Signals need to be separated in time, space, or frequency to prevent multiple transmissions from overlapping and interfering with one another. FDMA and TDMA techniques attempt to separate transmissions into different frequency bands and time slices, respectively. These systems allow multiple users in a single area to communicate without data collisions. However, networks can also be physically separated by space to prevent data collisions. In such cases, users can communicate at the same time on the same channel, so long as they are in different networks in different places. A cellular network or mobile network is a communication network where the last link is wireless. Wireless cellular networks are an integral part of modern telecommunication systems. Today it is hard to imagine our life without the use of such networks. Nevertheless, the development, implementation and operation of these networks require engineers and scientists to address a number of interrelated problems. The network is distributed over land areas called cells, each served by at least one fixed-location transceiver, known as a cell site or base station. This base station provides the cell with the network coverage which can be used for transmission of voice, data and others. Each cell has different frequency characteristics. This means that frequencies can be reused by non-adjacent cells without causing interference. User equipment (UE), such as mobile phones, is therefore able to communicate even if the equipment is moving through cells during transmission. Cellular networks give subscribers advanced features over alternative solutions, including increased capacity, small battery power usage, a larger geographical coverage area and reduced interference from other signals. Popular cellular technologies include the Global System for Mobile Communication, general packet radio service, 3GSM and code division multiple access. This book entitled Cellular Networks - Positioning, Performance Analysis, Reliability will be useful to researches in academic and industry and also to post-graduate students in telecommunication specialitiies.