Internet DRAFT - draft-geng-iiot-edge-computing-problem-statement

draft-geng-iiot-edge-computing-problem-statement







T2TRG                                                            L. Geng
Internet-Draft                                              China Mobile
Intended status: Standards Track                                M. Zhang
Expires: September 6, 2018                                    M. McBride
                                                                  B. Liu
                                                                  Huawei
                                                           March 5, 2018


   Problem Statement of Edge Computing on Premises for Industrial IoT
          draft-geng-iiot-edge-computing-problem-statement-01

Abstract

   This document introduces the concept of Beyond Edge Computing (BEC)
   which brings edge computing capabilities down to the level of
   customers' premises for industrial IoT use cases.  The purpose of the
   document is to discuss the general problem statement of BEC including
   capabilities, and use cases.  Potential technical gaps in IETF
   problem scope that are related to BEC are also evaluated.

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 September 6, 2018.

Copyright Notice

   Copyright (c) 2018 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
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect



Geng, et al.            Expires September 6, 2018               [Page 1]

Internet-Draft             IIoT Edge Computing                March 2018


   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  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   3
     1.2.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  The Concept and Capabilities of Beyond Edge Computing . . . .   3
     2.1.  Heterogeneous IoT Device Compatibility  . . . . . . . . .   4
     2.2.  Deterministic Networking  . . . . . . . . . . . . . . . .   5
     2.3.  Management of Massive Amount of Devices . . . . . . . . .   5
     2.4.  Support of Network Slicing  . . . . . . . . . . . . . . .   5
     2.5.  Multi-ecosystem Environment . . . . . . . . . . . . . . .   5
   3.  Reference Architecture  . . . . . . . . . . . . . . . . . . .   5
   4.  Use Cases of BEC  . . . . . . . . . . . . . . . . . . . . . .   7
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   9
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  10
   7.  Acknowledgement . . . . . . . . . . . . . . . . . . . . . . .  10
   8.  Normative References  . . . . . . . . . . . . . . . . . . . .  10
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  10

1.  Introduction

   Edge computing is an important network architecture particularly in
   the support of Industrial verticals such as Energy, Manufacturing,
   Healthcare, Mining and Smart City/Buildings.  Edge computing will
   provide local compute, storage and connectivity services particularly
   for latency and bandwidth sensitive applications.  There are several
   organizations which are working on edge computing definition and
   architecture with various emphases.  For instance, ETSI MEC
   (previously mobile edge computing and now multi-access edge
   computing) looks at edge computing from the perspective of the edge
   of the provider network.  It also has an successive convention of
   focusing on cellular network requirements.  The Industrial Internet
   Consortium (IIC) and Edge Computing Consortium (ECC) works on edge
   computing in a more general view of industrial IoT, where edge
   computing nodes are even closer to verticals (i.e. the very first
   hops where the service is connected to the network).  Typically, the
   edge computing nodes are located at customers' premises.  However,
   IIC and ECC are not standard organizations and they rely on
   communities such as IETF to provide protocols and API definitions for
   their architectural use especially as Operation Technology (OT),
   Information Technology (IT) and Communication Technology (CT)
   converge.




Geng, et al.            Expires September 6, 2018               [Page 2]

Internet-Draft             IIoT Edge Computing                March 2018


   Edge computing concepts have been presented in various groups within
   the IETF/IRTF.  The edge computing topic, similar to cloud computing,
   is much too broad to tackle within the IETF.  There are specific
   protocol/interface areas, however, that can be worked on in the IETF
   once we identify a specific area of focus.  BEC is one of the
   specific area which looks at edge computing from the industrial
   verticals such as factory, hospital, power and city/ building
   perspective and down to the level of local edge support for sensors,
   engines, pumps and machinery.

   A simple example, of BEC, is factory equipment having connected
   sensors which are generating data and sending to the equipment within
   an edge computing environment.  One sensor, connected to this
   equipment, could generate an event, such as overheating, and an
   connected actuator could quickly increase fan span or reduce engine
   speed depending upon the data within the local edge computing node.
   This type of event is being controlled today within closed industrial
   command and control protocols.  But what is not generally available
   is the ability for open edge computing equipment to generate
   predictive maintenance and command and control across factories,
   verticals and into the cloud.  This is where we see a gap in
   standards definitions and an opportunity for new protocols and
   interfaces, in which IETF could play a particularly important role.

