XML Web Services for Invisible Computing

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XML Web Services for Invisible Computing

• Johannes Helander
• Researcher
• Microsoft Research

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(No Transcript)
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Outline

• The goals of Invisible Computing
• Why Web Services?
• Our approach
• Table driven serialization
• Distributed real-time
• Trust and secure discovery
• Componentized RTOS
• Real-time C
• Developing code for small devices
• Educational research opportunities
• Availability

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Why Invisible Computing?

• The computers stay out of sight and do their job.
• No setup hassles
• Make everyday objects better by adding
  computation and communication
• Natural user interface not screen and mouse
• Rudimentary autonomous operation added value
  from services
• Incremental deployment
• Devices communicate with each other
• Devices communicate with big computers as needed

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Sample Applications

• Home appliances, security, lighting
• Medical electronic devices
• Wearable Computers
• Robotics, Industrial Control, National
  Infrastructure
• Sensor networks
• Wireless communication gadgets
• Audio Net
• Disaggregated PC, smart I/O cards
• Toys

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Hardware trends

• 32 bit microcontrollers are as cheap and power
  efficient as 8 bit MCUs
• Single chip computer is a reality
• Cost close to 5 (Home depot price point)
• No need to aim at lowest point ? sweet spot
• Aggregate of medium volume market is huge
• ? Partially reconfigurable hardware
• Make hardware easy for software people

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VCR
XP Embedded

Pacemaker

• Interoperability
• Security
• Data analysis

watch

• Power
• Bandwidth
• Processing
• Routing
• Security
• Real-Time
• Non-graphical UI
• Zero-configuration

An Invisible Computing Scenario
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What are Web Services?

• The general-purpose solution to communication, in
  XML
• Convergence of EDI, RPC, MSMQ, app specific
  protocols and formats Agnostic to underlying
  transport
• All about interoperation. Allows partial
  understanding
• Across-the-board presentation layer
• Common protocols obviate need for proxies
• Builds on critical mass and momentum

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Do they Scale?

• XML Web Services conceived to solvee-business
  interop problem
• Implementations geared towards high-end computers
• The same interop problem is the crux of
  Ubiquitous computing
• Critical mass required in any business
• Resource constraints
• Silicon footprint
• Energy parsing overhead
• Bandwidth size of messages
• ? Efficient implementation and compression

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SOAP example

• "Add" request, from PC to NTU simulator, via HTTP
• then forward to EB63 via encrypted UDP
• ltsoapEnvelope xmlnssoaphttp//schemas.xmlsoap.o
  rg/soap/envelope/ gt
• ltsoapHeader
• soapencodingStylehttp//schemas.xmlsoap.
  org/soap/encoding/ gt
• ltrppath xmlnsrphttp//schemas.xmlsoap.org/w
  s/2002/05/routing gt
• ltrpfwdgt
• ltrpvia gthttp//172.31.46.26/COB/calc.cob
  lt/rpviagt
• ltrpvia reservationsensor/button"gtx-udp-
  aes-soap//172.31.41.244/COB/calc.coblt/rpViagt
• lt/rpfwdgt
• ltrprevgtltmvia vid"1"/gtlt/rprevgt
• lt/rppathgt
• lt/soapHeadergt
• ltsoapBody
• soapencodingStylehttp//schemas.xmlsoap.
  org/soap/encoding/ gt
• ltmAdd xmlnsmhttp//tempuri.org/Calc/message
  / gt
• ltAgt14lt/Agt

The calculator is a popular interop test
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Yes, it Works!

