14 July, 2008 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Distributed and beacon-enabled multiple access control for WBAN] Date Submitted: [14 July, 2008] Source: [Youjin Kim, Hyungsoo Lee, Seung Hyong Rhee, Wangjong Lee, Hyukjoon Lee, Suwon Park] Company [ETRI/KWU] Address [161, Gajeong-dong, Youseong-gu, Daejeon, Korea] Voice:[+82-2-943-7607], FAX: [+82-2-943-7607], E-Mail:[{youjin,hsulee}@etri.re.kr, {rhee,woorihope,hlee,spark}@kw.ac.kr] Re: [] Abstract: [Unique requirements of WBAN MAC have been discussed so far. In this document, some preliminary simulation results are provided and a new way of multiple access control is suggested in order to satisfy the WBAN MAC requirements.] 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 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. <Kim, Rhee et al. >, <ETRI/KWU>

Distributed and Beacon-enabled Multiple Access Control for WBAN 14 July, 2008 Distributed and Beacon-enabled Multiple Access Control for WBAN ETRI/KWU <Kim, Rhee et al. >, <ETRI/KWU>

Outline Reservation vs. LBT 14 July, 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 Control channel with beacons Distributed reservation by outbody devices Unified multiple access in different bands Channel aggregation for high-throughput applications <Kim, Rhee et al. >, <ETRI/KWU>

Design Challenges for WBAN MAC 14 July, 2008 Design Challenges for WBAN MAC Requirements of WBAN MAC QoS assurance Reliability and robustness Co-existence Energy efficiency Great variety of traffic characteristics Additional requirements Unified MAC for both MICS and ISM Scalability with a large number of devices Security <Kim, Rhee et al. >, <ETRI/KWU>

How to access the channels? 14 July, 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>

Reservation vs. LBT (1 channel) 14 July, 2008 Reservation vs. LBT (1 channel) Attribute Value Superframe 5ms CTA 2ms Bandwidth 0.3Mb Traffic CBR Packet Size 10 bytes <Kim, Rhee et al. >, <ETRI/KWU>

Reservation vs. LBT: Observation 1 14 July, 2008 Reservation vs. LBT: Observation 1 Reservation outperforms LBT in most cases by avoiding collisions <Kim, Rhee et al. >, <ETRI/KWU>

Reservation vs. LBT (2 channels) 14 July, 2008 Reservation vs. LBT (2 channels) <Kim, Rhee et al. >, <ETRI/KWU>

Reservation vs. LBT: Observation 2 14 July, 2008 Reservation vs. LBT: Observation 2 Due to the listening periods, the throughput of LBT is degraded <Kim, Rhee et al. >, <ETRI/KWU>

Channel Plan One fixed channel for control 14 July, 2008 Channel Plan One fixed channel for control The remaining band is for data transfer Dynamic and distributed spectrum allocation MICS 402 405 [MHz] Control channel Data channels <Kim, Rhee et al. >, <ETRI/KWU>

14 July, 2008 Control Channel The first (outbody) device select a channel for the control purpose It avoids channels in use by listening Control channel MICS 402 405 [MHz] Metaids in use <Kim, Rhee et al. >, <ETRI/KWU>

Beacon Slots One beacon slot for one data channel 14 July, 2008 Beacon Slots One beacon slot for one data channel Outbody devices reserve data channels via beacons Control channel Data channels frequency time Beacon superframe <Kim, Rhee et al. >, <ETRI/KWU>

14 July, 2008 Channel Aggregation Outbody devices may reserve several channels via beacons Various traffic types can be satisfied by the channel aggregation frequency time Beacon superframe Data channels Control channel <Kim, Rhee et al. >, <ETRI/KWU>

Is Channel Aggregation Better? 14 July, 2008 Is Channel Aggregation Better? Attribute Value Superframe 12.4ms Data Transmit Period 11.5ms Bandwidth 0.9Mb / 0.3Mb Traffic CBR Packet size 10 bytes <Kim, Rhee et al. >, <ETRI/KWU>

Simulating the Channel Aggregation 14 July, 2008 Simulating the Channel Aggregation High-throughput applications can benefit by channel aggregations <Kim, Rhee et al. >, <ETRI/KWU>

Distributed Reservation among Outbody Devices 14 July, 2008 Distributed Reservation among Outbody Devices Control channel frequency outbody inbody <Kim, Rhee et al. >, <ETRI/KWU>

Superframe Structure Communications initiated by outbody device 14 July, 2008 Superframe Structure Communications initiated by outbody device Inbody device first listens to the control channel, and then goes to the designated channel Data superframe BP In → Out Sleep BP In → Out time time Beacon superframe <Kim, Rhee et al. >, <ETRI/KWU>

Unified Access Control in Different Bands 14 July, 2008 Unified Access Control in Different Bands Non-overlapping channels are also assumed in ISM band Same way of multiple access control in both bands MICS 402 405 [MHz] 300 KHz ISM 2400 2483.5 [MHz] several MHz <Kim, Rhee et al. >, <ETRI/KWU>

Single MAC for Two PHYs: Example 14 July, 2008 Single MAC for Two PHYs: Example WBAN MAC WBAN MAC MICS PHY ISM PHY MICS PHY ISM PHY outbody inbody MICS 1 2 3 4 5 6 7 402 405 [MHz] ISM 11 12 13 14 15 16 17 2400 2483.5 [MHz] <Kim, Rhee et al. >, <ETRI/KWU>

Advantages of the Beacon-enabled MAC 14 July, 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>

Synchronous Power Management: IEEE 802.15.4 14 July, 2008 Synchronous Power Management: IEEE 802.15.4 B B GTS 2 GTS 1 inactive Contention Access Period(CAP) Contention Free Period(CFP) BI (Beacon Interval) aBaseSuperframeDuration * 2BO symbols 15.4 devices May be in a sleep state during beacon intervals Should periodically listen the beacons Weak points of synchronous mechanism One may scan a whole beacon interval in order to catch a beacon Lower duty cycle requires expensive reference crystals <Kim, Rhee et al. >, <ETRI/KWU>

Asynchronous Power Management 14 July, 2008 Asynchronous Power Management Node 1 listen sleep listen sleep listen Node 2 listen sleep listen sleep Wakeup schedules can differ A couple of asynchronous mechanisms are studied in literature B-MAC WiseMAC <Kim, Rhee et al. >, <ETRI/KWU>

Efficient Asynchronous Power Saving 14 July, 2008 Efficient Asynchronous Power Saving (Inbody) device scans only the beacon superframe, not the long superframe at its wakeup state Control channel frequency time dev1 dev2 <Kim, Rhee et al. >, <ETRI/KWU>

doc.: IEEE 802.15-<doc#> <month year> doc.: IEEE 802.15-<doc#> 14 July, 2008 References F. Shu and G. Dolmans, MAC Design Issues and Wake-up Radio for Wireless BANs, IEEE 802.15-08-0276, May 2008 M. Patel, The MAC Protocol Requirements for BAN, IEEE 802.15-08-0053, Jan. 2008 S. Lee and Y. Yoon, MAC requirements for the BAN, IEEE 802.15-07-0756, July 2007 “MAC and PHY specifications for low-rate wireless personal area networks,” IEEE Std 802.15.4, IEEE, 2003 <Kim, Rhee et al. >, <ETRI/KWU> <author>, <company>