  One of the main challenges of the Internet of Things is the interoperability
of highly heterogeneous devices, mainly in terms of the communication
capabilities and network protocols used. As consequence, the interconnection
model of the different devices involves an intermediary device, known as
gateway. This gateway is a centralized element for the management of the
devices that make up an IoT application. In addition, it is essential for the
transmission of information to the Internet, especially when many IoT devices
are not IP-based. This chapter describes a proposed model for an IoT gateway
that allows the exchange of data through different wireless technologies and
forwarding of such data to the Internet.
  The proposed gateway has important advantages such as: supporting for
multiprotocol interconnectivity, the remote configuration of wireless nodes for
sensor and actuators management; a flexible algorithm totranslate the data
obtained by sensors into a uniform format for transmission to a cloud server;
low energy consumption due to efficient data transfer over MQTT protocol.
  In order to demonstrate the usefulness of the developed gateway, a proof of
concept test was implemented. The implemented scenario consists of 2 wireless
nodes responsible for sensing environmental variables and transmitting data to
the gateway node through different communication protocols. The obtained
results show the feasibility for simultaneous data transmission from the remote
wireless nodes to the gateway. Metrics on energy consumption in the devices are
also presented.
