System Research Perspective -through a Sensys lens

Sensys Soap Box

David Culler

UC Berkeley

11/8/2007 Sensys Soapbox 2

A System Research “formula”

• Imagine a plausible future

• Create an approximation of that vision using technology that exists.

• Discover what is True in that world–Empirical experience

»Bashing your head, stubbing your toe, rubbing your nose in it

–Quantitative measurement and analysis

–Analytics and Foundations

11/8/2007 Sensys Soapbox 3

Sensys – Truths• The idle listening problem!

• Distributed algorithms (e.g, routing) with bounded per-node state and non-trivial change and uncertainty

• Claim and hold the territory we’ve gained– areas of important incremental on-going improvement

– Low Power MAC, Multihop Forwarding, ..

• Not enough to just improve from paper to paper

• Finish the job with standards that matter– Still not a solid dominant MAC

– IEEE 802.15.4 superframes/beacon broken, Zigbee punted, Wireless HART?, ISA 100

– 6LoWPAN format done [RFC4944] but MAC interoperability island

• Where is the bar?– 99% x 10uA + 1% x 10mA => 110 uA is baseline, 20 uA is research goal

– 99.5-9% reliability over multiple 70% link

11/8/2007 Sensys Soapbox 4

Sensys – non-Truths (yet)• Excess Redundancy

– “Given the excess of redundant WSN nodes…”– Selective Coverage, Capacity spreading, …

• In-network processing– At source and dest, but IN?

• Placement by “blowing in the wind”– Capacity planning and placement should be easy, but they exist– Points of interest

• If you want to utilize “the excess” push the technology to make it real– SOC offerings– Beyond the “mote”

• If you want to enable in-network processing, develop and application that actually uses it– Beyond surge (sense and send)

• Placement assumptions should reflect placement reality

11/8/2007 Sensys Soapbox 5

Imagine…

• The Mote “future” is already here• We understand many of the truths and non-truths

in that world• Harvest that learning in defining the “next future”

– bold, concise, revolutionary goals to shoot for are invaluable

• One More Element of “Truth” –• Complexity constraints are even more critical

than resource constraints• Zillions of unattended, inaccessible networked

devices connected to the physical world engaged in critical functions– The have to be simple, robust, reliable, resilient, provable, …

• Beware Complexity

11/8/2007 Sensys Soapbox 6

One more thought

• Many of the beautiful ideas that “necessity” has “mothered” have tremendous value in the rest of the tiers of computing