Internet DRAFT - draft-bernardos-raw-use-cases
draft-bernardos-raw-use-cases
RAW G. Papadopoulos
Internet-Draft IMT Atlantique
Intended status: Standards Track P. Thubert
Expires: January 12, 2021 Cisco
F. Theoleyre
CNRS
CJ. Bernardos
UC3M
July 11, 2020
RAW use cases
draft-bernardos-raw-use-cases-04
Abstract
The wireless medium presents significant specific challenges to
achieve properties similar to those of wired deterministic networks.
At the same time, a number of use cases cannot be solved with wires
and justify the extra effort of going wireless. This document
presents wireless use cases demanding reliable and available
behavior.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 12, 2021.
Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
Papadopoulos, et al. Expires January 12, 2021 [Page 1]
Internet-Draft RAW use cases scenarios July 2020
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Aeronautical Communications . . . . . . . . . . . . . . . . . 5
2.1. Problem Statement . . . . . . . . . . . . . . . . . . . . 5
2.2. Specifics . . . . . . . . . . . . . . . . . . . . . . . . 5
2.3. Challenges . . . . . . . . . . . . . . . . . . . . . . . 6
2.4. The Need for Wireless . . . . . . . . . . . . . . . . . . 7
2.5. Requirements for RAW . . . . . . . . . . . . . . . . . . 7
3. Amusement Parks . . . . . . . . . . . . . . . . . . . . . . . 7
3.1. Use Case Description . . . . . . . . . . . . . . . . . . 7
3.2. Specifics . . . . . . . . . . . . . . . . . . . . . . . . 8
3.3. The Need for Wireless . . . . . . . . . . . . . . . . . . 8
3.4. Requirements for RAW . . . . . . . . . . . . . . . . . . 9
4. Wireless for Industrial Applications . . . . . . . . . . . . 9
4.1. Use Case Description . . . . . . . . . . . . . . . . . . 9
4.2. Specifics . . . . . . . . . . . . . . . . . . . . . . . . 10
4.2.1. Control Loops . . . . . . . . . . . . . . . . . . . . 10
4.2.2. Unmeasured Data . . . . . . . . . . . . . . . . . . . 10
4.3. The Need for Wireless . . . . . . . . . . . . . . . . . . 11
4.4. Requirements for RAW . . . . . . . . . . . . . . . . . . 11
5. Pro Audio and Video . . . . . . . . . . . . . . . . . . . . . 12
5.1. Use Case Description . . . . . . . . . . . . . . . . . . 12
5.2. Specifics . . . . . . . . . . . . . . . . . . . . . . . . 12
5.2.1. Uninterrupted Stream Playback . . . . . . . . . . . . 12
5.2.2. Synchronized Stream Playback . . . . . . . . . . . . 12
5.3. The Need for Wireless . . . . . . . . . . . . . . . . . . 12
5.4. Requirements for RAW . . . . . . . . . . . . . . . . . . 13
6. Wireless Gaming . . . . . . . . . . . . . . . . . . . . . . . 13
6.1. Use Case Description . . . . . . . . . . . . . . . . . . 13
6.2. Specifics . . . . . . . . . . . . . . . . . . . . . . . . 14
6.3. The Need for Wireless . . . . . . . . . . . . . . . . . . 14
6.4. Requirements for RAW . . . . . . . . . . . . . . . . . . 14
7. UAV platooning and control . . . . . . . . . . . . . . . . . 15
7.1. Use Case Description . . . . . . . . . . . . . . . . . . 15
7.2. Specifics . . . . . . . . . . . . . . . . . . . . . . . . 15
7.3. The Need for Wireless . . . . . . . . . . . . . . . . . . 15
7.4. Requirements for RAW . . . . . . . . . . . . . . . . . . 16
8. Edge Robotics control . . . . . . . . . . . . . . . . . . . . 16
8.1. Use Case Description . . . . . . . . . . . . . . . . . . 16
8.2. Specifics . . . . . . . . . . . . . . . . . . . . . . . . 17
Papadopoulos, et al. Expires January 12, 2021 [Page 2]
Internet-Draft RAW use cases scenarios July 2020
8.3. The Need for Wireless . . . . . . . . . . . . . . . . . . 17
8.4. Requirements for RAW . . . . . . . . . . . . . . . . . . 17
9. Emergencies: Instrumented emergency vehicle . . . . . . . . . 17
9.1. Use Case Description . . . . . . . . . . . . . . . . . . 17
9.2. Specifics . . . . . . . . . . . . . . . . . . . . . . . . 18
9.3. The Need for Wireless . . . . . . . . . . . . . . . . . . 18
9.4. Requirements for RAW . . . . . . . . . . . . . . . . . . 18
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19
11. Security Considerations . . . . . . . . . . . . . . . . . . . 19
12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 19
13. Informative References . . . . . . . . . . . . . . . . . . . 19
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22
1. Introduction
Based on time, resource reservation, and policy enforcement by
distributed shapers, Deterministic Networking provides the capability
to carry specified unicast or multicast data streams for real-time
applications with extremely low data loss rates and bounded latency,
so as to support time-sensitive and mission-critical applications on
a converged enterprise infrastructure.
