< draft-ietf-raw-technologies-03.txt   draft-ietf-raw-technologies-04.txt >
RAW P. Thubert, Ed. RAW P. Thubert, Ed.
Internet-Draft Cisco Systems Internet-Draft Cisco Systems
Intended status: Informational D. Cavalcanti Intended status: Informational D. Cavalcanti
Expires: 30 January 2022 Intel Expires: 4 February 2022 Intel
X. Vilajosana X. Vilajosana
Universitat Oberta de Catalunya Universitat Oberta de Catalunya
C. Schmitt C. Schmitt
Research Institute CODE, UniBwM Research Institute CODE, UniBwM
J. Farkas J. Farkas
Ericsson Ericsson
29 July 2021 3 August 2021
Reliable and Available Wireless Technologies Reliable and Available Wireless Technologies
draft-ietf-raw-technologies-03 draft-ietf-raw-technologies-04
Abstract Abstract
This document presents a series of recent technologies that are This document presents a series of recent technologies that are
capable of time synchronization and scheduling of transmission, capable of time synchronization and scheduling of transmission,
making them suitable to carry time-sensitive flows with high making them suitable to carry time-sensitive flows with high
reliability and availability. reliability and availability.
Status of This Memo Status of This Memo
skipping to change at page 1, line 40 skipping to change at page 1, line 40
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on 30 January 2022. This Internet-Draft will expire on 4 February 2022.
Copyright Notice Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/ Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document. license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components and restrictions with respect to this document. Code Components
extracted from this document must include Simplified BSD License text extracted from this document must include Simplified BSD License text
as described in Section 4.e of the Trust Legal Provisions and are as described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Simplified BSD License. provided without warranty as described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. On Scheduling . . . . . . . . . . . . . . . . . . . . . . . . 4 3. On Scheduling . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1. Benefits of Scheduling on Wires . . . . . . . . . . . . . 5 3.1. Benefits of Scheduling on Wires . . . . . . . . . . . . . 5
3.2. Benefits of Scheduling on Wireless . . . . . . . . . . . 5 3.2. Benefits of Scheduling on Wireless . . . . . . . . . . . 5
4. IEEE 802.11 . . . . . . . . . . . . . . . . . . . . . . . . . 6 4. IEEE 802.11 . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.1. Provenance and Documents . . . . . . . . . . . . . . . . 6 4.1. Provenance and Documents . . . . . . . . . . . . . . . . 6
4.2. 802.11ax High Efficiency (HE) . . . . . . . . . . . . . . 8 4.2. 802.11ax High Efficiency (HE) . . . . . . . . . . . . . . 8
4.2.1. General Characteristics . . . . . . . . . . . . . . . 8 4.2.1. General Characteristics . . . . . . . . . . . . . . . 8
4.2.2. Applicability to deterministic flows . . . . . . . . 9 4.2.2. Applicability to deterministic flows . . . . . . . . 10
4.3. 802.11be Extreme High Throughput (EHT) . . . . . . . . . 11 4.3. 802.11be Extreme High Throughput (EHT) . . . . . . . . . 11
4.3.1. General Characteristics . . . . . . . . . . . . . . . 11 4.3.1. General Characteristics . . . . . . . . . . . . . . . 12
4.3.2. Applicability to deterministic flows . . . . . . . . 12 4.3.2. Applicability to deterministic flows . . . . . . . . 12
4.4. 802.11ad and 802.11ay (mmWave operation) . . . . . . . . 13 4.4. 802.11ad and 802.11ay (mmWave operation) . . . . . . . . 13
4.4.1. General Characteristics . . . . . . . . . . . . . . . 13 4.4.1. General Characteristics . . . . . . . . . . . . . . . 14
4.4.2. Applicability to deterministic flows . . . . . . . . 13 4.4.2. Applicability to deterministic flows . . . . . . . . 14
5. IEEE 802.15.4 . . . . . . . . . . . . . . . . . . . . . . . . 14 5. IEEE 802.15.4 . . . . . . . . . . . . . . . . . . . . . . . . 14
5.1. Provenance and Documents . . . . . . . . . . . . . . . . 14 5.1. Provenance and Documents . . . . . . . . . . . . . . . . 14
5.2. TimeSlotted Channel Hopping . . . . . . . . . . . . . . . 15 5.2. TimeSlotted Channel Hopping . . . . . . . . . . . . . . . 16
5.2.1. General Characteristics . . . . . . . . . . . . . . . 16 5.2.1. General Characteristics . . . . . . . . . . . . . . . 16
5.2.2. Applicability to Deterministic Flows . . . . . . . . 18 5.2.2. Applicability to Deterministic Flows . . . . . . . . 18
6. 5G . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 6. 5G . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
6.1. Provenance and Documents . . . . . . . . . . . . . . . . 31 6.1. Provenance and Documents . . . . . . . . . . . . . . . . 32
6.2. General Characteristics . . . . . . . . . . . . . . . . . 33 6.2. General Characteristics . . . . . . . . . . . . . . . . . 34
6.3. Deployment and Spectrum . . . . . . . . . . . . . . . . . 34 6.3. Deployment and Spectrum . . . . . . . . . . . . . . . . . 35
6.4. Applicability to Deterministic Flows . . . . . . . . . . 35 6.4. Applicability to Deterministic Flows . . . . . . . . . . 36
6.4.1. System Architecture . . . . . . . . . . . . . . . . . 35 6.4.1. System Architecture . . . . . . . . . . . . . . . . . 36
6.4.2. Overview of The Radio Protocol Stack . . . . . . . . 37 6.4.2. Overview of The Radio Protocol Stack . . . . . . . . 38
6.4.3. Radio (PHY) . . . . . . . . . . . . . . . . . . . . . 38 6.4.3. Radio (PHY) . . . . . . . . . . . . . . . . . . . . . 39
6.4.4. Scheduling and QoS (MAC) . . . . . . . . . . . . . . 40 6.4.4. Scheduling and QoS (MAC) . . . . . . . . . . . . . . 41
6.4.5. Time-Sensitive Networking (TSN) Integration . . . . . 42 6.4.5. Time-Sensitive Networking (TSN) Integration . . . . . 43
6.5. Summary . . . . . . . . . . . . . . . . . . . . . . . . . 46 6.5. Summary . . . . . . . . . . . . . . . . . . . . . . . . . 46
7. L-band Digital Aeronautical Communications System . . . . . . 47 7. L-band Digital Aeronautical Communications System . . . . . . 47
7.1. Provenance and Documents . . . . . . . . . . . . . . . . 48 7.1. Provenance and Documents . . . . . . . . . . . . . . . . 48
7.2. General Characteristics . . . . . . . . . . . . . . . . . 49 7.2. General Characteristics . . . . . . . . . . . . . . . . . 49
7.3. Deployment and Spectrum . . . . . . . . . . . . . . . . . 50 7.3. Deployment and Spectrum . . . . . . . . . . . . . . . . . 50
7.4. Applicability to Deterministic Flows . . . . . . . . . . 50 7.4. Applicability to Deterministic Flows . . . . . . . . . . 50
7.4.1. System Architecture . . . . . . . . . . . . . . . . . 51 7.4.1. System Architecture . . . . . . . . . . . . . . . . . 51
7.4.2. Overview of The Radio Protocol Stack . . . . . . . . 51 7.4.2. Overview of The Radio Protocol Stack . . . . . . . . 51
7.4.3. Radio (PHY) . . . . . . . . . . . . . . . . . . . . . 52 7.4.3. Radio (PHY) . . . . . . . . . . . . . . . . . . . . . 52
7.4.4. Scheduling, Frame Structure and QoS (MAC) . . . . . . 53 7.4.4. Scheduling, Frame Structure and QoS (MAC) . . . . . . 53
skipping to change at page 3, line 45 skipping to change at page 3, line 45
caused by overbooked shared resources. In order to maintain a caused by overbooked shared resources. In order to maintain a
similar quality of service along a multihop path that is composed of similar quality of service along a multihop path that is composed of
wired and wireless hops, additional methods that are specific to wired and wireless hops, additional methods that are specific to
wireless must be leveraged to combat the sources of loss that are wireless must be leveraged to combat the sources of loss that are
also specific to wireless. also specific to wireless.
