The IEEE802.15.4e standard was published in 2012 as an amendment to the Medium Access Control (MAC) protocol defined by the IEEE802.15.4-2011 standard. The Timeslotted Channel Hopping (TSCH) mode of IEEE802.15.4e is the object of this page.
TSCH was designed to “allow IEEE802.15.4 devices to support a wide range of industrial applications”. At its core is a medium access technique which uses time synchronization to achieve ultra low-power operation and channel hopping to enable high reliability. This is very different from the “legacy” IEEE802.15.4 MAC protocol, and is therefore better described as a “redesign”. TSCH does not amend the physical layer; i.e., it can operate on any IEEE802.15.4-compliant hardware.
IEEE802.15.4e can be seen as the latest generation of ultra-lower power and reliable networking solutions for LLNs. RFC5673 discusses industrial applications, and highlights the harsh operating conditions as well as the stringent reliability, availability, and security requirements for an LLN to operate in an industrial environment. Commercial networking solutions are available today in which motes consume 10′s of micro-amps on average with end-to-end packet delivery ratios over 99.999%.
IEEE802.15.4e TSCH focuses on the MAC layer only. This clean layering allows for TSCH to fit under an IPv6 enabled protocol stack for LLNs, running 6LoWPAN — RFC6282 –, RPL –RFC6550 — and CoAP — I-D.ietf-core-coap –.
Bringing industrial-like performance into the LLN stack developed by the 6LoWPAN, ROLL and CORE working groups opens up new application domains for these networks. Sensors deployed in smart cities (see RFC5548) will be able to be installed for years without needing battery replacement. “Umbrella” networks will interconnect smart elements from different entities in smart buildings (see RFC5867). Peel- and-stick switches will obsolete the need for costly conduits for lighting solutions in smart homes (see RFC5826).
While IEEE802154e defines the mechanisms for a TSCH mote to communicate, it does not define the policies to build and maintain the communication schedule, match that schedule to the multi-hop paths maintained by RPL, adapt the resources allocated between neighbor nodes to the data traffic flows, enforce a differentiated treatment for data generated at the application layer and signalling messages needed by 6LoWPAN and RPL to discover neighbors, react to topology changes, self-configure IP addresses, or manage keying material. In other words, IEEE802.15.4e TSCH is designed to allow optimizations and strong customizations, simplifying the merging of TSCH with a protocol stack based on IPv6, 6LoWPAN, and RPL.
Referenced by OpenMote