Definition of Wireless Sensor Network
What are sensor networks? Why do you need to know about them in an enterprise wide area network (WAN) setting? This technology overview answers these questions and explains what network managers need to know about wireless sensor networks. What is a sensor network?
A sensor network comprises a group of tiny, typically battery-powered devices and wireless infrastructure that monitor and record conditions in any number of environments - from the factory floor to the data center to a hospital lab and even out in the wild. The sensor network connects to the Internet, an enterprise WAN or LAN, or a specialized industrial network so that collected data can be transmitted to back-end systems for analysis and used in applications.
Why do network managers need to know about sensor networks?
Once the purview of scientists and other specialists, wireless sensor networks have matured over the last 10-plus years to the point of being relatively easy to set up and use throughout the business world. Sensors can monitor temperatures, pressure, light and vibrations, for example, feeding companies a wealth of operational intelligence upon which they can take action. Use-case scenarios include such examples as these:
- Distribution supply chain and logistics
- Industrial tracking and visibility
- Location awareness and safety
- Data center resource management
What network managers need to know about sensor networks
Understanding of sensor networks begins with the devices themselves, often radio-frequency identification (RFID) tags and condition sensors. These small, low-powered devices can be deployed virtually anywhere, left to monitor and gather data on a particular space, object or interaction among objects or between an object and its environment. The devices are interconnected across an IEEE 802.15.4 wireless mesh network, with data transmitted either directly to a gateway server or from one node to another and then to an exit point.
Early sensor network schemes focused on ZigBee, a proprietary wireless mesh networking specification based on the 802.15.4 standard. In this scenario, the gateway device facilitates the handoff between the ZigBee-based network and an IP network. A vendor group called the ZigBee Alliance supports and develops the technology, with solutions for use in consumer electronics, energy management, healthcare, home automation and more.
Several years ago, the IETF stepped into the picture with the goal of making sensor networks part of the next-generation Internet and removing the learning curve for IT professionals by building off TCP/IP's pervasiveness within the enterprise. Via the IPv6 Low Power Wireless Personal Area Network (6LoWPAN) initiative, now RFC 4944, the IETF specifies how to carry IPv6 frames over the 802.15.4 wireless protocol.
With IP at the core, sensor nodes can communicate directly with other IP devices, be they on the wireless mesh network or another wireless or wired network, local or elsewhere across the Internet. Through a sensor network, IT professionals get direct, real-time access to sensor nodes and, presumably, the ability to manage and secure the nodes as they do other IP devices.