draft-ietf-detnet-use-cases-07.txt   draft-ietf-detnet-use-cases-08.txt 
Internet Engineering Task Force E. Grossman, Ed. Internet Engineering Task Force E. Grossman, Ed.
Internet-Draft DOLBY Internet-Draft DOLBY
Intended status: Informational C. Gunther Intended status: Informational C. Gunther
Expires: September 6, 2016 HARMAN Expires: September 8, 2016 HARMAN
P. Thubert P. Thubert
P. Wetterwald P. Wetterwald
CISCO CISCO
J. Raymond J. Raymond
HYDRO-QUEBEC HYDRO-QUEBEC
J. Korhonen J. Korhonen
BROADCOM BROADCOM
Y. Kaneko Y. Kaneko
Toshiba Toshiba
S. Das S. Das
Applied Communication Sciences Applied Communication Sciences
Y. Zha Y. Zha
HUAWEI HUAWEI
B. Varga B. Varga
J. Farkas J. Farkas
Ericsson Ericsson
F. Goetz F. Goetz
J. Schmitt J. Schmitt
Siemens Siemens
March 5, 2016 March 7, 2016
Deterministic Networking Use Cases Deterministic Networking Use Cases
draft-ietf-detnet-use-cases-07 draft-ietf-detnet-use-cases-08
Abstract Abstract
This draft documents requirements in several diverse industries to This draft documents requirements in several diverse industries to
establish multi-hop paths for characterized flows with deterministic establish multi-hop paths for characterized flows with deterministic
properties. In this context deterministic implies that streams can properties. In this context deterministic implies that streams can
be established which provide guaranteed bandwidth and latency which be established which provide guaranteed bandwidth and latency which
can be established from either a Layer 2 or Layer 3 (IP) interface, can be established from either a Layer 2 or Layer 3 (IP) interface,
and which can co-exist on an IP network with best-effort traffic. and which can co-exist on an IP network with best-effort traffic.
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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 http://datatracker.ietf.org/drafts/current/. Drafts is at http://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 September 6, 2016. This Internet-Draft will expire on September 8, 2016.
Copyright Notice Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the Copyright (c) 2016 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 Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 5
2. Pro Audio and Video . . . . . . . . . . . . . . . . . . . . . 5 2. Pro Audio and Video . . . . . . . . . . . . . . . . . . . . . 5
2.1. Use Case Description . . . . . . . . . . . . . . . . . . 5 2.1. Use Case Description . . . . . . . . . . . . . . . . . . 5
2.1.1. Uninterrupted Stream Playback . . . . . . . . . . . . 6 2.1.1. Uninterrupted Stream Playback . . . . . . . . . . . . 6
2.1.2. Synchronized Stream Playback . . . . . . . . . . . . 7 2.1.2. Synchronized Stream Playback . . . . . . . . . . . . 6
2.1.3. Sound Reinforcement . . . . . . . . . . . . . . . . . 7 2.1.3. Sound Reinforcement . . . . . . . . . . . . . . . . . 7
2.1.4. Deterministic Time to Establish Streaming . . . . . . 8 2.1.4. Deterministic Time to Establish Streaming . . . . . . 7
2.1.5. Secure Transmission . . . . . . . . . . . . . . . . . 8 2.1.5. Secure Transmission . . . . . . . . . . . . . . . . . 8
2.1.5.1. Safety . . . . . . . . . . . . . . . . . . . . . 8 2.1.5.1. Safety . . . . . . . . . . . . . . . . . . . . . 8
2.1.5.2. Digital Rights Management (DRM) . . . . . . . . . 8 2.1.5.2. Digital Rights Management (DRM) . . . . . . . . . 8
2.2. Pro Audio Today . . . . . . . . . . . . . . . . . . . . . 9 2.2. Pro Audio Today . . . . . . . . . . . . . . . . . . . . . 9
2.3. Pro Audio Future . . . . . . . . . . . . . . . . . . . . 9 2.3. Pro Audio Future . . . . . . . . . . . . . . . . . . . . 9
2.3.1. Layer 3 Interconnecting Layer 2 Islands . . . . . . . 9 2.3.1. Layer 3 Interconnecting Layer 2 Islands . . . . . . . 9
2.3.2. High Reliability Stream Paths . . . . . . . . . . . . 9 2.3.2. High Reliability Stream Paths . . . . . . . . . . . . 9
2.3.3. Link Aggregation . . . . . . . . . . . . . . . . . . 10 2.3.3. Link Aggregation . . . . . . . . . . . . . . . . . . 9
2.3.4. Integration of Reserved Streams into IT Networks . . 10 2.3.4. Integration of Reserved Streams into IT Networks . . 10
2.3.5. Use of Unused Reservations by Best-Effort Traffic . . 10 2.3.5. Use of Unused Reservations by Best-Effort Traffic . . 10
2.3.6. Traffic Segregation . . . . . . . . . . . . . . . . . 10 2.3.6. Traffic Segregation . . . . . . . . . . . . . . . . . 10
2.3.6.1. Packet Forwarding Rules, VLANs and Subnets . . . 11 2.3.6.1. Packet Forwarding Rules, VLANs and Subnets . . . 11
2.3.6.2. Multicast Addressing (IPv4 and IPv6) . . . . . . 11 2.3.6.2. Multicast Addressing (IPv4 and IPv6) . . . . . . 11
2.3.7. Latency Optimization by a Central Controller . . . . 11 2.3.7. Latency Optimization by a Central Controller . . . . 11
2.3.8. Reduced Device Cost Due To Reduced Buffer Memory . . 12 2.3.8. Reduced Device Cost Due To Reduced Buffer Memory . . 12
2.4. Pro Audio Asks . . . . . . . . . . . . . . . . . . . . . 12 2.4. Pro Audio Asks . . . . . . . . . . . . . . . . . . . . . 12
3. Electrical Utilities . . . . . . . . . . . . . . . . . . . . 12 3. Electrical Utilities . . . . . . . . . . . . . . . . . . . . 12
3.1. Use Case Description . . . . . . . . . . . . . . . . . . 12 3.1. Use Case Description . . . . . . . . . . . . . . . . . . 12
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5.3.1. Unified Wireless Network and Management . . . . . . . 39 5.3.1. Unified Wireless Network and Management . . . . . . . 39
5.3.1.1. PCE and 6TiSCH ARQ Retries . . . . . . . . . . . 41 5.3.1.1. PCE and 6TiSCH ARQ Retries . . . . . . . . . . . 41
5.3.2. Schedule Management by a PCE . . . . . . . . . . . . 42 5.3.2. Schedule Management by a PCE . . . . . . . . . . . . 42
5.3.2.1. PCE Commands and 6TiSCH CoAP Requests . . . . . . 42 5.3.2.1. PCE Commands and 6TiSCH CoAP Requests . . . . . . 42
5.3.2.2. 6TiSCH IP Interface . . . . . . . . . . . . . . . 43 5.3.2.2. 6TiSCH IP Interface . . . . . . . . . . . . . . . 43
5.3.3. 6TiSCH Security Considerations . . . . . . . . . . . 43 5.3.3. 6TiSCH Security Considerations . . . . . . . . . . . 43
5.4. Wireless Industrial Asks . . . . . . . . . . . . . . . . 44 5.4. Wireless Industrial Asks . . . . . . . . . . . . . . . . 44
6. Cellular Radio Use Cases . . . . . . . . . . . . . . . . . . 44 6. Cellular Radio Use Cases . . . . . . . . . . . . . . . . . . 44
6.1. Use Case Description . . . . . . . . . . . . . . . . . . 44 6.1. Use Case Description . . . . . . . . . . . . . . . . . . 44
6.1.1. Network Architecture . . . . . . . . . . . . . . . . 44 6.1.1. Network Architecture . . . . . . . . . . . . . . . . 44
6.1.2. Time Synchronization Requirements . . . . . . . . . . 45 6.1.2. Delay Constraints . . . . . . . . . . . . . . . . . . 45
6.1.3. Time-Sensitive Stream Requirements . . . . . . . . . 47 6.1.3. Time Synchronization Constraints . . . . . . . . . . 46
6.1.4. Security Considerations . . . . . . . . . . . . . . . 47 6.1.4. Transport Loss Constraints . . . . . . . . . . . . . 48
6.1.5. Security Considerations . . . . . . . . . . . . . . . 48
