Conventional power grid infrastructure is undergoing evolutionary changes with regard to the emerging smart grid concepts. Distribution Network Operators (DNOs) will experience considerable infrastructure changes in order to accomplish the massive task of developing novel, low-cost and scalable communication technologies required to exploit smart meters. Interoperable high speed communication solutions enable the control and observability of Medium Voltage and Low Voltage (MV/LV) network devices and hence improve overall network management and control at the distribution level. This paper presents the evaluation of throughput and latency performance for MV/LV communication links using the OPNET simulator. Various communication technologies, GPRS/UMTS and bus-link, have been tested. To validate the proposed simulation techniques, the results are compared against experimental tests performed by the IBM Haifa messaging group. The comparison of results proves that the simulation models match the practical experiments. Hence, the simulation techniques can be used to analyse the deployment of extensive communications infrastructure in advance of field trials. The simulation techniques can also be integrated within a novel Distribution Management System (DMS) test-bed to support the communication aspect of DMS functionalities before and during the field trial phase. A novel power line communications (PLC) model is proposed and implemented within the simulation tool OPNET, contributing towards further performance analysis of communication technologies for smart grids.