Such wireless-specific methods include per-hop retransmissions (HARQ) Such wireless-specific methods include per-hop retransmissions (HARQ)
and P2MP overhearing whereby multiple receivers are scheduled to and P2MP overhearing whereby multiple receivers are scheduled to
receive the same transmission, which balances the adverse effects of receive the same transmission, which balances the adverse effects of
the transmission losses that are experienced when a radio is used as the transmission losses that are experienced when a radio is used as
pure P2P. Those methods are collectively referred to as PAREO pure P2P. Those methods are collectively referred to as Packet
functions in the "Reliable and Available Wireless Architecture/ (hybrid) ARQ, Replication, Elimination and Ordering (PAREO) functions
Framework" [I-D.pthubert-raw-architecture]. in the "Reliable and Available Wireless Architecture/Framework"
[I-D.ietf-raw-architecture].
2. Terminology 2. Terminology
This specification uses several terms that are uncommon on protocols This specification uses several terms that are uncommon on protocols
that ensure bets effort transmissions for stochastics flows, such as that ensure bets effort transmissions for stochastics flows, such as
found in the traditional Internet and other statistically multiplexed found in the traditional Internet and other statistically multiplexed
packet networks. packet networks.
ARQ: Automatic Repeat Request, enabling an acknowledged transmission ARQ: Automatic Repeat Request, enabling an acknowledged transmission
and retries. ARQ is a typical model at Layer-2 on a wireless and retries. ARQ is a typical model at Layer-2 on a wireless
medium. It is typically avoided end-to-end on deterministic flows medium. It is typically avoided end-to-end on deterministic flows
because it introduces excessive indetermination in latency, but a because it introduces excessive indetermination in latency, but a
limited number of retries within a bounded time may be used over a limited number of retries within a bounded time may be used over a
wireless link and yet respect end-to-end constraints. wireless link and yet respect end-to-end constraints.
Availability: Availability is a measure of the relative amount of
time where a path operates in stated condition, in other words
(uptime)/(uptime+downtime).
Available: That is exempt of unscheduled outage, the expectation for Available: That is exempt of unscheduled outage, the expectation for
a network being that the flow is maintained in the face of any a network being that the flow is maintained in the face of any
single breakage. single breakage.
Deterministic Networking We refer to section 2 of [RFC8557] for this Deterministic Networking We refer to section 2 of [RFC8557] for this
term. term.
FEC: Forward error correction, sending redundant coded data to help FEC: Forward error correction, sending redundant coded data to help
the receiver recover transmission errors without the delays the receiver recover transmission errors without the delays
incurred with ARQ. incurred with ARQ.
HARQ: Hybrid ARQ, a combination of FEC and ARQ. HARQ: Hybrid ARQ, a combination of FEC and ARQ.
PCE: Path Computation Element. PCE: Path Computation Element.
PAREO (functions): the wireless extension of DetNet PREOF. PAREO PREOF : DetNet Packet Replication, Elimination and Ordering
functions include scheduled ARQ at selected hops, and expect the Functions.
use of new operations like overhearing where available.
Reliable: That consistently performs as expected, the expectation PAREO: Packet (hybrid) ARQ, Replication, Elimination and Ordering.
for a network being to always deliver a packet in due time. PAREO is a superset Of DetNet's PREOF that includes radio-specific
techniques such as short range broadcast, MUMIMO, constructive
interference and overhearing, which can be leveraged separately or
combined to increase the reliability.
Track: A DODAG oriented to a destination, and that enables Packet Reliability: Reliability is a measure of the probability that an
ARQ, Replication, Elimination, and Ordering Functions. item will perform its intended function for a specified interval
under stated conditions. For RAW, the service that is expected is
delivery within a bounded latency and a failure is when the packet
is either lost or delivered too late.
Track: A networking graph that can be used as a "path" to transport
RAW packets with equivalent treatment; a Track may fork and rejoin
to enable the PAREO operations.
3. On Scheduling 3. On Scheduling
The operations of a Deterministic Network often rely on precisely The operations of a Deterministic Network often rely on precisely
applying a tight schedule, in order to avoid collision loss and applying a tight schedule, in order to avoid collision loss and
guarantee the worst-case time of delivery. To achieve this, there guarantee the worst-case time of delivery. To achieve this, there
must be a shared sense of time throughout the network. The sense of must be a shared sense of time throughout the network. The sense of
time is usually provided by the lower layer and is not in scope for time is usually provided by the lower layer and is not in scope for
RAW. RAW.
skipping to change at page 6, line 46 skipping to change at page 7, line 13
after they have been published in PDF for six months. after they have been published in PDF for six months.
The IEEE 802.11 Wireless LAN (WLAN) standards define the underlying The IEEE 802.11 Wireless LAN (WLAN) standards define the underlying
MAC and PHY layers for the Wi-Fi technology. Wi-Fi/802.11 is one of MAC and PHY layers for the Wi-Fi technology. Wi-Fi/802.11 is one of
the most successful wireless technologies, supporting many the most successful wireless technologies, supporting many
application domains. While previous 802.11 generations, such as application domains. While previous 802.11 generations, such as
802.11n and 802.11ac, have focused mainly on improving peak 802.11n and 802.11ac, have focused mainly on improving peak
throughput, more recent generations are also considering other throughput, more recent generations are also considering other
performance vectors, such as efficiency enhancements for dense performance vectors, such as efficiency enhancements for dense
environments in 802.11ax, latency, reliability and enhancements environments in 802.11ax, latency, reliability and enhancements
supporting Time-Sensitive Networking (TSN) capabilities in P802.11be. supporting Time-Sensitive Networking (TSN) [IEEE802.1TSN]
capabilities in P802.11be.
