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Towards Wireless Overlay Network Architectures

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Title: Towards Wireless Overlay Network Architectures


1
The Bay Area Research Wireless Access Network
(BARWAN)
New Ideas Wireless Overlay Internetworking
Overlay IP extensions to Mobile IP
  Low Latency Inter-subnet Handoffs
High Thruput Reliable Transport
Class-Based Queuing Link Management
Subnet Bandwidth Load Balancing
Client-Proxy-Server Architecture
Bandwidth-aware Data Type Adaptation
  Web A/V Data Types over Wireless
Proxy-Aware API, Kerberos Integration
Delivery Class Abstraction Scalable
Wireline Processing for Mobiles
R. H. Katz E. A. Brewer, UC Berkeley Subcontract
or Hughes Research Labs
Impact Fundamental technology for 21st century
battlefield communications support for wide
diversity of hybrid asymmetric link
technologies, and end device display
computation capabilities Seamless roaming
application adaptation across 34 orders of
magnitude of wireless b/w and latency (10
kbps to 10 mbps, 1 ms to 1 s) Demonstrate
network application techniques able to
scale to support 10s of data users/room,
100s/building, 1000s/facility, 10000s/metro, and
100000s/region
Schedule
Measure Eval Wireless Ovrly Technologies
Demo in-building ovrlys h/os with dynamic b/w
alloc
Demo wide-area ovrlys low latency h/os w/
subnet load balancing
Aug 95 Start
Aug 96
Aug 97
Aug 98 End
Early Prototype Proxies (1-10 users)
Proto Scaled Proxies (100-1000 Users)
Scaled Proxies (1000-10000 Users)
Large Scale Scalability Demonstrations
Initial Architectural Specification
Scaled Architectural Specification
2
The Bay Area Research Wireless Access
NetworkTowards a Wireless Overlay
Internetworking Architecture
Satellite
Regional Area
Low-tier
High-tier
Local Area
Wide Area
Low Mobility
High Mobility
  • Randy H. Katz and Eric A. Brewer
  • Computer Science Division, EECS Department
  • University of California, Berkeley, CA 94720-1776
  • Subcontractor Hughes Malibu Research Laboratories

3
Presentation Outline
  • Retreat Purpose and Agenda
  • Project Objectives, Motivation, and Approach
  • Project and Testbed Status
  • Technology Developments
  • Review Project Plan
  • New Directions
  • Summary and Conclusions

4
Presentation Outline
  • Retreat Purpose and Agenda
  • Project Objectives, Motivation, and Approach
  • Project and Testbed Status
  • Technology Developments
  • Review Project Plan
  • New Directions

5
Retreat Goals Technology Transfer
People Project Status Work in Progress Prototype
Technology
Early Access to Technology Promising Directions
Reality Check Feedback
6
BARWAN/Hughes Team
  • Networking
  • Hari Balakrishnan (Reliable Transport)
  • Tom Henderson (Satellite-based Transport
    Routing Protocols)
  • Todd Hodes (Mobile Location Services)
  • Giao Nguyen (Channel Scaling)
  • Venkat Padmanabhan (Sessions-Transport Interface)
  • Mark Stemm (Performance Discovery)
  • Helen Wang (Vertical Handoff)
  • Applications
  • Elan Amir (Media Gateway/MASH)
  • Yatin Chawathe (Proxy Architecture/MASH)
  • Armando Fox (Proxy Architecture)
  • Steve Gribble (Scalable Servers)
  • Technical Support
  • Brian Shiratsuki (System Admin)
  • Keith Sklower (Sys Programming)
  • Admin Support
  • Terry Lessard Smith
  • Bob Miller
  • Hughes Malibu Research Laboratory
  • Son Dao
  • Yongguang Zhang
  • Dante De Lucia

Tao Ye finished her MS and went to
JavaSoft Daniel Jiang went to Daimler Benz
Research Laboratory
7
BARWAN Sponsors and Participants
  • DARPA GloMo Program
  • Rob Ruth, DARPA PM
  • US Army CECOM
  • NIST
  • SRI
  • Industrial Supporters
  • Daimler Benz
  • Ericsson (Reiner Ludwig, Visiting Industrial
    Fellow)
  • Fuji Xerox Palo Alto Labs
  • Hughes Research
  • IBM
  • Metricom
  • Toshiba (Masahiro Takagi, Visiting Industrial
    Fellow)
  • Friends
  • Hybrid Networks, Packeteer, Sandia, Stanford