6.2. Cellular Radio Networks Today . . . . . . . . . . . . . . 48 6.2. Cellular Radio Networks Today . . . . . . . . . . . . . . 48
6.3. Cellular Radio Networks Future . . . . . . . . . . . . . 48 6.2.1. Fronthaul . . . . . . . . . . . . . . . . . . . . . . 48
6.4. Cellular Radio Networks Asks . . . . . . . . . . . . . . 50 6.2.2. Midhaul and Backhaul . . . . . . . . . . . . . . . . 49
7. Cellular Coordinated Multipoint Processing (CoMP) . . . . . . 50 6.3. Cellular Radio Networks Future . . . . . . . . . . . . . 49
7.1. Use Case Description . . . . . . . . . . . . . . . . . . 50 6.4. Cellular Radio Networks Asks . . . . . . . . . . . . . . 51
7.1.1. CoMP Architecture . . . . . . . . . . . . . . . . . . 51 7. Industrial M2M . . . . . . . . . . . . . . . . . . . . . . . 52
7.1.2. Delay Sensitivity in CoMP . . . . . . . . . . . . . . 52 7.1. Use Case Description . . . . . . . . . . . . . . . . . . 52
7.2. CoMP Today . . . . . . . . . . . . . . . . . . . . . . . 52 7.2. Industrial M2M Communication Today . . . . . . . . . . . 53
7.3. CoMP Future . . . . . . . . . . . . . . . . . . . . . . . 52 7.2.1. Transport Parameters . . . . . . . . . . . . . . . . 53
7.3.1. Mobile Industry Overall Goals . . . . . . . . . . . . 52 7.2.2. Stream Creation and Destruction . . . . . . . . . . . 54
7.3.2. CoMP Infrastructure Goals . . . . . . . . . . . . . . 53 7.3. Industrial M2M Future . . . . . . . . . . . . . . . . . . 54
7.4. CoMP Asks . . . . . . . . . . . . . . . . . . . . . . . . 53 7.4. Industrial M2M Asks . . . . . . . . . . . . . . . . . . . 54
8. Industrial M2M . . . . . . . . . . . . . . . . . . . . . . . 54 8. Internet-based Applications . . . . . . . . . . . . . . . . . 55
8.1. Use Case Description . . . . . . . . . . . . . . . . . . 54 8.1. Use Case Description . . . . . . . . . . . . . . . . . . 55
8.2. Industrial M2M Communication Today . . . . . . . . . . . 55 8.1.1. Media Content Delivery . . . . . . . . . . . . . . . 55
8.2.1. Transport Parameters . . . . . . . . . . . . . . . . 55 8.1.2. Online Gaming . . . . . . . . . . . . . . . . . . . . 55
8.2.2. Stream Creation and Destruction . . . . . . . . . . . 56 8.1.3. Virtual Reality . . . . . . . . . . . . . . . . . . . 55
8.3. Industrial M2M Future . . . . . . . . . . . . . . . . . . 56 8.2. Internet-Based Applications Today . . . . . . . . . . . . 55
8.4. Industrial M2M Asks . . . . . . . . . . . . . . . . . . . 57 8.3. Internet-Based Applications Future . . . . . . . . . . . 55
9. Internet-based Applications . . . . . . . . . . . . . . . . . 57 8.4. Internet-Based Applications Asks . . . . . . . . . . . . 56
9.1. Use Case Description . . . . . . . . . . . . . . . . . . 57 9. Use Case Common Elements . . . . . . . . . . . . . . . . . . 56
9.1.1. Media Content Delivery . . . . . . . . . . . . . . . 57 10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 57
9.1.2. Online Gaming . . . . . . . . . . . . . . . . . . . . 57 10.1. Pro Audio . . . . . . . . . . . . . . . . . . . . . . . 57
9.1.3. Virtual Reality . . . . . . . . . . . . . . . . . . . 57 10.2. Utility Telecom . . . . . . . . . . . . . . . . . . . . 57
9.2. Internet-Based Applications Today . . . . . . . . . . . . 58 10.3. Building Automation Systems . . . . . . . . . . . . . . 58
9.3. Internet-Based Applications Future . . . . . . . . . . . 58 10.4. Wireless for Industrial . . . . . . . . . . . . . . . . 58
9.4. Internet-Based Applications Asks . . . . . . . . . . . . 58 10.5. Cellular Radio . . . . . . . . . . . . . . . . . . . . . 58
10. Use Case Common Elements . . . . . . . . . . . . . . . . . . 58 10.6. Industrial M2M . . . . . . . . . . . . . . . . . . . . . 58
11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 59 10.7. Internet Applications and CoMP . . . . . . . . . . . . . 58
11.1. Pro Audio . . . . . . . . . . . . . . . . . . . . . . . 59 11. Informative References . . . . . . . . . . . . . . . . . . . 58
11.2. Utility Telecom . . . . . . . . . . . . . . . . . . . . 60 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 68
11.3. Building Automation Systems . . . . . . . . . . . . . . 60
11.4. Wireless for Industrial . . . . . . . . . . . . . . . . 60
11.5. Cellular Radio . . . . . . . . . . . . . . . . . . . . . 60
11.6. Industrial M2M . . . . . . . . . . . . . . . . . . . . . 60
11.7. Internet Applications and CoMP . . . . . . . . . . . . . 60
12. Informative References . . . . . . . . . . . . . . . . . . . 61
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 69
1. Introduction 1. Introduction
This draft presents use cases from diverse industries which have in This draft presents use cases from diverse industries which have in
common a need for deterministic streams, but which also differ common a need for deterministic streams, but which also differ
notably in their network topologies and specific desired behavior. notably in their network topologies and specific desired behavior.
Together, they provide broad industry context for DetNet and a Together, they provide broad industry context for DetNet and a
yardstick against which proposed DetNet designs can be measured (to yardstick against which proposed DetNet designs can be measured (to
what extent does a proposed design satisfy these various use cases?) what extent does a proposed design satisfy these various use cases?)
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( ` . ) ) \ ( ` . ) ) \
`--(___.-'\_____+---+ (small cell sites) `--(___.-'\_____+---+ (small cell sites)
\ |SCe|__Y \ |SCe|__Y
+---+ +---+ +---+ +---+
Y__|eNB|__Y Y__|eNB|__Y
+---+ +---+
Y_/ \_Y ("local" radios) Y_/ \_Y ("local" radios)
Figure 7: Generic 3GPP-based Cellular Network Architecture Figure 7: Generic 3GPP-based Cellular Network Architecture
6.1.2. Delay Constraints
The available processing time for Fronthaul networking overhead is The available processing time for Fronthaul networking overhead is
limited to the available time after the baseband processing of the limited to the available time after the baseband processing of the
radio frame has completed. For example in Long Term Evolution (LTE) radio frame has completed. For example in Long Term Evolution (LTE)
radio, processing of a radio frame is allocated 3ms, but typically radio, processing of a radio frame is allocated 3ms but typically the
the processing completes much earlier (<400us) allowing the remaining processing uses most of it, allowing only a small fraction to be used
time to be used by the Fronthaul network. This ultimately determines by the Fronthaul network (e.g. up to 250us one-way delay, though the
the distance the remote radio heads can be located from the base existing spec ([NGMN-fronth]) supports delay only up to 100us). This
stations (200us equals roughly 40 km of optical fiber-based ultimately determines the distance the remote radio heads can be
transport, thus round trip time is 2*200us = 400us). located from the base stations (e.g., 100us equals roughly 20 km of
optical fiber-based transport). Allocation options of the available
time budget between processing and transport are under heavy
discussions in the mobile industry.