IEEE std 802.11-2012 introduced support for TSN time synchronization IEEE Std 802.11-2012 introduced support for TSN time synchronization
based on IEEE 802.1AS over 802.11 Timing Measurement protocol. IEEE based on IEEE 802.1AS over 802.11 Timing Measurement protocol. IEEE
802.11-2016 extended the 802.1AS operation over 802.11 Fine Timing Std 802.11-2016 extended the 802.1AS operation over 802.11 Fine
Measurement (FTM), as well as the Stream Reservation Protocol (IEEE Timing Measurement (FTM), as well as the Stream Reservation Protocol
802.1Qat). 802.11 WLANs can also be part of a 802.1Q bridged networks (IEEE 802.1Qat). 802.11 WLANs can also be part of a 802.1Q bridged
with enhancements enabled by the 802.11ak amendment. Traffic networks with enhancements enabled by the 802.11ak amendment now
classification based on 802.1Q VLAN tags is also supported in 802.11. retroffitted in IEEE Std 802.11-2020. Traffic classification based
Other 802.1 TSN capabilities such as 802.1Qbv and 802.1CB, which are on 802.1Q VLAN tags is also supported in 802.11. Other 802.1 TSN
media agnostic, can already operate over 802.11. The IEEE Std. capabilities such as 802.1Qbv and 802.1CB, which are media agnostic,
802.11ax-2021 adds new scheduling capabilities that can enhance the can already operate over 802.11. The IEEE Std 802.11ax-2021 adds new
timeliness performance in the 802.11 MAC and achieve lower bounded scheduling capabilities that can enhance the timeliness performance
latency. The IEEE 802.11be is undergoing efforts to enhance the in the 802.11 MAC and achieve lower bounded latency. The IEEE
support for 802.1 TSN capabilities especially related to worst-case 802.11be is undergoing efforts to enhance the support for 802.1 TSN
latency, reliability and availability. The IEEE 802.11 working group capabilities especially related to worst-case latency, reliability
has been working in collaboration with the IEEE 802.1 working group and availability. The IEEE 802.11 working group has been working in
for several years extending some 802.1 features over 802.11. As with collaboration with the IEEE 802.1 working group for several years
any wireless media, 802.11 imposes new constraints and restrictions extending some 802.1 features over 802.11. As with any wireless
to TSN-grade QoS, and tradeoffs between latency and reliability media, 802.11 imposes new constraints and restrictions to TSN-grade
guarantees must be considered as well as managed deployment QoS, and tradeoffs between latency and reliability guarantees must be
requirements. An overview of 802.1 TSN capabilities and challenges considered as well as managed deployment requirements. An overview
for their extensions to 802.11 are discussed in [Cavalcanti_2019]. of 802.1 TSN capabilities and challenges for their extensions to
802.11 are discussed in [Cavalcanti_2019].
Wi-Fi Alliance (WFA) is the worldwide network of companies that Wi-Fi Alliance (WFA) is the worldwide network of companies that
drives global Wi-Fi adoption and evolution through thought drives global Wi-Fi adoption and evolution through thought
leadership, spectrum advocacy, and industry-wide collaboration. The leadership, spectrum advocacy, and industry-wide collaboration. The
WFA work helps ensure that Wi-Fi devices and networks provide users WFA work helps ensure that Wi-Fi devices and networks provide users
the interoperability, security, and reliability they have come to the interoperability, security, and reliability they have come to
expect. expect.
The following [IEEE Std. 802.11] specifications/certifications are The following [IEEE Std 802.11] specifications/certifications are
relevant in the context of reliable and available wireless services relevant in the context of reliable and available wireless services
and support for time-sensitive networking capabilities: and support for time-sensitive networking capabilities:
Time Synchronization: IEEE802.11-2016 with IEEE802.1AS; WFA TimeSync Time Synchronization: IEEE802.11-2016 with IEEE802.1AS; WFA TimeSync
Certification. Certification.
Congestion Control: IEEE802.11-2016 Admission Control; WFA Admission Congestion Control: IEEE Std 802.11-2016 Admission Control; WFA
Control. Admission Control.
Security: WFA Wi-Fi Protected Access, WPA2 and WPA3. Security: WFA Wi-Fi Protected Access, WPA2 and WPA3.
Interoperating with IEEE802.1Q bridges: [IEEE Std. 802.11ak]. Interoperating with IEEE802.1Q bridges: IEEE Std 802.11-2020
incorporating 802.11ak.
Stream Reservation Protocol (part of [IEEE Std. 802.1Qat]): AIEEE802 Stream Reservation Protocol (part of [IEEE Std 802.1Qat]): AIEEE802.
.11-2016 11-2016
Scheduled channel access: IEEE802.11ad Enhancements for very high Scheduled channel access: IEEE802.11ad Enhancements for very high
throughput in the 60 GHz band [IEEE Std. 802.11ad]. throughput in the 60 GHz band [IEEE Std 802.11ad].
802.11 Real-Time Applications: Topic Interest Group (TIG) ReportDoc 802.11 Real-Time Applications: Topic Interest Group (TIG) ReportDoc
[IEEE_doc_11-18-2009-06]. [IEEE_doc_11-18-2009-06].
In addition, major amendments being developed by the IEEE802.11 In addition, major amendments being developed by the IEEE802.11
Working Group include capabilities that can be used as the basis for Working Group include capabilities that can be used as the basis for
providing more reliable and predictable wireless connectivity and providing more reliable and predictable wireless connectivity and
support time-sensitive applications: support time-sensitive applications:
IEEE 802.11ax D4.0: Enhancements for High Efficiency (HE). [IEEE IEEE 802.11ax D4.0: Enhancements for High Efficiency (HE). [IEEE Std
Std. 802.11ax] 802.11ax]
IEEE 802.11be Extreme High Throughput (EHT). [IEEE 802.11be WIP] IEEE 802.11be Extreme High Throughput (EHT). [IEEE 802.11be WIP]
IEE 802.11ay Enhanced throughput for operation in license-exempt IEE 802.11ay Enhanced throughput for operation in license-exempt
bands above 45 GHz. [IEEE Std. 802.11ay] bands above 45 GHz. [IEEE Std 802.11ay]
The main 802.11ax and 802.11be capabilities and their relevance to The main 802.11ax and 802.11be capabilities and their relevance to
RAW are discussed in the remainder of this document. RAW are discussed in the remainder of this document.
4.2. 802.11ax High Efficiency (HE) 4.2. 802.11ax High Efficiency (HE)
4.2.1. General Characteristics 4.2.1. General Characteristics
The next generation Wi-Fi (Wi-Fi 6) is based on the IEEE802.11ax The next generation Wi-Fi (Wi-Fi 6) is based on the IEEE802.11ax
amendment [IEEE Std. 802.11ax], which includes new capabilities to amendment [IEEE Std 802.11ax], which includes new capabilities to
increase efficiency, control and reduce latency. Some of the new increase efficiency, control and reduce latency. Some of the new
features include higher order 1024-QAM modulation, support for uplink features include higher order 1024-QAM modulation, support for uplink
multi-user MIMO, OFDMA, trigger-based access and Target Wake time multi-user MIMO, OFDMA, trigger-based access and Target Wake time
(TWT) for enhanced power savings. The OFDMA mode and trigger-based (TWT) for enhanced power savings. The OFDMA mode and trigger-based
access enable the AP, after acquiring the channel for a given access enable the AP, after reserving the channel using the clear
duration, to schedule multi-user transmissions, which is a key channel assessment procedure for a given duration, to schedule multi-
capability required to increase latency predictability and and user transmissions, which is a key capability required to increase
reliability for time-sensitive flows. 802.11ax can operate in up to latency predictability and reliability for time-sensitive flows.
160 MHz channels and it includes support for operation in the new 6 802.11ax can operate in up to 160 MHz channels and it includes
GHz band, which is expected to be open to unlicensed use by the FCC support for operation in the new 6 GHz band, which is expected to be
and other regulatory agencies worldwide. open to unlicensed use by the FCC and other regulatory agencies
worldwide.
