Future smart grids will require existing distribution networks to support novel distribution management system functionalities. Millions of smart meters will be deployed in the UK in near future. Vast amounts of data from such meters and other intelligent electronic devices (IEDs) in distribution network substations will require high speed communications. Such data will have to be concentrated at the local level before being transmitted to the control centre through different communication media. The performance of the underlying communication media should be evaluated to assure the required level of performance guarantees from the distribution network operators (DNOs) during the data transmission. Initially, an OPNET based Power Line Communication (PLC) simulation was verified using available experimental test results. Then a simulation study consisting of smart meters, concentrators and PLC links was used to evaluate the transmission time between local concentrators and smart meters for varying data sizes. Greater number of smart meters consumed higher bandwidth. This limitation was studied by varying the number of smart meters and concentrators connected to the PLC medium. The successful transmission rate for each configuration was also evaluated to confirm how many smart meters manage to send all the data to the concentrator within a specified time limit. Several other scenarios were used to evaluate the performance of the smart metering infrastructure.