How Dataflow is opening the Internet Frontier Dataflow-to-synthesis Retrospective David E. Culler UC Berkeley Arch Rock.
Download ReportTranscript How Dataflow is opening the Internet Frontier Dataflow-to-synthesis Retrospective David E. Culler UC Berkeley Arch Rock.
How Dataflow is opening the Internet Frontier Dataflow-to-synthesis Retrospective David E. Culler UC Berkeley Arch Rock The Internet 2 The Internet Frontier Low resolution Sensor, Test4, Increasing frequency 1 Acceleration (g) 0.5 0 -0.5 -1 0 2 4 6 8 10 Time (sec) 3 12 14 16 18 Why “Real” Information is so Important? Save Resources Improve Productivity Enable New Knowledge Increase Comfort Enhance Safety & Security Preventing Failures High-Confidence Transport Improve Food & H20 4 Protect Health …but what has Dataflow got to do with it? 5 all I ever learned … Arvind’s Law: Value derived from concurrent activities is inverse to the cost of integrating communication and computation - so tag it and do it all! Culler’s Corollary: but storage increases with concurrency - so do it with bounded resources 6 all I ever learned … 7 so at the public school … Log of Something Ninja Staged Event Driven Arch. for massive internet servers NOW Split-C Active Messages TAM Threaded Abstract Machine - two level scheduling hierarchy - expose network to the compiler - no allocation on arrival 8 Time Enabling Technology Microcontroller 9 Flash Storage Radio Communication IEEE 802.15.4 Sensors Enabling Technology Not your 3M’s • MIPs of proc. • KB of RAM / Prog • kbps of bandwith • uW of power Physical World 10 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 Silicon World Physical World 11 Wireless Processing Storage Sensors WSN Research Phenomenon… zeevo BT Intel rene’ SmartDust WeC Intel/UCB dot Sensit / Expeditions Rene XBOW rene2 Eyes NEST Mica Telos XBOW mica Sensicast 12 nest 6/02 1/02 TIP BTNode Intel cf-mica XBOW cc-dot Bosch cc-mica 11/00 Intel MOTE2 Intel iMOTE XBOW mica2 XBOW micaZ digital sun rain-mica Dust Inc blue cc-TI 3/03 5/04 trio Berkeley…and beyond Wireless Sensor Networks SmartDust Wireless 13 NEST Sensors Storage Processing TinyOS 2.0 The Systems Challenge Over-the-air Programming Network Protocols Link Radio Serial Applications and Services Blocks, Logs, Files Flash Scheduling, Management Streaming drivers MCU, Timers, Bus,… ADC, Sensor I/F WSN mote platform Wireless 14 Storage Processing Communication Centric Resource-Constrained Event-driven Execution Sensors 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! => Provide a framework for defining boundaries and let the new layers fall where they may. 15 What we mean by “Low Power” • 2 AA => 1.5 amp hours (~4 watt hours) • Cell => 1 amp hour (3.5 watt hours) Cell: 500 -1000 mW WiFi: 300 - 500 mW GPS: 50 – 100 mW => few hours active => several hours => couple days WSN: 50 mW active, 20 uW passive 450 uW => one year 45 uW => ~10 years * System design * Leakage (~RAM) * Nobody fools mother nature Ave Power = fact * Pact + fsleep * Psleep + fwaking * Pwaking 16 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 – – – – 17 needs to last for long periods must be self-managing, adaptive, robust Generates meaningful data for many uses Often mobile (!!!) Self-Organized Mesh Routing 2 2 2 2 1 1 2 0 18 Sensor Network “Networking” Appln Hood EnviroTrack FTSP Transport Routing Scheduling SPIN TTDD Phy 19 Ascent GPSR SPAN ReORg PC Drip Arrive MintRoute GRAD GAF FPS Yao SMAC PAMAS Link Trickle Deluge MMRP TORA CGSR AODVDSR ARA GSR DBF DSDV TBRPF Resynch Topology TinyDB Diffusion Regions WooMac TMAC Pico WiseMAC Bluetooth RadioMetrix RFM CC1000 eyes BMAC 802.15.4 nordic What WSNs really look like Client Tools External Tools Excel, Matlab Enshare, etc. GUI Internet Legacy Data analysis Embedded Network 20 Gateway Field Tools Deploy Query Command Visualize THE Question If Wireless Sensor Networks represent a future of “billions of information devices embedded in the physical world,” why don’t they run THE standard internetworking protocol? 