Deterministic Networking in the IP world is an attempt to eliminate
packet loss for a committed bandwidth while ensuring a worst case
end-to-end latency, regardless of the network conditions and across
technologies. It can be seen as a set of new Quality of Service
(QoS) guarantees of worst-case delivery. IP networks become more
deterministic when the effects of statistical multiplexing (jitter
and collision loss) are mostly eliminated. This requires a tight
control of the physical resources to maintain the amount of traffic
within the physical capabilities of the underlying technology, e.g.,
by the use of time-shared resources (bandwidth and buffers) per
circuit, and/or by shaping and/or scheduling the packets at every
hop.
Key attributes of Deterministic Networking include:
o time synchronization on all the nodes,
o centralized computation of network-wide deterministic paths,
o multi-technology path with co-channel interference minimization,
o frame preemption and guard time mechanisms to ensure a worst-case
delay, and
o new traffic shapers within and at the edge to protect the network.
Papadopoulos, et al. Expires January 12, 2021 [Page 3]
Internet-Draft RAW use cases scenarios July 2020
Wireless operates on a shared medium, and transmissions cannot be
fully deterministic due to uncontrolled interferences, including
self-induced multipath fading. RAW (Reliable and Available Wireless)
is an effort to provide Deterministic Networking Mechanisms on across
a path that include a wireless physical layer. Making Wireless
Reliable and Available is even more challenging than it is with
wires, due to the numerous causes of loss in transmission that add up
to the congestion losses and the delays caused by overbooked shared
resources.
The wireless and wired media are fundamentally different at the
physical level, and while the generic Problem Statement [RFC8557] for
DetNet applies to the wired as well as the wireless medium, the
methods to achieve RAW necessarily differ from those used to support
Time-Sensitive Networking over wires.
So far, Open Standards for Deterministic Networking have prevalently
been focused on wired media, with Audio/Video Bridging (AVB) and Time
Sensitive Networking (TSN) at the IEEE and DetNet [RFC8655] at the
IETF. But wires cannot be used in a number of cases, including
mobile or rotating devices, rehabilitated industrial buildings,
wearable or in-body sensory devices, vehicle automation and
multiplayer gaming.
Purpose-built wireless technologies such as [ISA100], which
incorporates IPv6, were developped and deployed to cope for the lack
of open standards, but they yield a high cost in OPEX and CAPEX and
are limited to very few industries, e.g., process control, concert
instruments or racing.
This is now changing [I-D.thubert-raw-technologies]:
o IMT-2020 has recognized Ultra-Reliable Low-Latency Communication
(URLLC) as a key functionality for the upcoming 5G.
o IEEE 802.11 has identified a set of real-applications
[ieee80211-rt-tig] which may use the IEEE802.11 standards. They
typically emphasize strict end-to-end delay requirements.
o The IETF has produced an IPv6 stack for IEEE Std. 802.15.4
TimeSlotted Channel Hopping (TSCH) and an architecture
[I-D.ietf-6tisch-architecture] that enables Reliable and Available
Wireless (RAW) on a shared MAC.
This draft extends the "Deterministic Networking Use Cases" document
[RFC8578] and describes a number of additional use cases which
require "reliable/predictable and available" flows over wireless
links and possibly complex multi-hop paths called Tracks. This is
Papadopoulos, et al. Expires January 12, 2021 [Page 4]
Internet-Draft RAW use cases scenarios July 2020
covered mainly by the "Wireless for Industrial Applications" use
case, as the "Cellular Radio" is mostly dedicated to the (wired)
transport part of a Radio Access Network (RAN). Whereas the
"Wireless for Industrial Applications" use case certainly covers an
area of interest for RAW, it is limited to 6TiSCH, and thus its scope
is narrower than the use cases described next in this document.
2. Aeronautical Communications
Aircraft are currently connected to ATC (Air-Traffic Control) and AOC
(Airline Operational Control) via voice and data communications
systems through all phases of a flight. Within the airport terminal,
connectivity is focused on high bandwidth communications while during
en-route high reliability, robustness and range is the main focus.
2.1. Problem Statement
Worldwide civil air traffic is expected to grow by 84% until 2040
compared to 2017 [EURO20]. Thus, legacy systems in air traffic
management (ATM) are likely to reach their capacity limits and the
need for new aeronautical communication technologies becomes
apparent. Especially problematic is the saturation of VHF band in
high density areas in Europe, the US, and Asia [KEAV20] [FAA20]
calling for suitable new digital approaches such as AeroMACS for
airport communications, SatCOM for remote domains, and LDACS as long-
range terrestrial aeronautical communications system. Making the
frequency spectrum's usage more efficient a transition from analogue
voice to digital data communication [PLA14] is necessary to cope with
the expected growth of civil aviation and its supporting
infrastructure. A promising candidate for long range terrestrial
communications, already in the process of being standardized in the
International Civil Aviation Organization (ICAO), is the L-band
Digital Aeronautical Communications System (LDACS) [ICAO18]
[I-D.maeurer-raw-ldacs].