The remainder of the "maximum delay budget" is consumed by all nodes For packet-based transport the allocated transport time (e.g. CPRI
would allow for 100us delay [CPRI-transp]) is consumed by all nodes
and buffering between the remote radio head and the baseband and buffering between the remote radio head and the baseband
processing, plus the distance-incurred delay. processing unit, plus the distance-incurred delay.
The baseband processing time and the available "delay budget" for the The baseband processing time and the available "delay budget" for the
fronthaul is likely to change in the forthcoming "5G" due to reduced fronthaul is likely to change in the forthcoming "5G" due to reduced
radio round trip times and other architectural and service radio round trip times and other architectural and service
requirements [NGMN]. requirements [NGMN].
6.1.2. Time Synchronization Requirements [METIS] documents the fundamental challenges as well as overall
technical goals of the future 5G mobile and wireless system as the
starting point. These future systems should support much higher data
volumes and rates and significantly lower end-to-end latency for 100x
more connected devices (at similar cost and energy consumption levels
as today's system).
For Midhaul connections, delay constraints are driven by Inter-Site
radio functions like Coordinated Multipoint Processing (CoMP, see
[CoMP]). CoMP reception and transmission is a framework in which
multiple geographically distributed antenna nodes cooperate to
improve the performance of the users served in the common cooperation
area. The design principal of CoMP is to extend the current single-
cell to multi-UE (User Equipment) transmission to a multi-cell-to-
multi-UEs transmission by base station cooperation.
CoMP has delay-sensitive performance parameters, which are "midhaul
latency" and "CSI (Channel State Information) reporting and
accuracy". The essential feature of CoMP is signaling between eNBs,
so Midhaul latency is the dominating limitation of CoMP performance.
Generally, CoMP can benefit from coordinated scheduling (either
distributed or centralized) of different cells if the signaling delay
between eNBs is within 1-10ms. This delay requirement is both rigid
and absolute because any uncertainty in delay will degrade the
performance significantly.
Inter-site CoMP is one of the key requirements for 5G and is also a
near-term goal for the current 4.5G network architecture.
6.1.3. Time Synchronization Constraints
Fronthaul time synchronization requirements are given by [TS25104], Fronthaul time synchronization requirements are given by [TS25104],
[TS36104], [TS36211], and [TS36133]. These can be summarized for the [TS36104], [TS36211], and [TS36133]. These can be summarized for the
current 3GPP LTE-based networks as: current 3GPP LTE-based networks as:
Delay Accuracy: Delay Accuracy:
+-8ns (i.e. +-1/32 Tc, where Tc is the UMTS Chip time of 1/3.84 +-8ns (i.e. +-1/32 Tc, where Tc is the UMTS Chip time of 1/3.84
MHz) resulting in a round trip accuracy of +-16ns. The value is MHz) resulting in a round trip accuracy of +-16ns. The value is
this low to meet the 3GPP Timing Alignment Error (TAE) measurement this low to meet the 3GPP Timing Alignment Error (TAE) measurement
requirements. requirements.
Packet Delay Variation: Timing Alignment Error:
Packet Delay Variation (PDV aka Jitter aka Timing Alignment Error) Timing Alignment Error (TAE) is problematic to Fronthaul networks
is problematic to Fronthaul networks and must be minimized. If and must be minimized. If the transport network cannot guarantee
the transport network cannot guarantee low enough PDV then low enough TAE then additional buffering has to be introduced at
additional buffering has to be introduced at the edges of the the edges of the network to buffer out the jitter. Buffering is
network to buffer out the jitter. Buffering is not desirable as not desirable as it reduces the total available delay budget.
it reduces the total available delay budget. Packet Delay Variation (PDV) requirements can be derived from TAE
for packet based Fronthaul networks.
* For multiple input multiple output (MIMO) or TX diversity * For multiple input multiple output (MIMO) or TX diversity
transmissions, at each carrier frequency, TAE shall not exceed transmissions, at each carrier frequency, TAE shall not exceed
65 ns (i.e. 1/4 Tc). 65 ns (i.e. 1/4 Tc).
* For intra-band contiguous carrier aggregation, with or without * For intra-band contiguous carrier aggregation, with or without
MIMO or TX diversity, TAE shall not exceed 130 ns (i.e. 1/2 MIMO or TX diversity, TAE shall not exceed 130 ns (i.e. 1/2
Tc). Tc).
* For intra-band non-contiguous carrier aggregation, with or * For intra-band non-contiguous carrier aggregation, with or
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Transport link contribution to radio frequency error: Transport link contribution to radio frequency error:
+-2 PPB. This value is considered to be "available" for the +-2 PPB. This value is considered to be "available" for the
Fronthaul link out of the total 50 PPB budget reserved for the Fronthaul link out of the total 50 PPB budget reserved for the
radio interface. Note: the reason that the transport link radio interface. Note: the reason that the transport link
contributes to radio frequency error is as follows. The current contributes to radio frequency error is as follows. The current
way of doing Fronthaul is from the radio unit to remote radio head way of doing Fronthaul is from the radio unit to remote radio head
directly. The remote radio head is essentially a passive device directly. The remote radio head is essentially a passive device
(without buffering etc.) The transport drives the antenna (without buffering etc.) The transport drives the antenna
directly by feeding it with samples and everything the transport directly by feeding it with samples and everything the transport
adds will be introduced to radio as-is. So if the transport adds will be introduced to radio as-is. So if the transport
causes additional frequence error that shows immediately on the causes additional frequency error that shows immediately on the
radio as well. radio as well.
The above listed time synchronization requirements are difficult to The above listed time synchronization requirements are difficult to
meet with point-to-point connected networks, and more difficult when meet with point-to-point connected networks, and more difficult when
the network includes multiple hops. It is expected that networks the network includes multiple hops. It is expected that networks
must include buffering at the ends of the connections as imposed by must include buffering at the ends of the connections as imposed by
the jitter requirements, since trying to meet the jitter requirements the jitter requirements, since trying to meet the jitter requirements
in every intermediate node is likely to be too costly. However, in every intermediate node is likely to be too costly. However,
every measure to reduce jitter and delay on the path makes it easier every measure to reduce jitter and delay on the path makes it easier
to meet the end-to-end requirements. to meet the end-to-end requirements.
In order to meet the timing requirements both senders and receivers In order to meet the timing requirements both senders and receivers
must remain time synchronized, demanding very accurate clock must remain time synchronized, demanding very accurate clock
distribution, for example support for IEEE 1588 transparent clocks in distribution, for example support for IEEE 1588 transparent clocks in
every intermediate node. every intermediate node.
In cellular networks from the LTE radio era onward, phase In cellular networks from the LTE radio era onward, phase
synchronization is needed in addition to frequency synchronization synchronization is needed in addition to frequency synchronization
([TS36300], [TS23401]). ([TS36300], [TS23401]).
6.1.3. Time-Sensitive Stream Requirements 6.1.4. Transport Loss Constraints
In addition to the time synchronization requirements listed in Fronthaul and Midhaul networks assume almost error-free transport.
Section Section 6.1.2 the Fronthaul networks assume practically Errors can result in a reset of the radio interfaces, which can cause
error-free transport. The maximum bit error rate (BER) has been reduced throughput or broken radio connectivity for mobile customers.
defined to be 10^-12. When packetized that would imply a packet
error rate (PER) of 2.4*10^-9 (assuming ~300 bytes packets). For packetized Fronthaul and Midhaul connections packet loss may be
Retransmitting lost packets and/or using forward error correction caused by BER, congestion, or network failure scenarios. Current
(FEC) to circumvent bit errors is practically impossible due to the tools for elminating packet loss for Fronthaul and Midhaul networks
additional delay incurred. Using redundant streams for better have serious challenges, for example retransmitting lost packets and/
guarantees for delivery is also practically impossible in many cases or using forward error correction (FEC) to circumvent bit errors is
due to high bandwidth requirements of Fronthaul networks. For practically impossible due to the additional delay incurred. Using
instance, current uncompressed CPRI bandwidth expansion ratio is redundant streams for better guarantees for delivery is also
roughly 20:1 compared to the IP layer user payload it carries. practically impossible in many cases due to high bandwidth
Protection switching is also a candidate but current technologies for requirements of Fronthaul and Midhaul networks. Protection switching
the path switch are too slow. We do not currently know of a better is also a candidate but current technologies for the path switch are
solution for this issue. too slow to avoid reset of mobile interfaces.
