Smart cities initiatives have been subject of discussion in various forums throughout the world. This innovation in urban infrastructure of cities and the impacts of intensive application of technology are still being identified and mapped. A fundamental aspect under technological viewpoint to make this novelty a reality, and most comprehensive as possible is related to communication networks. Concept of Internet of Things (IoT) only materializes through a combination of technologies based on private and public networks and the Internet as the main platform. Utilities companies have already started their participation in this process in sense that they are deploying smart grids using technologies like RF Mesh and PLC, being RF Mesh the most widespread in world markets. But it is necessary to insert smart grid projects in the context of smart cities and in its converging alternatives of communications infrastructure. This work explores an emerging technology named as Long Range Wide Area Network (LoRaWAN) and proposes that this is the current alternative best suited to the big scenario of IoT, in which smart grids are included, and also compares with the RF Mesh technology widely adopted for this application.

A new simple formulation is presented to calculate the skin-effect resistance and internal inductance of a solid cylindrical conductor. The formulation is obtained from the exact solution of Maxwell's wave equation of an electrical field in the direction of propagation. The Fourier transform method is used to obtain the frequency-domain solution. Results are presented in graphical form showing the conductor resistance and internal inductance as a function of frequency.

This paper presents a hybrid way mixing time and frequency domain for transmission lines modelling. The proposed methodology handles steady fundamental signal mixed with fast and slow transients, including impulsive and oscillatory behaviour. A transmission line model is developed based on lumped elements representation and state-space techniques. The proposed methodology represents an easy and practical procedure to model a three-phase transmission line directly in time domain, without the explicit use of inverse transforms. The proposed methodology takes into account the frequency-dependent parameters of the line, considering the soil and skin effects. In order to include this effect in the state matrices, a fitting method is applied. Furthermore the accuracy of proposed the developed model is verified, in frequency domain, by a simple methodology based on line distributed parameters and transfer function related to the input/output signals of the lumped parameters representation. In addition, this article proposes the use of a fast and robust analytic integration procedure to solve the state equations, enabling transient and steady-state simulations. The results are compared with those obtained by the commercial software Microtran (EMTP), taking into account a three-phase transmission line, typical in the Brazilian transmission system.