Stepping Stones to Ubiquitous Connectivity

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Stepping Stones to Ubiquitous Connectivity

• Jason Hill

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The Wireless IP Vision

• The key enabling technology of the future is a
  universal, wireless, digital communication
  standard

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The Wireless IP Vision (cont.)

• Enable cost effective internet connectivity to
  portable devices
• Have an ultra low power communication
  infrastructure
• Support automatic device detection
• Provide environment where all devices can
  interoperate

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Wouldnt it be nice if

• AT THE AIRPORT

Gate Information
Rental Car
Ticketing/Payment
Check-in
Departure Times
Stores/Restaurants
Ground Transportation
Baggage Location
Arrivals
Maps
THE INTERNET
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AT THE MALL
Sales
Search by Product
Payments
Stores
Restaurants -- Menus
Maps
Coupons
Movies -- Reviews
Parking
THE INTERNET
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AT THE OFFICE
Maps
Meeting Scheduling
Meeting Schedule
Supplies
Contact Databases
Announcements
Urgent Messages
Inventory
E-mail
Co-worker location
Presentation Notes
Resource Tracking
THE INTERNET
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Taking Ninja to the next level

• Many current ninja services assume the existence
  of connectivity
• Universal Messaging, Ninja Mail, Security
  Infrastructure
• Attempts at using existing technology have failed
• Wireless connectivity is essential for ninja unit
  development

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Attempted mobile ninja units

• What has been tried
• IR Connection points throughout soda hall
• Assembly of multiple wired access points
• Both failed because of bad connection models
• System must require zero configuration and have
  automatic connection protocols

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Requirements for Ubiquitous Connectivity

• Zero configuration required automatic
  connection protocols
• Low power
• Accept holes in coverage
• Incorporate mobile IP style routing
• Scale for device requirements
• Based on open standard broadly adoptable

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Related Technologies

• Hasnt someone else solved this problem?
• Bluetooth
• Wireless standard for 1Mbps portable networking
• Symbol Spectrum One
• Proprietary radio network designed for portable
  inventory control terminals
• CDPD (Cellular Digital Packet Data)
• Cellular based point to point data communication
  protocol (Palm VII and Sprint Wireless Web)
• Wireless Ethernet (802.11)
• Home RF (Modified 802.11)

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Major Shortcomings

• Power
• Inability to support large numbers of devices
• Inability to withstand holes in coverage
• Lack of developmental progress

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Eliminate the Virtual Wire

• Many wireless solutions attempt to create a
  Wireless wire
• Cant hide wireless characteristics from protocol
  and application layers
• intermittent connectivity
• Doesnt allow for protocol to be optimized for
  communication costs

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TCP/IP is not optimal for wireless devices

• TCP/IP requires continuous end to end
  connectivity
• Instead use optimized protocol over wireless
  links
• Use Ninja Active Proxies to bridge between
  wireless protocols and IP to achieve internet
  connectivity
• Provide the illusion of IP

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Use the power of a connected surrogate

• Enable data to be queued on behalf of low power
  clients
• Allows ultra low power radio protocols
• Use to seamlessly route data to a device while
  the devices is mobile
• Use to give appearance of continuous connectivity
  
• Wireless sensors
• Perform data transformations (encryption
  compression)

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Exploratory Project

• Semester project to reduce the power consumption
  of networking for Palm Pilot
• Replace generic IP over PPP connection with a low
  power protocol
• Use an infrastructure based active proxy to
  convert to IP

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Low power protocol

• Have device aggressively turn off interface to
  reduce power consumption
• Have device poll to receive data
• Let device determine when communication is
  necessary
• Endpoint of TCP/IP connection moved to the Proxy
• Allows device to appear connected continuously

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We use Active Proxy to

• Queue data sent to client while network interface
  is disabled
• Allow device to disable the networking interface
  between periods of communication
• Perform data compression to limit number of bits
  transmitted

Serial IP
TCP/IP
Client
Active Proxy
Internet
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Yield
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Design Beliefs

• Must disable networking interface whenever
  possible
• Protocol must not dictate minimum power
  consumption
• Protocol must allow interface to be disabled
  while logical connections are active
• Should harness power of connected surrogates
• Use Inter-Base stations communication to help
  orchestrate communications

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Possible Design
Master Controller
Internet
IP
IP
IP
IP
AP Base 1
AP Base 2
WIP
WIP
Client
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Key questions to be answered

• What is the correct radio technology
• What protocol will be most power efficient for
  clients
• How do we do automatic federation (devices
  joining and leaving automatically)
• Correct Active Proxy architecture

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The Future is Ubiquitous Connectivity

• Jason Hill

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Following slides give more detailed information
on related technologies
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Bluetooth

• Where is it?
• Bluetooth was started in 1998
• While 1300 companies are participating in the
  specification, there are only a handful of
  products on the market.
• Strengths
• Broad membership

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Bluetooth (cont.)

• Weaknesses
• Large emphasis on real time applications
  resulting in increased complexity (voice)
• Maximum of 8 nodes per piconet
• Requires piconet master
• Clients must be continuously listening to stay
  synchronized with master clock

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Symbol Spectrum One

• Actually deployed and successful. (over 10,000
  installations)
• Base stations communicate amongst each other
• Designed to operate with a set of pre-configured
  clients
• Low bandwidth lt 1Mbps
• Client server model

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CDPD

• Uses analog cellular telephone network
• Point to point
• Cost
• Energy Consumption

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802.11 (Wireless Ethernet)

• High Power
• Wavelan PCMCIA Cards consume 180mW in sleep mode
  and 1300 mW idle
• Cannot Completely disable network interface for
  low power standby
• Protocol dictates minimum power consumption of
  devices
• Cost
• Baystack cards are 400