2.2. Specifics
During the creation process of new communications system, analogue
voice is replaced by digital data communication. This sets a
paradigm shift from analogue to digital wireless communications and
supports the related trend towards increased autonomous data
processing that the Future Communications Infrastructure (FCI) in
civil aviation must provide. The FCI is depicted in Figure 1:
Papadopoulos, et al. Expires January 12, 2021 [Page 5]
Internet-Draft RAW use cases scenarios July 2020
Satellite
# #
# # #
# # #
# # #
# # #
# # #
# # #
# Satellite-based # #
# Communications # #
# SatCOM (#) # #
# # Aircraft
# # % %
# # % %
# # % Air-Air %
# # % Communications %
# # % LDACS A/A (%) %
# # % %
# Aircraft % % % % % % % % % % Aircraft
# | Air-Ground |
# | Communications |
# | LDACS A/G (|) |
# Communications in | |
# and around airports | |
# AeroMACS (-) | |
# | |
# Aircraft-------------+ | |
# | | |
# | | |
# Ground network | | Ground network |
SatCOM <---------------------> Airport <----------------------> LDACS
transceiver based GS
transceiver
Figure 1: The Future Communication Infrastructure (FCI): AeroMACS for
APT/TMA domain, LDACS A/G for TMA/ENR domain, LDACS A/G for ENR/ORP
domain, SatCOM for ORP domain communications
2.3. Challenges
This paradigm change brings a lot of new challenges:
o Efficiency: It is necessary to keep latency, time and data
overhead (routing, security) of new aeronautical datalinks at a
minimum.
Papadopoulos, et al. Expires January 12, 2021 [Page 6]
Internet-Draft RAW use cases scenarios July 2020
o Modularity: Systems in avionics usually operate up to 30 years,
thus solutions must be modular, easily adaptable and updatable.
o Interoperability: All 192 members of the international Civil
Aviation Organization (ICAO) must be able to use these solutions.
2.4. The Need for Wireless
In a high mobility environment such as aviation, the envisioned
solutions to provide worldwide coverage of data connections with in-
flight aircraft require a multi-system, multi-link, multi-hop
approach. Thus air, ground and space based datalink providing
technologies will have to operate seamlessly together to cope with
the increasing needs of data exchange between aircraft, air traffic
controller, airport infrastructure, airlines, air network service
providers (ANSPs) and so forth. Thus making use of wireless
technologies is a must in tackling this enormous need for a worldwide
digital aeronautical datalink infrastructure.
2.5. Requirements for RAW
Different safety levels need to be supported, from extremely safety
critical ones requiring low latency, such as a WAKE warning - a
warning that two aircraft come dangerously close to each other - and
high resiliency, to less safety critical ones requiring low-medium
latency for services such as WXGRAPH - graphical weather data.
Overhead needs to be kept at a minimum since aeronautical data links
provide comparatively small data rates in the order of kbit/s.
Policy needs to be supported when selecting data links. The focus of
RAW here should be on the selectors, responsible for the routing path
a packet takes to reach its end destination. This would minimize the
amount of routing information that has to travel inside the network
because of precomputed routing tables with the selector being
responsible for choosing the most appropriate option according to
policy and safety.
3. Amusement Parks
3.1. Use Case Description
The digitalization of Amusement Parks is expected to decrease
significantly the cost for maintaining the attractions. Such
deployment is a mix between industrial automation (aka. Smart
Factories) and multimedia entertainment applications.
Papadopoulos, et al. Expires January 12, 2021 [Page 7]
Internet-Draft RAW use cases scenarios July 2020
Attractions may rely on a large set of sensors and actuators, which
react in real time. Typical applications comprise:
o Emergency: safety has to be preserved, and must stop the
attraction when a failure is detected.
o Video: augmented and virtual realities are integrated in the
attraction. Wearable mobile devices (e.g., glasses, virtual
reality headset) need to offload one part of the processing tasks.
o Real-time interactions: visitors may interact with an attraction,
like in a real-time video game. The visitors may virtually
interact with their environment, triggering actions in the real
world (through actuators) [robots].
o Geolocation: visitors are tracked with a personal wireless tag so
that their user experience is improved.
o Predictive maintenance: statistics are collected to predict the
future failures, or to compute later more complex statistics about
the attraction's usage, the downtime, its popularity, etc.
3.2. Specifics
Amusement parks comprise a variable number of attractions, mostly
outdoor, over a large geographical area. The IT infrastructure is
typically multi-scale:
o Local area: the sensors and actuators controlling the attractions
are co-located. Control loops trigger only local traffic, with a
small end-to-end delay, typically inferior than 10 milliseconds,
like classical industrial systems [ieee80211-rt-tig].
o Wearable mobile devices are free to move in the park. They
exchange traffic locally (identification, personalization,
multimedia) or globally (billing, child tracking).
o Computationally intensive applications offload some tasks. Edge
computing seems an efficient way to implement real-time
applications with offloading. Some non time-critical tasks may
rather use the cloud (predictive maintenance, marketing).
3.3. The Need for Wireless
Amusement parks cover large areas and a global interconnection would
require a huge length of cables. Wireless also increases the
reconfigurability, enabling to update cheaply the attractions. The
frequent renewal helps to increase customer loyalty.