1.1.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

1.2.  Terminology

   o  BEC - Beyond Edge Computing, a concept of on-premises edge
      computing where the devices deployed directly at customers'
      premise are worked on.

2.  The Concept and Capabilities of Beyond Edge Computing

   Beyond Edge Computing (BEC) looks at the on-site intelligent
   evolution of industrial verticals.  It brings the edge computing
   capability down to the level of customer premises, which are typical
   beyond the access network of a service provider.









Geng, et al.            Expires September 6, 2018               [Page 3]

Internet-Draft             IIoT Edge Computing                March 2018


                     +-------------------------------+
                     |   Core Data Center            |
                     +-------------------------------+
                              ***   Backbone
                             *   *  Network
                              ***
                     +-------------------------------+
                     |   Regional Data Center        |
                     +-------------------------------+
                              ***   Metropolitan
                             *   *  Network
                              ***
                     +-------------------------------+
                     | Local Data Center/Access Point|
                     +-------------------------------+
                           ***   Access    ***
                          *   *  Network  *   *
                           ***             ***
                     +-----------+     +-----------+
                     |  Beyond   |     |  Beyond   |
                     |   Edge    |     |   Edge    |
                     | Computing |     | Computing |
                     +-----------+     +-----------+

              Figure 1: Beyond Edge Computing in the Network

   Figure 1 illustrates the schematic diagram of BEC in terms of its
   position in a overall network.  BEC takes care of the first hop where
   the service of a particular industrial vertical connects to the
   network.  It can be regarded as an extended intelligent connectivity
   capability of a service provider's network to industrial verticals.
   Meanwhile, it also expands the cloud computing ability directly to
   customers' sites.

2.1.  Heterogeneous IoT Device Compatibility

   Vertical industries have various interfaces for on-premises LAN and
   WAN.  This include both wireless and fixed line systems.  Taking the
   field bus as an example, 10 different specification are defined in
   IEC61158, which is only a small portion of the existing field bus
   technologies people can actually find in real world.  BEC should
   provide the capability of protocol translation and mapping, which
   enables the inter-operation between different systems.








Geng, et al.            Expires September 6, 2018               [Page 4]

Internet-Draft             IIoT Edge Computing                March 2018


2.2.  Deterministic Networking

   One of the most important motivation of BEC is to reduce the
   propagation latency by the deployment of services most closer to
   users.  However, the processing and scheduling latency cannot
   directly benefit from closer deployment.  Especially as the end-to-
   end propagation latency for a edge service has been reduced to less
   than 1 ms, processing and scheduling latency became even more
   essential.  At the same time, emerging services including AR/VR,
   Remote robot system and motion control rely on not only low but also
   a strictly deterministic latency.  Real-time operation system will be
   a preferred choice for BEC.  Additionally, high-precision time
   synchronization and packet preemption are also significant
   characteristics for deterministic network in BEC system.

2.3.  Management of Massive Amount of Devices

   It is expected the hundreds of millions of BEC nodes will be deployed
   in industrial internet scenario, typically in a form of gateway.
   Management is the key to provide reliable and flexible edge services
   using BEC nodes.  It is preferred to have unified interface to
   realize both device-level and resource-level management of BEC nodes.

2.4.  Support of Network Slicing

   An important benefit of BEC is the capability of edge service
   deployment.  Based on light-weight distributed NFV technologies, the
   resource on BEC nodes can be dedicated for particular application.
   At the same time, the packet of a certain edge service can be labeld
   and steered to the preferred network slice at the WAN side, creating
   a true end-to-end network slice for industrial verticals.

2.5.  Multi-ecosystem Environment

   It is preferred to have a unified set of APIs, which achieve a deep-
   level capability exposure of the BEC nodes.  The functions can be
   exposed to the upper layer applications in terms of forwarding,
   address, management and physical interface functionalities.

3.  Reference Architecture











Geng, et al.            Expires September 6, 2018               [Page 5]

