The smart grid concept provides a solution to the growing recognition that current utility grids need an ICT deployment infrastructure based upgrade to allow millions of potential market players to operate and to cope with distributed generation, wide-area situational awareness, demand response, electric storage, and efficient electric transportation. Smart grid deployment is mainly about defining the necessary standards for ICT solutions. The design of the communication network associated with the smart grid involves detailed analysis of its communication requirements, a proposal of the appropriate protocol architecture, the choice of the most suitable technologies for each case study, and a scheme for the resultant heterogeneous network management system. Given the smart grid use cases, this article is focused on proposing a heterogeneous communication paradigm for smart grids based on power line communications and wireless networks. The proposal is related to the framework of the ITU ubiquitous sensor network architecture using the ITU next-generation network model. This architecture allows for better management of the QoS in the smart grid and should facilitate interoperability with other technologies.