Fronthaul links are assumed to be symmetric, and all Fronthaul Fronthaul links are assumed to be symmetric, and all Fronthaul
streams (i.e. those carrying radio data) have equal priority and streams (i.e. those carrying radio data) have equal priority and
cannot delay or pre-empt each other. This implies that the network cannot delay or pre-empt each other. This implies that the network
must guarantee that each time-sensitive flow meets their schedule. must guarantee that each time-sensitive flow meets their schedule.
6.1.4. Security Considerations 6.1.5. Security Considerations
Establishing time-sensitive streams in the network entails reserving Establishing time-sensitive streams in the network entails reserving
networking resources for long periods of time. It is important that networking resources for long periods of time. It is important that
these reservation requests be authenticated to prevent malicious these reservation requests be authenticated to prevent malicious
reservation attempts from hostile nodes (or accidental reservation attempts from hostile nodes (or accidental
misconfiguration). This is particularly important in the case where misconfiguration). This is particularly important in the case where
the reservation requests span administrative domains. Furthermore, the reservation requests span administrative domains. Furthermore,
the reservation information itself should be digitally signed to the reservation information itself should be digitally signed to
reduce the risk of a legitimate node pushing a stale or hostile reduce the risk of a legitimate node pushing a stale or hostile
configuration into another networking node. configuration into another networking node.
6.2. Cellular Radio Networks Today 6.2. Cellular Radio Networks Today
6.2.1. Fronthaul
Today's Fronthaul networks typically consist of: Today's Fronthaul networks typically consist of:
o Dedicated point-to-point fiber connection is common o Dedicated point-to-point fiber connection is common
o Proprietary protocols and framings o Proprietary protocols and framings
o Custom equipment and no real networking o Custom equipment and no real networking
Current solutions for Fronthaul are direct optical cables or
Wavelength-Division Multiplexing (WDM) connections.
6.2.2. Midhaul and Backhaul
Today's Midhaul and Backhaul networks typically consist of: Today's Midhaul and Backhaul networks typically consist of:
o Mostly normal IP networks, MPLS-TP, etc. o Mostly normal IP networks, MPLS-TP, etc.
o Clock distribution and sync using 1588 and SyncE o Clock distribution and sync using 1588 and SyncE
Telecommunication networks in the cellular domain are already heading Telecommunication networks in the Mid- and Backhaul are already
towards transport networks where precise time synchronization support heading towards transport networks where precise time synchronization
is one of the basic building blocks. While the transport networks support is one of the basic building blocks. While the transport
themselves have practically transitioned to all-IP packet based networks themselves have practically transitioned to all-IP packet-
networks to meet the bandwidth and cost requirements, highly accurate based networks to meet the bandwidth and cost requirements, highly
clock distribution has become a challenge. accurate clock distribution has become a challenge.
Transport networks in the cellular domain are typically based on Time In the past, Mid- and Backhaul connections were typically based on
Division Multiplexing (TDM-based) and provide frequency Time Division Multiplexing (TDM-based) and provided frequency
synchronization capabilities as a part of the transport media. synchronization capabilities as a part of the transport media.
Alternatively other technologies such as Global Positioning System Alternatively other technologies such as Global Positioning System
(GPS) or Synchronous Ethernet (SyncE) are used [SyncE]. (GPS) or Synchronous Ethernet (SyncE) are used [SyncE].
Both Ethernet and IP/MPLS [RFC3031] (and PseudoWires (PWE) [RFC3985] Both Ethernet and IP/MPLS [RFC3031] (and PseudoWires (PWE) [RFC3985]
for legacy transport support) have become popular tools to build and for legacy transport support) have become popular tools to build and
manage new all-IP Radio Access Networks (RAN) manage new all-IP Radio Access Networks (RANs)
[I-D.kh-spring-ip-ran-use-case]. Although various timing and [I-D.kh-spring-ip-ran-use-case]. Although various timing and
synchronization optimizations have already been proposed and synchronization optimizations have already been proposed and
implemented including 1588 PTP enhancements implemented including 1588 PTP enhancements
[I-D.ietf-tictoc-1588overmpls][I-D.mirsky-mpls-residence-time], these [I-D.ietf-tictoc-1588overmpls] and [I-D.mirsky-mpls-residence-time],
solution are not necessarily sufficient for the forthcoming RAN these solution are not necessarily sufficient for the forthcoming RAN
architectures or guarantee the higher time-synchronization architectures nor do they guarantee the more stringent time-
requirements [CPRI]. There are also existing solutions for the TDM synchronization requirements such as [CPRI].
over IP [RFC5087] [RFC4553] or Ethernet transports [RFC5086].
There are also existing solutions for TDM over IP such as [RFC5087]
and [RFC4553], as well as TDM over Ethernet transports such as
[RFC5086].
6.3. Cellular Radio Networks Future 6.3. Cellular Radio Networks Future
Future Cellular Radio Networks will be based on a mix of different
xHaul networks (xHaul = front-, mid- and backhaul), and future
transport networks should be able to support all of them
simultaneously. It is already envisioned today that:
o Not all "cellular radio network" traffic will be IP, for example
some will remain at Layer 2 (e.g. Ethernet based). DetNet
solutions must address all traffic types (Layer 2, Layer 3) with
the same tools and allow their transport simultaneously.
o All form of xHaul networks will need some form of DetNet
solutions. For example with the advent of 5G some Backhaul
traffic will also have DetNet requirements (e.g. traffic belonging
to time-critical 5G applications).
We would like to see the following in future Cellular Radio networks: We would like to see the following in future Cellular Radio networks:
o Unified standards-based transport protocols and standard o Unified standards-based transport protocols and standard
networking equipment that can make use of underlying deterministic networking equipment that can make use of underlying deterministic
link-layer services link-layer services
o Unified and standards-based network management systems and o Unified and standards-based network management systems and
protocols in all parts of the network (including Fronthaul) protocols in all parts of the network (including Fronthaul)
New radio access network deployment models and architectures may New radio access network deployment models and architectures may
require time sensitive networking services with strict requirements require time- sensitive networking services with strict requirements
on other parts of the network that previously were not considered to on other parts of the network that previously were not considered to
be packetized at all. The time and synchronization support are be packetized at all. Time and synchronization support are already
already topical for Backhaul and Midhaul packet networks [MEF], and topical for Backhaul and Midhaul packet networks [MEF] and are
becoming a real issue for Fronthaul networks. Specifically in the becoming a real issue for Fronthaul networks also. Specifically in
Fronthaul networks the timing and synchronization requirements can be Fronthaul networks the timing and synchronization requirements can be
extreme for packet based technologies, for example, on the order of extreme for packet based technologies, for example, on the order of
sub +-20 ns packet delay variation (PDV) and frequency accuracy of sub +-20 ns packet delay variation (PDV) and frequency accuracy of
+0.002 PPM [Fronthaul]. +0.002 PPM [Fronthaul].
The actual transport protocols and/or solutions to establish required The actual transport protocols and/or solutions to establish required
transport "circuits" (pinned-down paths) for Fronthaul traffic are transport "circuits" (pinned-down paths) for Fronthaul traffic are
still undefined. Those are likely to include (but are not limited still undefined. Those are likely to include (but are not limited
to) solutions directly over Ethernet, over IP, and MPLS/PseudoWire to) solutions directly over Ethernet, over IP, and using MPLS/
transport. PseudoWire transport.