Internet-Draft             IIoT Edge Computing                March 2018


          +--------------------------------+
          |     BEC Management Platform    |
          |                                |
          | +----------------------------+ |   +-------------+
          | |     Application Management | |   |             |
          | +----------------------------+ |   | IoT         |
          | +------------+  +------------+ |   | Cloud       |
          | | Device     |  | Resource   | |   | Services    |
          | | Management |  | Management | |   |             |
          | +------------+  +------------+ |   |             |
          | +----------------------------+ |   |             |
          | |   SDN Platform             | |   +----+--------+
          | +----------------------------+ |        |
          +--------------------------------+        |
                          | Management              |Data
                          | Channel                 |Channel
          +----------------------------------------------------+
          | +-------------v-------------------+     |          |
          | |   Management Data Model         |     |          |
          | +---+-------+-------+---------+---+     |          |
          |     |       |       |         |         |          |
          |     |       |       |         |         |          |
          |     |       |       |     +------------------+     |
          |     |       |       |     |   +---------+    |     |
          |     |       |       |     |   |  APP    |    |     |
          |     |       |       |     |   +---------+    |     |
          |     |       |       |     |Container/VM      |     |
          |     |       |       |     +------------------+     |
          |     |       |     +-v----------------------------+ |
          |     |       |     |     Virtualization Layer     | |
          |     |       |     +------------------------------+ |
          |     | +-----v------------------------------------+ |
          |     | |       API Exposure                       | |
          |     | +------------------------------------------+ |
          | +---v--------------------------------------------+ |
          | |               Linux Kernel                     | |
          | +------------------------------------------------+ |
          |   Ethernet   Bluetooth    PLC      RF    RS485     |
          |   WiFI       FXS          DI/DO          RS232     |
          +----------------------------------------------------+




       Figure 2: The Reference Architecture of Beyond Edge Compuring

   Figure 2 demonstrates the reference architecture of BEC system with a
   managed BEC node and a cloud-based management platform.  An IoT



Geng, et al.            Expires September 6, 2018               [Page 6]

Internet-Draft             IIoT Edge Computing                March 2018


   gateway is the typical form of a BEC node device.  Gateways always
   play important role in the Cloud-Edge architecture since they are the
   most popular devices where verticals are provided with various
   capabilities such as computing, storage and networking.  In addition,
   applications for various vertical customers are developed by
   themselves or third-party while deployed on demand.  Giving the edge
   computing ability of BEC, much of the data can be processed by
   applications running on the gateway locally as required by vertical
   customers.  The gateways are commonly versatile protocol speakers so
   that devices speaking different protocols can communicate with the
   them.  The East-West connectivity between BEC nodes might be enabled
   by various protocols such as OPC-UA, MQTT, TSN and other
   deterministic Ethernet protocols, for example EtherCat, Ethernet/IP,
   Profinet.  To facilitate the operation of the BEC system, a central
   controller in the cloud is provisioned to the customer.  It mainly
   supervise the device, virtulization resource and application life
   cycle of the BEC node.

   The key requirements of BEC are in providing distribution service
   entities on the customers site (end AP, devices) to meet the growing
   demand for low latency, reliable, and secure vertical industries.
   The Computing, Storage, I/O isolation are remotely managed at the
   edge to provide certain dedication and quality guarantees.  Agile,
   flexible and scalable deployment of services from operator/third
   party down to the edge through software entities (VM/ Containers).  A
   light weight MANO like approach is needed to provide resource
   provisioning and VNF deployment.  A unified API definition is needed
   to support the co- existence of multi-ecosystem at the BEC node.  And
   there needs to be the ability for the edge device to map specific
   service requirements with an end to end network slice with certain
   guarantees and pass the policy identification along the path to the
   centralized DC.

4.  Use Cases of BEC

   1.  Elevator Networks

   Description: There are more than 15 million elevators around the
   world and the daily maintenance of these elevators costs elevator
   operators a large amount of revenue.  An elevator usually carries
   hundreds of sensors which are generating a large amount of data to be
   uploaded to the cloud.  The BEC nodes can preprosess the data
   gathered from elevator sensors so that the volume to be uploaded to
   the Cloud is greatly reduced.  Based on the input from elevator
   sensors, AI programs installed on BEC nodes may locally make
   decisions without the intervention of the Cloud.  For example, when
   the noise or vibration of an elevator exceeds a certain level, the




Geng, et al.            Expires September 6, 2018               [Page 7]

Internet-Draft             IIoT Edge Computing                March 2018


   BEC node may notify elevator maintainers to reach this elevator and
   perform maintanence or repair.

   Goal: BEC nodes are deployed into elevators to gather/preprocess/
   compress the data to save the communication cost.  Based on the data
   gathered from elevator sensors, BEC nodes can assist operators to do
   predictive maintenance.

   Requirements: Customized gateways operated by elevator providers.  An
   open platform with VMs/containers which can hold customized Apps.
   These Apps are managed by elevator operators while developed by
   gateway vendors or any other third parties.  Various connectivities
   are supported (2G/3G/LTE/eMTC/Ethernet) by BEC nodes.  A central
   controller to perform configuration and management of the network.
   AI models are trained on the Cloud while the reasoning of these AI
   models are performed at the Edge.

