agenda overview technology –tinyos; prof. phil levis, stanford –energy scavenging; prof. paul...
TRANSCRIPT
Agenda• Overview• Technology
– TinyOS; Prof. Phil Levis, Stanford– Energy Scavenging; Prof. Paul Wright, UC Berkeley– Low Power Radios
• Nate Pletcher, BWRC
• Ben Cook & Steven Lanzisera, BSAC
• Applications– Stewart Tansley, Microsoft– Mark Noworolski, Streetline Networks– Joe Polastre, Moteiv– Amy Wang, Mela Networks– Amine Haoui, Sensys Networks– David Culler, Arched Rock
Cost of Sensor Networks
Time
$
Computing Power
Sensors
Installation, Connection and Commissioning
Mesh Networking
IEEE 802.15.4 & WiFiOperating Frequency Bands
868MHz / 915MHz PHY
2.4 GHz
868.3 MHz
Channel 0 Channels 1-10
Channels 11-26
2.4835 GHz
928 MHz902 MHz
5 MHz
2 MHz
2.4 GHz PHY
Gutierrez
Spatial effect of multipath
Plot courtesy Matt Welsh, Harvard
Frequency dependent fading and interference
From: Werb et al., “Improved Quality of Service in IEEE 802.15.4 Networks”, Intl. Wkshp. On Wireless and Industrial Automation, San Francisco, March 7, 2005.
Network Types
Powered mesh infrastructure
Star-Mesh Full Mesh
Star-connected sensors
No infrastructure
Mesh-connected sensors
Star
X X
Why not use 802.11?
Radio Reliability in a Crowded Spectrum
• DSSS doesn’t cut it– Helpful, but only about 10dB
• +20 dBm doesn’t cut it– Helpful, but expensive in batteries– No guarantee: e.g. 802.11 & cordless phones
• Must frequency hop– Time synchronization required…
…but you probably needed that anyway.– Lots of channels, lots of bandwidth, better scaling, …
Implications of RF Challenges• “Transmit and forget” is unreliable
– Lost packets
• Single-path networks (trees) are very dangerous– Lost motes
• Single-channel networks are fatal– Lost networks
RF Solutions• Temporal Diversity
– Don’t quit until you get an acknowledgement
• Spatial Diversity– Multiple paths from every mote
• Frequency Diversity– Frequency hopping in addition to direct sequence spread
spectrum
50 motes, 7 hops3 floors, 150,000sf
>100,000 packets/day
50 motes, 7 hops3 floors, 150,000sf
>100,000 packets/day
Oil Refinery – Double Coker Unit
• Scope limited to Coker facility and support units spanning over 1200ft
• Expanded to 27 units, implemented 14 to start
• No repeaters were needed to ensure connectivity
• Gateway connected via Ethernet port in control room to process control network
• Electrical/Mechanical contractor installed per wired practices
GW
14 unit Network expanded to 27-- Expanding to 50+ in ‘06
Medium Access Approaches• Medium Access (MAC)
– How do motes share the radio spectrum?– How many can co-exist?
• Aloha• Slotted Aloha• CSMA (sometimes CSMA/CA)• CSMA/CD• TDMA• TDMA/CA
Aloha• Simplest MAC protocol
– talk when you want to!– Standard for early wireless sensor networks
• Fine for very light traffic (5%)• Chaotic collapse above ~10%• Theoretical throughput limit ~18% (1/e2)
G
B
A
Aloha!
Aloha!
Aloha! Aloha!
Aloha!
Aloha!
Aloha!
Aloha!
Slotted Aloha• Packets sent in time slots
– Still collisions, but fewer
• Requires time synchronization• Theoretical throughput limit ~37% (1/e)
G
B
A
Aloha!
Aloha!
Aloha! Aloha!
Aloha!
Aloha!
Aloha!
Aloha!
CSMA
• CSMA = Carrier Sense Multiple Access– Listen before talk– Only transmit if the channel is clear– “Carrier” is actually RF energy and/or valid symbols
G
B
A TX packet ACK
A listens to channel: idle TX
TX packet ACK
B listens (busy) B listens (idle)
?
? ?
CSMA Challenges
• A, B listen at the same time• Both detect an idle channel• Both begin to transmit, and collide• ~10% of packet time w/ 802.15.4 radios
G
B
A TX packet ACK
A listens (idle)
TX packet ACK
B listens (idle)
?
?
