Impact of Sensor Networks on Future InterNet Design

David E. CullerUniversity of California, Berkeley

culler@cs.berkeley.edu

Arched Rock Corporationdculler@archedrock.com

NSF FIND Info Meeting12-5-2005

12/5/05 NSF FIND 2

What does the Internet look like in 10 years?

0 2 4 6 8 10 12 14 16 18

-1

-0.5

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0.5

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Low resolution Sensor, Test4, Increasing frequency

Time (sec)

Acc

eler

atio

n (g

)

12/5/05 NSF FIND 3

In 10 years…

• 90% of the nodes on the “Internet” will embedded devices connected to the physical world

• Universal, host-host file-transfer and console access is the dominant usage pattern…..

NOT!

• So does it make sense to pay attention to the characteristics of these kind of nodes and applications in designing the future Internet?

12/5/05 NSF FIND 4

Transit Network (IP or not)

Access point - Base station - Proxy

Sensor Patch

Patch Network

Data Service

Intranet/Internet (IP)

Client Data Browsingand Processing

Sensor Node

GatewayGateway

Verification links

Other information sources

Sensor Node

Canonical Sensor Net Architecture Today

•An Analysis of a Large Scale Habitat Monitoring Application, Szewczyk, Polastre, Mainwaring, Anderson, and Culler, Sensys04

12/5/05 NSF FIND 5

The Next Tier

• Small sensors will be the most common nodes on the internet

• How will they be represented and accessed?

Clients Servers

Sensor Nets

12/5/05 NSF FIND 6

How will SensorNets and IP play together?

802.15.4, CC, …802.11Ethernet Sonet

IP

TCP / UDP

HTTP / FTP / SNMP

XML / RPC / REST / SOAP / OSGI

12/5/05 NSF FIND 7

Full IP stack throughout

802.15.4, CC, …802.11Ethernet Sonet

TCP / UDP

HTTP / FTP / SNMP

XML / RPC / REST / SOAP / OSGI

IP

12/5/05 NSF FIND 8

Beware “IP hype”

• Transmitting HTML over a wireless connection to a serial port attached to a PC is NOT running IP on the sensor network

12/5/05 NSF FIND 9

Where has Internet Research Reached and “struggled”?

• Aggregate communication => Multicast

• Resource constraints => QoS, DIFFSERV

• Communicate with data or logical services, not

just devices => URNs (DHTs?)

• Mobility => MobileIP, MANET

• In-network processing and storage => ActiveNets

• Intermittent connectivity => DTN ???

12/5/05 NSF FIND 10

What are the main characteristics of Sensor Networks?• Aggregate communication

– dissemination, data collection, aggregation

• Resource constraints– Limited bandwidth, limited storage, limited energy

• Communicate with data or logical services, not just devices

– Datacentric

• Mobility– Devices moving, tags, networks moving through networks

• In-network processing and storage– Really

• Intermittent connectivity– Low-power operation, out of range, obstructions

12/5/05 NSF FIND 11

Facing these challenges

• Today, we use a wide range of ad hoc, application specific techniques in the SensorNet patch

– Zillion different low-power MACs

– Many link-specific, app-specific multihop routing protocols

– Epidemic dissemination, directed diffusion, synopsis diffusion, …

– All sorts of communication scheduling and power management techniques

12/5/05 NSF FIND 12

Edge Network Approach

802.15.4, CC, …802.11Ethernet Sonet

IP

TCP / UDP

HTTP / FTP / SNMP

XML / RPC / REST / SOAP / OSGI

Pro

xy

/ Ga

tew

ay

12/5/05 NSF FIND 13

“Hacking it in” may not be so bad

• Security– No IP to the nodes, attacks have to get through the gateway or

be physically close

• Namespace management– Name nodes, networks, services– Hosts, URLs, …

• Mask intermittent connectivity– Terminate IP on the powered side– Loosely couple, energy aware protocols on the other

• Distillation proxies– Small binary packets where constrained– Expanded to full text, XML, HTML, web services

• Rich suite of networking techniques in the Patch unimpeded by the “ossification” of the rest

12/5/05 NSF FIND 14

Rethinking at Layer 7

IP Overlay NetworkGateways

SensorNet Patch

12/5/05 NSF FIND 15

Opportunity to rethink more deeply

• No dusty-decks yet

• Not a bunch of laptops running around with their sockets open trying to route through other laptops running around…

• Meaningful set of applications and associated traffic loads

– Environments, individual objects, interactions

• Chance to think through control as well as monitoring

• Physical embedding matters

• Techniques are likely to apply to the rest of the Internet

12/5/05 NSF FIND 16

Traditional Analysis

Delivered Performance

Offered Load

12/5/05 NSF FIND 17

Analysis that really matters

Reliability

Energy Expended

Delay

Traffic Load

Traffic Variability

Environmental variability

Bandwidth

Changes in network population

Mobility

12/5/05 NSF FIND 18

SensorNets need the Wisdom of the “Internet Architecture”

• Design for change!• Network protocols must work over a wide

variety of links– Links will evolve

• Network protocols must work for a variety of applications

– Applications will evolve

• Provide only simple primitives– Don’t confuse the networking standard with a

programming methodology

• Don’t try to lock-in your advantage in the spec

• Open process• Rough consensus AND running code

12/5/05 NSF FIND 19

XETF (Xternet Engineering and Technology Forum) ???

• Mission– Foster an open, innovative, and technically sound ecosystem around

interconnecting the physical world with modern networking and information technology through the creation of technical documents, protocols, reference implementations and APIs.

• Structure– Lean. Volunteer: BOD, steering comm., working groups.

• Membership– Individuals, corporate, academic, and gov’t

• Participation– Open. Role determined by contribution.

• IP Policy– Non-confidential. Disclosure and Contribution process. – Companies can develop own implementation.– BSD? Apache-like credit? MPL? LGPL?

• Output– RFC-like documents, reference implementations, forum for exchange and viz.– “Rough consensus AND running code”

12/5/05 NSF FIND 20

Uniting long-lost relatives

General Purpose Computing Instrumentation Computers

Mainframe

Minicomputer

Workstation

PC

VME

Dedicated Controllers

Home Automation

Building Automation

12/5/05 NSF FIND 21

Tides of Change

Log Stuff

Time

The successor emerges when prior regime is at its apex of strength – not at a point of weakness.

What was previously hard becomes easy, but its successor becomes possible…

Integration

Innovation

The Future Internet probably exists today; go find it

12/5/05 NSF FIND 22

Discussion