May 2008 doc IEEE 802 15 08 0286

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May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Project: IEEE P

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Project: IEEE P 802. 15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: Ranging as a requirement for BAN and study on existing ranging schemes Date Submitted: May 12, 2008 Source: Giriraj Goyal, Kiran Bynam, Ranjeet Kumar Patro, Arun Naniyat, Seung-Hoon Park, Noh-Gyoung Kang, Jaeseung Son, Eun. Tae Won Contact: Giriraj Goyal, giriraj. g@samsung. com, Samsung Electronics Voice: +91 80 41819999, E-Mail: giriraj. g@samsung. com Re: [] Abstract: Brief overview of existing ranging techniques Purpose: To identify ranging as a requirement for BAN applications set and present brief study on existing ranging mechanisms. Notice: This document has been prepared to assist the IEEE P 802. 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 in May’ 08 it would be made publicly available by P 802. 15. Submission 1 Giriraj Goyal, Samsung Electronics

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Agenda • Ranging

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Agenda • Ranging applications • Ranging as a Requirement criterion for BAN • Existing Ranging and localization Techniques Submission 2 Giriraj Goyal, Samsung Electronics

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Ranging applications •

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Ranging applications • • • GPS based application Radar applications Ship navigation Tracking ‘search & rescue’ Inventory Security and surveillance Submission 3 Giriraj Goyal, Samsung Electronics

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 BAN Applications requiring

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 BAN Applications requiring Ranging • Game application • Body posture detection • Tracking applications Submission 4 Giriraj Goyal, Samsung Electronics

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Common Ranging Techniques

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Common Ranging Techniques • Time-of-Arrival (TOA) – TOA/TWR – DTOA – TOA/OWR – TDOA • Received signal strength (RSS) • Angle-of-Arrival (AOA) Submission 5 Giriraj Goyal, Samsung Electronics

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Assumptions with ranging

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Assumptions with ranging techniques • Direct line of sight • Static channel condition • Anchor (reference) nodes and the nodes are static when distances are measured. • Anchor nodes positions are known to each other. Submission 6 Giriraj Goyal, Samsung Electronics

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Time Of Arrival

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Time Of Arrival (TOA) – 1 • TOA/TWR – Two way ranging (Single packet exchange) T 0 T 1 time TOF Dev A Transmits signal • • TResponse Dev B receives the signal TOF Dev B Respond back to dev A Dev A receives response from Dev B TOF = Time of flight for signal from Dev A to Dev B TResponse = Turnaround time for Dev B to respond back to Dev A (Prescribed Protocol Delay and/or Processing Time) Distance (between A and B) estimation done by A Submission 7 Giriraj Goyal, Samsung Electronics

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Time of Arrival

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Time of Arrival (TOA) - 2 Range estimation with TOA/TWR is affected by : – Relative clock drift between A and B – Clock accuracy in A and B – Prescribed response delay Submission 8 Giriraj Goyal, Samsung Electronics

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Time Of Arrival

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Time Of Arrival (TOA) – 3 • • TWR with Double packet exchange; known as DTOA (Differential Time of Arrival) DTOA is a modification of TOA/TWR technique, to remove effects of protocol/response delay (turn around time) Random Time Delay T 0 T 1 T’ 0 time TOF Dev A Tx signal • • TResponse Dev B rx signal Dev B Respond back to dev A TDelay = 2*TResponse TOF Dev A rx response from Dev B Dev A Tx signal TOF Dev B Respond back to dev A Dev B rx signal Dev A rx response from Dev B TOF = Time of flight for signal from Dev A to Dev B TResponse = Turnaround time for Dev B to respond back to Dev A (Prescribed Protocol Delay and/or Processing Time) Distance (between A and B) estimation done by A Submission 9 Giriraj Goyal, Samsung Electronics

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Time Of Arrival

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Time Of Arrival (TOA) - 4 • OWR – One way ranging, If Terminals are synchronized to a common clock, direct OWR can be used. T 0 T 1 time TOF Dev A* Transmits signal • • Dev* B receives the signal TOF = Time of flight for signal from Dev A to Dev B * Device A and Device B are isochronous Distance (between A and B) estimation done by B Submission 10 Giriraj Goyal, Samsung Electronics