8
Retreat Schedule
  • Wednesday, January 14
  • 1200 - 1300 Lunch
  • 1300 - 1400 Project Overview and Status, Randy
    Katz
  • 1400 - 1500 What We Learned About Extensible
    Proxies, Armando Fox
  • 1500 - 1530 Break
  • 1530 - 1800 Research Highlights
  • Passive Network Performance Discovery - Mark
    Stemm
  • Transport over Satellites - Tom Henderson
  • Multicast over DBS - Yongguang Zhang
  • OS Support for Scalable Network Services - Steve
    Gribble
  • Mobility Enhanced Network Services - Todd Hodes
  • 1800 - 1930 Dinner
  • 1930 - 2100 Poster Session and Demos
  • 2100 - Distributed Interactive Collaboration
    (aka Riven)

9
Retreat Schedule
  • Thursday, January 15
  • 0730 - 0830 Breakfast
  • 0830 - 1000 New Directions, Anthony Joseph
  • ProActive Infrastructure, Eric Brewer
  • Beyond Third Generation, Randy Katz
  • 1000 - 1030 Break
  • 1030 - 1200 New Directions, Continued
  • Brainstorming with sponsors on new directions
  • 1200 - 1300 Lunch
  • 1300 - 1630 Ski Break
  • 1800 - 1930 Dinner
  • 1930 - 2100 Invited Talks
  • Transport over Cellular, Reiner Ludwig, Ericsson
  • Rover Toolkit, Anthony Joseph, UC Berkeley
  • Hybrid Networks Technology, Subir Varma
  • 2100 - Distributed Problem Solving (aka Riven)

10
Retreat Schedule
  • Friday, January 16
  • 0730 - 0830 Breakfast
  • 0830 - 1000 Six Month Planning Session, Eric
    Brewer
  • 1000 - 1030 Break Check-out
  • 1030 - 1200 Sponsor Feedback Session, Randy Katz
  • 1200 - 1300 Lunch
  • 1300 - Depart Granlibakkan

11
Presentation Outline
  • Retreat Purpose and Agenda
  • Project Objectives, Motivation, and Approach
  • Project and Testbed Status
  • Technology Developments
  • Review Project Plan
  • New Directions
  • Summary and Conclusions

12
Heterogeneous Mobile Computing
People and their machines should be able to
access information and communicate with each
other easily and securely, in any medium or
combination of media -- voice, data, image,
video, or multimedia -- any time, anywhere, in a
timely,cost-effective way. G. Heilmeier, 1992
  • Three Overarching Strategies
  • Heterogeneous Wireless Networks
  • Network Optimization
  • Dynamic Adaptation
  • Access
  • Anytime, Anywhere
  • Wide-Area Coverage
  • Scalable Processing
  • Highly Available Operation
  • Easily
  • Transparent Access
  • Localized Service
  • Securely
  • Global Authentication
  • Any Medium
  • Multimedia Audio/Video/Graphics
  • Timely
  • Performance
  • Cost Effective
  • Heterogeneous Support via Proxies

13
Wireless Overlay Networks
Theatre of Operations
Rear Echelons
Bases, Depots, Ranges
Command Centers Training Centers
14
Asymmetric Heterogeneous Access
High Bandwidth
Command Post Disaster Relief  Remote
Clinic  Organization w/poor Internet
connectivity
Local Subnet
Low Bandwidth
15
XXI Century Battlefield Architecture
Rear Area
ATM Backbone
Packet Radio Network
Radio Access Point
16
BARWAN Testbed
DirecPC DBS (1 mbps)
Vertical Hand-Off
LOS Wireless Cable (6 mbps)
DARTNet II CAIRN
Metricom
Cellular Modem Cellular Packet Data Packet Radio
10-30 kbps
17
Client-PROXY-Server Architecture
  • Proxy
  • Mediates between wireless and wireline
    environment
  • Ideally executes at well-connected boundary of
    internetwork
  • Manages caches and chooses transport data
    representations on-the-fly
  • Trade transcoding time against communications time