CSMA Challenges
• A, B listen at the same time• Both detect an idle channel• Both begin to transmit, and collide• ~10% of packet time w/ 802.15.4 radios
G
B
A TX packet ACK
A listens (idle)
TX packet ACK
B listens (idle)
?
?
Collision!
CSMA Challenges• A, B both listen, detect a packet• At end of packet, both transmit and collide
G
B
A TX packet ACK
TX packet ACK
?
?
X
? ?
TX packet ACK?? ?
? ? ?
CSMA Challenges• A, B both listen, detect a packet• At end of packet, both transmit and collide
G
B
A TX packet ACK
TX packet ACK
?
?
X
? ?
TX packet ACK?? ?
? ? ?
Collision!
CSMA Challenges• A, B can’t hear each other• “Hidden node” or “Hidden terminal” problem• In the limit, reduces CSMA to Aloha
G
B
A TX packet ACK?
TX packet ACK?
CSMA Challenges• A, B can’t hear each other• “Hidden node” or “Hidden terminal” problem• In the limit, reduces CSMA to Aloha
G
B
A TX packet ACK?
TX packet ACK?
Collision!
CSMA Solutions• Many approaches
– Random exponential backoff– P-persisent CSMA– RTS/CTS– Slotted CSMA– Synchronized CSMA
• Hot topic in academia– MACA, B-MAC, S-MAC, T-MAC, …
TDMA
• TDMA = Time Division Multiple Access• Divide time into slots
– With 802.15.4, a slot is ~10ms– ~100 slots/second
• Like Aloha, but with assigned TX time slots– Unique TX slots means no collisions– Many motes can receive if desired
G
B
A
BG AG CBDC BG
TDMA with multiple channels
• Assign each mote a time slot and channel to transmit.– All channels can be used simultaneously
– Big increase in available bandwidth
– 802.15.4 gives ~ (100 slots/s)(16chan) = 1600 cells/sec
– Uniquely assigned no collisions
• RX need to be scheduled now too• No TX, no RX sleep!
G
B
AAG
CBDC
BG
AG
CBDC
BG
Ch0
Ch1
Ch2
Ch3
TDMA Challenges• Time synchronization
– Seems to be an article of faith with some that it’s impossible– Others just do it
• Sub-microsecond (pairwise) demonstrated in academia
• Sub-millisecond (entire network) available commercially
• Cell scheduling• Dynamic Bandwidth Allocation
TDMA with CSMA
• Backbone TDMA network– Baseline connectivity and time synchronization– Guaranteed bandwidth– ~10% of cells in a 10,000 mote network
• All or some of remaining cells are “open listens”– Slotted Aloha by default– Fancier algorithms possible
• All motes can listen, or just those with power
G
B
AAG
CBDC
BG
AG
CBDC
BG
Ch0
Ch1
Ch2
Ch3
TDMA with CSMA
• Backbone TDMA network– Baseline connectivity and time synchronization– Guaranteed bandwidth– ~10% of cells in a 10,000 mote network
• All or some of remaining cells are “open listens”– Slotted Aloha by default– Fancier algorithms possible
• All motes can listen, or just those with power
G
B
AAG
CBDC
BG
AG
CBDC
BG
Ch0
Ch1
Ch2
Ch3
A?
E?
D?
F? A-Z?
A-Z?
A-Z?
A-Z?
A-Z?
A-Z?
A-Z?
A-Z? A?
E? F?
D?
Scalability: Outdoor Test Network
Interferer(PosA)
10
SmartMeshManager
2
SmartMeshManager
1
SmartMeshManager 9.5
4.5
8
4.5
OPEN SPACE DEPLOYMENT
Netw ork deployed at 1 Thayer Road, Santa Cruz, CA, on roughpasture. Modifications to Implementation plan due to deployment fitinto "thin and hourglass" shape of site (no minimum plan distancescompromised). All measurements given in meters, and accurate to
w ithin +/-25 centimeters (gopher hole offsets).
