How Dataflow is opening the Internet Frontier

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How Dataflow is opening the Internet Frontier

• Dataflow-to-synthesis Retrospective
• David E. Culler
• UC Berkeley
• Arch Rock

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The Internet
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The Internet Frontier
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Why Real Information is so Important?
Increase Comfort
High-Confidence Transport
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but what has Dataflow got to do with it?
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all I ever learned
Cullers Corollary but storage increases with
concurrency - so do it with bounded resources
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all I ever learned
TTDA
Monsoon
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so at the public school
NOW
Split-C
Active Messages
TAM
Threaded Abstract Machine - two level scheduling
hierarchy - expose network to the compiler - no
allocation on arrival
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Enabling Technology
IEEE 802.15.4
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Enabling Technology

• Not your 3Ms
• MIPs of proc.
• KB of RAM / Prog
• kbps of bandwith
• uW of power

Physical World
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Enabling Research
Build an approximation of the future that you
imagine and study it to learn what is true in
that possible world.
Berkeley Mote / TinyOS Platform
Physical World
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WSN Research Phenomenon
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Berkeleyand beyond
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The Systems Challenge
TinyOS 2.0
WSN mote platform
Communication Centric Resource-Constrained Event-d
riven Execution
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The Solution

• Basically a dataflow engine in disguise
• Two-level Scheduling Hierarchy
• Asynchronous events integrate external world
• Computational Tasks
• Collections of Tasks and Events Bounded State
  form a Component.
• Never, never, never wait. Do work or go to
  sleep!!!!!!!!!!
• Recognition of reality
• Zillions of unattended devices embedded in a
  noisy physical world require an unprecedented
  level of robustness and SIMPLICITY
• Application Structured Graph of Components
  connected by Well-Designed Interfaces.
• Escape Velocity
• Our System and Network Abstractions (ca. Unix
  Sockets TCP) have been essentially unchanged
  for decades and are deeply steeped in the 3M
  design point!
• gt Provide a framework for defining boundaries
  and let the new layers fall where they may.

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What we mean by Low Power

• 2 AA gt 1.5 amp hours (4 watt hours)
• Cell gt 1 amp hour (3.5 watt hours)
• Cell 500 -1000 mW gt few hours active
• WiFi 300 - 500 mW gt several hours
• GPS 50 100 mW gt couple days
• WSN 50 mW active, 20 uW passive
• 450 uW gt one year
• 45 uW gt 10 years
• Ave Power fact Pact fsleep Psleep
  fwaking Pwaking

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Wireless Client vs Wireless Server

• Wireless Client
• needs to last a day or two
• has a human to keep them working properly
• mostly formats specific incoming data for display
• Wireless server
• needs to last for long periods
• must be self-managing, adaptive, robust
• Generates meaningful data for many uses
• Often mobile (!!!)

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Self-Organized Mesh Routing
0
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Sensor Network Networking
EnviroTrack
Hood
TinyDB
Regions
FTSP
Diffusion
SPIN
TTDD
Trickle
Deluge
Drip
MMRP
Arrive
TORA
Ascent
MintRoute
CGSR
AODV
GPSR
ARA
DSR
GSR
GRAD
DBF
DSDV
TBRPF
Resynch
SPAN
FPS
GAF
ReORg
PC
Yao
SP100.11a
SMAC
WooMac
PAMAS
BMAC
TMAC
WiseMAC
Pico
802.15.4
Bluetooth
eyes
RadioMetrix
CC1000
nordic
RFM
wHART
Zigbee
Zwave
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What WSNs really look like
Deploy Query Command Visualize
Client Tools
External Tools
Excel, Matlab Enshare, etc.
Internet
GUI
Legacy Data analysis
Field Tools
Gateway
Embedded Network
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THE Question

• If Wireless Sensor Networks represent a future of
  billions of information devices embedded in the
  physical world,

why dont they run THE standard internetworking
protocol?
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THE Question
?
Sonet
Serial
Self-Contained
Plugs and People
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The Answer

• They should
• Substantially advances the state-of-the-art in
  both domains.
• Implementing IP requires tackling the general
  case, not just a specific operational slice
• Interoperability with all other potential IP
  network links
• Potential to name and route to any IP-enabled
  device within security domain
• Robust operation despite external factors
• Coexistence, interference, errant devices, ...
• While meeting the critical embedded wireless
  requirements
• High reliability and adaptability
• Long lifetime on limited energy
• Manageability of many devices
• Within highly constrained resources

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LoWPAN - 802.15.4 the low-power wireless IP Link

• 1 of 802.11 power, easier to embed, as easy to
  use.
• 8-16 bit MCUs with KBs, not MBs.
• Off 99 of the time

Web Services
XML / RPC / REST / SOAP / OSGI
HTTP / FTP / SNMP
TCP / UDP
IP
802.15.4,
802.11
Ethernet
Sonet
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Making sensor nets make sense
Web Services
XML / RPC / REST / SOAP / OSGI
HTTP / FTP / SNMP
TCP / UDP
IP
802.15.4,
802.11
Ethernet
Sonet
IETF 6lowpan
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Challenges for IP over 802.15.4

• Header
• Standard IPv6 header is 40 bytes RFC 2460
• Entire 802.15.4 MTU is 127 bytes IEEE
• Often data payload is small
• Fragmentation
• Interoperability means that applications need not
  know the constraints of physical links that might
  carry their packets
• IP packets may be large, compared to 802.15.4 max
  frame size
• IPv6 requires all links support 1280 byte packets
  RFC 2460
• Allow link-layer mesh routing under IP topology
• 802.15.4 subnets may utilize multiple radio hops
  per IP hop
• Similar to LAN switching within IP routing domain
  in Ethernet
• Allow IP routing over a mesh of 802.15.4 nodes
• Options and capabilities already well-defines
• Various protocols to establish routing tables

