Wireless Sensor Networks and mHealth basics 1.

Building a Wireless Sensor Network is fine, but what are the unique characteristics of such a network:

• Limited power they can harvest or store
• Ability to withstand harsh environmental conditions
• Ability to cope with node failures
• Mobility of nodes
• Dynamic network topology
• Communication failures
• Heterogeneity of nodes
• Large scale of deployment
• Unattended operation
• Node capacity is scalable,only limited by bandwidth of gateway node.

Sensor nodes can be imagined as small computers, extremely basic in terms of their interfaces and their components. They usually consist of a processing unit with limited computational power and limited memory, sensors (including specific conditioning circuitry), a communication device (usually radio transceivers or alternatively optical), and a power source usually in the form of a battery. Other possible inclusions are energy harvesting modules, secondary ASICs, and possibly secondary communication devices (e.g. RS-232 or USB).

The base stations are one or more distinguished components of the WSN with much more computational, energy and communication resources. They act as a gateway between sensor nodes and the end user.