1. 28 October, 2008
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [Beacon-based Multi-Channel MAC for WBAN]
Date Submitted: [28 October, 2008]
Source: [Youjin Kim, Hyungsoo Lee, Seung Hyong Rhee, Wangjong Lee]
Company [ETRI/KWU] Address [161, Gajeong-dong, Youseong-gu, Daejeon, Korea]
Voice:[ ], FAX: [ ],
Re: []
Abstract: [A new way of multiple access control for the WBAN devices is suggested in order to satisfy the unique requirements of WBAN MAC. Some preliminary simulation results are provided. Coexistence problem with LBT devices and power saving mechanism are also discussed.]
Purpose: [To present some preliminary results, and also to suggest a framework for the WBAN MAC and have a discussion]
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
<Kim, Rhee et al. >, <ETRI/KWU>

2. Beacon-based Multi-channel MAC for WBAN
28 October, 2008
Beacon-based Multi-channel MAC for WBAN
ETRI/KWU
<Kim, Rhee et al. >, <ETRI/KWU>

3. Outline Reservation vs. LBT
28 October, 2008
Outline
Reservation vs. LBT
Which one is better for multiple access control for WBAN?
A framework for WBAN MAC
How to satisfy the unique requirements?
Distinctive features of proposed MAC
Dedicated control channel with beacons
Distributed reservation by wearable devices
Unified multiple access in different bands
Channel aggregation for high-throughput applications
<Kim, Rhee et al. >, <ETRI/KWU>

4. Design Challenges for WBAN MAC
28 October, 2008
Design Challenges for WBAN MAC
Requirements of WBAN MAC
Network recovery from link & node failures
QoS support (the reliability of the transmission)
Security and Privacy
Coexistence and Interference resistance
Power consumption to maximize the battery life
Asymmetric traffic flow
Data rates depend on applications
(~10kbps at the low end and ~10Mbps at the high end)
Additional requirements
Implantable BAN and wearable BAN should gracefully coexist in-and-around the body.  Unified MAC for MICS and ISM bands
Network configuration should be scalable up to a minimum of 256 nodes
<Kim, Rhee et al. >, <ETRI/KWU>

5. How to access the channels?
28 October, 2008
How to access the channels?
MICS
402
405
[MHz]
300 KHz
Channels in MICS band
Narrow band
Non-overlapping
Multiple access is controlled by LBT among
Medical devices
METAIDS (Meteorological aids service) devices
<Kim, Rhee et al. >, <ETRI/KWU>

6. Reservation vs. LBT 28 October, 2008
<Kim, Rhee et al. >, <ETRI/KWU>

7. 28 October, 2008
Reservation vs. LBT
Due to the listening periods, the throughput of LBT is degraded
<Kim, Rhee et al. >, <ETRI/KWU>

8. Proposed Channel Plan Common Control Channel for Reservation
28 October, 2008
Proposed Channel Plan
Common Control Channel for Reservation
 One (out of ten) fixed channel for control
The remaining bands are for data channels
Dynamic and distributed spectrum allocation
Control Channel
ISM band
and/or
Ch 1
Ch 2
Ch N
Ch0
Ch1
Ch2
Ch3
Ch4
Ch5
Ch6
Ch7
Ch8
Ch9
MICS band
402MHz
405MHz
<Kim, Rhee et al. >, <ETRI/KWU>

9. Control Channel
The first (outbody) device selects a channel for the control purpose
It avoids channels in use by listening
Control channel
MICS
402
405
[MHz]
Metaids in use

10. Beacon Slots One beacon slot for one data channel
28 October, 2008
Beacon Slots
One beacon slot for one data channel
Outbody devices reserve data channels via beacons
Control channel
Data channels (MICS or ISM Bands)
frequency
time
Beacon Superframe
Beacon slot
<Kim, Rhee et al. >, <ETRI/KWU>

11. 28 October, 2008
Channel Aggregation
Outbody devices may reserve several channels via beacons
The channel aggregation can be useful for the heterogeneous traffic types and asymmetric data flow
MICS and/or ISM bands
Data channel
<Kim, Rhee et al. >, <ETRI/KWU>