Even the current time-sensitive networking features may not be Even the current time-sensitive networking features may not be
sufficient for Fronthaul traffic. Therefore, having specific sufficient for Fronthaul traffic. Therefore, having specific
profiles that take the requirements of Fronthaul into account is profiles that take the requirements of Fronthaul into account is
desirable [IEEE8021CM]. desirable [IEEE8021CM].
The really interesting and important existing work for time sensitive Interesting and important work for time-sensitive networking has been
networking has been done for Ethernet [TSNTG], which specifies the done for Ethernet [TSNTG], which specifies the use of IEEE 1588 time
use of IEEE 1588 time precision protocol (PTP) [IEEE1588] in the precision protocol (PTP) [IEEE1588] in the context of IEEE 802.1D and
context of IEEE 802.1D and IEEE 802.1Q. While IEEE 802.1AS IEEE 802.1Q. [IEEE8021AS] specifies a Layer 2 time synchronizing
[IEEE8021AS] specifies a Layer-2 time synchronizing service other service, and other specifications such as IEEE 1722 [IEEE1722]
specification, such as IEEE 1722 [IEEE1722] specify Ethernet-based specify Ethernet-based Layer-2 transport for time-sensitive streams.
Layer-2 transport for time-sensitive streams. New promising work
seeks to enable the transport of time-sensitive fronthaul streams in
Ethernet bridged networks [IEEE8021CM]. Similarly to IEEE 1722 there
is an ongoing standardization effort to define Layer-2 transport
encapsulation format for transporting radio over Ethernet (RoE) in
IEEE 1904.3 Task Force [IEEE19043].
All-IP RANs and various "haul" networks would benefit from time New promising work seeks to enable the transport of time-sensitive
fronthaul streams in Ethernet bridged networks [IEEE8021CM].
Analogous to IEEE 1722 there is an ongoing standardization effort to
define the Layer-2 transport encapsulation format for transporting
radio over Ethernet (RoE) in the IEEE 1904.3 Task Force [IEEE19043].
All-IP RANs and xHhaul networks would benefit from time
synchronization and time-sensitive transport services. Although synchronization and time-sensitive transport services. Although
Ethernet appears to be the unifying technology for the transport Ethernet appears to be the unifying technology for the transport,
there is still a disconnect providing Layer-3 services. The protocol there is still a disconnect providing Layer 3 services. The protocol
stack typically has a number of layers below the Ethernet Layer-2 stack typically has a number of layers below the Ethernet Layer 2
that shows up to the Layer-3 IP transport. It is not uncommon that that shows up to the Layer 3 IP transport. It is not uncommon that
on top of the lowest layer (optical) transport there is the first on top of the lowest layer (optical) transport there is the first
layer of Ethernet followed one or more layers of MPLS, PseudoWires layer of Ethernet followed one or more layers of MPLS, PseudoWires
and/or other tunneling protocols finally carrying the Ethernet layer and/or other tunneling protocols finally carrying the Ethernet layer
visible to the user plane IP traffic. While there are existing visible to the user plane IP traffic.
technologies, especially in MPLS/PWE space, to establish circuits
through the routed and switched networks, there is a lack of While there are existing technologies to establish circuits through
signaling the time synchronization and time-sensitive stream the routed and switched networks (especially in MPLS/PWE space),
requirements/reservations for Layer-3 flows in a way that the entire there is still no way to signal the time synchronization and time-
transport stack is addressed and the Ethernet layers that needs to be sensitive stream requirements/reservations for Layer-3 flows in a way
configured are addressed. that addresses the entire transport stack, including the Ethernet
layers that need to be configured.
Furthermore, not all "user plane" traffic will be IP. Therefore, the Furthermore, not all "user plane" traffic will be IP. Therefore, the
same solution also must address the use cases where the user plane same solution also must address the use cases where the user plane
traffic is again another layer or Ethernet frames. There is existing traffic is a different layer, for example Ethernet frames.
work describing the problem statement
There is existing work describing the problem statement
[I-D.finn-detnet-problem-statement] and the architecture [I-D.finn-detnet-problem-statement] and the architecture
[I-D.finn-detnet-architecture] for deterministic networking (DetNet) [I-D.finn-detnet-architecture] for deterministic networking (DetNet)
that targets solutions for time-sensitive (IP/transport) streams with that targets solutions for time-sensitive (IP/transport) streams with
deterministic properties over Ethernet-based switched networks. deterministic properties over Ethernet-based switched networks.
6.4. Cellular Radio Networks Asks 6.4. Cellular Radio Networks Asks
A standard for data plane transport specification which is: A standard for data plane transport specification which is:
o Unified among all *hauls o Unified among all xHauls
o Deployed in a highly deterministic network environment o Deployed in a highly deterministic network environment
A standard for data flow information models that are: A standard for data flow information models that are:
o Aware of the time sensitivity and constraints of the target o Aware of the time sensitivity and constraints of the target
networking environment networking environment
o Aware of underlying deterministic networking services (e.g. on the o Aware of underlying deterministic networking services (e.g., on
Ethernet layer) the Ethernet layer)
Mapping the Fronthaul requirements to IETF DetNet
[I-D.finn-detnet-architecture] Section 3 "Providing the DetNet
Quality of Service", the relevant features are:
o Zero congestion loss.
o Pinned-down paths.
7. Cellular Coordinated Multipoint Processing (CoMP) 7. Industrial M2M
7.1. Use Case Description 7.1. Use Case Description
In cellular wireless communication systems, Inter-Site Coordinated
Multipoint Processing (CoMP, see [CoMP]) is a technique implemented
within a cell site which improves system efficiency and user quality
experience by significantly improving throughput in the cell-edge
region (i.e. at the edges of that cell site's radio coverage area).
CoMP techniques depend on deterministic high-reliability
communication between cell sites, however such connections today are
IP-based which in current mobile networks can not meet the QoS
requirements, so CoMP is an emerging technology which can benefit
from DetNet.
Here we consider the JT (Joint Transmit) application for CoMP, which
provides the highest performance gain (compared to other
applications).
7.1.1. CoMP Architecture
+--------------------------+
| CoMP |
+--+--------------------+--+
| |
+----------+ +------------+
| Uplink | | Downlink |
+-----+----+ +--------+---+
| |
------------------- -----------------------
| | | | | |
+---------+ +----+ +-----+ +------------+ +-----+ +-----+
| Joint | | CS | | DPS | | Joint | | CS/ | | DPS |
|Reception| | | | | |Transmission| | CB | | |
+---------+ +----+ +-----+ +------------+ +-----+ +-----+
| |
|----------- |-------------
| | | |
+------------+ +---------+ +----------+ +------------+
| Joint | | Soft | | Coherent | | Non- |
|Equalization| |Combining| | JT | | Coherent JT|
+------------+ +---------+ +----------+ +------------+
Figure 8: Framework of CoMP Technology
As shown in Figure 8, CoMP reception and transmission is a framework
in which multiple geographically distributed antenna nodes cooperate
to improve the performance of the users served in the common
cooperation area. The design principal of CoMP is to extend the
current single-cell to multi-UE (User Equipment) transmission to a
multi-cell- to-multi-UEs transmission by base station cooperation.
7.1.2. Delay Sensitivity in CoMP
In contrast to the single-cell scenario, CoMP has delay-sensitive
performance parameters, which are "backhaul latency" and "CSI
(Channel State Information) reporting and accuracy". The essential
feature of CoMP is signaling between eNBs, so the backhaul latency is
the dominating limitation of the CoMP performance. Generally, JT can
benefit from coordinated scheduling (either distributed or
centralized) of different cells if the signaling delay between eNBs
is within 4-10ms. This delay requirement is both rigid and absolute
because any uncertainty in delay will degrade the performance
significantly.
7.2. CoMP Today
Due to the strict sensitivity to latency and synchronization, CoMP
between eNB has not been deployed yet. This is because the current
interface path between eNBs cannot meet the delay bound because it is
usually IP-based and passing through multiple network hops (this
interface is called "X2" or "eX2" for "enhanced X2"). Today lack of
absolute delay guarantee on X2/eX2 traffic is the main obstacle to JT
and multi-eNB coordination.