18
Overlay Network Challenge
Latency as critical as bandwidth in wireless
networks Wide diversity of network performance
parameters Competing infrastructure providers
Pedestrian vs. vehicular mobility
19
Application Support Challenge
  • Client variation spans an order of magnitude

20
Cross-Cutting Architectural Issues
  • Dynamic resource allocation and adaptation
  • Proxies adapt representations for available
    bandwidth and latency
  • Vertical handoff-based event notification
  • Proxy transcoder load balancing refinement
    caching
  • Performance discovery
  • Network meeting performance promises for
    classes of users and types of data
  • Choosing best available overlay for
    connectivity
  • Scheduling bandwidth-constrained (wireless) links
  • Exploit channel state for higher channel
    utilization
  • Leverage existing Internet standards
  • Mobile IP, TCP, Service location protocols, HTTP,
    POP, IMAP, etc.
  • But allow architecture-aware applications to
    obtain enhanced functionality

21
Daedalus/GloMop Architecture
22
Daedalus/GloMop Architectural Components
Mobile Applications
Proxy Agents
Location-Dependent Services
Transport (Asymmetric, Heterogeneous, Lossy Links)
Sessions
Snoop Agent
Link Scheduling
23
Presentation Outline
  • Retreat Purpose and Agenda
  • Project Objectives, Motivation, and Approach
  • Project and Testbed Status
  • Technology Developments
  • Review Project Plan
  • New Directions

24
Project Strategy
Architectural Design Scaled Implementations
Early Prototypes Proof of Concepts Measurements
Evaluation
25
Project Plan and Status
67
Project Start 15 Aug 95 (Start 29 Months)
Scalability
95
Demonstrate Ability to Scale to Large
Communities of Mobile Users
Functionality
100
Demonstrate Seamless Roaming over Local and Wide
Area
Early Proof of Concept Implementations
NOWs Local Wide-Area Wireless Overlays Enhanced
E2E Performance
Establishment of BARWAN Testbed
Measure Alternative Overlay Network Performance
Extend with Emerging Technologies
100
26
AchievementsJanuary 1996
  • Establishment of heterogeneous wide-area and
    local area wireless access technology testbed
    (BARWAN)
  • Proof of concept prototypes of proxies for
    web/image, video, postscript, maps
  • Leveraged in UCB InfoPad and UCLA WAMIS Projects
  • Prototype bandwidth adaptive applications
  • PDA MIME mail, Internet conferencing/collaboration
    tools
  • Prototype implementations of reliable transport
    and mobile handoff mechanisms
  • Algorithms leveraged in UCB InfoPad Project
  • Development of industrial collaborations for
    eventual technology transfer

27
AchievementsJune 1996
  • Enhancement of BARWAN Testbed
  • Successful integration of Metricom WAP, Unix DBS
    Driver, Infrared
  • Implementation and evaluation of vertical handoff
  • Transfer of software to SRI for evaluation in
    OOTW/LE testbed
  • Proxy Development
  • Demonstration of Internet Video over DBS,
    Metricom packet radio
  • Demonstration of rapid proxy adaptation across
    vertical handoffs
  • Reliable Transport
  • Deployment of Snoop Agent in UCSC Reinas Wide
    Area Testbed
  • Dramatic improvement in performance for wide-area
    sensor network
  • New Industrial Collaborations
  • PCSI, Daimler Benz join BARWAN consortium
  • Geoworks for proxy software technology transfer
  • Serious discussions with Ericsson and Nokia

28
AchievementsJanuary 1997
  • Enhancement of BARWAN Testbed
  • Integration of Wireless Cable high bandwidth LOS
    technology
  • Placement of test machine at Hughes Germantown
    up-link site
  • Initial connectivity with DartNet II/Cairn ATM
    WAN testbed
  • Proxy Development
  • Generalized Web proxy
  • Scalable proxy design and initial implementation
  • Reliable Transport
  • Evaluation of IBM Olympic Web server traffic
    dynamics
  • Early evaluation of asymmetric transport
    algorithms
  • New Industrial Collaborations
  • Wink Communications to join BARWAN consortium
  • Geoworks signs(?) proxy software evaluation
    license
  • Serious discussions with Ericsson