Papadopoulos, et al. Expires January 12, 2021 [Page 8]
Internet-Draft RAW use cases scenarios July 2020
Some parts of the attraction are mobile, e.g., trucks of a roller-
coaster, robots. Since cables are prone to frequent failures in this
situation, wireless transmissions are recommended.
Wearable devices are extensively used for a user experience
personalization. They typically need to support wireless
transmissions. Personal tags may help to reduce the operating costs
[disney-VIP] and to increase the number of charged services provided
to the audience (VIP tickets, interactivity, etc.) Some applications
rely on more sophisticated wearable devices such as digital glasses
or Virtual Reality (VR) headsets for an immersive experience.
3.4. Requirements for RAW
The network infrastructure has to support heterogeneous traffic, with
very different critical requirements. Thus, flow isolation has to be
provided.
We have to schedule appropriately the transmissions, even in presence
of mobile devices. While the [I-D.ietf-6tisch-architecture] already
proposes an architecture for synchronized, IEEE Std. 802.15.4 Time-
Slotted Channel Hopping (TSCH) networks, we still need multi-
technology solutions, able to guarantee end-to-end requirements
across heterogeneous technologies, with strict SLA requirements.
Nowadays, long-range wireless transmissions are used mostly for best-
effort traffic. On the contrary, [IEEE802.1TSN] is used for critical
flows using Ethernet devices. However, we need an IP enabled
technology to interconnect large areas, independent of the PHY and
MAC layers.
We expect to deploy several different technologies (long vs. short
range) which have to cohabit in the same area. Thus, we need to
provide layer-3 mechanisms able to exploit multiple co-interfering
technologies.
4. Wireless for Industrial Applications
4.1. Use Case Description
A major use case for networking in Industrial environments is the
control networks where periodic control loops operate between a
sensor that measures a physical property such as the temperature of a
fluid, a Programmable Logic Controller (PLC) that decides an action
such as warm up the mix, and an actuator that performs the required
action, e.g., inject power in a resistor.
Papadopoulos, et al. Expires January 12, 2021 [Page 9]
Internet-Draft RAW use cases scenarios July 2020
4.2. Specifics
4.2.1. Control Loops
Process Control designates continuous processing operations, e.g.,
heating Oil in a refinery or mixing drinking soda. Control loops in
the Process Control industry operate at a very low rate, typically 4
times per second. Factory Automation, on the other hand, deal with
discrete goods such as individual automobile parts, and requires
faster loops, in the order of 10ms. Motion control that monitors
dynamic activities may require even faster rates in the order of a
few ms. Finally, some industries exhibit hybrid behaviors, like
canned soup that will start as a process industry while mixing the
food and then operate as a discrete manufacturing when putting the
final product in cans and shipping them.
In all those cases, a packet must flow reliably between the sensor
and the PLC, be processed by the PLC, and sent to the actuator within
the control loop period. In some particular use cases that inherit
from analog operations, jitter might also alter the operation of the
control loop. A rare packet loss is usually admissible, but
typically 4 losses in a row will cause an emergency halt of the
production and incur a high cost for the manufacturer.
4.2.2. Unmeasured Data
A secondary use case deals with monitoring and diagnostics. This so-
called unmeasured data is essential to improve the performances of a
production line, e.g., by optimizing real-time processing or
maintenance windows using Machine Learning predictions. For the lack
of wireless technologies, some specific industries such as Oil and
Gas have been using serial cables, literally by the millions, to
perform their process optimization over the previous decades. But
few industries would afford the associated cost and the Holy Grail of
the Industrial Internet of Things is to provide the same benefits to
all industries, including SmartGrid, Transportation, Building,
Commercial and Medical. This requires a cheap, available and
scalable IP-based access technology.
Inside the factory, wires may already be available to operate the
Control Network. But unmeasured data are not welcome in that network
for a number of reasons. On the one hand it is rich and
asynchronous, meaning that using they may influence the deterministic
nature of the control operations and impact the production. On the
other hand, this information must be reported to the carpeted floor
over IP, which means the potential for a security breach via the
interconnection of the Operational Technology (OT) network with the
Internet technology (IT) network and possibly enable a rogue access.
Papadopoulos, et al. Expires January 12, 2021 [Page 10]
Internet-Draft RAW use cases scenarios July 2020
4.3. The Need for Wireless
Ethernet cables used on a robot arm are prone to breakage after a few
thousands flexions, a lot faster than a power cable that is wider inn
diameter, and more resilient. In general, wired networking and
mobile parts are not a good match, mostly in the case of fast and
recurrent activities, as well as rotation.
When refurbishing older premises that were built before the Internet
age, power is usually available everywhere, but data is not. It is
often impractical, time consuming and expensive to deploy an Ethernet
fabric across walls and between buildings. Deploying a wire may take
months and cost tens of thousands of US Dollars.
Even when wiring exists, e.g., in an existing control network,
asynchronous IP packets such as diagnostics may not be welcome for
operational and security reasons (see Section 4.2.1). An alternate
network that can scale with the many sensors and actuators that equip
every robot, every valve and fan that are deployed on the factory
floor and may help detect and prevent a failure that could impact the
production. IEEE Std. 802.15.4 Time-Slotted Channel Hopping (TSCH)
[RFC7554] is a promising technology for that purpose, mostly if the
scheduled operations enable to use the same network by asynchronous
and deterministic flows in parallel.
