1.0 Introduction
The purpose of a computer communications network is to allow moving information from one point to another inside the network. The information could be stored on a device, such as a personal computer in the network, it could be generated live outside the network, such as speech, or could be generated by a process on another piece of information, such as automatic sales transactions at the end of a business day. The device does not necessarily have to be a computer; it could be a hard disk, a camera or even a printer on the network. Due to a large variety of information to be moved, and due to the fact that each type of information has its own conditions for intelligibility, the computer network has evolved into a highly complex system. Specialized knowledge from many areas of science and engineering goes into the design of networks. It is practically impossible for a single area of science or engineering to be entirely responsible for the design of all the components. Therefore, a study of computer networks branches into many areas as we go up from fundamentals to the advanced levels. http://wiki.answers.com/Q/Introduction_computer_networks_and_communications 2.0 Mobile Computing
2.1 Definition
Mobile computing is a form of human–computer interaction where a computer is expected to be transported during normal usage. Mobile computing has three aspects: mobile communication, mobile hardware and mobile software. The first aspect addresses communication issues in ad-hoc and infrastructure networks as well as communication properties, protocols, data formats and concrete technologies. The second aspect focuses on the hardware, i.e. mobile devices or device components. The third aspect deals with the characteristics and requirements of mobile applications. http://en.wikipedia.org/wiki/Mobile_computing 2.2 Specification, services, and frequencies of Mobile Computing