1. <July 2008>
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [Slot Considerations in BAN]
Date Submitted: [July, 2008]
Source: [Changle Li, Bin Zhen, Huan-Bang Li and Ryuji Kohno] Company [National Institute of Information and Communications Technology (NICT)]
Address [3-4 Hikarino-oka, Yokosuka, , Kanagawa, Japan]
Voice:[ ], FAX: [ ],
Abstract: [Slot considerations in BAN.]
Purpose: [To illustrate the considerations on the slot design including the number of slots and the slot duration in a TDMA-based BAN.]
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
<C. Li, B. Zhen, H.-B. Li and R. Kohno>, <NICT>

2. Slot Considerations in BAN
<July 2008>
Slot Considerations in BAN
Changle Li, Bin Zhen, Huan-Bang Li and Ryuji Kohno
National Institute of Information and Communications Technology (NICT)
<C. Li, B. Zhen, H.-B. Li and R. Kohno>, <NICT>

3. Outline 1. Background 2. Number of Slots 3. Duration of a Slot
<July 2008>
Outline
1. Background
2. Number of Slots
3. Duration of a Slot
4. Conclusions
<C. Li, B. Zhen, H.-B. Li and R. Kohno>, <NICT>

4. 1. Background Data packet transmission MAC characteristics TR document
<July 2008>
1. Background
Data packet transmission
TDMA based
MAC characteristics
Simplicity
TR document
What is a slot?
A short time interval, but long enough for a dedicated data packet transmission from a BAN device.
<C. Li, B. Zhen, H.-B. Li and R. Kohno>, <NICT>

5. 1. Background (cont.) Applications Leads/ Sensors/ Devices Measu-
<July 2008>
1. Background (cont.)
Applications
Leads/
Sensors/
Devices
Measu-
rement time
Frequency (times
/day)
Traffic load
Payload
(byte/
device)
Medical
ECG 12
30 s 2
6kbps/lead
750/s
Body temperature 1
10 s
1packet/5s
Heart rate
1packet/10s
Blood pressure
Respiratory monitor*
8 hours
5kbps
625/s
SpO2 pulse oximeter
Implanted glucose sensor
1 s
24*6
1packet/10min
Insulin pump
1packet/time
Capsule endoscope#
2.8Mbps/each(up)
1packet/~mins(down)
346k/s(up)
16(down)
Non-medical
^Streaming video/audio, Gaming
multiple
continuously
256k/1M/5Mbps
>32k/s
medium
data rate
~kbps
low data rate
~bps
implanted
high
data rate
~Mbps
*Real-time transmission of respiration waveform
# capsule-endoscope-using-an-implant-wban.pdf
^ study-of-phy-requirements-for-non-medical-ban.ppt
<C. Li, B. Zhen, H.-B. Li and R. Kohno>, <NICT>

6. 2. Number of Slots Depends on the number of devices in a BAN
<July 2008>
2. Number of Slots
Depends on the number of devices in a BAN
A few sensors in typical applications in a BAN around the human body
Fixed 16 slots in a superframe (4-bit slot sequence number)
Optional redundancy period (RP) is kept for contention and/or inactive/sleep mode
considered in this file
tack: aMACProcessingDelay + aTurnaroundTime
IFS: interframe space
<C. Li, B. Zhen, H.-B. Li and R. Kohno>, <NICT>

7. 2. Number of Slots (cont.) Extension for supporting more devices
<July 2008>
2. Number of Slots (cont.)
Extension for supporting more devices
Combine 16 superframes getting the ability to allocate 16*16=256 slots at most.
A slot is ascertained by the slot sequence number
and the superframe sequence number.
<C. Li, B. Zhen, H.-B. Li and R. Kohno>, <NICT>

8. 3. Duration of a Slot Concerns
<July 2008>
3. Duration of a Slot
Concerns
Basically, a slot is long enough to transmit a typical-length data packet
Payload of a packet is flexible for different applications
For simplicity, slot duration is constant per PHY in a BAN
<C. Li, B. Zhen, H.-B. Li and R. Kohno>, <NICT>

9. 3. Duration of a Slot (cont.)
<July 2008>
3. Duration of a Slot (cont.)
Optimal slot duration has a strong relationship with MAC/PHY
MAC payload (application data)
Synchronization/PHY header (preamble)
Source: IEEE
Source: IEEE a-2007
7-bit “Frame Length” field.
127 octets of Max. PSDU size.
<C. Li, B. Zhen, H.-B. Li and R. Kohno>, <NICT>

10. 3. Duration of a Slot (cont.)
<July 2008>
3. Duration of a Slot (cont.)
Example (without FEC)
Narrowband PHY
(20 kbps, from 15.4)
UWB PHY (0.98 MHz Data Symbol Rate, from 15.4a)
SHR (µs)
2000
71.5
PHR (µs)
400
15.9
Data PSDU (octets)
127
Ack PSDU (octets) 5
tack (µs)
1600
31.8
IFS (µs)
39.7
Duration of a slot (ms)
61.2
1.324
Duration of CFP (ms)
979.2
21.2
<C. Li, B. Zhen, H.-B. Li and R. Kohno>, <NICT>

11. 4. Conclusions Simplicity at the cost of the efficiency
<July 2008>
4. Conclusions
Simplicity at the cost of the efficiency
16 slots of each superframe
Constant slot duration
Treated as protocol parameters with respect to the corresponding PHY type
Future work
Quantitatively results based on the superframe structure design
<C. Li, B. Zhen, H.-B. Li and R. Kohno>, <NICT>

12. Thanks for your attention!
<July 2008>
Thanks for your attention!
<C. Li, B. Zhen, H.-B. Li and R. Kohno>, <NICT>