s and utilise the existing 3G CN elements and functionality as much as possible. Also, the 4G RAN will experience major changes, in particular on a physical transmission layer. The network physical links configuration is one of the major problems of mobile communications network planning because it determines the long-term performance and service quality of networks. The solutions for the 3G/4G network planning problems are: a method for estimating the number of prospective 4G users; an estimation method for finding data traffic generated by 4G users. The following parameters of the data traffic are to be estimated: the specific (per user) rate of transactions in a busy hour; the average duration of 3G/4G calls; the specific (per user) traffic intensity created by 3G calls in a busy hour; the total traffic intensity on nodes of the IMS; the performance evaluation methods for the IMS nodes, taking into account the self-similar nature of the multiservice traffic. The following probabilistic and time characteristics of the nodes are determined: the upper bound and lower bound of the server service rates; the average queue length in the buffers; the average service time of information units; server utilisation. The solution methods for solving the 4G RAN problems can be supposed to be: The method for a quantitative estimation of reliability and cost parameters of different RAN topologies. The parameters of ring, multiring and radial topologies can be considered and compared with each other. The method of a physical links ring configuration between 4G RAN elements with a minimal deploy- ment cost. It is therefore observed that for network planning the following requirements are needed: the requirements to equipment internal IP networks, such as the throughput of channels and the per- formance of nodes and routers in the 3G/4G systems; the requirements to equipment gateways providing the interaction between 3G/4G systems and external networks. However, as mentioned below, when planning a complete 4G network, an underst