4.2.1.1. Multi-User OFDMA and Trigger-based Scheduled Access 4.2.1.1. Multi-User OFDMA and Trigger-based Scheduled Access
802.11ax introduced a new orthogonal frequency-division multiple 802.11ax introduced a new orthogonal frequency-division multiple
access (OFDMA) mode in which multiple users can be scheduled across access (OFDMA) mode in which multiple users can be scheduled across
the frequency domain. In this mode, the Access Point (AP) can the frequency domain. In this mode, the Access Point (AP) can
initiate multi-user (MU) Uplink (UL) transmissions in the same PHY initiate multi-user (MU) Uplink (UL) transmissions in the same PHY
Protocol Data Unit (PPDU) by sending a trigger frame. This Protocol Data Unit (PPDU) by sending a trigger frame. This
centralized scheduling capability gives the AP much more control of centralized scheduling capability gives the AP much more control of
the channel in its Basic Service Set (BSS) and it can remove the channel in its Basic Service Set (BSS) and it can remove
skipping to change at page 9, line 28 skipping to change at page 9, line 47
environments. The possibility to operate with smaller resource units environments. The possibility to operate with smaller resource units
(e.g. 2 MHz) enabled by OFDMA also helps reduce noise power and (e.g. 2 MHz) enabled by OFDMA also helps reduce noise power and
improve SNR, leading to better packet error rate (PER) performance. improve SNR, leading to better packet error rate (PER) performance.
802.11ax supports beamforming as in 802.11ac, but introduces UL MU 802.11ax supports beamforming as in 802.11ac, but introduces UL MU
MIMO, which helps improve reliability. The UL MU MIMO capability is MIMO, which helps improve reliability. The UL MU MIMO capability is
also enabled by the trigger based access operation in 802.11ax. also enabled by the trigger based access operation in 802.11ax.
4.2.1.3. Support for 6GHz band 4.2.1.3. Support for 6GHz band
The 802.11ax specification [IEEE Std. 802.11ax] includes support for The 802.11ax specification [IEEE Std 802.11ax] includes support for
operation in the new 6 GHz band. Given the amount of new spectrum operation in the new 6 GHz band. Given the amount of new spectrum
available as well as the fact that no legacy 802.11 device (prior available as well as the fact that no legacy 802.11 device (prior
802.11ax) will be able to operate in this new band, 802.11ax 802.11ax) will be able to operate in this new band, 802.11ax
operation in this new band can be even more efficient. operation in this new band can be even more efficient.
4.2.2. Applicability to deterministic flows 4.2.2. Applicability to deterministic flows
TSN capabilities, as defined by the IEEE 802.1 TSN standards, provide TSN capabilities, as defined by the IEEE 802.1 TSN standards, provide
the underlying mechanism for supporting deterministic flows in a the underlying mechanism for supporting deterministic flows in a
Local Area Network (LAN). The 802.11 working group has incorporated Local Area Network (LAN). The 802.11 working group has incorporated
support for absolute time synchronization to extend the TSN 802.1AS support for absolute time synchronization to extend the TSN 802.1AS
protocol so that time-sensitive flow can experience precise time protocol so that time-sensitive flow can experience precise time
synchronization when operating over 802.11 links. As IEEE 802.11 and synchronization when operating over 802.11 links. As IEEE 802.11 and
IEEE 802.1 TSN are both based on the IEEE 802 architecture, 802.11 IEEE 802.1 TSN are both based on the IEEE 802 architecture, 802.11
devices can directly implement TSN capabilities without the need for devices can directly implement TSN capabilities without the need for
a gateway/translation protocol. Basic features required for a gateway/translation protocol. Basic features required for
operation in a 802.1Q LAN are already enabled for 802.11. Some TSN operation in a 802.1Q LAN are already enabled for 802.11. Some TSN
capabilities, such as 802.1Qbv, can already operate over the existing capabilities, such as 802.1Qbv, can already operate over the existing
802.11 MAC SAP [SUR2021]. Nevertheless, the IEEE 802.11 MAC/PHY 802.11 MAC SAP [Sudhakaran2021]. Nevertheless, the IEEE 802.11 MAC/
requires further extensions to improve the operation of IEEE 802.1 PHY requires further extensions to improve the operation of IEEE
TSN features and achieve better performance metrics [CAL1287]. 802.1 TSN features and achieve better performance metrics
[Cavalcanti1287].
TSN capabilities supported over 802.11 (which also extends to TSN capabilities supported over 802.11 (which also extends to
802.11ax), include: 802.11ax), include:
1. 802.1AS based Time Synchronization (other time synchronization 1. 802.1AS based Time Synchronization (other time synchronization
techniques may also be used) techniques may also be used)
2. Interoperating with IEEE802.1Q bridges as per IEEE 802.11ak 2. Interoperating with IEEE802.1Q bridges
3. Time-sensitive Traffic Stream Identification and Classification 3. Time-sensitive Traffic Stream Classification
The exiting 802.11 TSN capabilities listed above, and the 802.11ax The existing 802.11 TSN capabilities listed above, and the 802.11ax
OFDMA and AP-controlled access within a BSS provide a new set of OFDMA and AP-controlled access within a BSS provide a new set of
tools to better serve time-sensitive flows. However, it is important tools to better serve time-sensitive flows. However, it is important
to understand the tradeoffs and constraints associated with such to understand the tradeoffs and constraints associated with such
capabilities, as well as redundancy and diversity mechanisms that can capabilities, as well as redundancy and diversity mechanisms that can
be used to provide more predictable and reliable performance. be used to provide more predictable and reliable performance.
4.2.2.1. 802.11 Managed network operation and admission control 4.2.2.1. 802.11 Managed network operation and admission control
Time-sensitive applications and TSN standards are expected to operate Time-sensitive applications and TSN standards are expected to operate
under a managed network (e.g. industrial/enterprise network). Thus, under a managed network (e.g. industrial/enterprise network). Thus,
the Wi-Fi operation must also be carefully managed and integrated the Wi-Fi operation must also be carefully managed and integrated
with the overall TSN management framework, as defined in the with the overall TSN management framework, as defined in the
[IEEE8021Qcc] specification. [IEEE8021Qcc] specification.
Some of the random-access latency and interference from legacy/ Some of the random-access latency and interference from legacy/
unmanaged devices can be minimized under a centralized management unmanaged devices can be reduced under a centralized management mode
mode as defined in [IEEE8021Qcc]. as defined in [IEEE8021Qcc].
Existing traffic stream identification, configuration and admission Existing traffic stream identification, configuration and admission
control procedures defined in [IEEE Std. 802.11] QoS mechanism can be control procedures defined in [IEEE Std 802.11] QoS mechanism can be
re-used. However, given the high degree of determinism required by re-used. However, given the high degree of determinism required by
many time-sensitive applications, additional capabilities to manage many time-sensitive applications, additional capabilities to manage
interference and legacy devices within tight time-constraints need to interference and legacy devices within tight time-constraints need to
be explored. be explored.
4.2.2.2. Scheduling for bounded latency and diversity 4.2.2.2. Scheduling for bounded latency and diversity
As discussed earlier, the [IEEE Std. 802.11ax] OFDMA mode introduces As discussed earlier, the [IEEE Std 802.11ax] OFDMA mode introduces
the possibility of assigning different RUs (frequency resources) to the possibility of assigning different RUs (frequency resources) to
users within a PPDU. Several RU sizes are defined in the users within a PPDU. Several Resource Unit (RU) sizes are defined in
specification (26, 52, 106, 242, 484, 996 subcarriers). In addition, the specification (26, 52, 106, 242, 484, 996 subcarriers). In
the AP can also decide on MCS and grouping of users within a given addition, the AP can also decide on MCS and grouping of users within
OFMDA PPDU. Such flexibility can be leveraged to support time- a given OFMDA PPDU. Such flexibility can be leveraged to support
sensitive applications with bounded latency, especially in a managed time-sensitive applications with bounded latency, especially in a
network where stations can be configured to operate under the control managed network where stations can be configured to operate under the
of the AP, in a controlled environment (which contains only devices control of the AP, in a controlled environment (which contains only
operating on the unlicensed band installed by the facility owner and devices operating on the unlicensed band installed by the facility
where unexpected interference from other systems and/or radio access owner and where unexpected interference from other systems and/or
technologies only sporadically happens), or in a deployment where radio access technologies only sporadically happens), or in a
channel/link redundancy is used to minimize the impact of unmanaged deployment where channel/link redundancy is used to reduce the impact
devices/interference. of unmanaged devices/interference.