There is still lack of Layer-3 (IP) transport protocol and signaling
that is capable of low latency services; current techniques such as
MPLS and PWE focus on establishing circuits using pre-routed paths
but there is no such signaling for reservation of time-sensitive
stream.
7.3. CoMP Future
7.3.1. Mobile Industry Overall Goals
[METIS] documents the fundamental challenges as well as overall
technical goals of the 5G mobile and wireless system as the starting
point. These future systems should support (at similar cost and
energy consumption levels as today's system):
o 1000 times higher mobile data volume per area
o 10 times to 100 times higher typical user data rate
o 10 times to 100 times higher number of connected devices
o 10 times longer battery life for low power devices
o 5 times reduced End-to-End (E2E) latency
The current LTE networking system has E2E latency less than 20ms
[LTE-Latency] which leads to around 5ms E2E latency for 5G networks.
To fulfill these latency demands at similar cost will be challenging
because as the system also requires 100x bandwidth and 100x connected
devices, simply adding redundant bandwidth provisioning can no longer
be an efficient solution.
In addition to bandwidth provisioning, reserved critical flows should
not be affected by other flows no matter the pressure of the network.
Deterministic networking techniques in both layer-2 and layer-3 using
IETF protocol solutions can be promising to serve these scenarios.
7.3.2. CoMP Infrastructure Goals
Inter-site CoMP is one of the key requirements for 5G and is also a
near-term goal for the current 4.5G network architecture. Assuming
network architecture remains unchanged (i.e. no Fronthaul network and
data flow between eNB is via X2/eX2) we would like to see the
following in the near future:
o Unified protocols and delay-guaranteed forwarding network
equipment that is capable of delivering deterministic latency
services.
o Unified management and protocols which take delay and timing into
account.
o Unified deterministic latency data model and signaling for
resource reservation.
7.4. CoMP Asks
To fully utilize the power of CoMP, it requires:
o Very tight absolute delay bound (100-500us) within 7-10 hops.
o Standardized data plane with highly deterministic networking
capability.
o Standardized control plane to unify backhaul network elements with
time-sensitive stream reservation signaling.
In addition, a standardized deterministic latency data flow model
that includes:
o Network-aware constraints on the networking environment
o Time-aware description of flow characteristics and network
resources, which may not need to be bandwidth based
o Application-aware description of deterministic latency services.
8. Industrial M2M
8.1. Use Case Description
Industrial Automation in general refers to automation of Industrial Automation in general refers to automation of
manufacturing, quality control and material processing. In this manufacturing, quality control and material processing. In this
"machine to machine" (M2M) use case we consider machine units in a "machine to machine" (M2M) use case we consider machine units in a
plant floor which periodically exchange data with upstream or plant floor which periodically exchange data with upstream or
downstream machine modules and/or a supervisory controller within a downstream machine modules and/or a supervisory controller within a
local area network. local area network.
The actors of M2M communication are Programmable Logic Controllers The actors of M2M communication are Programmable Logic Controllers
(PLCs). Communication between PLCs and between PLCs and the (PLCs). Communication between PLCs and between PLCs and the
supervisory PLC (S-PLC) is achieved via critical control/data streams supervisory PLC (S-PLC) is achieved via critical control/data streams
Figure 9. Figure 8.
S (Sensor) S (Sensor)
\ +-----+ \ +-----+
PLC__ \.--. .--. ---| MES | PLC__ \.--. .--. ---| MES |
\_( `. _( `./ +-----+ \_( `. _( `./ +-----+
A------( Local )-------------( L2 ) A------( Local )-------------( L2 )
( Net ) ( Net ) +-------+ ( Net ) ( Net ) +-------+
/`--(___.-' `--(___.-' ----| S-PLC | /`--(___.-' `--(___.-' ----| S-PLC |
S_/ / PLC .--. / +-------+ S_/ / PLC .--. / +-------+
A_/ \_( `. A_/ \_( `.
(Actuator) ( Local ) (Actuator) ( Local )
( Net ) ( Net )
/`--(___.-'\ /`--(___.-'\
/ \ A / \ A
S A S A
Figure 9: Current Generic Industrial M2M Network Architecture Figure 8: Current Generic Industrial M2M Network Architecture
This use case focuses on PLC-related communications; communication to This use case focuses on PLC-related communications; communication to
Manufacturing-Execution-Systems (MESs) are not addressed. Manufacturing-Execution-Systems (MESs) are not addressed.
This use case covers only critical control/data streams; non-critical This use case covers only critical control/data streams; non-critical
traffic between industrial automation applications (such as traffic between industrial automation applications (such as
communication of state, configuration, set-up, and database communication of state, configuration, set-up, and database
communication) are adequately served by currently available communication) are adequately served by currently available
prioritizing techniques. Such traffic can use up to 80% of the total prioritizing techniques. Such traffic can use up to 80% of the total
bandwidth required. There is also a subset of non-time-critical bandwidth required. There is also a subset of non-time-critical
skipping to change at page 55, line 18 skipping to change at page 53, line 12
provide end-to-end delivery of M2M messages within specific timing provide end-to-end delivery of M2M messages within specific timing
constraints, for example in closed loop automation control. Today constraints, for example in closed loop automation control. Today
this level of determinism is provided by proprietary networking this level of determinism is provided by proprietary networking
technologies. In addition, standard networking technologies are used technologies. In addition, standard networking technologies are used
to connect the local network to remote industrial automation sites, to connect the local network to remote industrial automation sites,
e.g. over an enterprise or metro network which also carries other e.g. over an enterprise or metro network which also carries other
types of traffic. Therefore, flows that should be forwarded with types of traffic. Therefore, flows that should be forwarded with
deterministic guarantees need to be sustained regardless of the deterministic guarantees need to be sustained regardless of the
amount of other flows in those networks. amount of other flows in those networks.
8.2. Industrial M2M Communication Today 7.2. Industrial M2M Communication Today
Today, proprietary networks fulfill the needed timing and Today, proprietary networks fulfill the needed timing and
availability for M2M networks. availability for M2M networks.
The network topologies used today by industrial automation are The network topologies used today by industrial automation are
similar to those used by telecom networks: Daisy Chain, Ring, Hub and similar to those used by telecom networks: Daisy Chain, Ring, Hub and
Spoke, and Comb (a subset of Daisy Chain). Spoke, and Comb (a subset of Daisy Chain).
PLC-related control/data streams are transmitted periodically and PLC-related control/data streams are transmitted periodically and
carry either a pre-configured payload or a payload configured during carry either a pre-configured payload or a payload configured during
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nodes. For such time-coordinated PLCs, accuracy of 1 microsecond is nodes. For such time-coordinated PLCs, accuracy of 1 microsecond is
required. Even in the case of "non-time-coordinated" PLCs time sync required. Even in the case of "non-time-coordinated" PLCs time sync
may be needed e.g. for timestamping of sensor data. may be needed e.g. for timestamping of sensor data.
Industrial network scenarios require advanced security solutions. Industrial network scenarios require advanced security solutions.
Many of the current industrial production networks are physically Many of the current industrial production networks are physically
separated. Preventing critical flows from be leaked outside a domain separated. Preventing critical flows from be leaked outside a domain
is handled today by filtering policies that are typically enforced in is handled today by filtering policies that are typically enforced in
firewalls. firewalls.
8.2.1. Transport Parameters 7.2.1. Transport Parameters
The Cycle Time defines the frequency of message(s) between industrial The Cycle Time defines the frequency of message(s) between industrial
actors. The Cycle Time is application dependent, in the range of 1ms actors. The Cycle Time is application dependent, in the range of 1ms
- 100ms for critical control/data streams. - 100ms for critical control/data streams.