4.4. Requirements for RAW
As stated by the "Deterministic Networking Problem Statement"
[RFC8557], a Deterministic Network is backwards compatible with
(capable of transporting) statistically multiplexed traffic while
preserving the properties of the accepted deterministic flows. While
the [I-D.ietf-6tisch-architecture] serves that requirement, the work
at 6TiSCH was focused on best-effort IPv6 packet flows. RAW should
be able to lock so-called hard cells for use by a centralized
scheduler, and program so-called end-to-end Tracks over those cells.
Over the course of the recent years, major Industrial Protocols,
e.g., [ODVA] with EtherNet/IP [EIP] and [Profinet], have been
migrating towards Ethernet and IP. In order to unleash the full
power of the IP hourglass model, it should be possible to deploy any
application over any network that has the physical capacity to
transport the industrial flow, regardless of the MAC/PHY technology,
wired or wireless, and across technologies. RAW mechanisms should be
able to setup a Track over a wireless access segment such as TSCH and
a backbone segment such as Ethernet or WI-Fi, to report a sensor data
or a critical monitoring within a bounded latency. It is also
important to ensure that RAW solutions are interoperable with
existing wireless solutions in place, and with legacy equipment which
Papadopoulos, et al. Expires January 12, 2021 [Page 11]
Internet-Draft RAW use cases scenarios July 2020
capabilities can be extended using retrofitting. Maintanability, as
a broader concept than reliability is also important in industrial
scenarios [square-peg].
5. Pro Audio and Video
5.1. Use Case Description
Many devices support audio and video streaming by employing 802.11
wireless LAN. Some of these applications require low latency
capability. For instance, when the application provides interactive
play, or when the audio takes plays in real time (i.e. live) for
public addresses in train stations or in theme parks.
The professional audio and video industry ("ProAV") includes:
o Virtual Reality / Augmented Reality (VR/AR)
o Public address, media and emergency systems at large venues
(airports, train stations, stadiums, theme parks).
5.2. Specifics
5.2.1. Uninterrupted Stream Playback
Considering the uninterrupted audio or video stream, a potential
packet losses during the transmission of audio or video flows cannot
be tackled by re-trying the transmission, as it is done with file
transfer, because by the time the packet lost has been identified it
is too late to proceed with packet re-transmission. Buffering might
be employed to provide a certain delay which will allow for one or
more re-transmissions, however such approach is not efficient in
application where delays are not acceptable.
5.2.2. Synchronized Stream Playback
In the context of ProAV, latency is the time between the transmitted
signal over a stream and its reception. Thus, for sound to remain
synchronized to the movement in the video, the latency of both the
audio and video streams must be bounded and consistent.
5.3. The Need for Wireless
The devices need the wireless communication to support video
streaming via 802.11 wireless LAN for instance.
Papadopoulos, et al. Expires January 12, 2021 [Page 12]
Internet-Draft RAW use cases scenarios July 2020
During the public address, the deployed announcement speakers, for
instance along the platforms of the train stations, need the wireless
communication to forward the audio traffic in real time.
5.4. Requirements for RAW
The network infrastructure needs to support heterogeneous types of
traffic (including QoS).
Content delivery with bounded (lowest possible) latency.
The deployed network topology should allow for multipath. This will
enable for multiple streams to have different (and multiple) paths
through the network to support redundancy.
6. Wireless Gaming
6.1. Use Case Description
The gaming industry includes [IEEE80211RTA] real-time mobile gaming,
wireless console gaming and cloud gaming. For RAW, wireless console
gaming is the most relevant one. We next summarize the three:
o Real-time Mobile Gaming: Different from traditional games, real
time mobile gaming is very sensitive to network latency and
stability. The mobile game can connect multiple players together
in a single game session and exchange data messages between game
server and connected players. Real-time means the feedback should
present on screen as users operate in game. For good game
experience, the end to end latency plus game servers processing
time should not be noticed by users as they play the game.
o Wireless Console Gaming: Playing online on a console has 2 types
of internet connectivity, which is either wired or Wi-Fi. Most of
the gaming consoles today support Wi-Fi 5. But Wi-Fi has an
especially bad reputation among the gaming community. The main
reasons are high latency, lag spikes and jitter.
o Cloud Gaming: The cloud gaming requires low latency capability as
the user commands in a game session need to be sent back to the
cloud server, the cloud server would update game context depending
on the received commands, and the cloud server would render the
picture/video to be displayed at user devices and stream the
picture/video content to the user devices. User devices might
very likely be connected wirelessly.
Papadopoulos, et al. Expires January 12, 2021 [Page 13]
Internet-Draft RAW use cases scenarios July 2020
6.2. Specifics
While a lot of details can be found on [IEEE80211RTA], we next
summarize the main requirements in terms of latency, jitter and
packet loss:
o Intra BSS latency: less than 5 ms.
o Jitter variance: less than 2 ms.
o Packet loss: less than 0.1 percent.
6.3. The Need for Wireless
It is clear that gaming is evolving towards wireless, as players
demand being able to play anywhere. Besides, the industry is
changing towards playing from mobile phones, which are inherently
connected via wireless technologies.
