There are two basic categories: the IP-based and the non IPbased
objects. The IP based objects normally have high
capabilities and are able to connect to the Internet by running
operating systems and they only have energy and memory
constraints for supporting the TCP/IP protocol. Sensors have
natural limitations such as limited energy resources, low
memory and processing capability, which make them difficult
to provide full IP protocol stack support. For that reason,
suitable OSs have been developed for tiny embedded systems
and sensors with limited requirements such as Contiki,
TinyOS and FreeRTOS (Vasseur and Dunkels, 2010; TinyOS;
FreetOS; Contici-OS). For the connectivity and communication
of non-IP objects, protocols, such as ZigBee (ZigBee Alliance)
have been developed for short-range low-power and low bit-