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: [Ranging Protocol Considerations] Date Submitted: [16 January 2014] Source: [Rainer Hach] Company [nanotron Technologies] Address [Alt-Moabit 60, 10555 Berlin, Germany ] Voice:[+49 (0)30 399 954 103], FAX: [], E-Mail:[r.hach@nanotron.com] Re: [] Abstract: [basic principles of ranging protocols] Purpose: [Initial input to SG4r ] 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. Rainer Hach, nanotron Technologies

2. Ranging Protocol Considerations Rainer Hach, nanotron Technologies

3. Driving applications • Dynamic scenarios • Collision avoidance • forklift / equipment, worker • truck / equipment, worker • Loss protection • equipment • assets • Static scenarios • Network management • ?? Rainer Hach, nanotron Technologies

4. Motivation • Estimating the physical distance between two peer devices is called „ranging“ • Ranging can be performed based on various observations e.g.: • decay of signal power • time of flight (TOF) • round trip time of flight • phase measurements • … • All these techniques require transmission or even mutual exchange of information between the peers. • E.g. • decay of signal power -> original TX power • TOF -> time of departure • Some techniques need explicit bandwidth (dedicated control frames, channel time), • other techniques can be piggyback ranging with data commincation Rainer Hach, nanotron Technologies

5. Initiating ranging transceiver Responding ranging transceiver Data SIFS TReply TRound Ack t t Two way ranging with Data-Ack Figure from ISO/IEC 24730-5 Values for TRound and TReply must be collected at initiator and/or responder and/or third device RTTOF= (TRound – Treply)/2 Rainer Hach, nanotron Technologies

6. Ranging transceiver A Ranging transceiver B T1R1 TReplyB TRoundA Ack TT1R2 T1R2 TReplyA Ack TRoundB TT1R3 T1R3 Ack Ranging packet exchange type 1: SDS-TWR*, initiator (A) estimates range Figure from ISO/IEC 24730-5 * SDS-TWR: Symetric Double Sided Two Way Ranging, see Annex 802.15.4a or Annex E.2.4 of Std 802.15.4-2011 Rainer Hach, nanotron Technologies

7. Rangin transceiver A Ranging transceiver B T2R1 TReplyB TRoundA Ack TT2R2 T2R2 TReplyA Ack TRoundB TT2R3 T2R3 Ack Ranging packet exchange type 2: SDS-TWR, responder(B) estimates range Figure from ISO/IEC 24730-5 Rainer Hach, nanotron Technologies

8. How to exchange ranging related information? • Exchange of information between wireless devices (from different vendors) –> standardization needed • exchanged information should be meaningful formatted • e.g. integer in 1ns instead of implementation specific registers • However ranging information is not nessarily part of the MAC protocol itself-> Better (because easier to realize): defer to higher layer (e.g. ISO/IEC 24730-5) or use IE (information element) (e.g. 802.11p) Rainer Hach, nanotron Technologies

9. Suggested course 1) Complete list of ranging techniques which could benefit from this work -Review and classify required bandwidth and information exchange Assumption: IEs are more flexible than frame formats: 2) Develop basic structure of ranging frame -Check whether additional 15.4 MAC frame is required and realistic 3) Develop basic structure of ranging IE 4) Define IE(s) for known techniques such that procedure for modification and enhancement of IE(s) is obvious Rainer Hach, nanotron Technologies

10. Thank you! Rainer Hach, nanotron Technologies