The latest advances in electronic and telecommunication have led to the introduction of intelligent and complex systems: the Wireless Sensor Networks. This technology has become even more important with the advent of the Internet of Things: each node acquires an IPv6 address and can be directly accessed from remote when the switch from IPv4 to IPv6 will take place. Such systems are actually applied in environment monitoring, home automation, industry, and lot of other fields. The Ambient Assisted Living scenery is a perfect field of application for sensor networks based on the IP protocol. The monitoring of elderly people, the automation of home appliances and the assistance to the person can be easily achieved through a network based on IPv6. Furthermore, such a system allows to obtain a maximum interoperability with existent networks, avoiding the need for inconvenient gateways to interface systems with different communication protocols. The presented work describes a complete hardware and software system able to solve the interoperability issue among Smart Home and Ambient Assisted Living. Sub GHz frequency, mesh topology and low power consumption give a competitive advantage to the system against Bluetooth Low Energy or ZigBee technology.