   2.  Intelligent Street Lights

   Description: BEC nodes are placed on street lights to act as board
   routers of LLNs.  BEC nodes may act as RSUs of vehicle networks.
   With AI programs installed on the BEC nodes, reasoning and decisions
   might be made locally at the edge.  For example, For example, BEC
   nodes can adjust the lights' brightness and operating hours according
   to environment parameters, providing illumination when needed while
   reducing power consumption.  With sensors on trash cans, BEC nodes
   are aware whether a trash can is full.  Trash collecting cars can
   communicate with the BEC nodes to determine whether to reach a trash
   can to collect the trash.

   Goal: BEC nodes gather data from sensors which are used to monitor
   various information (e.g., brightness, temperature, humidity) of a
   district.

   Requirements: BEC nodes SHOULD support ROLL [RFC] in order to join
   the LLN as a board router.  Various wired/wireless communication
   protocols such as Radio Frequency (RF) protocols (e.g., Zigbee, WI-
   SUN) and Power Line Communication (PLC) should be supported.  The BEC
   nodes can use 2G/3G/LTE/Ethernet to communicate with the Cloud.

   3.  Smart Manufacturing

   Description: BEC nodes join the industiral manufacturing network and
   provide the networking function.  Control messages that requires
   deterministic latency will be carried on this network.  BEC nodes
   need to support deteministic networking protocols such IEEE Time
   Sensitive Networking (TSN), Profinet, Ethernet/IP, EtherCat, etc.




Geng, et al.            Expires September 6, 2018               [Page 8]

Internet-Draft             IIoT Edge Computing                March 2018


   The gateway can also help monitor the equipments' status, and send
   out alarms or warnings when malfunction is detected or predicted.

   Goal: Edge computing enables interconnection of deterministic
   networks.

   Requirements: BEC nodes should support industrial machine-to-machine
   message bus connectivity protocols such as OPC-UA, DDS, MQTT.  The
   network may be configured by a central controller using Netconf/YANG.
   BEC nodes should support the interconnection of heterogeneous
   deterministic Ethernet protocols.

   4.  Smart grid

   Description: BEC nodes can be deployed in three scenarios of the
   smart grid.  In advanced metering infrastructure (AMI), besides the
   routing function, it can also act as a concentrator to collect and
   aggregate the meters' data.  It can also provide primary analysis to
   detect theft and outage.  Firewall function can be deployed at the
   gateway to deal with attacks from the edge.  In distribution
   automation (DA), BEC nodes provide bounded latency connection between
   controller and actuators such as switches and transformers.  Edge
   computing applications can be implemented on these devices to monitor
   the status and react rapidly to faults.  In terms of microgrid, the
   BEC node monitors the local power generation and storage, and helps
   smoothly integrate the energy generated by photovoltaic panels and
   wind turbines, whose power is very unstable, into the macro grid.

   Goal: In AMI, the BEC node works as a router, firewall and
   concentrator, providing data preprocess services.  In DA, BEC node
   enables the deterministic connection between controllers and
   actuators.  In microgrid, BEC node is the coordinator between
   distributed and centralized generation.

   Requirements: The gateway should support various wired/wireless
   communication protocols, such as Power Line Communication (PLC),
   Radio Frequency (RF), NB-IOT and 2G/3G/LTE.  Bounded latency is
   required in automation use cases.  Open platforms are needed to
   accommodate various applicaitons providing data analysis, fault
   detection and automation control capabilities.

5.  IANA Considerations

   N/A







Geng, et al.            Expires September 6, 2018               [Page 9]

Internet-Draft             IIoT Edge Computing                March 2018


6.  Security Considerations

   Security considerations will be a critical component of IIoT edge
   computing particularly as intelligence is moved to the extreme edge.

7.  Acknowledgement

   The authors would like to thank Sami Kekki for his feedback on this
   draft.

8.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

Authors' Addresses

   Liang Geng
   China Mobile

   Email: gengliang@chinamobile.com


   Mingui (Martin) Zhang
   Huawei

   Email: zhangmingui@huawei.com


   Mike McBride
   Huawei

   Email: michael.mcbride@huawei.com


   Bing Liu
   Huawei

   Email: remy.liubing@huawei.com










Geng, et al.            Expires September 6, 2018              [Page 10]