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A little example
Internet
WiFi
192.168.1.xxx
App Server andPresentation
WiFi ArchRockDemo
Router
Web Services Proxy Server
6LoWPAN Router (6to4)
192.168.1.109
10.97.0.xxx FD97xxx
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IEEE 802.15.4

• Low Bandwidth (250 kbps), low power (1 mW) radio
• Moderately spread spectrum (QPSK) provides
  robustness
• Simple MAC allows for general use
• Many TinyOS-based protocols (MintRoute, LQI, BVR,
  ), TinyAODV, Zigbee, SP100.11, Wireless HART,
• 6LoWPAN gt IP
• Choice among many semiconductor suppliers
• Small Packets to keep packet error rate low and
  permit media sharing

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6LoWPAN Format Design

• Orthogonal stackable header format
• Almost no overhead for the ability to
  interoperate and scale.
• Pay for only what you use

IEEE 802.15.4 Frame Format
D pan
Dst EUID 64
S pan
Src EUID 64
preamble
Dst16
Src16
DSN
Network Header
Application Data
IETF 6LoWPAN Format
HC1
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6LoWPAN IPv6 Header
IEEE 802.15.4 Frame Format
D pan
Dst EUID 64
S pan
Src EUID 64
preamble
Dst16
Src16
DSN
Network Header
Application Data
dsp
IETF 6LoWPAN Format
01
1
Uncompressed IPv6 address RFC2460
0
40 bytes
0
0
0
0
01
0
1
0
0
0
0
HC1
Fully compressed 1 byte
Source address derived from link
address Destination address derived from link
address Traffic Class Flow Label zero Next
header UDP, TCP, or ICMP
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A new internet citizen
Rich Web View per Node Web Services / WSDL SNMP,
Ganglia, Email Adapters Data Warehouse
Sensor Mgmt Services HTTPm Systat, Netstat,
Echo Ping, Traceroute, DHCP Reboot
Browser, Enterprise, Controller
IP - layer 7
TCP/UDP IP
WiFi
GPRS
EtherNet
LoWPAN
High Reliability Triply Redundant Ultra-low
power Highly Responsive AES128 Secured IP-based
Mesh Network
nc, telnet, ping, traceroute
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Support the Complete Lifecycle of the Wireless
Sensor Net
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Reliable Mesh Networking

• Triply redundant routing topology
• Adaptive to changing RF environment through
  passive and very-low bandwidth active observation
• Link-level retransmission coupled with rerouting
  among well-qualified candidates
• Temporal and spatial (receiver) diversity
• Designed for scale
• Accommodates high neighbor density or deep
  topology with no arbitrary limits

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Responsive for Manageability

• Responsive on human timescales for management
• Dial down responsiveness to decrease listening
  cost and increase lifetime

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Ease of Development

• Rich sensor/actuator configuration and
  composition without embedded programming

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Low-Power Schedule-Free Routing

• Extends preamble sampling DARPA packet radio,
  1984 and low-power listening UC Berkeley, 2000
  to enable battery powered routers.
• Simplicity of an always on network at low-duty
  cycle by shifting effort from (frequent)
  listening to (infrequent) transmission.
• Flexible and configurable
• Overlay time synchronization service for
  correlated sampling and scheduling optimizations.
• Eliminates need for connectivity / interference
  survey
• Eliminates schedule incompatibility across
  clusters
• Eliminates costly scan for schedule on join /
  rejoin

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Low Impact of 6LoWPAN on Lifetime Comparison to
Raw 802.15.4 Frame


Energy ? for fixed payload
Max Payload
fully compressed header
additional 16-byte IPv6 address
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Power of IP Connectivity
Firewall
Firewall
Ethernet
WiFi
GPRS
LoWPAN
send (IP_addr, port, UDP, data, len)
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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

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Still a Role for Proxies
Rich Web View per Node Web Services / WSDL SNMP,
Ganglia, Email Adapters Data Warehouse
Sensor Mgmt Services HTTPm Systat, Netstat,
Echo Ping, Traceroute, DHCP Reboot
Browser, Enterprise, Controller
IP - layer 7
TCP/UDP IP
WiFi
GPRS
EtherNet
LoWPAN
High Reliability Triply Redundant Ultra-low
power Highly Responsive AES128 Secured IP-based
Mesh Network
nc, telnet, ping, traceroute
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Service Oriented Architecture
Service Registry
Service Provider
Service Requestor

• Service Description gt interface implementation
• Operations supported, input/output objects
• Bindings to network and data encoding schemes
• Network address where service can be invoked
• Enough that client can generate code to access
  the service well

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Embedded Web Services
lt get temp set sample_rate set alarm gt
www.weather.com
Web Services
ltvaluegt sourcelibrary time1253
temp26.7 lt\valuegt
ltvaluegt sourcelibrary time1231
temp25.1 lt\valuegt
XML information
Wireless Packets
802.15.4
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A new WSN world
client
tier1
server
AquaLogic
tier2
Perl
Python
C
Embedded Services
NetWeaver
Excel
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The Next Tier

• Today we can connect essentially everybody
• Tomorrow we will be able to connect and observe
  essentially everything of value
• physical spaces, objects, and their interactions
• physical information, not just keystrokes
• and we know dataflow is the technology of tomorrow

CompPeople
11,000,000
Mainframe
Mini
11,000
Workstation
PC
11
Laptop
PDA
Phone
10001
Motes
years
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Happy Birthday
and may the dataflowers bloom
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and a new IETF working group

• mailto rsn_at_ietf.org

Thanks