025
Mote
16
619
Mote
053
Mote
8
6
038
Mote
037
Mote
6
4.5
060
Mote
059
Mote
8
3
8
10
13
13
002
Mote8 8
3
050
Mote
004
Mote
13
005
Mote
13
054
Mote
061
Mote
001
Mote
6
003
Mote10
006
Mote
13
13
10
049
Mote
8
8
4.5
013
Mote
052
Mote
056
Mote6
6
235
Mote
233
Mote
232
Mote
88
234
Mote
8
231
Mote
8
8
12.5
9
11.5
4.5
4.5
4.5
11.5
10.5
3
8
014
Mote8
9
4
SmartMeshManager
148
Mote
4.5
147
Mote
8
015
Mote
16
190
Mote
8
4.5
8
187
Mote
188
Mote
189
Mote
016
Mote
018
Mote6 6
3.5
017
Mote
019
Mote
021
Mote
020
Mote
023
Mote
6
3.5
6
3.5
3.5
022
Mote
3.5
6
024
Mote6
3.5
151
Mote
154
Mote
3.5
159
Mote
3.5
150
Mote
155
Mote
3.5
158
Mote
3.5
156
Mote
153
Mote
66
6
6
6
66 6
149
Mote6
157
Mote6
152
Mote6
160
Mote6
3.5
3.5
3.5
3.5
165
Mote
163
Mote6 6
3.5
164
Mote
172
Mote
170
Mote
171
Mote
178
Mote
6
3.5
6
3.5
3.5
179
Mote
3.5
6
177
Mote6
3.5
162
Mote
173
Mote
3.5
176
Mote
3.5
166
Mote
169
Mote
3.5
180
Mote
3.5
168
Mote
174
Mote
66
6
6
6
66 6
167
Mote6
183
Mote6
161
Mote6
186
Mote6
3.5
3.5
3.5
3.5
3.5
3.5
3.5
3.5
3.5
3.5
3.5
182
Mote6
3.5
181
Mote6
175
Mote6
3.5
185
Mote6
184
Mote
3.5
3.5
3.5
16
4.5
026
Mote
242
Mote
8
4.5
9.5
031
Mote
241
Mote
243
Mote
4.5
236
Mote
237
Mote
238
Mote
8
8
239
Mote
8
240
Mote
8
8
19
19
4.5
4.5
255
Mote
Interferer(PosD)
Interferer(PosC)
4.5
4.5
027
Mote
285
Mote 4.5
3
304
Mote
286
Mote
303
Mote
302
Mote
3.5
3
4.5
3
287
Mote
3
4.54
279
Mote
278
Mote
3
277
Mote
3
262
Mote
4.5
4.5
4.54.5
261
Mote 4.5
263
Mote 4.5
267
Mote 4.5
4.5
3
3
288
Mote 4.54.5
4.5
301
Mote
289
Mote
300
Mote
299
Mote
5
4.5
4.5
4.54.5
290
Mote
4.5
4.55.5
4.5
276
Mote
275
Mote
4.5
274
Mote
4.5
265
Mote
4.5
4.5
4.54.5
264
Mote 4.5
291
Mote 4.56
4.5
4.5
3
4.53
33
273
Mote 4.5
4.5
266
Mote 4.5
4.5
6
298
Mote
4.5
250
Mote
029
Mote
4
4
3
249
Mote
030
Mote
251
Mote
028
Mote
252
Mote
4
4
307
Mote
282
Mote
253
Mote
254
Mote
3
8
8
269
Mote 4.5
4.5
293
Mote 4.5
4.5
271
Mote 4.5296
Mote
4.5
4.5
268
Mote 4.5
4.5
292
Mote 4.5
4.5
272
Mote 4.5297
Mote
4.5
4.5
3
33
3
260
Mote 4.5284
Mote 4.5
280
Mote 4.5305
Mote
3
33
3
259
Mote 4.5283
Mote 4.5
281
Mote 4.5306
Mote
294
Mote 4.5
4.5
270
Mote 4.5295
Mote
4.5
4.5
258
Mote
8
248
Mote
247
Mote
256
Mote
8
8
245
Mote
246
Mote
257
Mote244
Mote
8
8
88
13
10.5
6
3
4.5
3
4.5
309
Mote
310
Mote
311
Mote
312
Mote
313
Mote
314
Mote
315
Mote
4.5
9
4.5
8
9.59.5
Interferer(PosE)
Interferer(PosB)
7
SmartMeshManager
6
SmartMeshManager
5
SmartMeshManager
4.5
4.5
322
Mote
321
Mote
4.5
320
Mote
4.5
325
Mote
3
4
3.5 3.5
326
Mote4
4.5
319
Mote
318
Mote
4.5
317
Mote
4.5
328
Mote
4.5
5.5
5 5
327
Mote4.5
316
Mote
4.5
4.5
4.54.5
329
Mote5.5
4.5
4.5
453
Mote
518
Mote
512
Mote
511
Mote
331
Mote
337
Mote
335
Mote
338
Mote
339
Mote
336
Mote
334
Mote
