size, battery, cost, etc., and the mobile attributes include the dynamic attributes of both temporal and spatial features. The external diversity of networks can basically be defined just by assuming the large size of networks around the globe today, e.g. the Internet. Air interfaces can integrate all kinds of standards and work in different frequencies. Moreover, multiple operators deploy networks with multiple standards and protocols. Internal Diversity This gives the solution for adaptability. As it lies within the target it is therefore called internal diversity. Internal diversity of users are people with different interfaces, e.g. hearing, speech, etc., while internal diversity of terminals means that one terminal may integrate multiple functions, modes, interfaces, flexibilities, etc. The internal diversity of networks, on the other hand, refers to the interconnection between the various networks and the sharing of load between them. For applications, internal diversity means that one application can be tailored or drawn into multiple levels of quality, various styles, different kinds of release shape, etc. 5.4 Planning Overview for 4G Networks Planning 4G networks would not be as straightforward as seen in the previous chapters. Each of the individual networks GSM, EGPRS and UMTS have been planned in their respective domains, e.g. radio, transmission or core. Network planning in 4G networks will require an understanding of more technologies, of which a few are covered in this chapter, and their interworking with other technologies. As the 4G network will be an integrated wireless system that enables seamless roaming between technologies, a user can be operating in a cellular technology network and then be handed over to the satellite based network and back to a fixed wireless network, depending upon the network coverage and the user's preference of charging. Planning a network basically involves an initial layout of the system structure, which includes the spectrum, cell radius and hierarchical service ar