6.4. Requirements for RAW
o Time sensitive networking extensions. Extensions, such as time-
aware shaping and redundancy (FRE) can be explored to address
congestion and reliability problems present in wireless networks.
o Priority tagging (Stream identification). One basic requirement
to provide better QoS for time-sensitive traffic is the capability
to identify and differentiate time-sensitive packets from other
(e.g. best-effort) traffic.
o Time-aware shaping. This capability (defined in IEEE 802.1Qbv)
consists of gates to control the opening/closing of queues that
share a common egress port within an Ethernet switch. A scheduler
defines the times when each queue opens or close, therefore
eliminating congestion and ensuring that frames are delivered
within the expected latency bounds.
o Dual/multiple link. Due to the competitions and interference are
common and hardly in control under wireless network, in order to
improve the latency stability, dual/multiple link proposal is
brought up to address this issue. Two modes are defined:
duplicate and joint.
o Admission Control. Congestion is a major cause of high/variable
latency and it is well known that if the traffic load exceeds the
capability of the link, QoS will be degraded. QoS degradation
maybe acceptable for many applications today, however emerging
time-sensitive applications are highly susceptible to increased
Papadopoulos, et al. Expires January 12, 2021 [Page 14]
Internet-Draft RAW use cases scenarios July 2020
latency and jitter. In order to better control QoS, it is
important to control access to the network resources.
7. UAV platooning and control
7.1. Use Case Description
Unmanned Aerial Vehicles (UAVs) are becoming very popular for many
different applications, including military and civil use cases. The
term drone is commonly used to refer to a UAV.
UAVs can be used to perform aerial surveillance activities, traffic
monitoring (e.g., Spanish traffic control has recently introduced a
fleet of drones for quicker reactions upon traffic congestion related
events), support of emergency situations, and even transportation of
small goods.
UAVs typically have various forms of wireless connectivity:
o cellular: for communication with the control center, for remote
maneuvering as well as monitoring of the drone;
o IEEE 802.11: for inter-drone communications (e.g., platooning) and
providing connectivity to other devices (e.g., acting as Access
Point).
7.2. Specifics
Some of the use cases/tasks involving drones require coordination
among drones. Others involve complex compute tasks that might not be
performed using the limited computing resources that a drone
typically has. These two aspects require continuous connectivity
with the control center and among drones.
Remote maneuvering of a drone might be performed over a cellular
network in some cased, however, there are situations that need very
low latencies and deterministic behavior of the connectivity.
Examples involve platooning of drones or share of computing resources
among drones (e.g., a drone offload some function to a neighboring
drone).
7.3. The Need for Wireless
UAVs cannot be connected through any type of wired media, so it is
obvious that wireless is needed.
Papadopoulos, et al. Expires January 12, 2021 [Page 15]
Internet-Draft RAW use cases scenarios July 2020
7.4. Requirements for RAW
The network infrastructure is actually composed by the UAVs
themselves, requiring self-configuration capabilities.
Heterogeneous types of traffic need to be supported, from extremely
critical ones requiring ultra low latency and high resiliency, to
traffic requiring low-medium latency.
When a given service is decomposed into functions -- hosted at
different drones -- chained, each link connecting two given functions
would have a well-defined set of requirements (latency, bandwidth and
jitter) that have to be met.
8. Edge Robotics control
8.1. Use Case Description
The Edge Robotics scenario consists of several robots, deployed in a
given area (for example a shopping mall), inter-connected via an
access network to a network's edge device or a data center. The
robots are connected to the edge so complex computational activities
are not executed locally at the robots, but offloaded to the edge.
This brings additional flexibility in the type of tasks that the
robots do, as well as reducing the costs of robot manufacturing (due
to their lower complexity), and enabling complex tasks involving
coordination among robots (that can be more easily performed if
robots are centrally controlled).
A simple example of the use of multiples robots is cleaning,
delivering of goods from warehouses to shops or video surveillance.
Multiple robots are simultaneously instructed to perform individual
tasks by moving the robotic intelligence from the robots to the
network's edge (e.g., data center). That enables easy
synchronization, scalable solution and on-demand option to create
flexible fleet of robots.
Robots would have various forms of wireless connectivity:
o IEEE 802.11: for connection to the edge and also inter-robot
communications (e.g., for coordinated actions).
o Cellular: as an additional communication link to the edge, though
primarily as backup, since ultra low latencies are needed.
Papadopoulos, et al. Expires January 12, 2021 [Page 16]
Internet-Draft RAW use cases scenarios July 2020
8.2. Specifics
Some of the use cases/tasks involving robots might benefit from
decomposition of a service in small functions that are distributed
and chained among robots and the edge. These require continuous
connectivity with the control center and among drones.
Robot control is an activity requiring very low latencies between the
robot and the location where the control intelligence resides (which
might be the edge or another robot).
8.3. The Need for Wireless
Deploying robots in scenarios such as shopping malls for the
aforementioned applications cannot be done via wired connectivity.
8.4. Requirements for RAW
The network infrastructure needs to support heterogeneous types of
traffic, from robot control to video streaming.