333
Mote
340
Mote
341
Mote
342
Mote
343
Mote
344
Mote
345
Mote
346
Mote
355
Mote
354
Mote
353
Mote
352
Mote
351
Mote
350
Mote
349
Mote
356
Mote
357
Mote
358
Mote
359
Mote
360
Mote
361
Mote
362
Mote
371
Mote
370
Mote
369
Mote
368
Mote
367
Mote
366
Mote
365
Mote
372
Mote
373
Mote
374
Mote
375
Mote
376
Mote
4.5
4.5
4.5
4.5
4.5
4.5
3-6m 3-6m 3-6m 4.5
4.5
4.54.5 4.5 4.5
4.54.5
4.54.5
4.5
4.5 4.54.5 4.5 4.5
4.5
4.5
4.5
4.5
4.5
4.5
4.5
4.5
4.5
4.5
4.5 4.5 4.54.5
4.5 4.5 4.5 4.5
4.54.5
4.54.5
4.5
4.5 4.5 4.54.5 4.5
3-6m 3-6m 3-6m 3-6m 3-6m
4.5 4.54.5 4.5 4.5
4.54.5
4.54.5
383
Mote8
392
Mote16
391
Mote
393
Mote
403
Mote
404
Mote
405
Mote
406
Mote
415
Mote
416
Mote
417
Mote
418
Mote
429
Mote
430
Mote
431
Mote
4.5 4.54.5
4.5 4.54.5
4.5 4.5 4.5
4.5
4.5
4.5
4.5
4.5
4.54.5
4.54.5 4.5 4.5
438
Mote
448
Mote
452
Mote
465
Mote
1414
14 14
464
Mote
478
Mote
477
Mote
476
Mote
490
Mote
489
Mote
488
Mote
487
Mote
502
Mote
501
Mote
500
Mote
4 4 4
44
4
4 4 4
4.54.5
4.5
4.5 4.5
4.5 4.54.5 4.5
466
Mote
467
Mote
475
Mote
499
Mote
463
Mote
479
Mote
486
Mote
503
Mote
462
Mote
480
Mote
485
Mote
4.5 4.54.5
4.54.5 4.5 4.5
4.54.5
4.5
4 4 4
44
4 44
390
Mote432
Mote
419
Mote
4.5
4.5
4.5
4.54.5
510
Mote
513
Mote
517
Mote
522
Mote
14 1414
14
523
Mote
382
Mote
380
Mote
384
Mote
4.5
4.5
521
Mote
520
Mote
386
Mote
4.5
455
Mote
389
Mote
388
Mote
407
Mote
408
Mote
409
Mote
412
Mote
413
Mote
414
Mote
433
Mote
434
Mote
4.5 4.54.5
4.5 4.54.5
4.5
4.5
4.5
4.5
4.5
4.5 4.5
4.5 4.5 4.5 4.5
387
Mote435
Mote
4.5
4.5
4.54.5
397
Mote
396
Mote
399
Mote
400
Mote
401
Mote
420
Mote
421
Mote
422
Mote
425
Mote
426
Mote
4.5 4.5 4.5
4.5 4.5 4.5
3-6m
4.5
4.5
4.5
4.5
4.5
395
Mote
427
Mote
4.5
4.5
3-6m3-6m
394
Mote
402
Mote 4.54.5
4.5 4.5
428
Mote
4.5
4.5
4.54.5 4.5 4.5
410
Mote
411
Mote4.5
4.5 4.5
436
Mote
4.5
4.5
504
Mote4
4.5
460
Mote
461
Mote
482
Mote
481
Mote
484
Mote
483
Mote
506
Mote
505
Mote
44 3-6m
44 4
4.5
4.5
4.5
4.5
4.5 4.5
4.5
4.5
468
Mote
469
Mote
474
Mote
473
Mote
472
Mote
493
Mote
492
Mote
491
Mote
498
Mote
497
Mote
4.5 4 4
4 4 4
4
4.5
4.5
4.5
4.5
4.5 4.5
4.5 4.54.5 4.5
470
Mote
496
Mote
4.5
4.5
44
471
Mote
494
Mote4
4.5 4.5
495
Mote
4.5
4
519
Mote
323
Mote
347
Mote
377
Mote
348
Mote
4.5
364
Mote
308
Mote332
Mote
524
Mote
4.5
398
Mote
525
Mote
4.5
424
Mote
527
Mote
526
Mote
446
Mote
440
Mote
4.5
4.5
449
Mote
437
Mote
450
Mote
1414
1414
14 1414
14
451
Mote
363
Mote
379
Mote457
Mote
445
Mote
507
Mote
508
Mote
515
Mote4.5
4.5
456
Mote
442
Mote
9.5
459
Mote
458
Mote
441
Mote
4.5
443
Mote
444
Mote
4.5
423
Mote
378
Mote
385
Mote
381
Mote
8 16
16447
Mote
439
Mote
454
Mote
1414 14
14 509
Mote14
514
Mote
516
Mote
1414 14
330
Mote
324
Mote
8
8
10.5
8
8
7
8
4.5
8
4.5
4.5
4.5
4.5
4.5
4.5