12. Is Channel Aggregation Better?
28 October, 2008
Is Channel Aggregation Better?
MICS or ISM bands
Attribute
Value
Superframe
12.4ms
Data Transmit Period
11.5ms
Bandwidth
0.9Mb / 0.3Mb
Traffic
CBR
Packet size
10 bytes
MICS or ISM bands
<Kim, Rhee et al. >, <ETRI/KWU>

13. Simulating the Channel Aggregation
28 October, 2008
Simulating the Channel Aggregation
Bulky traffic applications can benefit by the channel aggregation
Also various types of QoS can be supported
<Kim, Rhee et al. >, <ETRI/KWU>

14. Distributed Reservation among Out-body Devices
28 October, 2008
Distributed Reservation among Out-body Devices
frequency
Control channel
<Kim, Rhee et al. >, <ETRI/KWU>

15. Coexistence with LBT: Control Channel
28 October, 2008
Coexistence with LBT: Control Channel
In case beacon slots are empty during more than 5㎳
LBT devices may listen and transmit over the control channel!
<Kim, Rhee et al. >, <ETRI/KWU>

16. 28 October, 2008
Beacon Repeat
<Kim, Rhee et al. >, <ETRI/KWU>

17. Coexistence with LBT: Data Channel
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doc.: IEEE <doc#>
28 October, 2008
Coexistence with LBT: Data Channel
<Kim, Rhee et al. >, <ETRI/KWU>
<author>, <company>

18. RTS/ACK Packets 28 October, 2008
<Kim, Rhee et al. >, <ETRI/KWU>

19. Waiting on Data Channel
28 October, 2008
Waiting on Data Channel
<Kim, Rhee et al. >, <ETRI/KWU>

20. Channel Reselection due to Timeout
28 October, 2008
Channel Reselection due to Timeout
<Kim, Rhee et al. >, <ETRI/KWU>

21. Issue (3) : Control Channel Collision
28 October, 2008
Issue (3) : Control Channel Collision
Collision with LBT devices
<Kim, Rhee et al. >, <ETRI/KWU>

22. Changing the Control Channel
28 October, 2008
Changing the Control Channel
<Kim, Rhee et al. >, <ETRI/KWU>

23. 28 October, 2008
Beacon Shift
<Kim, Rhee et al. >, <ETRI/KWU>

24. Power Saving Issues Asynchronous mode No synchronization among devices
28 October, 2008
Power Saving Issues
Asynchronous mode
No synchronization among devices
Low cost and flexibility
Asymmetric power saving
Extremely long battery life is required for inbody devices
Moderate power management for outbody devices
Two modes of power management
Inbody devices awake
Outbody device wakes up the inbody devices
<Kim, Rhee et al. >, <ETRI/KWU>

25. Power Saving : Asynchronous Wakeup
28 October, 2008
Power Saving : Asynchronous Wakeup
<Kim, Rhee et al. >, <ETRI/KWU>

26. Power Saving : Wakeup Call (1)
28 October, 2008
Power Saving : Wakeup Call (1)
<Kim, Rhee et al. >, <ETRI/KWU>

27. Power Saving : Wakeup Call (2)
28 October, 2008
Power Saving : Wakeup Call (2)
<Kim, Rhee et al. >, <ETRI/KWU>

28. Advantages of the Beacon-enabled MAC
28 October, 2008
Advantages of the Beacon-enabled MAC
The beacon-enable MAC satisfies most requirements of WBAN MAC
Requirements of WBAN MAC
QoS assurance
Reliability and robustness
Co-existence
Energy efficiency
Great variety of traffic characteristics
Debatable, but also strongly preferred
Unified MAC for both MICS and ISM
Scalability with a large number of devices
Security
<Kim, Rhee et al. >, <ETRI/KWU>

29. doc.: IEEE 802.15-<doc#>
<month year>
doc.: IEEE <doc#>
28 October, 2008
References
F. Shu and G. Dolmans, MAC Design Issues and Wake-up Radio for Wireless BANs, IEEE , May 2008
M. Patel, The MAC Protocol Requirements for BAN, IEEE , Jan. 2008
S. Lee and Y. Yoon, MAC requirements for the BAN, IEEE , July 2007
Y.Kim, and Y. Choi, Priority QoS Facility in the MAC layer for WBAN, IEEE , July 2008
“MAC and PHY specifications for low-rate wireless personal area networks,” IEEE Std , IEEE, 2003
<Kim, Rhee et al. >, <ETRI/KWU>
<author>, <company>