29
AchievementsJune 1997
  • Enhancement of Research Infrastructure
  • Extensive development of wireless network
    simulation environment, based on McCannes ns
    simulator, supporting scalability analyses
  • Overlay Network Development
  • Extensive analysis of transport protocols over
    asymmetric and hybrid networks (DBS, wireless
    cable, Metricom PR)
  • Improved throughput via state dependent channel
    allocation in wireless cells
  • Proxy Development
  • Successful large-scale deployment of scalable
    proxy to Berkeley modem pool community (reported
    in press)
  • Research and Industrial Collaborations
  • Ericsson joins industrial consortium
  • Badri from Rutgers to spend sabbatical with group
    AY 97-98
  • Anthony Joseph from MIT Rover Group to join
    faculty Jan 98

30
AchievementsJanuary 1998
  • Proxy Development
  • Wingman Pilot Graphical Web Browser
  • Demonstration of extensible proxies
  • MASH Toolkit-TranSend Proxy Server integration
  • Overlay Network Development
  • Developed new transport protocol tuned for high
    latency, highly asymmetric satellite environment
    (STP)
  • Snoop V2 Beta with Explicit Loss Notification
  • TCP sessions with integrated congestion control
    and recovery
  • Enhanced right edge loss recovery scheme
    suitable for slow speed links and short transfer
    size Web traffic
  • Other TCP enhancements for Web traffic
    characteristics (fast start)
  • Research Infrastructure
  • VINT enhancements for wireless simulation cable
    modem network, LANs, wireless links, asymmetric
    networks, TCP variations, routers, RTP

31
Local Area Wireless TestbedSoda Hall, UC Berkeley
  • 3rd, 4th, 5th, 6th, 7th floors covered by WaveLAN
    BSs
  • Low latency handoff co-resident with DHCP
  • Private Metricom network (1 WAP, 6 Infra Radios)

32
Wide-Area Wireless Testbed
  • Non-Cooperating Wide-Area
  • Wireless Networks no control
  • over basestations
  • Metricom PR Network
  • DirecPC DBS Service
  • Wireless Cable Network
  •  Cellular Modems
  •   Cellular Digital Packet Data
  •   GSM General Packet Radio
  • Service

(GSM technology finally deployed in SF Bay
Area as PCS 1900 by PacBell Mobile Services in
Spring 1997)
33
BARWAN Testbed
GSM Circuit Switched Cellular
Metricom
Wide Area
WLAN RF
Base
IBM IR
Station
DirecPC
Basestation
Hughes DBS
Basestation
Soda Hall
Gateway
Ethernet
Gateway
Internet
Metricom "WAP"
34
Presentation Outline
  • Retreat Purpose and Agenda
  • Project Objectives, Motivation, and Approach
  • Project and Testbed Status
  • Technology Developments
  • Review Project Plan
  • New Directions
  • Summary and Conclusions

35
Mobile Computing Challenges
Low Data Rate High Latency
Adaptability
Mobility
Unreliability
36
Overlay Routing Mobile IP Multi-homed Hosts
Correspondent Host
Berkeley CS
Home Agent
IPhome
Internet
Route Optimization
Choice of routing path based on Bandwidth
Latency Coverage Load
P(Retranmission) Cost
Sockets
Stanford CS
TCP/UDP
Overlay IP
IPx
Metri- com
CDPD
Mobile Subnet
Vertical Handoff
Link Layer
Wireless Subnet
IPy
IPz
Wireless Subnet
Physical Layer
37
Low Latency Handoff
Home Agent
Multicast Tunnel
Use hints about terminal trajectory to form MC
groups Multicast packets to regional base
stations to smooth hand-offs for
R/T streams Minimize location update traffic to
home agent and mobility aware CHs
Foreign Agent
Local Multicast Group
Packet Video Steam
Base Station
Base Station
38
Reliable Mobile TransportSnoop Packet Filter
TCP-aware agent at BS End-to-end semantics
unchanged
Local retransmissions
TCP acks
Nack lost packets
Retransmit
Cache unacknowledged packets at BS (costs extra
soft state) Perform local retransmissions based
on duplicate acks time outs Base station
explicitly NACKs lost packets from MH using
Selective Ack (SACK) mechanism
39
Video Stream Proxy Video Gateway
Layered DCT
JPEG Decoder
LDCT Encoder
High Bandwidth Audio/Video Stream 1 - 2 mbps
H.261 Decoder
H.261 Encoder
Ipadvq Encoder
Nv Decoder
128 kbps 256 kbps
Infopad VQ
Heterogeneous Video Conferencing Environments RTP
knowledgeable multicast-to-unicast routing
40
Web Proxy On-Demand Distillation
78 colors, 49K bytes
16 colors, 12K bytes, lt6 sec.
4 grays, 530 bytes, lt2 sec.
gt256 colors, 759K bytes (1024x768)
  • Lossy compression that preserves semantic content
  • Each transcoder is datatype-specific, and not
    just images Postscript to HTML Compressed
    HTML Progressive Map Refinement
  • Distillation works in real time on desktop PCs