4.5 4.54.5
4.5
4.5
4.5
6.5
4.5
8
16.5
9.5
4.5
9.5
16
9.5
6
033
Mote10
055
Mote
032
Mote6
3
571
Mote
6.5
034
Mote
035
Mote8
4.5
8
036
Mote
16
528
Mote
16
Tree
N
16
058
Mote
620
Mote
13
039
Mote
621
Mote10
13
11.5
Forest Edge
19
16
TreeTrunk
9
SmartMeshManager
661
Mote
057
Mote
646
Mote
665
Mote
663
Mote6 6
664
Mote
658
Mote
657
Mote
044
Mote
651
Mote
6
3
5
33
652
Mote
3
5
650
Mote6
3
662
Mote
659
Mote
3
649
Mote
3
666
Mote
656
Mote
3.5
653
Mote
3
655
Mote
660
Mote
55
5
5
6
66 6
625
Mote6
654
Mote6
622
Mote6
648
Mote6
333
3
641
Mote
643
Mote6 5
3
642
Mote
634
Mote
636
Mote
635
Mote
043
Mote
5
3
6
33
628
Mote
3
6
629
Mote5
3
644
Mote
633
Mote
3
630
Mote
3
640
Mote
637
Mote
3
627
Mote
3
638
Mote
632
Mote
56
5
5
6
66 6
639
Mote6
040
Mote6
645
Mote6
623
Mote5
33
3
3
3 3 33 33
624
Mote6
3
626
Mote6
631
Mote6
3
042
Mote5
041
Mote
3 33
669
Mote
671
Mote
8
667
Mote
668
Mote
670
Mote
672
Mote
673
Mote
679
Mote
678
Mote
045
Mote
677
Mote
676
Mote
675
Mote
674
Mote
680
Mote
046
Mote
047
Mote
048
Mote
681
Mote
682
Mote
683
Mote
690
Mote
689
Mote
688
Mote
687
Mote
686
Mote
685
Mote
684
Mote
691
Mote
692
Mote
693
Mote
694
Mote
695
Mote
696
Mote
697
Mote
703
Mote
702
Mote
701
Mote
700
Mote
699
Mote
6 5 6 6
6656
56
6 5
6 5 6 5 6 6
665656
6 5
3-6m
6 5
3-6m 3-6m
6 6
3-6m
3 3 3 3 3 3 33333333
3 3 3 3 3 3 3
3 3 3 3 3 3 3
3-6
m
3-6
m
3-6
m
3-6
m
3-6
m
698
Mote
647
Mote4.5
16
TreeStump
TreeStump
3 Trees
Stump"Well"
3
SmartMeshManager
107
Mote
051
Mote
064
Mote
065
Mote6 6
3
008
Mote
069
Mote
071
Mote
070
Mote
077
Mote
6
3
6
33
076
Mote
3
6
078
Mote6
3
007
Mote
068
Mote
3
079
Mote
3
063
Mote
072
Mote
3
075
Mote
3
073
Mote
067
Mote
66
6
6
6
66 6
062
Mote6
074
Mote6
066
Mote6
080
Mote6
333
3
087
Mote
085
Mote6 6
3
086
Mote
093
Mote
092
Mote
009
Mote
098
Mote
6
3
6
33
099
Mote
3
6
097
Mote6
3
084
Mote
010
Mote
3
096
Mote
3
088
Mote
091
Mote
3
100
Mote
3
090
Mote
094
Mote
66
6
6
6
64.5 6
089
Mote6
103
Mote6
083
Mote6
106
Mote6
33
3
3
3 33 33 33
102
Mote6
101
Mote3
095
Mote6
3
105
Mote6
104
Mote
3 33
011
Mote
012
Mote
66
112
Mote
111
Mote
110
Mote
109
Mote
108
Mote
113
Mote
114
Mote
115
Mote
116
Mote
117
Mote
118
Mote
119
Mote
126
Mote
125
Mote
124
Mote
123
Mote
122
Mote
121
Mote
120
Mote
127
Mote
128
Mote
129
Mote
130
Mote
131
Mote
132
Mote
133
Mote
141
Mote
140
Mote
139
Mote
138
Mote
137
Mote
136
Mote
135
Mote
142
Mote
143
Mote
144
Mote
145
Mote
146
Mote
3 3 333
33
33
3333
3 3 3 3 333 33 3
3
33
3
33
33
33
6 6 6 6
66 6 6 6 6
66 6 6 6 6
66 6 6 6 6
6 6 6 6 6 6
666666
081
Mote
082
Mote
134
Mote
4.5
9.5
19
16
15
BrushPile
StumpTree
4.5
4.5
4.5
1,100 m
600 m
-1400 Motes -20 Managers - 32 Acres
Standards• 802.15.4• Zigbee, Zensys Z-wave• Wireless HART, ISA SP-100• LonWorks
