doc.: IEEE e Submission January, 2009 Kris Pister et al.Slide 1 Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Time Slotted, Channel Hopping MAC Behaviors] Date Submitted: [21 January, 2009] Source: [Kris Pister, Chol Su Kang, Kuor Hsin Chang, Rick Enns, Clint Powell, José A. Gutierrez, Ludwig Winkel] Companies [UC Berkeley, Dust Networks, Freescale, Emerson, Siemens AG] Address: [30695 Huntwood Avenue, Hayward, CA USA; 890 N. McCarthy Blvd, Suite 120, Milpitas, CA USA; 8000 West Florissant Avenue St. Louis, Missouri USA; Siemensallee 74, Karlsruhe, Germany] Voice:[+1 (510) , +1 (408) , +1 (650) , +1 (480) , +1 (314) , +49 (721) ] kuor- Re: [n/a] Abstract:[This document describes the MAC behaviors of proposed extensions for IEEE MAC] Purpose:[This document is a response to the Call For Proposal, IEEE P ] Notice: This document has been prepared to assist the IEEE P 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 P

doc.: IEEE e SubmissionSlide 2 Time Slotted, Channel Hopping (TSCH) MAC Behaviors Kris Pister – UC Berkeley & Dust Networks Chol Su Kang - Dust Networks Kuor Hsin Chang - Freescale Rick Enns - Consultant Clinton Powell - Freescale José A. Gutierrez – Emerson Ludwig Winkel – Siemens January, 2009 Kris Pister et al. January, 2009

doc.: IEEE e SubmissionKris Pister et al.Slide 3 Proposed Timeslot Access Slot Frame Cycle Unallocated SlotAllocated Slot Tx Rx RX startup Transmit Packet: Preamble, SFD, Headers, Payload, CRC RX packetVerify MIC Calculate ACK MIC Transmit ACK RX startup or TX->RX RX ACK RX/TX turnaround CCA: RX startup, listen, RX->TX timeslot TX/RX packet TX/RX ACK January, 2009

doc.: IEEE e SubmissionSlide 4 Extended ACK TSCH extends the ACK to support clock propagation and improved security: ACK carries time adjustment information ACK contains addressing and MIC32 Can be new ACK frame type, or use existing data frame Kris Pister et al. January, 2009

doc.: IEEE e SubmissionSlide 5 Channel Hopping TSCH supports channel diversity and improves reliability by: Hopping over selected channels (configurable black list) Hopping every timeslot Kris Pister et al. January, 2009

doc.: IEEE e SubmissionSlide 6 TDMA TSCH supports deterministic access and shared access using TDMA Each timeslot supports CCA, packet transmission and ACK reception Each timeslot can be used for dedicated or shared transmission. Each timeslot can be extended to support a configurable CAP period Configurable to support multiple PHYs Kris Pister et al. January, 2009

doc.: IEEE e SubmissionSlide 7 Slotframes have configurable periods Multiple slotframes with different lengths can operate at the same time. Devices can be configured with more than one slotframe 250ms 1,000ms 250ms Proposed Slotframe Kris Pister et al. January, 2009

doc.: IEEE e SubmissionSlide 8 Slotframes Resource allocation requirement, low power requirement, scalability requirement, and fast join requirement Configurable slotframe period Multiple slotframe in one device Slotframes described; CAP periods can be accommodated. Kris Pister et al. January, 2009

doc.: IEEE e Submission Low Power TSCH proposal supports low duty cycle –Less than 0.01% duty cycle is necessary to keep the network synchronized with inexpensive 32kHz quartz crystal

doc.: IEEE e Submission Overhead Reduction Short MAC headers can be supported in dedicated timeslots in TSCH Further innovation can be accommodated for time critical (low latency) applications

doc.: IEEE e SubmissionSlide 11 Mesh Support TSCH was developed for Mesh networks, and has been deployed in Mesh networks. TSCH improves reliability, coverage, and path diversity Transmissions and retransmissions are spread over multiple paths and channels Kris Pister et al. January, 2009

doc.: IEEE e SubmissionSlide 12 Proposed Time Synchronization Kris Pister et al. January, 2009

doc.: IEEE e SubmissionSlide 13 TSCH supports clock propagation Node-to-node (parent-to-child) clock propagation Minimal data traffic keeps time. Keepalive packets when traffic is low. Beaconing, keepalives, or mixed as appropriate. Network-wide synchronization to <<1ms Time Synchronization Kris Pister et al. January, 2009