Because industrial applications assume deterministic transport for Because industrial applications assume deterministic transport for
critical Control-Data-Stream parameters (instead of defining latency critical Control-Data-Stream parameters (instead of defining latency
and delay variation parameters) it is sufficient to fulfill the upper and delay variation parameters) it is sufficient to fulfill the upper
bound of latency (maximum latency). The underlying networking bound of latency (maximum latency). The underlying networking
infrastructure must ensure a maximum end-to-end delivery time of infrastructure must ensure a maximum end-to-end delivery time of
skipping to change at page 56, line 31 skipping to change at page 54, line 25
"down" by the Application. "down" by the Application.
As network downtime may impact the whole production system the As network downtime may impact the whole production system the
required network availability is rather high (99,999%). required network availability is rather high (99,999%).
Based on the above parameters we expect that some form of redundancy Based on the above parameters we expect that some form of redundancy
will be required for M2M communications, however any individual will be required for M2M communications, however any individual
solution depends on several parameters including cycle time, delivery solution depends on several parameters including cycle time, delivery
time, etc. time, etc.
8.2.2. Stream Creation and Destruction 7.2.2. Stream Creation and Destruction
In an industrial environment, critical control/data streams are In an industrial environment, critical control/data streams are
created rather infrequently, on the order of ~10 times per day / week created rather infrequently, on the order of ~10 times per day / week
/ month. Most of these critical control/data streams get created at / month. Most of these critical control/data streams get created at
machine startup, however flexibility is also needed during runtime, machine startup, however flexibility is also needed during runtime,
for example when adding or removing a machine. Going forward as for example when adding or removing a machine. Going forward as
production systems become more flexible, we expect a significant production systems become more flexible, we expect a significant
increase in the rate at which streams are created, changed and increase in the rate at which streams are created, changed and
destroyed. destroyed.
8.3. Industrial M2M Future 7.3. Industrial M2M Future
We would like to see a converged IP-standards-based network with We would like to see a converged IP-standards-based network with
deterministic properties that can satisfy the timing, security and deterministic properties that can satisfy the timing, security and
reliability constraints described above. Today's proprietary reliability constraints described above. Today's proprietary
networks could then be interfaced to such a network via gateways or, networks could then be interfaced to such a network via gateways or,
in the case of new installations, devices could be connected directly in the case of new installations, devices could be connected directly
to the converged network. to the converged network.
8.4. Industrial M2M Asks 7.4. Industrial M2M Asks
o Converged IP-based network o Converged IP-based network
o Deterministic behavior (bounded latency and jitter ) o Deterministic behavior (bounded latency and jitter )
o High availability (presumably through redundancy) (99.999 %) o High availability (presumably through redundancy) (99.999 %)
o Low message delivery time (100us - 50ms) o Low message delivery time (100us - 50ms)
o Low packet loss (burstless, 0.1-1 %) o Low packet loss (burstless, 0.1-1 %)
o Precise time synchronization accuracy (1us) o Precise time synchronization accuracy (1us)
o Security (e.g. prevent critical flows from being leaked between o Security (e.g. prevent critical flows from being leaked between
physically separated networks) physically separated networks)
9. Internet-based Applications 8. Internet-based Applications
9.1. Use Case Description 8.1. Use Case Description
There are many applications that communicate across the open Internet There are many applications that communicate across the open Internet
that could benefit from guaranteed delivery and bounded latency. The that could benefit from guaranteed delivery and bounded latency. The
following are some representative examples. following are some representative examples.
9.1.1. Media Content Delivery 8.1.1. Media Content Delivery
Media content delivery continues to be an important use of the Media content delivery continues to be an important use of the
Internet, yet users often experience poor quality audio and video due Internet, yet users often experience poor quality audio and video due
to the delay and jitter inherent in today's Internet. to the delay and jitter inherent in today's Internet.
9.1.2. Online Gaming 8.1.2. Online Gaming
Online gaming is a significant part of the gaming market, however Online gaming is a significant part of the gaming market, however
latency can degrade the end user experience. For example "First latency can degrade the end user experience. For example "First
Person Shooter" (FPS) games are highly delay-sensitive. Person Shooter" (FPS) games are highly delay-sensitive.
9.1.3. Virtual Reality 8.1.3. Virtual Reality
Virtual reality (VR) has many commercial applications including real Virtual reality (VR) has many commercial applications including real
estate presentations, remote medical procedures, and so on. Low estate presentations, remote medical procedures, and so on. Low
latency is critical to interacting with the virtual world because latency is critical to interacting with the virtual world because
perceptual delays can cause motion sickness. perceptual delays can cause motion sickness.
9.2. Internet-Based Applications Today 8.2. Internet-Based Applications Today
Internet service today is by definition "best effort", with no Internet service today is by definition "best effort", with no
guarantees on delivery or bandwidth. guarantees on delivery or bandwidth.
9.3. Internet-Based Applications Future 8.3. Internet-Based Applications Future
We imagine an Internet from which we will be able to play a video We imagine an Internet from which we will be able to play a video
without glitches and play games without lag. without glitches and play games without lag.
For online gaming, the maximum round-trip delay can be 100ms and For online gaming, the maximum round-trip delay can be 100ms and
stricter for FPS gaming which can be 10-50ms. Transport delay is the stricter for FPS gaming which can be 10-50ms. Transport delay is the
dominate part with a 5-20ms budget. dominate part with a 5-20ms budget.
For VR, 1-10ms maximum delay is needed and total network budget is For VR, 1-10ms maximum delay is needed and total network budget is
1-5ms if doing remote VR. 1-5ms if doing remote VR.
Flow identification can be used for gaming and VR, i.e. it can Flow identification can be used for gaming and VR, i.e. it can
recognize a critical flow and provide appropriate latency bounds. recognize a critical flow and provide appropriate latency bounds.
9.4. Internet-Based Applications Asks 8.4. Internet-Based Applications Asks
o Unified control and management protocols to handle time-critical o Unified control and management protocols to handle time-critical
data flow data flow
o Application-aware flow filtering mechanism to recognize the timing o Application-aware flow filtering mechanism to recognize the timing
critical flow without doing 5-tuple matching critical flow without doing 5-tuple matching
o Unified control plane to provide low latency service on Layer-3 o Unified control plane to provide low latency service on Layer-3
without changing the data plane without changing the data plane
o OAM system and protocols which can help to provide E2E-delay o OAM system and protocols which can help to provide E2E-delay
sensitive service provisioning sensitive service provisioning
10. Use Case Common Elements 9. Use Case Common Elements
Looking at the use cases collectively, the following common desires Looking at the use cases collectively, the following common desires
for the DetNet-based networks of the future emerge: for the DetNet-based networks of the future emerge:
o Open standards-based network (replace various proprietary o Open standards-based network (replace various proprietary
networks, reduce cost, create multi-vendor market) networks, reduce cost, create multi-vendor market)
o Centrally administered (though such administration may be o Centrally administered (though such administration may be
distributed for scale and resiliency) distributed for scale and resiliency)
skipping to change at page 59, line 35 skipping to change at page 57, line 26
loops may be less than 1ms, but larger for wide area networks) loops may be less than 1ms, but larger for wide area networks)
o High availability (99.9999 percent up time requested, but may be o High availability (99.9999 percent up time requested, but may be
up to twelve 9s) up to twelve 9s)
o Reliability, redundancy (lives at stake) o Reliability, redundancy (lives at stake)
o Security (from failures, attackers, misbehaving devices - o Security (from failures, attackers, misbehaving devices -
sensitive to both packet content and arrival time) sensitive to both packet content and arrival time)
11. Acknowledgments 10. Acknowledgments
11.1. Pro Audio 10.1. Pro Audio
This section was derived from draft-gunther-detnet-proaudio-req-01. This section was derived from draft-gunther-detnet-proaudio-req-01.
The editors would like to acknowledge the help of the following The editors would like to acknowledge the help of the following
individuals and the companies they represent: individuals and the companies they represent:
Jeff Koftinoff, Meyer Sound Jeff Koftinoff, Meyer Sound
Jouni Korhonen, Associate Technical Director, Broadcom Jouni Korhonen, Associate Technical Director, Broadcom
Pascal Thubert, CTAO, Cisco Pascal Thubert, CTAO, Cisco
Kieran Tyrrell, Sienda New Media Technologies GmbH Kieran Tyrrell, Sienda New Media Technologies GmbH
11.2. Utility Telecom 10.2. Utility Telecom
This section was derived from draft-wetterwald-detnet-utilities-reqs- This section was derived from draft-wetterwald-detnet-utilities-reqs-
02. 02.
