Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: Low Energy Service Discovery MAC protocol for PAC WPAN Date Submitted: [July 2013] Source:[Wun-Cheol Jeong, Chang-Sub Shin, Tae-Joon Park, Hoyong Kang] Company: [ETRI] E-Mail:[wjeong@etri.re.kr] Re: [] Abstract: This proposal document describes how common discovery is supported from the MAC’s perspective. 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. Low Energy Service Discovery MAC Protocol for PAC WPAN Wun-Cheol Jeong, Chang-Sub Shin, Tae-Joon Park, Hoyong Kang ETRI

3. Low Energy Service Discovery Protocol • Abbreviations and acronyms • CS Channel Sampling • LESD Low Energy Service Discovery • MAC Medium Access Control • MHR MAC Header • MLME MAC sublayer Management Entity • MLSDE MAC sublayer Service Discovery Entity • PAN Personal Area Network • PD PAC Device • PLME PHY layer Management Entity • WPAN Wireless Personal Area Network

4. State Diagram of LESD Passive LESD scan Search Success Join PAN Search Fail Channel Sampling (CS) Active LESD scan Start PAN Search Success Search Fail

5. Passive LESD Scan Procedure NHL MLSDE MLSDE-LESD-SCAN.request Passive LESD Scan LESD response LESD notification MLSDE-LESD.confirm LESD notification MLSDE-LESD-NOTIFY.indication MLSDE-LESD-SCAN.confirm

6. Active LESD Scan Procedure NHL MLSDE MLSDE NHL MLSDE-LESD.request LESD request MLSDE-LESD.indication macLESDResponseWaitTime MLSDE-LESD.response LESD response LESD notification MLSDE-LESD-NOTIFY.indication MLSDE-LESD.confirm macNumLESDRequestRetries > macMaxLESDRequestRetries MLSDE-LESD-SCAN.confirm

7. Channel Sampling (CS) State Sleep Timer fire Sleep Rx macCSduration Tx completion Receive LESD request command Send Response Command

8. Illustration of CS procedure LESD request command CS Interval Sender TBRB LIFS CS Interval Receiver CSDuration

9. CS Procedure NHL MLSDE MLSDE-LESD-CS.request MLSDE-LESD-CS.confirm LESD request Rx on for macCSDuration MLME-LESD.indication MLME-LESD.response LESD response macCSInterval Rx off

10. MAC Primitives for LESD

11. MLSDE-LESD-SCAN: request MLSDE‑LESD-SCAN.request ( NumBRB, ServiceID, LESDChannelID, AvailableChannelID ) MLSDE‑LESD-SCAN.request parameters

12. MLSDE-LESD-SCAN: confirm MLSDE‑LESD-SCAN.confirm ( Status ) MLSDE‑LESD-SCAN.confirm parameters

13. MLSDE-LESD: request MLSDE‑LESD.request ( NumBRB, ServiceID, LESDChannelID, AvailableChannelID ) MLSDE‑LESD.request parameters

14. MLSDE-LESD: indication MLSDE‑LESD.indication ( ServiceID, AvailableChannelID ) MLSDE‑LESD.indication parameters

15. MLSDE-LESD: response MLSDE‑LESD.response ( PANID, ServiceID, CommunicationChannelID ) MLSDE‑LESD.response parameters

16. MLSDE-LESD: confirm MLSDE‑LESD.confirm ( PANID, ServiceID, CommunicationChannelID, Status ) MLSDE‑LESD.confirm parameters

17. MLSDE-LESD-NOTIFY: indication MLSDE‑LESD-NOTIFY.indication ( PANID, ServiceID, CommunicationChannelID ) MLSDE‑LESD-NOTIFY.indication parameters

18. MLSDE-LESD-NOTIFY: indication MLSDE‑LESD-CS.request ( PANID, NumBRB, ServiceID, CSDuration, CommunicationChannelID ) MLSDE‑LESD-CS.request parameters

