Nowadays the number of users and services that must be guaranteed in cellular networks are growing, this up growth brings new challenges in terms of capacity, coverage and interference of the cells to this networks; for this reason it is necessary to search new alternatives that help us to meet all the requirements requested by both users and services provided. One alternative to solve the aforementioned problems, in the fourth generation networks, is the deployment of relay base stations; however, although the installation of these stations results in a clear improvement in terms of transmission capacity, quality of service (QoS), signal strength, increased transmission speed; brings a substantial increase in the costs of installation, and maintenance and operation. Therefore, it is necessary to develop an optimization model that allows the selection of the optimal location of these stations taking into account the network parameters and the user and service requirements. In this paper, we proposed a model for selecting the relay stations for a fourth generation cellular network in order to provide users a reliable communication, ensuring the required bandwidth in voice, data and video services. The proposed model was implemented in the GAMS mathematical software in order to validate its work, as a result the model produced interesting results, giving solution to the raised problem.