1. doc.: IEEE 802.15-05-0221-01-004a Submission April, 2005 Brethour, Time DomainSlide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Proposed classes of Ranging service] Date Submitted: [1 May, 2005] Source: [Vern Brethour] Company [Time Domain Corp.] Address [7057 Old Madison Pike; Suite 250; Huntsville, Alabama 35806; USA] Voice:[(256) 428-6331], FAX: [(256) 922-0387], E-Mail: [vern.brethour@timedomain.com] Re: [802.15 4a.] Abstract:[3 Classes of ranging service are proposed for adoption by 802.15.4a.] Purpose:[To serve as “targets” in the selection of signaling parameters and protocols for 802.15.4a.] 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 802.15-05-0221-01-004a Submission April, 2005 Brethour, Time DomainSlide 2 3 Classes of ranging service for 802.15.4a Proposed to serve as “targets” for determining aspects of signaling.

3. doc.: IEEE 802.15-05-0221-01-004a Submission April, 2005 Brethour, Time DomainSlide 3 The three classes roughly defined: Accurate Ranging Fast Ranging Cost-effective Ranging

4. doc.: IEEE 802.15-05-0221-01-004a Submission April, 2005 Brethour, Time DomainSlide 4 Accurate Ranging One way message accuracy of 25 cm or better at 50 meters in 4 ms in 90% of channels. Against White Gaussian Noise All nodes stationary during measurement No other 15.4a transmitters operating (on any channel) during the measurement (Targeting a 2 way ranging accuracy 25 cm.) (Targeting a positioning accuracy of 1 meter with a GDOP degradation factor of 4.)

5. doc.: IEEE 802.15-05-0221-01-004a Submission April, 2005 Brethour, Time DomainSlide 5 Fast Ranging One way message accuracy of 25 cm or better at 20 meters in 500 us in 90% of channels. Against White Gaussian Noise All nodes stationary during measurement No other 15.4a transmitters operating (on any channel) during the measurement (Targeting a 2 way ranging accuracy 25 cm.) (Targeting a positioning accuracy of 1 meter with a GDOP degradation factor of 4.)

6. doc.: IEEE 802.15-05-0221-01-004a Submission April, 2005 Brethour, Time DomainSlide 6 Cost-effective Ranging One way message accuracy of 1m or better at 20 meters in 4 ms in 90% of channels. Against White Gaussian Noise All nodes stationary during measurement No other 15.4a transmitters operating (on any channel) during the measurement This service is intended for ranging – not precision positioning.

7. doc.: IEEE 802.15-05-0221-01-004a Submission April, 2005 Brethour, Time DomainSlide 7 Comments The allowance factor {GDOP degradation = 4} simply represents an experience based guess, actual results will vary wildly depending upon node placement upon deployment. What is actually measured in two way ranging is the round trip range which will be the sum of two one way ranges, each with a statistical error having a maximum of 25 cm. We will divide that sum by 2 to get the one way error which now should have an error of less than 25 cm (hoping to get lucky with the statistics). The hope is that there will be additional luck left over to cover crystal drift during message turn-around time, and round-off errors and a host of little things. The “Fast Ranging” service is intended to better deal with relative motion in the nodes, but to keep our workload sane, we will only simulate stationary nodes.

8. doc.: IEEE 802.15-05-0221-01-004a Submission April, 2005 Brethour, Time DomainSlide 8 Comments “One Way” ranging in the definition slides means one half of a two way exchange. This is intended to keep our simulation burden more manageable. “One Way” ranging in the definition slides does not mean true one way time difference of arrival to nodes having pre-synchronized clocks. If we decide that we want to support true One Way Ranging with time difference of arrival, we will have to define a target performance for that mode.