• Implementation shows you can successfully
• Realize web services on small low-cost devices,
  providing good interoperability with PCs and
  other devices
• Achieve a high level of security and privacy on
  those devices
• Integrate security, discovery, and functional
  assignment into a hassle-free user experience
• Setup your home completely independently, yet
  securely federate with external entities such as
  e-business
• Use web services for real-time tasks
• ? Demoed at booth 31

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Microsoft Invisible Computing

• A software platform for low cost embedded systems
• that communicate with each other and with big
  computers
• Flexible development for multiple platforms
• Interoperation with small and big computers
• Web services and .NET
• Security and privacy
• Real-Time
• Energy aware
• Low parts cost (targeted for lt 5 computer)
• Sweet spot enough for real use and critical mass
  but no frills
• XML Web Services interoperability, tuned for
  performance
• Component Based RTOS
• Standard protocols TCP/IP, SOAP, PKCS1, etc.
• .NET virtual machine for C games or other
  extensions

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Invisible continued

• Interoperates with ASP and SOAP Toolkit on
  Windows XP
• Client and server, P2P
• Complete TCP/IP, HTTP, SOAP, Automation,
  discovery, trust security, RTOS (dynamic
  memory, threads, etc), drivers, application with
  complex data.
• ? Runs in computer with 32KB of RAM, 256KB of
  ROM.
• Fewer components ? smaller footprint. TCP/IP is
  biggest hog. Crypto not optimized for size.

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Outline

• The goals of Invisible Computing
• Why Web Services?
• Our approach
• Table driven serialization
• Distributed real-time
• Trust and secure discovery
• Componentized RTOS
• Real-time C
• Developing code for small devices
• Educational research opportunities
• Availability

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Table Driven Serialization

• Processes messages automatically according to
  description
• XML metadata description
• Compiled offline into compact description
• Extensible at runtime
• Process while receiving
• Zero copy networking
• Serializer parser share buffers with network
  stack crypto
• COM-Lite automation
• Turns messages into object calls
• Multiple methods in one message
• Multiple transports and encodings
• UDP, HTTP, Encryption, Compression
• Routing, roles, and conversion

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Distributed Real-Time

• Experiment in distributed scheduling
• Real-time data-flow

Instigator
Producer
Consumer
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Real-Time continued

• Serialize scheduling trees into XML
• Reservations pre-declare future activity at each
  node
• Instigator of activity orchestrates and tunes
  reservations based on feedback samples
• Worker nodes accept/reject schedules
• ? Merge of trees. Location independent. Could
  write scheduler in XSL.
• Coordinated schedules allow shared resource
  scheduling. Could turn off radio.
• Statistical decision making
• Confidence test, quality control sampling
  schedules, probability based admission control
• Concept demo shown at booth 31

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Real-Time continued
Serialized reservation example

• ltrstask xmlnsrshttp//tempuri.org/X-Reservation
  namesense1gt
• ltrsreservation nameproducer
  deadLine2004-12-31T000000.5Z
• tolerance"P456S
  duration"P0.1S"gt
• ltrsresource namecpu"gt
• ltrsquantitygt2000lt/rsquantitygt
• lt/rsresourcegt
• ltrsresource nameRF-transmitter-1"gt
• ltrsquantitygt77lt/rsquantitygt
• lt/rsresourcegt
• lt/rsreservationgt
• ltrsreservation nameconsumer"
  deadLine"2004-12-31T000000.2Z
• tolerance"P82S"
  duration"P0.1S"gt
• ltrsresource nameRF-receiver"gt
• ltrsquantitygt100lt/rsquantitygt
• lt/rsresourcegt
• lt/rsreservationgt
• lt/rstaskgt

Triggers, sub-reservations, resource estimates,
tolerances
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A Secure Invisible Home
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Setting up a Secure Home

• Create house authority, e.g. usbkey
• Touch each device once with usbkey
• Admits device into trust domain
• Determines functional relationships heuristically
• Discovery process finds device with desired
  function does key exchange
• House authority can be offline
• RSA AES
• Write hash of house authoritys key on check to
  establish trust with bank
• ? Federation of independent trust domains

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Trust and Discovery

• Simple SOAP based trust and service discovery for
  ad hoc networks
• Integrate trust and functional setup
• Integrate key exchange with discovery
• Simple user interaction
• No external CA required
• Use Global XML Architecture when infrastructure
  present
• Optimized for cluster of nodes. Base station (PC)
  deals with global issues
• PKI works on small devices (but can be boosted)
• 13s RSA decrypt, 0.03s AES on 25MHz Arm7
• FPGA takes times down by factors of 3000 and
  10000 (3ms 2µs)
• Strong crypto necessary for marketability
• Would people buy surveillance equipment against
  themselves?

