The LTE is a powerful technology concept for high-capacity high-data rate cellular systems. It is an OFDM-based radio access architecture that will provide, among other services, voice connectivity. The realisation of this service on the complex radio access network of LTE requires specific radio configurations. In this contribution, we would like to study the voice service of LTE at the RRM, Radio Resource Management, level while taking into account the QoS, Quality of Service, requirements. The objectives of this presentation are to provide : - short and clear summary of the LTE radio access ; - LTE session establishment concepts and relation to the QoS management ; - simple capacity estimations for different environment configurations.