1. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [ Factory Automation Subgroup Report ] Date Submitted: [22 September 2009 ] Source: [ Michael Bahr ] Company [ Siemens AG, Corporate Technology ] Address [ Otto-Hahn-Ring 6, 80200 Munich, Germany ] Voice:[ +49-89-636-49926 ], FAX: [ ], E-Mail: [ bahr et siemens dod com ] Re: [ Request for draft text for proposal for factory automation] Abstract:[ The document contains the status of the factory automation subgroup and an introduction to the draft text provided for the low latency networks proposal. ] Purpose:[] Notice:This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release:The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15.

2. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 2 Factory Automation Subgroup Report Michael Bahr (Siemens AG, Corporate Technology)

3. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 3 Factory Automation Subgroup Michael Bahr (Siemens AG) Zafer Sahinoglu, editor (Mitsubishi Electric Research Labs) Rudy Belliardi (Schneider Electric) Paul Dixon (HiSilicon Technologies Co., LTD.) Jose Gutierrez (Emerson ) Ryoji Ono (Mitsubishi Electric) Rene Struik (Certicom) Ludwig Winkel (Siemens AG)

4. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 4 Subgroup Status Draft text: further completion and polishing of draft text submitted draft text 15-09/0401r3 to TG4e editor in normative text, transition of terminology from Factory Automation Network to Low Latency Network editor: Zafer Sahinoglu (Mitsubishi Electric Research Labs) TG 4e preliminary draft: text for low latency networks included in preliminary TG 4e draft still some tbds Next steps fill remaining tbds discuss text for this in subgroup conference calls

5. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 5 Factory Automation Draft Text Introduction

6. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 6 Proposal for Factory Automation Goals Requirements usage in factory automation possible high determinism / low latency: –transmission of sensor data in  10 ms for 15 devices roaming coexistence with IEEE 802.11 scalability in number of sensors sensors per gateway –might be more than 100 sensors per gateway –trade-off with latency Assumptions assume controlled envi-ronment (factory floor) configuration for optimal performance network management and frequency planning for avoidance of co-existence issues

7. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 7 Proposal for Factory Automation Main Ideas: Network Topology star topology gateway devices –sensors: unidirectional data exchange from devices to gateway –actuators: bidirectional data exchange between devices and gateway –management devices (temporary)

8. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 8 Proposal for Factory Automation Main Ideas: General Concept IEEE 802.15.4 PHY frames Time Division Multiple Access –superframe with timeslots of fixed (base) length (can be brief) –shared group timeslots with CSMA –flexible configuration of superframe structure –addressing based on timeslot location or short address –modified MAC frame with very short header (1 octet) new frame type for differentiation reduces overhead  reduced latency Roaming capability

9. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 9 TDMA Superframe Superframe –starts with beacon –followed by n base timeslots of equal, fixed length Timeslots –one device per timeslot (dedicated timeslot) –multiple devices per timeslot (shared group timeslot) –determinism (re-)synchronization through beacon –allows sleep mode / power save of devices

10. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 10 Shared Group Timeslots more than one device per timeslot (simplified) carrier sense multiple access within shared group timeslot guaranteed access for designated device, contention-based access for other devices 1 or more continuous timeslots concatenated to a shared group timeslot all timeslots in single shared group timeslot  network with CSMA mixture between fixed, deterministic timeslots and shared group timeslots possible further details in 15-08/0827r0

11. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 11 Structure of Superframe existence of management timeslots configurable during setup number of (timeslots for) sensors and actuators configurable during setup first sensor time slots may be reserved for dynamic retransmissions time slot for GACK configurable

12. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 12 Very Short MAC Frame Format implicit addressing through slot number –omits MAC address fields in MAC header very short MAC header of 1 byte very short PSDU increases efficiency dramatically –turnaround time / latency main criteria FCS for error recognition

13. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 13 Shortened Frame Control Frame Type –corresponds to frame type subfield of IEEE 802.15.4-2006 –set to b100 –indicates frames with shortened MAC header Sub Frame Type –indicates frame type with shortened MAC header –beacon, command, ack, data frame

14. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 14 Transmission Modes 3 transmission modes, signalled in beacon –Discovery –Configuration –Online Discovery: network setup, addition of new devices Configuration: (re-)configuration of network and devices further details see 15-08/0571r1

15. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 15 not part of this proposal, but would be useful would fall into the scope of IEEE 802.15.4f/g Problem (depending on sensitivity of receiver) –transmissions on channel x might be received on channel (x-1), not only as interference!, due to receiver sensitivity. –devices on channel (x-1) might consider such a transmission as belonging to their channel –consequences for channel access Proposed solution –different PHY preamble depending on channel  devices (chips) cannot synchronize to received transmission on neighboring channels A Related PHY Preamble Issue

16. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 16 Changes to Standard Section 5 5 General Description –5.3 Network Topologies added network concept for low latence networks –5.5. Functional Overview 5.5.1 Superframe structure –added description of superframe structure for low latency networks –new behavior defined when using frames with 1-octet MAC header 5.5.2 Data transfer model 5.5.3 Frame structure

17. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 17 Changes to Standard Section 7 7.1 MAC sublayer service specification –MCPS.DATA –existing MLME primitives to be reviewed –new MLME-SFCF-SUPERFRAME-CONFIGURATION primitives 7.2 MAC frame formats –new frame type b100 –contains four subtypes: data, ack, beacon, command –defined general frame format (7.2.1a) and individiual frame formats (7.2.2a) different types of acknowledgement (e.g. group ack (GACK)) 7.3 MAC command frames –new command frames defined Discover Response Configuration Response Configuration Request CTS Shared Group Request to send (RTS) Clear to Send (CTS)

18. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 18 Changes to Standard Section 7 7.4 MAC constants and PIB attributes –new MAC constants defined macFAlowlatencePAN macFAnumTimeSlots macFAnumSensorTS macFAnumRetransmitTS macFAnumActuatorTS macFAmgmtTS –probably missed some

19. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 19 Changes to Standard Section 7 7.5 MAC functional description –7.5.1 Channel access new clause „Superframe structure with beacons with shortened frame control” –superframe definition –timeslot description –channel access in dedicated and shared group timeslots –7.5.1.4 CSMA-CA algorithm extension with simplified scheme for shared group timeslots (tbd) –7.5.7a Transmission modes in factory automation networks new clause describing discover, configuration, and online modes –7.5.2 Starting and maintaining PANs –7.5.3 Association and disassociation –7.5.4 Synchronization –7.5.5 Transaction handling –7.5.6 Transmission, reception, and acknowledgement need to be reviewed and extended if necessary 7.7 Message sequence charts –to be done

20. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 20 Changes to Standard Annex Annex D PICS proforma –to be done at the end Annex Fa (informative) –motivation and lyrical explanation for factory automation networks

21. doc.: IEEE 802.15-09/0667r0 Submission September 2009 Michael Bahr, Siemens AGSlide 21 References 15-09-0411-02 „ Factory Automation Draft Text Introduction” 15-09-0401-03 „Draft Text for Factory Automation“ 15-09-0228-00 “Proposal for Factory Automation“ 15-08-0254-01 “Proposal for Factory Automation“ 15-08-0827-00 „Shared Group Timeslots” 15-08-0420-00 „Extending the MAC Superframe of 802.15.4 Spec” 15-09-0199-00 „ Factory Automation Sub-Group Deliverables” 15-09-0024-00 „Proposal for Factory Automation & MAC TG4e MAC Categories”