Arch Rock Corporation submitted a draft specification to the IETF, describing an approach to implement “… a UDP/IP adaptation of the IEEE 802.15.4-based ZigBee Application Protocol that enables IP hosts to communicate using the application profiles and data models described by that protocol, over a wide range of links. This modified version of the ZigBee Application Protocol is named CAP (Compact Application Protocol), and it is intended to provide a complete stack of application profiles, data exchange, binding operations, security protocols, and discovery to IP-networked hosts and embedded devices. The protocol’s domain of applicability includes IEEE 802.15.4-based 6LoWPAN devices, but also those on conventional wired and wireless links and emerging powerline communication networks.”
CAP is intended to extend the scope of the ZigBee Application Profiles beyond IEEE 802.15.4 and ZigBee networks to encompass all IP based protocols. The CAP defines a methodology for devices to run CAP services on an UDP port, and exchange ZigBee application profile messages with any other IP device or server.
Why is it important to provide ZigBee application services on IP networks?
ZigBee Application Profiles are well designed for operation on devices with reduced or limited resources.
ZigBee Application Profiles assume the existence of an underlying ZigBee network only.
With the addition of real-world requirements, such as support for mobility, longer range, or integration into an existing IP-based network, a ZigBee-only network may not prove optimal.
Presently, this type of interoperability with other networks is accomplished by the use of gateway devices and application compatibility bridging (i.e. BacNet to ZigBee) which can be avoided with the CAP translation to an IP network.
What are the business implications?
By adopting IP as the common transport protocol, CAP simplifies the deployment of large-scale sensor networks and application by reducing or eliminating the number of protocol translation nodes. This, in turn enables a wider audience to take advantage of the accumulated knowledge used in the definition of the ZigBee Application Profiles. This approach also frees the ZigBee Alliance to focus on the high-value applications for wireless sensor networks such as Energy management and Industrial control.
While customers may not care how many layers you use, layers help you provide what the customer needs.
For more information about the draft specification, see http://www.ietf.org/internet-drafts/draft-tolle-cap-00.txt
