1. doc.: IEEE 802.15-09-0114-00-004g-Trends-in-SUN-capacity
<month year>
Sept. 2012
Project: IEEE P Working Group for Wireless Personal Area Networks(WPANs)
Submission Title: Benefits of ranging bit in PHY for TG4m ranging
Date Submitted: Sept. 2012
Source: Mi-Kyung Oh, Jae-Hwan Kim, Jae-Young Kim, and Sangsung Choi (ETRI), Soo- Young Chang (SYCA)
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Abstract: This contribution presents benefits of ranging bit in PHY for TG4m ranging
Purpose: Notice: This document has been prepared to assist the IEEE P 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 P
Slide 1
ETRI
Emmanuel Monnerie, Landis+Gyr

2. Sept. 2012
Outline
The goal of this document is to provide benefits of ranging bit in the PHY header for TG4m ranging
This document includes several examples to use the ranging bit in PHR
ETRI

3. Sept. 2012
Issues on Ranging Bit
In addition to the ranging information request IE in the MAC frame, Doc suggested the ranging bit in PHR to indicate that the particular frame is intended for ranging
Do we really need the ranging bit in PHR?
ETRI

4. Ranging Counter Overview
Sept. 2012
Ranging Counter Overview
The complete two-way ranging exchange
Data Payload
PHR
SHR
Early in time
Later in time
Ranging
originator Tx
responder Rx
ACK
The ranging counter in the originator
The ranging counter in the responder
Start
Stop
ETRI

5. Sept. 2012
Ranging Bit in PHY
The ranging bit itself does not cause any additional PHY overhead and any additional power consumption since one of reserved bits in PHR is used for the ranging bit
If there is any benefit of exploiting a ranging bit in PHY, it will be better to use the ranging bit
Since we already have well-developed UWB ranging standard in , it will be better to keep consistency
15.4a, PD-DATA.confirm & PD-DATA.indication primitives provide the parameter named RangingReceived which is determined by RNG from the received PHR
ETRI

6. Benefits of Ranging Bit in PHY
Sept. 2012
Benefits of Ranging Bit in PHY
The ranging bit in PHY enables efficient implementation of ranging operation at the receiver
Efficient on/off of ranging counter
Triggering a timing correction logic for enhancing accuracy
Reducing MAC overhead
There will be many approaches to use the ranging bit in PHY in the view of implementation
ETRI

7. Ranging Counter Operation
Sept. 2012
Ranging Counter Operation
Ranging bit in PHR can trigger the ranging counter in the receiver
The ranging counter can start its operation upon ranging bit arrival
Received RMARKER timing can be achieved due to fixed known timing offset between RMARKER and ranging bit
Therefore, the ranging counter does not need to run at every packet reception
RMARKER
Ranging Bit
PHY
Layer
SHR
PHR
PSDU
Fixed known offset
ETRI

8. Timing Correction for Accuracy
Sept. 2012
Timing Correction for Accuracy
Ranging bit in PHR can trigger a timing correction logic for ranging accuracy
Capturing the ranging counter value itself is not difficult
Timing correction should be carried out and applied to the captured ranging counter values
Clock frequency offset consideration
Some mechanisms for sub-sample accuracy
First path detection in multipath channel
In addition, it will help to selectively produce the ranging figure of merit (FoM) for the ranging frame to indicate ranging confidence level
ETRI

9. Sept. 2012
Reducing MAC Overhead
Ranging bit in PHR can help reducing MAC overhead when ranging is enabled
During the ranging mode, there would be many normal data exchanges which are not intended for ranging
Reporting RangingReceived=0/1 to the MAC makes it easy to handle the ranging operation in the MAC
ETRI

10. Sept. 2012
Conclusions
The ranging bit in PHY does not cause any additional PHY overhead and power consumption since one of reserved bits in PHR is used for the ranging bit
Benefits of the ranging bit in PHY
Triggering the ranging counter operation and efficient on/off of ranging counter
Triggering the timing correction logic and selectively producing FoM for the ranging frame
Reducing MAC overhead
and others…
The ranging bit in PHY will make our ranging capable TG4m PHY smart in the view of implementation
ETRI