When the network in lightly loaded, it is possible to achieve When the network in lightly loaded, it is possible to achieve
latencies under 1 msec when Wi-Fi is operated in contention-based latencies under 1 msec when Wi-Fi is operated in contention-based
(i.e., without OFDMA) mode. It is also has been shown that it is (i.e., without OFDMA) mode. It is also has been shown that it is
possible to achieve 1 msec latencies in controlled environment with possible to achieve 1 msec latencies in controlled environment with
higher efficiency when multi-user transmissions are used (enabled by higher efficiency when multi-user transmissions are used (enabled by
OFDMA operation) [Cavalcanti_2019]. Obviously, there are latency, OFDMA operation) [Cavalcanti_2019]. Obviously, there are latency,
reliability and capacity tradeoffs to be considered. For instance, reliability and capacity tradeoffs to be considered. For instance,
smaller Resource Units (RU)s result in longer transmission durations, smaller RUs result in longer transmission durations, which may impact
which may impact the minimal latency that can be achieved, but the the minimal latency that can be achieved, but the contention latency
contention latency and randomness elimination in an interference-free and randomness elimination in an interference-free environment due to
environment due to multi-user transmission is a major benefit of the multi-user transmission is a major benefit of the OFDMA mode.
OFDMA mode.
The flexibility to dynamically assign RUs to each transmission also The flexibility to dynamically assign RUs to each transmission also
enables the AP to provide frequency diversity, which can help enables the AP to provide frequency diversity, which can help
increase reliability. increase reliability.
4.3. 802.11be Extreme High Throughput (EHT) 4.3. 802.11be Extreme High Throughput (EHT)
4.3.1. General Characteristics 4.3.1. General Characteristics
The ongoing [IEEE 802.11be WIP] project is the next major 802.11 The ongoing [IEEE 802.11be WIP] project is the next major 802.11
amendment (after [IEEE Std. 802.11ax-2021]) for operation in the 2.4, amendment (after IEEE Std 802.11ax-2021) for operation in the 2.4, 5
5 and 6 GHz bands. 802.11be is expected to include new PHY and MAC and 6 GHz bands. 802.11be is expected to include new PHY and MAC
features and it is targeting extremely high throughput (at least 30 features and it is targeting extremely high throughput (at least 30
Gbps), as well as enhancements to worst case latency and jitter. It Gbps), as well as enhancements to worst case latency and jitter. It
is also expected to improve the integration with 802.1 TSN to support is also expected to improve the integration with 802.1 TSN to support
time-sensitive applications over Ethernet and Wireless LANs. time-sensitive applications over Ethernet and Wireless LANs.
The 802.11be Task Group started its operation in May 2019, therefore, The 802.11be Task Group started its operation in May 2019, therefore,
detailed information about specific features is not yet available. detailed information about specific features is not yet available.
Only high level candidate features have been discussed so far, Only high level candidate features have been discussed so far,
including: including:
skipping to change at page 14, line 28 skipping to change at page 15, line 12
Scientific and Medical (ISM) bands. This has imposed requirements in Scientific and Medical (ISM) bands. This has imposed requirements in
terms of frame size, data rate and bandwidth to achieve reduced terms of frame size, data rate and bandwidth to achieve reduced
collision probability, reduced packet error rate, and acceptable collision probability, reduced packet error rate, and acceptable
range with limited transmission power. The PHY layer supports frames range with limited transmission power. The PHY layer supports frames
of up to 127 bytes. The Medium Access Control (MAC) sublayer of up to 127 bytes. The Medium Access Control (MAC) sublayer
overhead is in the order of 10-20 bytes, leaving about 100 bytes to overhead is in the order of 10-20 bytes, leaving about 100 bytes to
the upper layers. IEEE802.15.4 uses spread spectrum modulation such the upper layers. IEEE802.15.4 uses spread spectrum modulation such
as the Direct Sequence Spread Spectrum (DSSS). as the Direct Sequence Spread Spectrum (DSSS).
The Timeslotted Channel Hopping (TSCH) mode was added to the 2015 The Timeslotted Channel Hopping (TSCH) mode was added to the 2015
revision of the IEEE802.15.4 standard [IEEE Std. 802.15.4]. TSCH is revision of the IEEE802.15.4 standard [IEEE Std 802.15.4]. TSCH is
targeted at the embedded and industrial world, where reliability, targeted at the embedded and industrial world, where reliability,
energy consumption and cost drive the application space. energy consumption and cost drive the application space.
At the IETF, the 6TiSCH Working Group (WG) [TiSCH] deals with best At the IETF, the 6TiSCH Working Group (WG) [TiSCH] deals with best
effort operation of IPv6 [RFC8200] over TSCH. 6TiSCH has enabled effort operation of IPv6 [RFC8200] over TSCH. 6TiSCH has enabled
distributed scheduling to exploit the deterministic access distributed scheduling to exploit the deterministic access
capabilities provided by TSCH. The group designed the essential capabilities provided by TSCH. The group designed the essential
mechanisms to enable the management plane operation while ensuring mechanisms to enable the management plane operation while ensuring
IPv6 is supported. Yet the charter did not focus to providing a IPv6 is supported. Yet the charter did not focus to providing a
solution to establish end to end Tracks while meeting quality of solution to establish end to end Tracks while meeting quality of
skipping to change at page 15, line 26 skipping to change at page 16, line 7
functions, and end-to-end secured IPv6/CoAP connectivity. functions, and end-to-end secured IPv6/CoAP connectivity.
The 6TiSCH architecture [RFC9030] identifies different models to The 6TiSCH architecture [RFC9030] identifies different models to
schedule resources along so-called Tracks (see Section 5.2.2.2) schedule resources along so-called Tracks (see Section 5.2.2.2)
exploiting the TSCH schedule structure however the focus at 6TiSCH is exploiting the TSCH schedule structure however the focus at 6TiSCH is
on best effort traffic and the group was never chartered to produce on best effort traffic and the group was never chartered to produce
standard work related to Tracks. standard work related to Tracks.
Useful References include: Useful References include:
1. IEEE Std 802.15.4: "IEEE Std. 802.15.4, Part. 15.4: Wireless 1. IEEE Std 802.15.4: "IEEE Std 802.15.4, Part. 15.4: Wireless
Medium Access Control (MAC) and Physical Layer (PHY) Medium Access Control (MAC) and Physical Layer (PHY)
Specifications for Low-Rate Wireless Personal Area Networks" Specifications for Low-Rate Wireless Personal Area Networks"
[IEEE Std. 802.15.4]. The latest version at the time of this [IEEE Std 802.15.4]. The latest version at the time of this
writing is dated year 2015. writing is dated year 2015.