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RTOS Architecture

• Support for web services on a chip
• General purpose in the abstract. Code and
  interface reuse.
• Special in the concrete. Only take what you need.
• Component Based
• Objects everywhere
• COM interfaces
• Unified namespace
• Same interfaces implemented by many components
• Multiple implementations of any component
• Specialized to task
• Pay as you go
• Late binding and mutation
• Adaptive to changing requirements
• Real-time scheduling with application feedback
• XML based configuration and communication

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RTOS continued

• Hardware platforms
• ARM (many), i386, H8, MIPS, TriMedia, Map1000,
  68k, eCOG1
• Numerous development boards. Prototype gadgets.
  Smart I/O cards
• Can be compiled with numerous compilers
• ROM sizes e.g. 10KB, 20KB, 200KB on ARM 26KB,
  240KB on x86
• Power e.g. 40mW on 5x7 cm 2.8V ARM board with LCD
  when playing a simple game (snake)

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It Still Has to be Small!
WinXp
Invisible
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Real-Time C

• CLR desirable option for embedded systems
• Great for extensions, games, apps
• Not practical as the exclusive solution in
  embedded systems
• Our real-time scheduling extensions
• Prototype API implemented
• Work Item Scheduler allows mixing native and
  managed threads
• Native execution stacks are multiplexed

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Outline

• The goals of Invisible Computing
• Why Web Services?
• Our approach
• Table driven serialization
• Distributed real-time
• Trust and secure discovery
• Componentized RTOS
• Real-time C
• Developing code for small devices
• Educational research opportunities
• Availability

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Developing Code

• for embedded systems using Microsoft Invisible
  Computing
• Start with emulation, then simulation, and
  finally real hardware
• Debugging on real embedded h/w painful
• ? minimize time spent on this
• All MS Invisible Computing environments have the
  same interfaces and basic configurations
• Winbig
• NTU
• Giano
• Boards

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1 Winbig

• Runs on Windows XP
• Uses XP sockets, threads, files
• i386 binaries
• Pleasant development underVisual Studio
• Smallest SOAP stack for Windows XP
• big is the configuration where everything is
  linked together? usually used for ROM images

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2 NTU

• Runs on Windows with i386 binaries
• Implements its own threads and scheduling, etc.
• Closer to real thing
• One thread for CPU, one for timer chip
• Enables debugging network stack and scheduler
  under Visual Studio

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3 Giano

• Hardware simulator
• Interprets ARM instruction set
• FPGA simulation enables hardware- software
  co-design work
• Easy to add new hardware peripherals
• 14 MHz eb63 board on fast PC
• Easier to work with than real boards
• Extremely close to real hardware,except for
  real-world interactions (e.g. no A/D pins)

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4 Boards

• Real boards test actual hardware reality check
• Development boards still not exactly the same as
  a real product
• ?Another step closer
• Instrumentation and monitoring through FPGA
  co-board
• JTAG debugging, still unpleasant
• Most software development done in simulators
  very little left to do here

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Education and Research

• Microsoft Invisible Computing is a research
  prototype
• Experiments in seamless computing through
  embedded web services
• Has been used by academia
• Steve Liu at Texas AM
• Open invitation to participate

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Availability

• http//research.microsoft.com/invisible
• Community Source License allows research and
  education use with few strings attached
• New code will be added periodically
• No support available at this time
• The work presented in this talk was contributed
  by the MSR Invisible Computing Group
• Alessandro Forin, Johannes Helander,Behnam
  Neekzad, Stefan SigurdssonSpecial thanks Paul
  Pham, Yong Xiong