When a given service is decomposed into functions -- hosted at
different robots -- chained, each link connecting two given functions
would have a well-defined set of requirements (latency, bandwidth and
jitter) that have to be met.
9. Emergencies: Instrumented emergency vehicle
9.1. Use Case Description
An instrumented ambulance would be one that has a LAN to which are
connected these end systems:
o vital signs sensors attached to the casualty in the ambulance.
Relay medical data to hospital emergency room,
o radionavigation sensor to relay position data to various
destinations including dispatcher,
o voice communication for ambulance attendant (e.g. consult with ER
doctor),
o voice communication between driver and dispatcher,
o etc.
The LAN needs to be routed through radio-WANs to complete the
internetwork linkage.
Papadopoulos, et al. Expires January 12, 2021 [Page 17]
Internet-Draft RAW use cases scenarios July 2020
9.2. Specifics
What we have today is multiple communications systems to reach the
vehicle:
o A dispatching system,
o a cellphone for the attendant,
o a special purpose telemetering system for medical data,
o etc.
This redundancy of systems, because of its stovepiping, does not
contribute to availability as a whole.
Most of the scenarios involving the use of an instrumented ambulance
are composed of many different flows, each of them with slightly
different requirements in terms of reliability and latency.
Destinations might be either at the ambulance itself (local traffic),
at a near edge cloud or at the general Internet/cloud.
9.3. The Need for Wireless
Local traffic between the first responders/ambulance staff and the
ambulance equipment cannot be doine via wireled connectivity as the
responders perform initial treatment outside of the ambulance. The
communications from the ambulance to external services has to be
wireless as well.
9.4. Requirements for RAW
We can derive some pertinent requirements from this scenario:
o High availability of the internetwork is required.
o The internetwork needs to operate in damaged state (e.g. during an
earthquake aftermath, heavy weather, wildfire, etc.). In addition
to continuity of operations, rapid restoral is a needed
characteristic.
o End-to-end security, both authenticity and confidentiality, is
required of traffic. All data needs to be authenticated; some
(such as medical) needs to be confidential.
o The radio-WAN has characteristics similar to cellphone -- the
vehicle will travel from one radio footprint to another.
Papadopoulos, et al. Expires January 12, 2021 [Page 18]
Internet-Draft RAW use cases scenarios July 2020
10. IANA Considerations
This document has no IANA actions.
11. Security Considerations
This document covers a number of representative applications and
network scenarios that are expected to make use of RAW technologies.
Each of the potential RAW use cases will have security considerations
from both the use-specific perspective and the RAW technology
perspective. [I-D.ietf-detnet-security] provides a comprehensive
discussion of security considerations in the context of Deterministic
Networking, which are generally applicable also to RAW.
12. Acknowledgments
Nils Maeurer, Thomas Graeupl and Corinna Schmitt have contributed
significantly to this document, providing input for the Aeronautical
communications section. Rex Buddenberg has also contributed to the
document, providing input to the Emergency: instrumented emergency
vehicle section.
The authors would like to thank Toerless Eckert, Xavi Vilajosana
Guillen and Rute Sofia for their valuable comments on previous
versions of this document.
The work of Carlos J. Bernardos in this draft has been partially
supported by the H2020 5Growth (Grant 856709) and 5G-DIVE projects
(Grant 859881).
13. Informative References
[disney-VIP]
Wired, "Disney's $1 Billion Bet on a Magical Wristband",
March 2015,
<https://www.wired.com/2015/03/disney-magicband/>.
[EIP] http://www.odva.org/, "EtherNet/IP provides users with the
network tools to deploy standard Ethernet technology (IEEE
802.3 combined with the TCP/IP Suite) for industrial
automation applications while enabling Internet and
enterprise connectivity data anytime, anywhere.",
<http://www.odva.org/Portals/0/Library/
Publications_Numbered/
PUB00138R3_CIP_Adv_Tech_Series_EtherNetIP.pdf>.
Papadopoulos, et al. Expires January 12, 2021 [Page 19]
Internet-Draft RAW use cases scenarios July 2020
[EURO20] EUROCONTROL, "EUROCONTROL's Challenges of Growth 2018
Study Report", 2018, <https://www.eurocontrol.int/sites/de
fault/files/content/documents/officialdocuments/reports/
challenges-of-growth-2018.pdf>.
[FAA20] U.S. Department of Transportation Federal Aviation
Administration (FAA), "Next Generation Air Transportation
System", 2019, <https://www.faa.gov/nextgen/ >.
[I-D.ietf-6tisch-architecture]
Thubert, P., "An Architecture for IPv6 over the TSCH mode
of IEEE 802.15.4", draft-ietf-6tisch-architecture-28 (work
in progress), October 2019.
[I-D.ietf-detnet-security]
Mizrahi, T. and E. Grossman, "Deterministic Networking
(DetNet) Security Considerations", draft-ietf-detnet-
security-10 (work in progress), May 2020.
[I-D.maeurer-raw-ldacs]
Maeurer, N., Graeupl, T., and C. Schmitt, "L-band Digital
Aeronautical Communications System (LDACS)", draft-
maeurer-raw-ldacs-04 (work in progress), July 2020.
