Pascal, Per our discussion on Friday, we need to do a slight rewording of WP 2&3 to take into account the new terminology introduced in https://tools.ietf.org/html/draft-wang-6tisch-6top-sublayer-02. For that, we need to agree on a new name for OF. I'll start a 24h polling period in a separate e-mail, then we'll have the final proposed rewording. Thomas
On Mon, Oct 12, 2015 at 1:35 PM, Pascal Thubert (pthubert) < [email protected]> wrote: > 6TiSCH: "IPv6 over the TSCH mode of IEEE 802.15.4e". > > Background/Introduction: > ------------------------ > > Low-power and Lossy Networks (LLNs) interconnect a possibly large number > of resource-constrained nodes to form a wireless mesh network. The > 6LoWPAN, ROLL and CoRE IETF Working Groups have defined protocols at > various layers of the protocol stack, including an IPv6 adaptation > layer, a routing protocol and a web transfer protocol. This protocol > stack has been used with IEEE802.15.4 low-power radios. > > The Timeslotted Channel Hopping (TSCH) mode was introduced in 2012 as an > amendment to the Medium Access Control (MAC) portion of the IEEE802.15.4 > standard. TSCH is the emerging standard for industrial automation and > process control LLNs, with a direct inheritance from WirelessHART and > ISA100.11a. Defining IPv6 over TSCH, 6TiSCH is a key to enable the > further adoption of IPv6 in industrial standards and the convergence of > Operational Technology (OT) with Information Technology (IT). > > The nodes in a IEEE802.15.4 TSCH network communicate by following a > Time Division Multiple Access (TDMA) schedule. A timeslot in this > schedule provides a unit of bandwidth that is allocated for > communication between neighbor nodes. The allocation can be programmed > such that the predictable transmission pattern matches the traffic. This > avoids idle listening, and extends battery lifetime for constrained > nodes. Channel-hopping improves reliability in the presence of narrow- > band interference and multi-path fading. > > These techniques enable a new range of use cases for LLNs, including: > - Control loops in a wireless process control network, in which high > reliability and a fully deterministic behavior are required. > - Service Provider networks transporting data from different independent > clients, and for which an operator needs flow isolation and traffic > shaping. > - Networks comprising energy harvesting nodes, which require an > extremely low and predictable average power consumption. > > IEEE802.15.4 only defines the link-layer mechanisms. It does not define > how the network communication schedule is built and matched to the > traffic requirements of the network. > > Description of Working Group: > ----------------------------- > > The Working Group will focus on enabling IPv6 over the TSCH mode of the > IEEE802.15.4 standard. The extent of the problem space for the WG is > one or more LLNs, possibly federated through a common backbone link > via one or more LLN Border Routers (LBRs). The WG will rely on, and if > necessary extend, existing mechanisms for authenticating LBRs. > > Initially, the WG has limited its scope to distributed routing over a > static schedule using the Routing Protocol for LLNs (RPL) on the resulting > network. This new charter allows for the dynamic allocation of cells and > their exchange between adjacent peers to accommodate the available > bandwidth > to the variations of throughput in IP traffic. > > The WG will continue working on securing the join process and making that > fit > within the constraints of high latency, low throughput and small frame > sizes > that characterize IEEE802.15.4 TSCH. > > Additionally, IEEE802.15.4 TSCH being a deterministic MAC, it is envisioned > that 6TiSCH will benefit from the work of detnet WG to establish the > so-called > deterministic tracks. The group will define the objects and methods that > needs > to be configured, and provide the associated requirements to detnet. > > The WG will interface with other appropriate groups in the IETF > Internet, Operations and Management, Routing and Security areas. > > Work Items: > ----------- > > The group will: > > 1. Produce "6TiSCH architecture" to describe the design of 6TiSCH > networks. This document will highlight the different architectural > blocks and signaling flows, including the operation of the network in > the presence of multiple LBRs. The existing document will be augmented > to cover dynamic scheduling and application of the DetNet work. > > 2. Produce an Information Model containing the management requirements > of a 6TiSCH node. This includes describing how an entity can manage the > TSCH schedule on a 6TiSCH node, and query timeslot information from that > node. MAC-layer interactions to negotiate Time Slots between peers will > be proposed, to be eventually continued at IEEE. > > 3. Produce an "On-the-fly" (OTF) specification to enable a distributed > dynamic > scheduling of time slots, negotiated between adjacent peers, with the > capability > for 6TiSCH routers to appropriate chunks of the Time/frequency matrix > without > starving, or interfering with, other 6TiSCH nodes. > This particular work will focus on IP traffic since the work on tracks is > not > yet advanced enough to specify their requirements for OTF operations. > > 4. Produce a specification for a secure 6TiSCH network bootstrap, adapted > to the constraints of 6TiSCH nodes and leveraging existing art when > possible. > > 5. Produce requirements to the detnet WG, detailing the 6TiSCH tracks and > the > data models to manipulate them from a central controller such as a PCE. > > > The work will include a best practice configuration for RPL and OF0 > operation over the static schedule. Based on that experience the group > may produce a requirements draft for OF0 extensions, to be studied in ROLL. > > Non-milestone work items: > ------------------------- > > The Working Group will develop 6TiSCH Test Description documents which > will be > updated as the technology evolves, and will be used for running > interoperability > events, under ETSI support (i.e., 6TiSCH ETSI Plugtests). > > Such documents will be helpful for implementers, providing details and > clarifications, needed for running code, and implementing the 6TiSCH > technology. > > Each document may address specific 6TiSCH features, in scope of the > specific > Plugtest's edition. > > _______________________________________________ > 6tisch mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/6tisch >
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