2. Morell, A. , Vilajosana, X. , Vicario, J. L. and Watteyne, T. 2. Morell, A. , Vilajosana, X. , Vicario, J. L. and Watteyne, T.
(2013), Label switching over IEEE802.15.4e networks. Trans. (2013), Label switching over IEEE802.15.4e networks. Trans.
Emerging Tel. Tech., 24: 458-475. doi:10.1002/ett.2650" Emerging Tel. Tech., 24: 458-475. doi:10.1002/ett.2650"
[morell13]. [morell13].
3. De Armas, J., Tuset, P., Chang, T., Adelantado, F., Watteyne, T., 3. De Armas, J., Tuset, P., Chang, T., Adelantado, F., Watteyne, T.,
Vilajosana, X. (2016, September). Determinism through path Vilajosana, X. (2016, September). Determinism through path
diversity: Why packet replication makes sense. In 2016 diversity: Why packet replication makes sense. In 2016
skipping to change at page 17, line 28 skipping to change at page 17, line 52
Channel hopping provides increased reliability to multi-path fading Channel hopping provides increased reliability to multi-path fading
and external interference. It is handled by TSCH through a channel and external interference. It is handled by TSCH through a channel
hopping sequence referred as macHopSeq in the IEEE802.15.4 hopping sequence referred as macHopSeq in the IEEE802.15.4
specification. specification.
The Time-Frequency Division Multiple Access provided by TSCH enables The Time-Frequency Division Multiple Access provided by TSCH enables
the orchestration of traffic flows, spreading them in time and the orchestration of traffic flows, spreading them in time and
frequency, and hence enabling an efficient management of the frequency, and hence enabling an efficient management of the
bandwidth utilization. Such efficient bandwidth utilization can be bandwidth utilization. Such efficient bandwidth utilization can be
combined to OFDM modulations also supported by the IEEE802.15.4 combined to OFDM modulations also supported by the IEEE802.15.4
standard [IEEE Std. 802.15.4] since the 2015 version. standard [IEEE Std 802.15.4] since the 2015 version.
TSCH networks operate in ISM bands in which the spectrum is shared by TSCH networks operate in ISM bands in which the spectrum is shared by
different coexisting technologies. Regulations such as FCC, ETSI and different coexisting technologies. Regulations such as FCC, ETSI and
ARIB impose duty cycle regulations to limit the use of the bands but ARIB impose duty cycle regulations to limit the use of the bands but
yet interference may constraint the probability to deliver a packet. yet interference may constraint the probability to deliver a packet.
Part of these reliability challenges are addressed at the MAC Part of these reliability challenges are addressed at the MAC
introducing redundancy and diversity, thanks to channel hopping, introducing redundancy and diversity, thanks to channel hopping,
scheduling and ARQ policies. Yet, the MAC layer operates with a scheduling and ARQ policies. Yet, the MAC layer operates with a
1-hop vision, being limited to local actions to mitigate 1-hop vision, being limited to local actions to mitigate
underperforming links. underperforming links.
skipping to change at page 20, line 11 skipping to change at page 20, line 22
It results that the tagging that is used for a DetNet flow outside It results that the tagging that is used for a DetNet flow outside
the 6TiSCH LLN MUST be swapped into 6TiSCH formats and back as the the 6TiSCH LLN MUST be swapped into 6TiSCH formats and back as the
packet enters and then leaves the 6TiSCH network. packet enters and then leaves the 6TiSCH network.
Note: The method and format used for encoding the RPLInstanceID at Note: The method and format used for encoding the RPLInstanceID at
6lo is generalized to all 6TiSCH topological Instances, which 6lo is generalized to all 6TiSCH topological Instances, which
includes Tracks. includes Tracks.
5.2.2.1.1.2. Replication, Retries and Elimination 5.2.2.1.1.2. Replication, Retries and Elimination
PRE establishes several paths in a network to provide redundancy and The 6TiSCH Architecture [RFC9030] leverages the Packet Replication,
parallel transmissions to bound the end-to-end delay. Considering Retries and Elimination (PRE) functions (PREF), the precursor to what
the scenario shown in Figure 3, many different paths are possible for the RAW Architecture [I-D.ietf-raw-architecture] calls PAREO
S to reach R. A simple way to benefit from this topology could be to functions. PREF establishes several paths in a network to provide
use the two independent paths via nodes A, C, E and via B, D, F. But redundancy and parallel transmissions to bound the end-to-end delay.
more complex paths are possible as well. Considering the scenario shown in Figure 3, many different paths are
possible for S to reach R. A simple way to benefit from this
topology could be to use the two independent paths via nodes A, C, E
and via B, D, F. But more complex paths are possible as well.
(A) (C) (E) (A) (C) (E)
source (S) (R) (destination) source (S) (R) (destination)
(B) (D) (F) (B) (D) (F)
Figure 3: A Typical Ladder Shape with Two Parallel Paths Toward Figure 3: A Typical Ladder Shape with Two Parallel Paths Toward
the Destination the Destination
skipping to change at page 22, line 5 skipping to change at page 22, line 10
whether a transmission succeeded in another branch. It is also whether a transmission succeeded in another branch. It is also
possible to place cells to different next-hop routers in a possible to place cells to different next-hop routers in a
same'OR'group. This allows to route along multi-path Tracks, trying same'OR'group. This allows to route along multi-path Tracks, trying
one next-hop and then another only if sending to the first fails. one next-hop and then another only if sending to the first fails.
On the receive side, all timeSlots are programmed in a same'OR'group. On the receive side, all timeSlots are programmed in a same'OR'group.
Retries of a same copy as well as converging branches for elimination Retries of a same copy as well as converging branches for elimination
are converged, meaning that the first successful reception is enough are converged, meaning that the first successful reception is enough
and that all the other timeSlots can be ignored. and that all the other timeSlots can be ignored.
5.2.2.1.1.3. Differentiated Services Per-Hop-Behavior
Additionally, an IP packet that is sent along a Track uses the
Differentiated Services Per-Hop-Behavior Group called Deterministic
Forwarding, as described in
[I-D.svshah-tsvwg-deterministic-forwarding].
5.2.2.1.2. Topology and capabilities 5.2.2.1.2. Topology and capabilities
6TiSCH nodes are usually IoT devices, characterized by very limited 6TiSCH nodes are usually IoT devices, characterized by very limited
amount of memory, just enough buffers to store one or a few IPv6 amount of memory, just enough buffers to store one or a few IPv6
packets, and limited bandwidth between peers. It results that a node packets, and limited bandwidth between peers. It results that a node
will maintain only a small number of peering information, and will will maintain only a small number of peering information, and will
not be able to store many packets waiting to be forwarded. Peers can not be able to store many packets waiting to be forwarded. Peers can
be identified through MAC or IPv6 addresses. be identified through MAC or IPv6 addresses.
Neighbors can be discovered over the radio using mechanism such as Neighbors can be discovered over the radio using mechanism such as
skipping to change at page 25, line 27 skipping to change at page 25, line 40
oveall energy consumption in the network but improves significantly oveall energy consumption in the network but improves significantly
the availability of the network as well as the packet delivery ratio. the availability of the network as well as the packet delivery ratio.
A Track may also branch off and rejoin, for the purpose of the so- A Track may also branch off and rejoin, for the purpose of the so-
called Packet Replication and Elimination (PRE), over non congruent called Packet Replication and Elimination (PRE), over non congruent
branches. PRE may be used to complement layer-2 Automatic Repeat branches. PRE may be used to complement layer-2 Automatic Repeat
reQuest (ARQ) and receiver-end Ordering to form the PAREO functions. reQuest (ARQ) and receiver-end Ordering to form the PAREO functions.