Zigbee• Great marketing tool, but…
– Nothing interoperable yet– “Zigbee” products typically aren’t– Zigbee typically mean 802.15.4 + proprietary MAC
• Member survey on requirements for Wireless Sensor Networking due 3/17
• Lost industrial automation in 2005• Losing building automation in 2006?• Likely winner in home automation
ISA SP-100
• http://www.isa.org/community/SP100 • A Word from the Chairman
– “In working to assure confidence in, and the integrity of, wireless technology, and to provide criteria for implementation in manufacturing automation and control systems, the ISA-SP100 Committee recently launched four project teams. Each team’s goal is to develop documents that will help users make the right decision on industrial wireless implementations.”
– Physics of Radio– Interoperability– Requirements– User Guide
• Update: hijacked by Honeywell
Wireless HART• “The Wireless HART working group, an activity of the
HART Communication Foundation (HCF), has set an aggressive goal to produce draft specifications for a Wireless HART standard in early 2006.”
• ABB, Adaptive Instruments, Elpro Technologies, Emerson, Endress+Hauser, Honeywell, Omnex Controls, Phoenix Contact, Siemens, Smar and Yokogawa
• Update: 802.15.4 TDMA network likely to win
~2 mm^2 ASIC
Mote on a Chip? (circa 2001)
• Goals:– Standard CMOS– Low power– Minimal external components
uP SRAM
RadioADC
Temp
Ampinductor
crystal
battery
antenna
~$1
System Cost, 2005• E.g. Chipcon cc2510
– 2.4 GHz, 500kbps
– 8051, AES
– Temp sensor
• One of many single-chip options
Single-chip $1.50
Passives $0.20
PCB Assembly & Test $0.20
Battery $0.10
Total $2
Radio Performance
200k Bit rate (bps)100k 300k
I RX (
mA
)
5
10
20
15
25
X cc1000
Molnar 04 (0.4mA)
X
X cc2420
XOtis 05 (0.4mA)
Cook 06 (300 W)
X
With software:10 years D cell
With software:10 years coin cell
~4 mm^2 ASIC
Mote on a Chip
• Goals:– Standard CMOS– Low power– Minimal external components
uP SRAM
RadioADC
Temp
Ampinductor
crystal
battery
antenna
Security
Location
Time
~4 mm^2 ASIC
Mote on a Chip
• Goals:– Standard CMOS– Low power– Minimal external components
uP SRAM
RadioADC
Temp
Amp
Security
Location
Time
ZeroResonant antenna on-chip•Demonstrated (e.g. Ken O, U. Florida)
RF Inductor on-chip•Commercially available
Crystal/timing on-chip•Demonstrated (many MEMS papers)
Solar cell on-chip•Commercially available (CMOS cameras ~10% efficient conversion)
Directions• <1W mote• 1mm3 mote• True single-chip mote• Mobility
– Hopping, flying, gliding
• “Integrated” MEMS sensors– Accelerometers, magnetometers, visible & IR cameras,
chem/bio, …
• Bio-interfacing– Neural, inertial, mechanical, chemical
Flexible Platform
Conclusion