doc.: IEEE e Submission Resource Scheduling Radio resource can be divided further in timeslots to make efficient utilization Timeslot size is configurable Radio resource scheduling can be centralized or distributed –TSCH provides mechanism –Scheduling/routing is a higher-layer function (e.g , IETF, …)

doc.: IEEE e Submission Portability TSCH is flexible to dynamically configure number of links for advertisement and listening duty cycle to aid fast association/disassociation and network formation –Sub-second association –Sub-second dissociation detection

doc.: IEEE e Submission Platform Portability Demonstrated on – radios from 3 different semiconductor vendors –3 different 8 bit and 16 bit microprocessors –Less than 20kB program memory –Less than 0.5kB RAM

doc.: IEEE e Submission Beacon scheduling Beacon transmission for legacy equipment can be accommodated with slotframe –CCA disabled (always transmit) –Timeslot profile with Transmit offset to zero (transmit immediately in the timeslot)

doc.: IEEE e Submission Scalability TSCH supports efficient scalability –number of field devices supported in the network is only limited by the addressability. –Not limited by CSMA collisions –Not limited by preamble overhead –Approaching 80% of 16*250kbps available MPDU BW –65,000 devices reporting 110B acknowledged MPDU once per minute is possible Bandwidth can be dynamically adjusted –For a field devices in the network or for the network –Up to the limit allowed by radio resource E.g. 10ms time slots  1600 packets/sec packets/sec routinely demonstrated

doc.: IEEE e Submission Really Simple Can teach it to undergrads Easy to simulate Simulation matches measurements

doc.: IEEE e Submission January, 2009 Slide 20 Added MAC PAN Service Primitives PrimitiveDescriptionRe- quest Con- firm Res- ponse Indica -tion SET-SLOTFRAME Add, delete, or modify a superframe XX SET-LINK Add, delete, or modify a link XX TSCH-MODE Operate in Time Slot Channel Hopping mode XX LISTEN Start listening for an advertisement XXX Chol Su Kang et al.

doc.: IEEE e Submission January, 2009 Slide 21 SET-SLOTFRAME Request (Device Management  TSCH MAC) –Add, delete, or change a slotframe –Parameters: slotframe Id, operation, slotframe size, channel page, channel map, active flag Confirm (TSCH MAC  Device Management) –Reports the results of SET-SLOTFRAME request command –Parameters: slotframe Id, status Chol Su Kang et al.

doc.: IEEE e Submission January, 2009 Slide 22 SET-LINK Request (Device Management  TSCH MAC) –Add, change, or delete a link –Parameters1: operation type=ADD or CHANGE, link handle, frame Id, timeslot, channel offset, link options, link type, node addresses –Parameters2: operation type=DELETE, link handle Confirm (TSCH MAC  Device Management) –Indicates the result of add, change or delete link command –Parameters: status, link handle Chol Su Kang et al.

doc.: IEEE e Submission January, 2009 Slide 23 TSCH-MODE Request (Device Management  TSCH MAC) –Puts the MAC to TSCH mode of operation –Parameters: ON or OFF Confirm (TSCH MAC  Device Management) –Reports the result of the TSCH-MODE request –Parameters: ON or OFF Chol Su Kang et al.

doc.: IEEE e Submission January, 2009 Slide 24 LISTEN Request (Device Management  TSCH MAC) –Request the MAC to search for a network –Parameters: channel page, channel, duration Confirm (TSCH MAC  Device Management) –Reports when the MAC completes the listen operation –Parameters: status Indication (TSCH MAC  Device Management) –Indicates that the MAC received an ADVERTISEMENT packet while listening –Parameters: link quality, PAN ID, channel map, join priority, slotframes, links in each slotframe (these parameters, except link quality, are received in ADVERTISEMENT packet) Chol Su Kang et al.

doc.: IEEE e Submission TSCH Summary Excellent performance –Power consumption Energy per delivered payload bit Power for a given latency –Scalability Easy to implement –Several companies, universities –Several platforms, RTOSes Peer reviewed –Rigorous analysis at HART, ISA Proven to work –Hundreds/Thousands of deployments –Thousands of nodes in some deployments –Tens of thousands of node-years of successful experience