PAREO functions enable to meet industrial expectations in PDR within PAREO functions enable to meet industrial expectations in PDR within
bounded delivery time over a Track that includes wireless links, even bounded delivery time over a Track that includes wireless links, even
when the Track extends beyond the 6TiSCH network. when the Track extends beyond the 6TiSCH network.
The RAW Track described in the RAW Architecture
[I-D.ietf-raw-architecture] inherits directly from that model. RAW
extends the graph beyond a DODAG as long as a given packet cannot
loop within the Track.
+-----+ +-----+
| IoT | | IoT |
| G/W | | G/W |
+-----+ +-----+
^ <---- Elimination ^ <---- Elimination
| | | |
Track branch | | Track branch | |
+-------+ +--------+ Subnet Backbone +-------+ +--------+ Subnet Backbone
| | | |
+--|--+ +--|--+ +--|--+ +--|--+
skipping to change at page 58, line 23 skipping to change at page 58, line 23
and Maintenance (OAM) Tools", RFC 7276, and Maintenance (OAM) Tools", RFC 7276,
DOI 10.17487/RFC7276, June 2014, DOI 10.17487/RFC7276, June 2014,
<https://www.rfc-editor.org/info/rfc7276>. <https://www.rfc-editor.org/info/rfc7276>.
[RFC8279] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A., [RFC8279] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,
Przygienda, T., and S. Aldrin, "Multicast Using Bit Index Przygienda, T., and S. Aldrin, "Multicast Using Bit Index
Explicit Replication (BIER)", RFC 8279, Explicit Replication (BIER)", RFC 8279,
DOI 10.17487/RFC8279, November 2017, DOI 10.17487/RFC8279, November 2017,
<https://www.rfc-editor.org/info/rfc8279>. <https://www.rfc-editor.org/info/rfc8279>.
[I-D.pthubert-raw-architecture] [I-D.ietf-raw-architecture]
Thubert, P., Papadopoulos, G. Z., and L. Berger, "Reliable Thubert, P., Papadopoulos, G. Z., and L. Berger, "Reliable
and Available Wireless Architecture/Framework", Work in and Available Wireless Architecture/Framework", Work in
Progress, Internet-Draft, draft-pthubert-raw-architecture- Progress, Internet-Draft, draft-ietf-raw-architecture-00,
09, 7 July 2021, <https://datatracker.ietf.org/doc/html/ 12 July 2021, <https://datatracker.ietf.org/doc/html/
draft-pthubert-raw-architecture-09>. draft-ietf-raw-architecture-00>.
[I-D.ietf-roll-nsa-extension] [I-D.ietf-roll-nsa-extension]
Koutsiamanis, R., Papadopoulos, G., Montavont, N., and P. Koutsiamanis, R., Papadopoulos, G., Montavont, N., and P.
Thubert, "Common Ancestor Objective Function and Parent Thubert, "Common Ancestor Objective Function and Parent
Set DAG Metric Container Extension", Work in Progress, Set DAG Metric Container Extension", Work in Progress,
Internet-Draft, draft-ietf-roll-nsa-extension-10, 29 Internet-Draft, draft-ietf-roll-nsa-extension-10, 29
October 2020, <https://datatracker.ietf.org/doc/html/ October 2020, <https://datatracker.ietf.org/doc/html/
draft-ietf-roll-nsa-extension-10>. draft-ietf-roll-nsa-extension-10>.
[I-D.papadopoulos-paw-pre-reqs] [I-D.papadopoulos-paw-pre-reqs]
skipping to change at page 59, line 26 skipping to change at page 59, line 26
July 2021, <https://datatracker.ietf.org/doc/html/draft- July 2021, <https://datatracker.ietf.org/doc/html/draft-
ietf-bier-te-arch-10>. ietf-bier-te-arch-10>.
[I-D.ietf-6tisch-coap] [I-D.ietf-6tisch-coap]
Sudhaakar, R. S. and P. Zand, "6TiSCH Resource Management Sudhaakar, R. S. and P. Zand, "6TiSCH Resource Management
and Interaction using CoAP", Work in Progress, Internet- and Interaction using CoAP", Work in Progress, Internet-
Draft, draft-ietf-6tisch-coap-03, 9 March 2015, Draft, draft-ietf-6tisch-coap-03, 9 March 2015,
<https://datatracker.ietf.org/doc/html/draft-ietf-6tisch- <https://datatracker.ietf.org/doc/html/draft-ietf-6tisch-
coap-03>. coap-03>.
[I-D.svshah-tsvwg-deterministic-forwarding] [IEEE Std 802.15.4]
Shah, S. and P. Thubert, "Deterministic Forwarding PHB", IEEE standard for Information Technology, "IEEE Std
Work in Progress, Internet-Draft, draft-svshah-tsvwg-
deterministic-forwarding-04, 30 August 2015,
<https://datatracker.ietf.org/doc/html/draft-svshah-tsvwg-
deterministic-forwarding-04>.
[IEEE Std. 802.15.4]
IEEE standard for Information Technology, "IEEE Std.
802.15.4, Part. 15.4: Wireless Medium Access Control (MAC) 802.15.4, Part. 15.4: Wireless Medium Access Control (MAC)
and Physical Layer (PHY) Specifications for Low-Rate and Physical Layer (PHY) Specifications for Low-Rate
Wireless Personal Area Networks". Wireless Personal Area Networks".
[IEEE Std. 802.11] [IEEE Std 802.11]
"IEEE Standard 802.11 - IEEE Standard for Information IEEE standard for Information Technology, "IEEE Standard
Technology - Telecommunications and information exchange 802.11 - IEEE Standard for Information Technology -
between systems Local and metropolitan area networks - Telecommunications and information exchange between
Specific requirements - Part 11: Wireless LAN Medium systems Local and metropolitan area networks - Specific
Access Control (MAC) and Physical Layer (PHY) requirements - Part 11: Wireless LAN Medium Access Control
Specifications.". (MAC) and Physical Layer (PHY) Specifications.",
<https://ieeexplore.ieee.org/document/9363693>.
[IEEE Std. 802.11ak]
"802.11ak: Enhancements for Transit Links Within Bridged
Networks", 2017.
[IEEE Std. 802.11ax] [IEEE Std 802.11ax]
"802.11ax D4.0: Enhancements for High Efficiency WLAN". IEEE standard for Information Technology, "802.11ax:
Enhancements for High Efficiency WLAN", 2021,
<https://ieeexplore.ieee.org/document/9442429>.
[IEEE Std. 802.11ay] [IEEE Std 802.11ay]
"802.11ay: Enhanced throughput for operation in license- IEEE standard for Information Technology, "802.11ay:
exempt bands above 45 GHz". Enhanced throughput for operation in license-exempt bands
above 45 GHz", 2021,
<https://ieeexplore.ieee.org/document/9502046/>.
[IEEE Std. 802.11ad] [IEEE Std 802.11ad]
"802.11ad: Enhancements for very high throughput in the 60 "802.11ad: Enhancements for very high throughput in the 60
GHz band". GHz band", 2012,
<https://ieeexplore.ieee.org/document/6392842/>.
[IEEE 802.11be WIP] [IEEE 802.11be WIP]
"802.11be: Extreme High Throughput". IEEE standard for Information Technology, "802.11be:
Extreme High Throughput PAR",
<https://mentor.ieee.org/802.11/dcn/18/11-18-1231-04-0eht-
eht-draft-proposed-par.docx>.
