Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [WiseMAC – HA : A Flexible, Scalable, Robust and Ultra Low Power MAC Protocol for Medical BANs] Date Submitted: [10 July, 2008] Source: [JérômeRousselot] Company [CSEM SA] Address [Jaquet-Droz 1, CH-2002 Neuchatel, Switzerland] Voice:[0041327205829], FAX: [0041327205720], E-Mail:[jerome.rousselot@csem.ch] Re: [If this is a proposed revision, cite the original document.] [If this is a response to a Call for Contributions, cite the name and date of the Call for Contributions to which this document responds, as well as the relevant item number in the Call for Contributions.] [Note: Contributions that are not responsive to this section of the template, and contributions which do not address the topic under which they are submitted, may be refused or consigned to the “General Contributions” area.] Abstract:WiseMAC-HA, a MAC protocol designed specifically for body area networks, is presented and evaluated. Its design guarantees robustness against interferences and node failures, flexibility in network topology, scalability in network size, coexistence with independent networks and an ultra low power consumption. Purpose: [Description of what the author wants P802.15 to do with the information in the document.] 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. Jérôme Rousselot, CSEM

2. WiseMAC – HA A Flexible, Scalable, Robust and Ultra Low PowerMAC Protocol for Medical BANs Jérôme Rousselot, CSEM

3. Outline • Targeted BAN Applications and Requirements • Ultra Low Power MAC Protocols • The WiseMAC High Availability Protocol • Performance Evaluation • Conclusion Jérôme Rousselot, CSEM

4. Targeted Applications Medical Body Area Networks Continuous measurements Main Requirements • Low Power • Scalability • Robustness • Coexistence [ESENSE 2006] Jérôme Rousselot, CSEM

5. Ultra Low Power MAC Design Types of Energy Waste Idle Listening Signaling Overhead Useless Talking MAC Protocol Families Overhearing Collisions Radio in Rx Mode Radio in Tx Mode Jérôme Rousselot, CSEM

6. Ultra Low Power MAC Design Types of Energy Waste Idle Listening Signaling Overhead Useless Talking MAC Protocol Families Overhearing Collisions Radio in Rx Mode Radio in Tx Mode No Synchronization More Scalable Jérôme Rousselot, CSEM

7. WiseMAC Ultra Low Power MAC Scheme • Periodic Sampling • Link-local Synchronization Only WiseNET: an ultralow-power wireless sensor network solution, IEEE Computer, Enz et. al., 2004. WiseMAC: An Ultra Low Power MAC Protocol for Multi-hop Wireless Sensor Networks, El-Hoiydi, Decotignie, AlgoSens 2004. Jérôme Rousselot, CSEM

8. WiseMAC Ultra Low Power MAC Scheme Forward Store Node Node Node N = 10 LMAC Crankshaft WiseMAC Deviations from Ideality • High Traffic: low costof wake-up preamble • Low Traffic: only the cost of sampling S-MAC SCP-MAC WiseMAC Ideal (Texas Instruments CC 2420 radio transceiver) Low Power Medium Access Control Protocols for Wireless Sensor Networks, Jérôme Rousselot, Amre El-Hoiydi and Jean-Dominique Decotignie, European Wireless Conference 2008 (EW 2008), 22-25 June 2008, Prague, Czech Republic. Jérôme Rousselot, CSEM

9. MultiChannel WiseMAC Three Channels Jérôme Rousselot, CSEM

10. MultiChannel WiseMAC Advantages • Ultra Low Power • Robustness to Interference • Scalability with network size • Flexibility (star and mesh topologies) • Low latency Drawbacks • Inefficient Broadcasts • Limited Throughput • Sub-optimal for heterogeneous networks Have some nodes switch to an interoperable modethat does not exhibit limited throughput= CSMA (IEEE 802.15.4 Non Beacon Enabled Mode)‏ WiseMAC High Availability Jérôme Rousselot, CSEM

11. Power Consumption Sensor Sensor Sensor Sink Sensor Sensor CSMA S-MAC - sink WiseMAC-HA - sensor Ideal - sink S-MAC - sensor Ideal - sensor 5 sensor devices 16 bytes data packets 4 bytes Ack messages FM-UWB (250 kbps)‏ 8 mW Rx 4 mWTx WiseMAC Jérôme Rousselot, CSEM

12. Latency Sensor Sensor Sensor Sink Sensor Sensor 100 25 10 5 Traffic limited, not device limited WiseMAC 100 25 10 5 CSMA Jérôme Rousselot, CSEM

13. Conclusions WiseMAC-HA • Robust and reliable: Detect-and-Avoid interferers • Ultra Low Power for all nodes: no need to synchronize • Scalable: traffic limited • Coexistence: the protocol’s fairness allows simultaneous operation of independent networks • Throughput and Latency vs. Energy trade-off • Flexibility to decide mode changes • Flexibility to accomodate other operating modes Jérôme Rousselot, CSEM