19. MLSDE-LESD-NOTIFY: indication MLSDE‑LESD-CS.confirm ( Status ) MLSDE‑LESD-CS.confirm parameters

20. MAC Commands for LESD • LESD request command • LESD response command • LESD notification command

21. LESD Command Frames LESDrequest command format LESDresponse command format LESDnotification command format

22. CSMA-CA Algorithm START BE=macBE BC=random(2BE-1) Start Backoff Counter Perform CCA Channel idle? No BRB check Rx off Wait for (TBRB-TCCA) Yes No Rx BRB? FALSE EndOfBackoff? Yes Process BRB TRUE No BRB check Perform CCA Rx BRB? Channel idle? Yes Yes No Tx Process BRB

23. Backoff counter for CSMA-CA Algorithm Start Backoff counter BC=BC-1 Delay for UnitBackoff EndOfBackoff = FALSE No BC=0 Yes EndOfBackoff=TRUE

24. Clear Channel Assessment (CCA) PHY Frame structure Octets 6 2 1 Variable Preamble SFD PHY Header PHY Payload Basic Repetition Block (BRB) SHR PHR PSDU • - Samples the channel for 6 bit symbol periods • - Find the average value of channel samples • Compare the average value (ravg) with CCAThreshold • Declare • Busy if ravg > CCAThreshold • Idle otherwise

25. CSMA-CA Algorithm for LESD: BRB Check PHY Frame structure Octets 6 2 1 Variable Preamble SFD PHY Header PHY Payload Basic Repetition Block (BRB) SHR PHR PSDU IFS LESD request command TBRB LESD response command LESD notification command

26. CSMA-CA Algorithm for LESD: BRB Check PHY Frame structure BRB Octets 6 2 1 Variable Preamble SFD PHY Header PHY Payload SHR PHR PSDU Preamble consists of multiple of 8-bit sequence 01010101.

27. CSMA-CA Algorithm for LESD: BRB Check PHY Frame structure BRB Octets 6 2 1 Variable Preamble SFD PHY Header PHY Payload SHR PHR PSDU SFD Format If PHY detects command frame of interest, decodes the rest of BRB + PSDU, and passes it to MAC. PHY discards the rx frames otherwise.

28. CSMA-CA Algorithm for LESD: BRB Check PHY Frame structure BRB Octets 6 2 1 Variable Preamble SFD PHY Header PHY Payload SHR PHR PSDU

29. CSMA-CA Algorithm for LESD: BRB Processing Switch Rx Command Frame Type Case LESD request command: If T0 is 1, turn off the radio for (BRB Count -1) x (TBRB+TLIFS). Then, switch to Rx to receive the last BRB. Then, resume BC timer. If T0 is 0, MAC check the pending frame type. - If it is LESD request command with the same serviceID, discard the pending frame, and set timer for macLESDResponseWaitTime to wait for response (or notificaiton) command. - Otherwise, MAC discards the received frame and resume BC to send the pending frame.

30. CSMA-CA Algorithm for LESD: BRB Processing Switch Rx Command Frame Type Case LESD response command - If the pending command type is either request or response command, perform valid frame check. If it is valid, then discard the pending command and report the reception to NHL via MLSDE-LESD.confirm. - Otherwise, PD discards the received frame and resume BC to transmit the pending frame.

31. CSMA-CA Algorithm for LESD: BRB Processing Switch Rx Command Frame Type • Case LESD notification command • MAC performs valid frame check. • If it is valid and the pending frame is either request or response command frame, then discard the pending command and report the reception to NHL via MLSDE-LESD-NOTIFY.indication. • If it is valid and the pending frame is notification command frame, and discard the received frame and remove the pending frame. • - Otherwise, PD discards the received frame and resume BC to transmit the pending frame.

32. MAC PIB attributes

33. MAC PIB attributes (cont’d)

34. Thank you. Q & A