Raw Status PagesReliable and Available Wireless (Active WG)
Rtg Area: Alvaro Retana, Deborah Brungard, Martin Vigoureux | 2020-Feb-07 —Chairs:
IETF-107 raw minutes
Session 2020-03-24 2000-2200: Virtual Track 2 - raw chatroom
********************************************************************** Agenda & Minutes ********************************************************************** 20:00 Intro Chairs [10mn] 20:10 Use cases Carlos Bernardos [20mn] draft-bernardos-raw-use-cases-03 20:30 LDACS Nils Maeurer [20mn] draft-maeurer-raw-ldacs-01 20:50 5G Janos Farkas [20mn] draft-farkas-5g-raw-00 21:10 Georgios Papadopoulos Pareo draft-papadopoulos-raw-pareo-reqs-01 [15mn] OAM draft-theoleyre-raw-oam-support-01 [10mn] 21:35 Discussion Chairs [25mn] Additional RAW drafts: draft-pthubert-raw-problem-statement-04 draft-thubert-raw-technologies-04 * Introduction (Chairs) Eve introduces the first non F2F meeting with history of past meetings. Eve presents herself, was cochair of mmusic. Eve is also part of the IOT directorate, interested in QOS Motivation for RAW: companion WG to DetNet. Going from probabilistic to Deterministic DetNet was missing use cases related to wireless. Also gaps in MANET. Eve lists typical DetNet properties, including bounded latency; RAW examinizes wireless technologies that can be scheduled. Eve introduces the charter, going through it. Short term 12 to 18 months, informational RFCs for the first run Use cases articulated around wireless; by Year End have an evaluation of existing IETF technologies and a gap analysis Rick discusses the document workflow at the IETF. RAW is to be short lived, we need to make sure we get the docs finished off promptly. RAW use case ------------------- Carlos Bernardos presents v -03 The named evolved with the tentative WG name; documents 7 use cases. Presentation focusing on industrial application and gaming taken as example due to limited time. Identifying the distinguished properties for RAW. Carlos introduces the plant connectivity with sensors, actuators and PLCs. Specifics: * heterogeneous technologies * multiple simultaneous links for reliability * variable link conditions, not always due to mobility * different traffic types, e.g., control loops with reliability and latency constraints, co-existing with monitoring. Requirements: * coexistence * multiple access technologies simultaneously Carlos introduces wireless gaming Specifics * shared real time information between players for real time gaming * also console gaming, low latency and jitter => a focus for RAW * and cloud gaming Requirements * Carlos provides numbers * for RAW: time sensitive, priority, time-aware shaping, see slides Summary * input from multiple people * inviting others like smart grid Toerless: * slide 8 seems not requirements but technology list. Need analysing methods that can be used, should be more. * in multicast there's a document for multicast in wireless where solutions are compared Rick: * plerase find that doc for the WG Carsten: * There's req that this need to work over paths with multiple wireless links. Does that mean it works over links that thenconstitute paths or is it working across multiple links spanning. Carlos: * some use cases have multiple links of multiple technologies. Can be multihop networks, or single hop with multiple physical links. Carsten: * the latter is answering my question: Yes, work across multiple links Bob Hinden: * what's the need for gaming? Seems to be going on already. Carlos Bernardos: * I did not propose that use case, need exists, offline to ML Rick Taylor: * not just about wireless gaming. This is afrom left field use case, a lot of others exist too Eve Schooler: * multiple streams from multiple cameras, precision stitching and better visulalization Kuhnn: * muted Eve Schooler introduces LDCAS as the next presentation Rick Taylor: There will be no humming for adoption in this sessioN Nils Mäurer present LDACS * second version of the draft * comes from aeronautics communication, foreseen trabsition to IPv6 and several links, one of them LDACS (and AeroMACs for airports communication) * does not matter which link it takes, what's important is in-time delivery * draft 01 introduces the technology and IPv6 over it. Going through the TOC. * no standard at ICAO, opportunity to define the rules for an IPv6 link that covers multiple datalinks * details the protocol stack and services, see slide 7 * OFDMA hardened for aeronautical interference, FDD 2*500KHz, superframes * ground station GS controller handles 500 planes * How do we transport IPv6 safely to the plane? * < 2Mbps over <400Km in regulated 1GHz spectrum * RAW: multihop multi link system, LDACS is an open standard in development at ICAO Stuart Card: * how this related to ICAO trust framework (GRAIN), will post slide from X Da Silva on that Thomas Gräupl : * this is an FAA project not what we are doing at ICAO; GRAIN uses commercial off the shelf. The use of COTS for air traffic control is debated, no standard at ICAO can do that legally as of now. ICAO dedicates links. Rest is far in the future Janos Farkas on 5G: * provide some details on 5G, indicates it is a reliable and available tech, good match for RAW; Torsten Dudda: * outline, industrial use cases a focus * 5G include URLLC, all about providing bounded low latency, include