DetNet H. Wang Internet Draft P. Wang Intended status: Standards Track H. Yang Expires: November 12, 2017 Chongqing University of Posts and Telecommunications May 11, 2017 Joint Deterministic Scheduling Requirements for Industrial Field/Backhaul Networks draft-wang-detnet-backhaul-requirements-01 Abstract This document analyzes the joint deterministic scheduling requirements for industrial field/backhaul networks, mainly including the determinacy, time synchronization, compatibility, scalability and scheduling cost demands. 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), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. 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. 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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 ................................................ 2 2. Network Structure ........................................... 3 3. Joint Scheduling Requirements ............................... 4 3.1. Determinacy ............................................ 4 3.2. Time Synchronization ................................... 4 3.3. Compatibility .......................................... 4 3.4. Scalability ............................................ 4 3.5. Scheduling cost ........................................ 5 4. Security Considerations ..................................... 5 5. IANA Considerations ......................................... 5 6. References .................................................. 5 6.1. Normative References ................................... 5 6.2. Informative References ................................. 5 Authors' Addresses ............................................. 6 1. Introduction Using three industrial wireless networking standards: ISA100.11a[IEC62734], WirelessHART[IEC62591] and WIA-PA[IEC62601], a deterministic network can be constructed by industrial field network. However, these industrial field networks belong to small and medium- sized networks whose network coverage is constant, for example, a range of plant. Therefore, industrial backhaul network can be introduced to make the industrial field network access higher-level network, or transit to other industrial field network. Thus, a new network architecture, the deterministic industrial field network - backhaul network is proposed in this draft. Some questions of deterministic network have been described in the draft [draft-finn- detnet-problem-statement-04], and the architecture and application have been illustrated in [draft-finn-detnet-architecture-04] and [draft-bas-usecase-detnet-02] separately. This network architecture is mainly used in industrial production, and it has a very high demand on the network data packet loss ratio, Wang, et al. Expires November 12, 2017 [Page 2] Internet-Draft DetNet Backhaul Requirements May 2017 low jitter and determinacy and so on. Besides, due to the backhaul network is heterogeneous with field network. The backhaul industry network, has a centralized controller, and can schedule network resources such as bandwidth and cache. However, for some industrial field networks such as ISA100.11a, WirelessHART, these networks have their own system manager. At the same time, there are some networks which have no system manager. Therefore, it is an issue to be studied about how to carry out joint scheduling. 2. Network Structure As shown in the figure 1, it is a typical deterministic industrial field networks - backhaul networks structure. The field network is composed of ISA100.11a, which is the standard of the international industrial wireless network. This network standard uses TDMA (time division multiple access) mechanism to implement the network time slot, and provide the deterministic guarantee for the data. Then the field networks can be access to industrial backhaul networks. In the other end of industrial backhaul networks, can be another industrial field networks, and can also be access to the internet application or the enterprise information management system like MES/ERP. +------------------------+ | ISA100.11a field | | wireless network | ------------+ +------------------------+ | +---------------------+ +-----------+ | Industrial backhaul | |Internet or| | network | ---| MES/ERP | +---------------------+ +-----------+ +------------------------+ | | ISA100.11a field | ------------+ | wireless network | +------------------------+ Figure 1. Typical network structure Wang, et al. Expires November 12, 2017 [Page 3] Internet-Draft DetNet Backhaul Requirements May 2017 Thus, in such a network structure, the former field network nodes deployed in a plant can communicate with the field network nodes deployed in another plant through the industrial backhaul network. At the same time, the internet or information management system can manage the sensor nodes of the field network remotely through the industrial backhaul network. 3. Joint Scheduling Requirements 3.1. Determinacy The data of industrial field network directly related to the monitoring and control of industrial production process, so the requirement of data determinism is very high, and need data to arrive at a certain time. Industrial field network-backhaul network is also a kind of network which is mainly used in the process of industrial production, so also need to meet the needs of the data determinism in the joint scheduling. 3.2. Time Synchronization Since the industrial field/backhaul network is a converged network and need some scheduling methods to ensure deterministic data stream. So it requires high time synchronization accuracy between devices in the network. The time synchronization accuracy should be in a range of 10ns to 10ms according to different network applications. At present, the existing time synchronization protocol include IEEE1588 and IEEE802.1 As, which is developed by following Time Sensitive Networking (TSN) Task Group 3.3. Compatibility Industrial field network and backhaul network are both heterogeneous networks. Industrial field networks such as ISA100.11a, WirelessHART usually have built-in systems management, which can allocate network communication resources to conduct deterministic scheduling. Some field networks have no system manager. While industrial backhaul network is able to control the network with central controller, so some mechanisms, interfaces will be necessary when conducting joint scheduling to be compatibility with industrial field/backhaul network. 3.4. Scalability Generally, the field network data cannot be transmitted across domain or across network, while in the deterministic industrial field/backhaul network, the characteristic of cross-networks should Wang, et al. Expires November 12, 2017 [Page 4] Internet-Draft DetNet Backhaul Requirements May 2017 be supported. So data scalability should be ensured during joint scheduling process. 3.5. Scheduling cost The joint scheduling in industrial field/backhaul networks refers to different networks, so when the network manager calculates the scheduling results, it should satisfy a low scheduling cost, namely low computation time, or it will bring too much extra delay to the data stream. 4. Security Considerations 5. IANA Considerations This memo includes no request to IANA. 6. References 6.1. Normative References 6.2. Informative References [IEC62734] ISA/IEC, "ISA100.11a, Wireless Systems for Automation, also IEC 62734", 2011, . [IEC62591] www.hartcomm.org, "Industrial Communication Networks - Wireless Communication Network and Communication Profiles - WirelessHART - IEC 62591", 2010,< [IEC62601] IEC, "Industrial networks - Wireless communication network and communication profiles - WIA-PA - IEC 62601", 2015, < https://webstore.iec.ch/preview/info_iec62601%7Bed2.0%7Db.pdf> [I-D.finn-detnet-problem-statement] Finn, N. and P. Thubert, "Deterministic Networking Problem Statement", draft-finn-detnet-problem-statement-04 (work in progress), October 2015. Wang, et al. Expires November 12, 2017 [Page 5] Internet-Draft DetNet Backhaul Requirements May 2017 [I-D.finn-detnet-architecture] Finn, N., Thubert, P., and M. Teener, "Deterministic Networking Architecture", draft-finn-detnetarchitecture-03 (work in progress), March 2016. [I-D.bas-usecase-detnet] Kaneko, Y., Toshiba and Das, S, "Building Automation Use Cases and Requirements for Deterministic Networking", draft- bas-usecase-detnet-00 (work in progress), April 2016. [IEEE802.1AS-2011] IEEE, "Timing and Synchronizations (IEEE 802.1AS-2011)", 2011, . Authors' Addresses Heng Wang Chongqing University of Posts and Telecommunications 2 Chongwen Road Chongqing, 400065 China Phone: (86)-23-6248-7845 Email: wangheng@cqupt.edu.cn Ping Wang Chongqing University of Posts and Telecommunications 2 Chongwen Road Chongqing, 400065 China Phone: (86)-23-6246-1061 Email: wangping@cqupt.edu.cn Hang Yang Chongqing University of Posts and Telecommunications 2 Chongwen Road Chongqing, 400065 China Phone: (86)-23-6246-1061 Email: 18716322620@163.com Wang, et al. Expires November 12, 2017 [Page 6]