Faramarz Maghsoodlou, Ph. D. IoT Connected Industries and Energy Faramarz Maghsoodlou, Ph. D. IoT Connected Industries and Energy
Practice Cisco Practice Cisco
Pascal Thubert, CTAO Cisco Pascal Thubert, CTAO Cisco
11.3. Building Automation Systems 10.3. Building Automation Systems
This section was derived from draft-bas-usecase-detnet-00. This section was derived from draft-bas-usecase-detnet-00.
11.4. Wireless for Industrial 10.4. Wireless for Industrial
This section was derived from draft-thubert-6tisch-4detnet-01. This section was derived from draft-thubert-6tisch-4detnet-01.
This specification derives from the 6TiSCH architecture, which is the This specification derives from the 6TiSCH architecture, which is the
result of multiple interactions, in particular during the 6TiSCH result of multiple interactions, in particular during the 6TiSCH
(bi)Weekly Interim call, relayed through the 6TiSCH mailing list at (bi)Weekly Interim call, relayed through the 6TiSCH mailing list at
the IETF. the IETF.
The authors wish to thank: Kris Pister, Thomas Watteyne, Xavier The authors wish to thank: Kris Pister, Thomas Watteyne, Xavier
Vilajosana, Qin Wang, Tom Phinney, Robert Assimiti, Michael Vilajosana, Qin Wang, Tom Phinney, Robert Assimiti, Michael
Richardson, Zhuo Chen, Malisa Vucinic, Alfredo Grieco, Martin Turon, Richardson, Zhuo Chen, Malisa Vucinic, Alfredo Grieco, Martin Turon,
Dominique Barthel, Elvis Vogli, Guillaume Gaillard, Herman Storey, Dominique Barthel, Elvis Vogli, Guillaume Gaillard, Herman Storey,
Maria Rita Palattella, Nicola Accettura, Patrick Wetterwald, Pouria Maria Rita Palattella, Nicola Accettura, Patrick Wetterwald, Pouria
Zand, Raghuram Sudhaakar, and Shitanshu Shah for their participation Zand, Raghuram Sudhaakar, and Shitanshu Shah for their participation
and various contributions. and various contributions.
11.5. Cellular Radio 10.5. Cellular Radio
This section was derived from draft-korhonen-detnet-telreq-00. This section was derived from draft-korhonen-detnet-telreq-00.
11.6. Industrial M2M 10.6. Industrial M2M
The authors would like to thank Feng Chen and Marcel Kiessling for The authors would like to thank Feng Chen and Marcel Kiessling for
their comments and suggestions. their comments and suggestions.
11.7. Internet Applications and CoMP 10.7. Internet Applications and CoMP
This section was derived from draft-zha-detnet-use-case-00. This section was derived from draft-zha-detnet-use-case-00.
This document has benefited from reviews, suggestions, comments and This document has benefited from reviews, suggestions, comments and
proposed text provided by the following members, listed in proposed text provided by the following members, listed in
alphabetical order: Jing Huang, Junru Lin, Lehong Niu and Oilver alphabetical order: Jing Huang, Junru Lin, Lehong Niu and Oilver
Huang. Huang.
12. Informative References 11. Informative References
[ACE] IETF, "Authentication and Authorization for Constrained [ACE] IETF, "Authentication and Authorization for Constrained
Environments", <https://datatracker.ietf.org/doc/charter- Environments", <https://datatracker.ietf.org/doc/charter-
ietf-ace/>. ietf-ace/>.
[bacnetip] [bacnetip]
ASHRAE, "Annex J to ANSI/ASHRAE 135-1995 - BACnet/IP", ASHRAE, "Annex J to ANSI/ASHRAE 135-1995 - BACnet/IP",
January 1999. January 1999.
[CCAMP] IETF, "Common Control and Measurement Plane", [CCAMP] IETF, "Common Control and Measurement Plane",
skipping to change at page 61, line 34 skipping to change at page 59, line 24
[CONTENT_PROTECTION] [CONTENT_PROTECTION]
Olsen, D., "1722a Content Protection", 2012, Olsen, D., "1722a Content Protection", 2012,
<http://grouper.ieee.org/groups/1722/contributions/2012/ <http://grouper.ieee.org/groups/1722/contributions/2012/
avtp_dolsen_1722a_content_protection.pdf>. avtp_dolsen_1722a_content_protection.pdf>.
[CPRI] CPRI Cooperation, "Common Public Radio Interface (CPRI); [CPRI] CPRI Cooperation, "Common Public Radio Interface (CPRI);
Interface Specification", CPRI Specification V6.1, July Interface Specification", CPRI Specification V6.1, July
2014, <http://www.cpri.info/downloads/ 2014, <http://www.cpri.info/downloads/
CPRI_v_6_1_2014-07-01.pdf>. CPRI_v_6_1_2014-07-01.pdf>.
[CPRI-transp]
CPRI TWG, "CPRI requirements for Ethernet Fronthaul",
November 2015,
<http://www.ieee802.org/1/files/public/docs2015/
cm-CPRI-requirements-1115-v01.pdf>.
[DCI] Digital Cinema Initiatives, LLC, "DCI Specification, [DCI] Digital Cinema Initiatives, LLC, "DCI Specification,
Version 1.2", 2012, <http://www.dcimovies.com/>. Version 1.2", 2012, <http://www.dcimovies.com/>.
[DICE] IETF, "DTLS In Constrained Environments", [DICE] IETF, "DTLS In Constrained Environments",
<https://datatracker.ietf.org/doc/charter-ietf-dice/>. <https://datatracker.ietf.org/doc/charter-ietf-dice/>.
[EA12] Evans, P. and M. Annunziata, "Industrial Internet: Pushing [EA12] Evans, P. and M. Annunziata, "Industrial Internet: Pushing
the Boundaries of Minds and Machines", November 2012. the Boundaries of Minds and Machines", November 2012.
[ESPN_DC2] [ESPN_DC2]
skipping to change at page 66, line 21 skipping to change at page 64, line 21
SPECIFICATION V1.1b", December 2006. SPECIFICATION V1.1b", December 2006.
[net5G] Ericsson, "5G Radio Access, Challenges for 2020 and [net5G] Ericsson, "5G Radio Access, Challenges for 2020 and
Beyond", Ericsson white paper wp-5g, June 2013, Beyond", Ericsson white paper wp-5g, June 2013,
<http://www.ericsson.com/res/docs/whitepapers/wp-5g.pdf>. <http://www.ericsson.com/res/docs/whitepapers/wp-5g.pdf>.
[NGMN] NGMN Alliance, "5G White Paper", NGMN 5G White Paper v1.0, [NGMN] NGMN Alliance, "5G White Paper", NGMN 5G White Paper v1.0,
February 2015, <https://www.ngmn.org/uploads/media/ February 2015, <https://www.ngmn.org/uploads/media/
NGMN_5G_White_Paper_V1_0.pdf>. NGMN_5G_White_Paper_V1_0.pdf>.
[NGMN-fronth]
NGMN Alliance, "Fronthaul Requirements for C-RAN", March
2015, <https://www.ngmn.org/uploads/media/NGMN_RANEV_D1_C-
RAN_Fronthaul_Requirements_v1.0.pdf>.
[PCE] IETF, "Path Computation Element", [PCE] IETF, "Path Computation Element",
<https://datatracker.ietf.org/doc/charter-ietf-pce/>. <https://datatracker.ietf.org/doc/charter-ietf-pce/>.
[profibus] [profibus]
IEC, "IEC 61158 Type 3 - Profibus DP", January 2001. IEC, "IEC 61158 Type 3 - Profibus DP", January 2001.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
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