21 THE Question Web Services XML / RPC / REST / SOAP / OSGI HTTP / FTP / SNMP TCP / UDP IP Ethernet Sonet Enet 10M Enet 100M Enet 1G10G Enet GPRS Serial Plugs and People 22 802.11 802.11a 802.11b 802.11g RFM,CC10k,…,802.15.4 Self-Contained 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 – – – – 23 High reliability and adaptability Long lifetime on limited energy Manageability of many devices Within highly constrained resources LoWPAN - 802.15.4 the lowpower wireless IP Link Web Services XML / RPC / REST / SOAP / OSGI HTTP / FTP / SNMP • 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 TCP / UDP IP Ethernet 24 Sonet 802.11 802.15.4, … Web Services XML / RPC / REST / SOAP / OSGI HTTP / FTP / SNMP Proxy / Gateway Making sensor nets make sense TCP / UDP IP Ethernet Sonet 802.11 802.15.4, … IETF 6lowpan 25 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 26 A little example Internet WiFi 192.168.1.xxx WiFi ArchRockDemo 6LoWPAN Router (6to4) 10.97.0.xxx FD97::xxx 27 Router App Server and Presentation Web Services Proxy Server 192.168.1.109 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 FCF DSN Len preamble Dst EUID 64 SFD D pan S pan Src EUID 64 Max 127 bytes Dst16 Src16 Fchk HC1 Message > Frame fragmentation 29 dsp HC1 HC1 frag dsp mhop frag Mesh (L2) routing UDP HC1 Header compression IP dsp Dispatch: coexistence mhop IETF 6LoWPAN Format dsp Network Header Application Data A new internet citizen Browser, Enterprise, Controller Rich Web View per Node Web Services / WSDL SNMP, Ganglia, Email Adapters Data Warehouse IP - layer 7 Sensor & Mgmt Services HTTPm Systat, Netstat, Echo Ping, Traceroute, DHCP Reboot Proxy Gateway TCP/UDP IP WiFi GPRS EtherNet nc, telnet, ping, traceroute… 31 Router LoWPAN High Reliability Triply Redundant Ultra-low power Highly Responsive AES128 Secured IP-based Mesh Network 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 36 Low Impact of 6LoWPAN on Lifetime – Comparison to *Raw* 802.15.4 Frame Energy Cost of Packet Communication vs. Data Size * uAs per Packet Energy Δ for fixed payload * Max Payload RCV 6LoWPAN Local <= Global RCV 6LoWPAN Local <= Local RCV Raw 802.15.4 TX 6LoWPAN Local => Global TX 6LoWPAN Local => Local TX Raw 802.15.4 0 20 * fully compressed header * additional 16-byte IPv6 address 37 40 60 80 Bytes of Payload 100 120 Power of IP Connectivity Ethernet WiFi GPRS 38 LoWPAN send (IP_addr, port, UDP, &data, len) Still a Role for Proxies Browser, Enterprise, Controller Rich Web View per Node Web Services / WSDL SNMP, Ganglia, Email Adapters Data Warehouse IP - layer 7 Sensor & Mgmt Services HTTPm Systat, Netstat, Echo Ping, Traceroute, DHCP Reboot Proxy Gateway TCP/UDP IP WiFi GPRS EtherNet nc, telnet, ping, traceroute… 40 Router LoWPAN High Reliability Triply Redundant Ultra-low power Highly Responsive AES128 Secured IP-based Mesh Network Service Oriented Architecture Service Registry Service Description find Service Requestor publish bind Service Provider • Service Description => 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 41 Embedded Web Services Web Services < get temp … set sample_rate set alarm … > <request www.weather.com service> Service Description <value> <value> source=library source=library time=12:53 time=12:31 temp=26.7 temp=25.1 <\value> <\value> XML information Wireless Packets Sampled Value int temp; 802.15.4 11 010110111 010010001 010010001 Low resolution Sensor, Test4, Increasing frequency 1 Physical Signal 42 Acceleration (g) 0.5 0 -0.5 -1 0 2 4 6 8 10 Time (sec) 12 14 16 18 A new WSN world client tier1 AquaLogic server tier2 Perl tier3 SensorNet GW/Proxy Python physical info net tier4 NetWeaver C# Excel 43 Embedded Services SensorNet mote Sensor The Next Tier • Today: we can connect essentially everybody Comp:People • Tomorrow: we will be able to connect and observe essentially everything of value 1:1,000,000 Mainframe 1:1,000 Mini Workstation PC 1:1 Laptop PDA Phone 1000:1 years 44 Motes – physical spaces, objects, and their interactions – physical information, not just keystrokes – and we know dataflow is the technology of tomorrow 45 …and a new IETF working group • mailto: [email protected] 46