In a market characterized by great fragmentation, it is crucial that users carefully evaluate which wireless technology best suits their needs. Although Wireless Sensor Networks (WSNs) have collectively garnered much attention, differences in technologies and respective implementations from different vendors are quite significant. Many systems on the market today are silo solutions that, although compelling for specific applications, aren’t suited for all situations. E-Senza has recognized this shortcoming, and therefore architected a framework to provide broader applicability and to keep pace with technology evolution as the industry continues to grow. This framework is named SenzaNET.
Due to its ability to support not only sensing but also actuation, SenzaNET is best categorized as a Wireless Device Network (WDN). Strengths and competitive advantages of SenzaNET include the following:
SenzaNET relies on the proven IEEE 802.15.4 physical layer and MAC. IEEE 802.15.4 is uniquely designed for low-rate and low-cost wireless communications, and offers better power efficiency than WLAN or Bluetooth radios. Higher layer networking functions are defined by standards such as WirelessHART and 6LoWPAN, which are built on top of IEEE 802.15.4. SenzaNET is compatible with both, and our SenzaStack implementation is forward-compatible with WirelessHART.
Extended operation on battery power or the use of energy scavenging is a key requirement in the deployment of wireless device networks. SenzaNET utilizes a precise time synchronization algorithm, allowing all SenzaNET nodes to remain in standby mode when not required to perform a measurement or wireless transaction. In standby mode, nodes can operate on extremely low amounts of current since most hardware components are powered off. As a result, overall power consumption is dramatically reduced and largely correlated with the desired sample rate, rather than unnecessarily drained by idle states.
Bounded communication latency
A secondary benefit of the time synchronization approach is its ability to provide balanced medium access and predictable transmission slots. This keeps latency within tolerable limits, enabling real-time monitoring of assets and guaranteed delivery of time-critical information such as alarms and control commands.
True mesh networking
The self-organizing and self-healing properties of SenzaNET provide maximum fault tolerance and deployment flexibility. SenzaNET nodes establish connections and transmission paths by themselves, and are capable of multi-hop routing for formation of arbitrary topologies and bridging of extended distances. In contrast to ZigBee, SenzaNET routing nodes do not depend on mains power and can run on batteries. This makes SenzaNET particularly suitable for environments where hardwiring would be difficult or prohibitively expensive.
Robust and secure transmissions
For maximum reliability, SenzaNET employs automatic retries, acknowledgements, and a channel hopping scheme. Network security is provided through encryption of all data transmissions, and each individual data packet is integrity protected. In addition, join requests by new nodes can be authenticated via access control list so that only known and legitimate nodes are granted access, based on their unique MAC address.
Field device and fieldbus connectivity
SenzaNET adapters accept 0-20 mA, 4-20 mA, 0-2 V, 0-10 V analog, PT100, pulse, and digital inputs from field devices or meters. Seamless integration with fieldbus and management systems is provided through serial, Ethernet, Profibus, Modbus, CAN, and GPRS gateway interfaces.
|Last Updated on Tuesday, 18 September 2012 10:45|