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: Application Requirements for a Low-power, Responsive, Adaptive, IP-friendly 15.4 MAC Date Submitted: 13 May, 2008 Source: Wei Hong, Company: Arch Rock Corporation Address: 501 2nd Street, Suite 410, San Francisco, CA 94707, USA Voice: 415-692-0828, FAX: 415-278-0441, E-Mail: whong@archrock.com Re: Application Requirements for 802.15.4e Abstract: Application Requirements for a Low-power, Responsive, Adaptive, IP-friendly 15.4 MAC Purpose: Outline requirements for a Low-power, Responsive, Adaptive, IP-friendly 15.4 MAC 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. Wei Hong, Arch Rock Corporation

2. Application Requirements for a Low-power, Responsive, Adaptive, IP-friendly 15.4 MAC Wei Hong VP of Engineering Arch Rock Corp. Wei Hong, Arch Rock Corporation

3. Outline • The Case for IP-centric Sensor Networks • 15.4 as a new IP link • Low-power vs. Responsiveness • The need for Adaptiveness • A framework towards a solution • Requirements taken for granted • Enabling low-power mesh networking • Low-power routers and edge nodes • Reliability • Security Wei Hong, Arch Rock Corporation

4. The IP-centric Vision Wei Hong, Arch Rock Corporation

5. Many Advantages of IP • Extensive interoperability • Other wireless embedded 802.15.4 network devices • Devices on any other IP network link (WiFi, Ethernet, GPRS, Serial lines, …) • Established security • Authentication, access control, and firewall mechanisms • Network design and policy determines access, not the technology • Established naming, addressing, translation, lookup, discovery • Established proxy architectures for higher-level services • NAT, load balancing, caching, mobility • Established application level data model and services • HTTP/HTML/XML/SOAP/REST, Application profiles • Established network management tools • Ping, Traceroute, SNMP, … OpenView, NetManager, Ganglia, … • Transport protocols • End-to-end reliability in addition to link reliability • Most “industrial” (wired and wireless) standards support an IP option Wei Hong, Arch Rock Corporation

6. Users’ View of IP • IPv4 and IPv6 builtin to Windows, Mac OS and Linux • The ubiquitous web browser • Socket API for TCP and UDP • SOAP or REST-based API • Wireshark and Ethereal • IPSec, VPN, Firewalls Wei Hong, Arch Rock Corporation

7. (including runtime) Myth: IP Stack Is Too Large? Low-power with modified 15.4 MAC Wei Hong, Arch Rock Corporation

8. Market Demand for IP Over 15.4 • 15.4 as a cheaper IP link: replacing existing expensive, power-hungry GPRS, WiFi, Bluetooth links Wei Hong, Arch Rock Corporation

9. Market Demand for IP Over 15.4 (cont) • Where IT departments rule, e.g., data centers • Familiar access and management paradigm for IT staff • Future proofing investment • Utility HAN • Will 15.4 be the only link for HAN for the next 20 years? Wei Hong, Arch Rock Corporation

10. Properties of an IP-friendly Link • Always On (illusion) • Talk to a neighbor any time • Low Latency • Low transmission delay neighbor-to-neighbor • Multicast Capable • Broadcast to all neighbors • Synchronous Acks • Reliable datagram delivery to a neighbor Wei Hong, Arch Rock Corporation

11. Requirement for Being Low-power AND Responsive • Fundamentally sensor networks must be able to respond to unexpected events • How to maintain low-power while waiting for a rare event • Application examples • Mobile applications • 1st Responder Monitoring • Smart package tracking • Perimeter Security • 2-second max latency for intrusion detection • 5-10 year battery lifetime Wei Hong, Arch Rock Corporation

12. The Need for Adaptiveness • Example: Train axle condition monitor • Dynamic environment • Cars shuffle • Surroundings change en route • Unpredictable workload • Temperature threshold increases vibration sampling Wei Hong, Arch Rock Corporation

13. Optimizations Power – Channel Utilization – Average Latency – Throughput Repairing 15.4 Acks False Positives – Security – Payload 15.4 HDR Sampled Listening Stateless – Low Latency – Always On Abstraction – Robust PAN DST SRC SEC Timing Payload 15.4 FTR Scheduling Streaming A Possible Solution Wei Hong, Arch Rock Corporation

14. Abstraction Provide the mechanisms Upper layers define the policy A Possible Solution (cont) Net Link Data Ack Media Management Control Remote Media Link Stats Local Media Phy Wei Hong, Arch Rock Corporation

15. Evaluation: Link Layer Primitive Profiles Overhear Receive (26 bytes) Receive (127 bytes) Channel Sample Transmit (26 bytes) Transmit (127 bytes) Preamble + Transmit (64 ms) Preamble + Transmit (128 ms) Wei Hong, Arch Rock Corporation

16. Evaluation: Link Power Model Wei Hong, Arch Rock Corporation

17. Discussions • Channel Sample Period: knob for trading off responsiveness for low power consumption • Tradeoff between send and receive cost • Maintain low-power state when fallen out of network • Scheduling can be layered on top of Sampled Listening for further power reduction • Channel hopping can be incorporated Wei Hong, Arch Rock Corporation

18. Summary • Requirements for 15.4 • IP-friendly: always-on illusion • Responsive and low-power: passive vigilance • Adaptive to dynamically changing environment and workload • And of course • Enabling low-power meshing • Reliable • Secure • A solution exists Wei Hong, Arch Rock Corporation

19. Thanks You • Questions? Wei Hong, Arch Rock Corporation