1. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Ranging with the 15.4 MAC] Date Submitted: [21 September, 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:[A review of the 15.4a applications asking for location awareness & a possible approach for serving a high number of tracked nodes.] Purpose:[To promote discussion in 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 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 2 A review of applications for UWB ranging & the associated system requirements.

3. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 3 First, a review of applications. The next few slides list the applications that are usually discussed in the context of UWB ranging and positioning.

4. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 4 Safety of life. Safety interlock on dangerous equipment: Some nasty machine turns off when humans (wearing appropriate radios) get too close. Tracking firefighters in dangerous environments. Tracking soldiers or policemen in hostile buildings.

5. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 5 Tracking material Pallets in warehouses. Equipment in hospitals. Shipping containers in ports. Luggage in airports & ports. Cars in huge lots. Lost car keys & TV remotes.

6. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 6 Automatic meter reading? In the 4a applications, this was listed as an application for “location awareness”. (???) In other market characterizations, this is strictly a communications application. The meter has an ID number associated with an account to be billed. We usually want to know the meter reading, not the location.

7. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 7 Tracking animals Pets and Agricultural livestock are self propelled high value assets with “minds” of their own. It’s useful to know where they are and where they have been. (How often has Bessie been to the feed trough?)

8. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 8 Tracking people Children in amusement parks & malls Workers on hazardous job sites Alzheimer’s patients Prisoners First Responders

9. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 9 The “most asked for” application. This is hands down the most requested application in Huntsville Alabama. Second place is not even close: Tracking Teenage Daughters.

10. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 10 Now, let’s go through the applications again and look at what the system requirements to support them. Generalizations follow: let’s look for the trends.

11. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 11 Safety of life applications Support of mobility is essential. High update rates are required. Cost and battery life are not so critical.

12. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 12 Tracking material This is probably the best fit for 4a. Pallets of dog food in a warehouse need to be findable, but they don’t move around often and do not need to be tracked while in motion. Some high value assets (pallets of processor chips) need high update rates and tolerance of mobility so they can be detected when they try to wander off.

13. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 13 Location Awareness for meter reading? Where is the meter?

14. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 14 The meter is right here on the side of the house. (Same place it was last month.) The REAL question the meter reader cares about: Where is the pit bull?

15. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 15 Automatic meter reading. This is an excellent application for UWB and 15.4a communications. I do not believe that this is an application requiring location awareness.

16. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 16 Tracking animals High update rates are usually required. This might be an application that can be served by 15.4a if we only care occasionally where the animals are.

17. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 17 Tracking People In general, the goal is detecting people going where they should not (because they are mobile). This requires a high update rate.

18. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 18 What does this mean for the 4a MAC? High update rates (implying high traffic levels on the air) might not be appropriate for the 4a MAC. Many of the applications for UWB location are calling for high update rates. Even the support of “mode 2” ranging will be difficult.

19. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 19 Remember “mode 2” ranging? We said in Australia that we wanted to support this. The red nodes (typically in the fixed infrastructure) need a common high accuracy clock. Key: Sync Pulse Location Pulse TDOA backhaul Mode 2 - Active controller reference node SOI

20. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 20 The establishment and maintenance of the high accuracy clock will be tough with the 15.4 MAC Clock sync usually wants timestamps and oscillator drift rate information exchanged regularly. Mode 2 - Active SOI Black arrows are clock sync messages.

21. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 21 Maybe, we let the Mode 2 infrastructure be outside of the standard. Key: Sync Pulse Location Pulse TDOA backhaul Mode 2 - Active controller reference node SOI The red nodes do their clock sync thing some proprietary way that is not part of the standard. All red nodes in a particular installation would have to be from the same vendor (interoperability of infrastructure nodes is not guaranteed by the standard.) We define the behavior of the blue nodes as 15.4a standard behavior and blue nodes can come from any vendor and work with any infrastructure.

22. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 22 The warehouse application: The warehouse infrastructure is made of proprietary radios which are not necessarily interoperable with infrastructure radios from other vendors. (Infrastructure is potentially wired into the building.) Screwed to each pallet is a standard 4a device from any vendor that will work in any infrastructure. This is a perfect “15.4” fit: inexpensive, long battery life, low duty cycle, etc.

23. doc.: IEEE 802.15-05-0491-01-004a Submission September, 2005 Brethour, Time DomainSlide 23 The proprietary infrastructure. This is a way to let our worldwide deployable system (with low traffic rates on the air) still support tracking of very large quantities of nodes. As the regulators squeeze us, this might be our best response.