[I-D.thubert-raw-technologies]
Thubert, P., Cavalcanti, D., Vilajosana, X., Schmitt, C.,
and J. Farkas, "Reliable and Available Wireless
Technologies", draft-thubert-raw-technologies-05 (work in
progress), May 2020.
[ICAO18] International Civil Aviation Organization (ICAO), "L-Band
Digital Aeronautical Communication System (LDACS)",
International Standards and Recommended Practices Annex 10
- Aeronautical Telecommunications, Vol. III -
Communication Systems , 2018.
[IEEE802.1TSN]
IEEE standard for Information Technology, "IEEE
802.1AS-2011 - IEEE Standard for Local and Metropolitan
Area Networks - Timing and Synchronization for Time-
Sensitive Applications in Bridged Local Area Networks".
[ieee80211-rt-tig]
IEEE, "IEEE 802.11 Real Time Applications TIG Report",
Nov. 2018,
<http://www.ieee802.org/11/Reports/rtatig_update.htm>.
Papadopoulos, et al. Expires January 12, 2021 [Page 20]
Internet-Draft RAW use cases scenarios July 2020
[IEEE80211RTA]
IEEE standard for Information Technology, "IEEE 802.11
Real Time Applications TIG Report", Nov 2018.
[ISA100] ISA/ANSI, "ISA100, Wireless Systems for Automation",
<https://www.isa.org/isa100/>.
[KEAV20] T. Keaveney and C. Stewart, "Single European Sky ATM
Research Joint Undertaking", 2019,
<https://www.sesarju.eu/>.
[ODVA] http://www.odva.org/, "The organization that supports
network technologies built on the Common Industrial
Protocol (CIP) including EtherNet/IP.".
[PLA14] Plass, S., Hermenier, R., Luecke, O., Gomez Depoorter, D.,
Tordjman, T., Chatterton, M., Amirfeiz, M., Scotti, S.,
Cheng, Y., Pillai, P., Graeupl, T., Durand, F., Murphy,
K., Marriott, A., and A. Zaytsev, "Flight Trial
Demonstration of Seamless Aeronautical Networking", IEEE
Communications Magazine, vol. 52, no. 5 , May 2014.
[Profinet]
http://us.profinet.com/technology/profinet/, "PROFINET is
a standard for industrial networking in automation.",
<http://us.profinet.com/technology/profinet/>.
[RFC7554] Watteyne, T., Ed., Palattella, M., and L. Grieco, "Using
IEEE 802.15.4e Time-Slotted Channel Hopping (TSCH) in the
Internet of Things (IoT): Problem Statement", RFC 7554,
DOI 10.17487/RFC7554, May 2015,
<https://www.rfc-editor.org/info/rfc7554>.
[RFC8557] Finn, N. and P. Thubert, "Deterministic Networking Problem
Statement", RFC 8557, DOI 10.17487/RFC8557, May 2019,
<https://www.rfc-editor.org/info/rfc8557>.
[RFC8578] Grossman, E., Ed., "Deterministic Networking Use Cases",
RFC 8578, DOI 10.17487/RFC8578, May 2019,
<https://www.rfc-editor.org/info/rfc8578>.
[RFC8655] Finn, N., Thubert, P., Varga, B., and J. Farkas,
"Deterministic Networking Architecture", RFC 8655,
DOI 10.17487/RFC8655, October 2019,
<https://www.rfc-editor.org/info/rfc8655>.
Papadopoulos, et al. Expires January 12, 2021 [Page 21]
Internet-Draft RAW use cases scenarios July 2020
[robots] Kober, J., Glisson, M., and M. Mistry, "Playing catch and
juggling with a humanoid robot.", 2012,
<https://doi.org/10.1109/HUMANOIDS.2012.6651623>.
[square-peg]
Martinez, B., Cano, C., and X. Vilajosana, "A Square Peg
in a Round Hole: The Complex Path for Wireless in the
Manufacturing Industry", 2019,
<https://ieeexplore.ieee.org/document/8703476>.
Authors' Addresses
Georgios Z. Papadopoulos
IMT Atlantique
Office B00 - 114A
2 Rue de la Chataigneraie
Cesson-Sevigne - Rennes 35510
FRANCE
Phone: +33 299 12 70 04
Email: georgios.papadopoulos@imt-atlantique.fr
Pascal Thubert
Cisco Systems, Inc
Building D
45 Allee des Ormes - BP1200
MOUGINS - Sophia Antipolis 06254
FRANCE
Phone: +33 497 23 26 34
Email: pthubert@cisco.com
Fabrice Theoleyre
CNRS
ICube Lab, Pole API
300 boulevard Sebastien Brant - CS 10413
Illkirch 67400
FRANCE
Phone: +33 368 85 45 33
Email: theoleyre@unistra.fr
URI: http://www.theoleyre.eu
Papadopoulos, et al. Expires January 12, 2021 [Page 22]
Internet-Draft RAW use cases scenarios July 2020
Carlos J. Bernardos
Universidad Carlos III de Madrid
Av. Universidad, 30
Leganes, Madrid 28911
Spain
Phone: +34 91624 6236
Email: cjbc@it.uc3m.es
URI: http://www.it.uc3m.es/cjbc/
Papadopoulos, et al. Expires January 12, 2021 [Page 23]