time synchronization * 5G NR is scheduled by gNB, QoS framework, include packet error rate * low latency features, see slides Janos Farkas * 5G has options for multi connectivity. e.g; DUal UEs, see slides * TSN integration with 5G added in release 16 * virtual TSN bridges incorporate the ethernet PDU sessions, enables end-to-end deterministic ethernet * done to cover Carlos' requirements earlier * TSN translator the key component * DetNet had TSN in mind as subnet technology. Rechartering DetNet to enable others. * How do we combine 5G for DetNet. Various combonations possible, see slides * Summary, see slides Rick Taylor: * are the drafts presented in scope of the charter? I believe 5G is interesting, does it apply to RAW? RAW looks at heterogeneous. * Are the authors calling for WG adoption? Tom Kapela: How to avoid deadlocks? Solves similar problems push flow control to the edges, convergence at odds with congension mgmt activities. How does that apply here? Janos: PRE offers 1+1 protection with duplicate copies with seq nb on different path 802.1CB replication and elimination, disjoint paths, sequence numbers. No failover time. Job of central controller in SDN approach. Scheduling and the central controller avoids congestion loss Tom: What about single UE contacted by multiple incoming sources - how do we deal with that, potential deadlock. Janos: Agree, need to deal with that. Abdussalam Baryun: * I'm interested in use cases to know challenges, so what are the main challenges for this technology use case. Janos Farkas: * high availability and reliability critical for industrial. Downtime is expensive. * typical closed control loops with periodic CBR, time requirements must be met. Latency also a factor. Defering next questions in interest of time Georgios Papadopoulos presents PAREO requirements * slides 6-12 detail the PAREO operation over a scheduled multihop mesh * Alternative parent selection not written in the draft yet, to be discussed in ML whether we add it or not Lou Berger: * What about this is specific to wireless (vs. any DetNet). Georgios Papadopoulos: * Overhearing, constructive interference Lou Berger: * interaction between subnet and IP and how this is exposed * such as one subnet path taking away resources from another - how is this exposed to IP layer. Greg Mirsky: Where RAW reliability is built Georgios Papadopoulos: * can do tricks at MAC layer for single or multiple acks in case of overhearing. Need to avoid ack collision, to be discussed at layer 2 Rick Taylor: * Discussing different things: probability of delivery vs guarantee of delivery. * I think this is interesting work not in the immediate charter but could be adopted and worked on, whether it ends up here or not is secondary Georgios Papadopoulos presents OAM: Could be topic for RAW or DetNet, TBD. * specific challenges, how much resource to allocate, energy efficiency Rick Taylor: * Req for adoption - address on the ML * for Nils, unclear if you are requesting adoption, will send email Nils Mäurer * We are looking for reviews and are aiming for working group adoption at IETF 108 :) Toerless Eckert: * Interested in PREOF, most interesting part of DetNet. * scared if tried to limit to known building blocks for PREOF, there's a lot of research out there Florin Baboescu on 5G: Lou Berger: * Fundamental question for the group is what is the model of integration for the DetNet layer and wireless subnet layer? Is it integrated or layered? * WRTo Tom's question earlier re flow control - there are two control loops, a longer control loop that requires subnet information to be exposed to the control(ler) -- for it to pick the right (IP) paths and a shorter control loop that allows the IP sub-net entry point's queuing to adjust to congestion at the wireless sub-net level. While we're not at solutions yet DLEP from the MANET WG can be used to support both Stewart Bryant: Reconciling guaranteed delivery vs guaranteed latency - can't solve for both. Can just increase probabiity of losing a packet by some amount. Would have to wait an infinite amount of time for guarantee. Pascal Thubert: Yes this is correct, working for bounded latency, best delivery ration. Even wired has limited number of nines, wireless will have fewer. Looking at all the ways to increase the number of nines for wireless. Stewart: But then how do you set a number around that? Puzzled since worked on PREOF solution, still trying to define this e.g. for safety of life system. Toerless: In DetNet zero percent loss, or 100% bounded latency - depends on which use case for what the requirements are for this. Less strict requirements can be acceptable given the use case. So incremental improvement options would help even if not purely deterministic a la DetNet. Stewart: Benchmark is to just multiply the bandwidth and see if that is good enough. Janos: Are you considering this as an issue just with wireless or with wired also? Eric: Please take to the list. Eve: So there are good questions here about mission and gaps, specifying QoS, determinism or broader, reconciling competing requirements. Good for future discussions. Any comments from chat window - make sure they were captured in notes. Maybe there were 73 participants - not all in blue sheet? Will make request to ML to verify. Meeting adjourned.