[IEEE Std. 802.1Qat] [IEEE Std 802.1Qat]
"802.1Qat: Stream Reservation Protocol". "802.1Qat: Stream Reservation Protocol".
[IEEE8021Qcc] [IEEE8021Qcc]
"802.1Qcc: IEEE Standard for Local and Metropolitan Area IEEE standard for Information Technology, "802.1Qcc: IEEE
Networks--Bridges and Bridged Networks -- Amendment 31: Standard for Local and Metropolitan Area Networks--Bridges
Stream Reservation Protocol (SRP) Enhancements and and Bridged Networks -- Amendment 31: Stream Reservation
Performance Improvements". Protocol (SRP) Enhancements and Performance Improvements".
[Cavalcanti_2019] [Cavalcanti_2019]
Dave Cavalcanti et al., "Extending Time Distribution and Dave Cavalcanti et al., "Extending Time Distribution and
Timeliness Capabilities over the Air to Enable Future Timeliness Capabilities over the Air to Enable Future
Wireless Industrial Automation Systems, the Proceedings of Wireless Industrial Automation Systems, the Proceedings of
IEEE", June 2019. IEEE", June 2019.
[Nitsche_2015] [Nitsche_2015]
Thomas Nitsche et al., "IEEE 802.11ad: directional 60 GHz Thomas Nitsche et al., "IEEE 802.11ad: directional 60 GHz
communication for multi-Gigabit-per-second Wi-Fi", communication for multi-Gigabit-per-second Wi-Fi",
December 2014. December 2014.
[Ghasempour_2017] [Ghasempour_2017]
Yasaman Ghasempour et al., "802.11ay: Next-Generation 60 Yasaman Ghasempour et al., "802.11ay: Next-Generation 60
GHz Communications for 100 Gb/s Wi-Fi", December 2017. GHz Communications for 100 Gb/s Wi-Fi", December 2017.
[IEEE_doc_11-18-2009-06] [IEEE_doc_11-18-2009-06]
"802.11 Real-Time Applications (RTA) Topic Interest Group IEEE standard for Information Technology, "802.11 Real-
(TIG) Report", November 2018. Time Applications (RTA) Topic Interest Group (TIG)
Report", November 2018.
[IEEE_doc_11-19-0373-00] [IEEE_doc_11-19-0373-00]
Kevin Stanton et Al., "Time-Sensitive Applications Support Kevin Stanton et Al., "Time-Sensitive Applications Support
in EHT", March 2019. in EHT", March 2019.
[morell13] Antoni Morell et al., "Label switching over IEEE802.15.4e [morell13] Antoni Morell et al., "Label switching over IEEE802.15.4e
networks", April 2013. networks", April 2013.
[dearmas16] [dearmas16]
Jesica de Armas et al., "Determinism through path Jesica de Armas et al., "Determinism through path
skipping to change at page 63, line 36 skipping to change at page 63, line 36
[IEEE802.1AS] [IEEE802.1AS]
IEEE, "IEEE Standard for Local and metropolitan area IEEE, "IEEE Standard for Local and metropolitan area
networks -- Timing and Synchronization for Time-Sensitive networks -- Timing and Synchronization for Time-Sensitive
Applications", IEEE 802.1AS-2020, Applications", IEEE 802.1AS-2020,
<https://standards.ieee.org/content/ieee-standards/en/ <https://standards.ieee.org/content/ieee-standards/en/
standard/802_1AS-2020.html>. standard/802_1AS-2020.html>.
[IEEE802.1CB] [IEEE802.1CB]
IEEE, "IEEE Standard for Local and metropolitan area IEEE, "IEEE Standard for Local and metropolitan area
networks -- Frame Replication and Elimination for networks -- Frame Replication and Elimination for
Reliability", DOI 10.1109/IEEESTD.2017.8091139, IEEE Reliability", DOI 10.1109/IEEEStd2017.8091139, IEEE
802.1CB-2017, 802.1CB-2017,
<https://ieeexplore.ieee.org/document/8091139>. <https://ieeexplore.ieee.org/document/8091139>.
[IEEE802.1Qbv] [IEEE802.1Qbv]
IEEE, "IEEE Standard for Local and metropolitan area IEEE, "IEEE Standard for Local and metropolitan area
networks -- Bridges and Bridged Networks -- Amendment 25: networks -- Bridges and Bridged Networks -- Amendment 25:
Enhancements for Scheduled Traffic", IEEE 802.1Qbv-2015, Enhancements for Scheduled Traffic", IEEE 802.1Qbv-2015,
<https://ieeexplore.ieee.org/document/7440741>. <https://ieeexplore.ieee.org/document/7440741>.
[IEEE802.1Qcc] [IEEE802.1Qcc]
skipping to change at page 65, line 42 skipping to change at page 65, line 42
[EHA11] Ehammer, M. and T. Graeupl, "AeroMACS - An Airport [EHA11] Ehammer, M. and T. Graeupl, "AeroMACS - An Airport
Communications System", IEEE 30th Digital Avionics Systems Communications System", IEEE 30th Digital Avionics Systems
Conference (DACS), pp. 1-16, New York, NY, USA , September Conference (DACS), pp. 1-16, New York, NY, USA , September
2011. 2011.
[SCH14] Schnell, M., Epple, U., Shutin, D., and N. [SCH14] Schnell, M., Epple, U., Shutin, D., and N.
Schneckenburger, "LDACS: Future Aeronautical Schneckenburger, "LDACS: Future Aeronautical
Communications for Air- Traffic Management", IEEE Communications for Air- Traffic Management", IEEE
Communications Magazine, 52(5), 104-110 , 2017. Communications Magazine, 52(5), 104-110 , 2017.
[CAL1287] Cavalcanti, D., Venkatesan, G., Cariou, L., and C. [Cavalcanti1287]
Cavalcanti, D., Venkatesan, G., Cariou, L., and C.
Vordeiro, "TSN support in 802.11 and potential extensions Vordeiro, "TSN support in 802.11 and potential extensions
for TGbe", 2019, for TGbe", 2019,
<https://mentor.ieee.org/802.11/dcn/19/11-19-1287>. <https://mentor.ieee.org/802.11/dcn/19/11-19-1287>.
[SUR2021] Sudhakaran, S., Montgomery, K., Kashef, M., Cavalcanti, [Sudhakaran2021]
Sudhakaran, S., Montgomery, K., Kashef, M., Cavalcanti,
D., and R. Candell, "Wireless Time Sensitive Networking D., and R. Candell, "Wireless Time Sensitive Networking
for Industrial Collaborative Robotic Workcells", 17th IEEE for Industrial Collaborative Robotic Workcells", 17th IEEE
International Conference on Factory Communication Systems International Conference on Factory Communication Systems
(WFCS) , 2021, (WFCS) , 2021,
<https://ieeexplore.ieee.org/abstract/document/9483447>. <https://ieeexplore.ieee.org/abstract/document/9483447>.
Authors' Addresses Authors' Addresses
Pascal Thubert (editor) Pascal Thubert (editor)
Cisco Systems, Inc Cisco Systems, Inc
 End of changes. 61 change blocks. 
159 lines changed or deleted 178 lines changed or added

This html diff was produced by rfcdiff 1.48. The latest version is available from http://tools.ietf.org/tools/rfcdiff/