performance parameters have been studied extensively and are all aimed to express (and guarantee) a certain service level with respect to reliability and performance. Another increasingly important issue in computer networks, and especially in wireless networks, is security.