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Time Of Arrival

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Time Of Arrival (TOA) – 5 TOA Localization (circle geometry): Calculate Algorithm for drawing circle trajectory and finding common point of intersection A 1 Anchor 1 (x 1, y 1) M Mobile Node (xm, ym) Estimation • • 3 anchors with known positions (at least) are required to retrieve a 2 D-position 4 anchors with known positions (at least) are required to retrieve a 3 D-position Submission A 2 Anchor 2 (x 1, y 1) A 3 Anchor 3 (x 1, y 1) • Anchors A 1, A 2 & A 3 are centers of circles. • Three circles will pass through one common point for a single solution. 11 Giriraj Goyal, Samsung Electronics

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Time Of Arrival

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Time Of Arrival (TOA) - 6 • TDOA (Time Difference of Arrival) localization is a modification of TOA localization technique T 0 Mobile* Tx Anchor 2* Rx TOF 2 T 2 Anchor 3* Rx TOF 3 T 3 time Anchor 2 sends T 2 info to Anchor 1 TDOA Estimation Anchor 3 sends T 3 info to Anchor 1 TOF 1 Anchor 1* Rx T 1 Mobile Node M Tx signal Anchor 2 Rx signal Anchor 1 Rx signal Reference time • • Time of flight information by anchor nodes can be calculated by any of TOA method. Example shows Time Difference by a anchor node (anchor 1) can be calculated by any reference time if TOA/OWR ranging method Submission 12 Giriraj Goyal, Samsung Electronics

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Time Of Arrival

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Time Of Arrival (TOA) - 7 TDOA Localization (hyperbola geometry): Calculate Algorithm for drawing hyperbolic trajectory and finding point of intersection A 3 Anchor 3 (x 1, y 1) A 1 Anchor 1 (x 1, y 1) A 2 Anchor 2 (x 1, y 1) M Mobile Node (xm, ym) Estimate Note: 3 anchors with known positions (at least) are required to retrieve a 2 D-position Submission • Anchors A 1, A 2 & A 3 are Foci of Hyperbola • Hyperbolas are drawn for locus of M with and as constant. 13 Giriraj Goyal, Samsung Electronics

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Received Signal Strength

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Received Signal Strength (RSS) – 1 Data link Processing unit Anchor/reference node Nodes required being located -Devices calculate ranges to their neighbors -Location is jointly estimated using collective information -Location Accuracy/ Range Extension Submission 14 Giriraj Goyal, Samsung Electronics

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Received Signal Strength

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Received Signal Strength (RSS) – 2 • RSS is an alternative solution to TOA/TDOA as it lowers requirements in terms of synchronization and clock precision The Disadvantages are – • RSSI requires precise channel behavioral model • This technique is sensitive to channel inconsistency Submission 15 Giriraj Goyal, Samsung Electronics

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Angle of Arrival

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Angle of Arrival (AOA) AOA could be an alternative solution to TOA/TDOA I. Lower requirements in terms of synchronization and clock precision II. Two anchors are sufficient for 2 D-positioning and three for 3 Dpositioning • AOA requires precise calibration at anchor nodes • Cost increases with size and size may not be reduced Submission 16 Giriraj Goyal, Samsung Electronics

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Comparison chart Ranging

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Comparison chart Ranging Techniques TOA RSS AOA Submission Advantages Disadvantages Highly accurate for wide bands transmission as synchronization accuracy is high Less complexity • Clock drift issue • Clock accuracy in nodes • Clock synchronization is required Effected by channel dynamics • Localization technique • Multi-path effects changes phase of a signal and • Number of anchors required for 2 -D can yield large positioning errors. and 3 -D positioning are lesser than • Requires array of antenna TOA technique. 17 Giriraj Goyal, Samsung Electronics

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Ranging challenges •

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Ranging challenges • • MAC role/computation complexities Energy attenuation Multi-path channel Clock synchronization Submission 18 Giriraj Goyal, Samsung Electronics

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Reference • 15

May 2008 doc. : IEEE 802. 15 -08 -0286 -02 -0006 Reference • 15 -04 -0581 -07 -004 a-rangingsubcommittee-final-report. doc • http: //rfdesign. com/mag/radio_uwb_techno logy_locationaware/ Submission 19 Giriraj Goyal, Samsung Electronics