41
PDA Applications
  • Integrate PDA islands with desktop/wireline
    world via Internet standards
  • Proxy Mail Virtual folders, MIME images,
    graceful disconnection
  • Proxy architecture for authentication, white board

42
Scalable Proxy Architecture

html
gif
jpg

Cache control

Front End
PTM
Control Panel
To Internet
NOW Cluster
SAN (high speed)
Cache partition

Utility (10baseT)
Datatype-specific distiller
...
Coordination bus
43
Asymmetric Networks
  • Many wide-area networks are asymmetric
  • Applications induce asymmetries
  • Reverse channel bandwidth, losses, congestion, or
    delay variability severely limit connection
    throughput
  • Fairness problems for connections with large
    bandwidth-delay products at bottleneck links
  • Techniques Ack Congestion Control, Ack
    Filtering, Sender Adaptation, Ack Reconstruction

44
ns Simulator Extensions
  • Steve McCannes event-based network simulator ns
  • Extensively used by Internet engineering
    community for wide-area network design at routing
    layer and above
  • New version ns-2, more object-oriented
  • Our extensions
  • Ported transport models from ns-1 to ns-2
  • Extensive development of new LAN and wireless
    network models
  • MAC protocols CSMA/CA, CSMA/CD (Ethernet-like),
    IEEE 802.11, RTS/CTS-based protocols for multihop
    packet radio networks (Metricom-like)
  • Variety of link-layer protocols (stop-and-wait,
    go back n, snoop agent)
  • Scheduling algorithms in Router LAN interface
    queues
  • Shared channel with wireless error models (CSDP)
  • TCP router scheduling for asymmetric networks
  • Support for tracing TCP state variables
  • WWW traffic generator based on Mahs INSANE
    simulator

45
Recent Publications(since July)
  • Seshan, Stemm, Katz, SPAND Shared Passive
    Network Performance Discovery, USITS '97,
    Monterey, CA, December 1997.
  • Gribble, Brewer, System Design Issues for
    Internet Middleware Services Deductions from a
    Large ClientTraces, USITS97, Monterey,
    California, December 1997.
  • Fox, Gribble, Chawathe, Polito, Huang, Ling,
    Brewer, Orthogonal Extensions to the WWW User
    Interface Using Client-Side Technologies, Proc.
    10th Annual Symposium on User Interface Software
    and Technology (UIST 97), October 1997, Banff,
    Canada.
  • Fox, Gribble, Chawathe, Brewer, Cluster-Based
    Scalable Network Services, Proc. 1997 Symposium
    on Operating Systems Principles (SOSP-16),
    St-Malo, France, (Oct. 1997).
  • Balakrishnan, Padmanabhan, Seshan, Stemm, Amir,
    Katz, TCP Improvements for Heterogeneous
    Networks The Daedalus Approach, Proc. 35th
    Annual Allerton Conference on Communication,
    Control, and Computing, Urbana, Illinois, October
    1997.
  • Henderson , Katz. Satellite Transport Protocol
    An SSCOP-based Transport Protocol for Datagram
    Satellite Networks, Proceedings of 2nd
    International Workshop on Satellite-based
    Information Systems, (WOSBIS 97), Budapest,
    Hungary, October 1997.
  • Hodes, Katz, Servan-Schreiber, Rowe, Composable
    Ad-hoc Mobile Services for Universal
    Interaction, Proceedings of 3rd ACM/IEEE
    MobiCom, Budapest, Hungary, September 1997. Best
    Student Paper Award.
  • Balakrishnan, Padmanabhan, Katz, The Effects of
    Asymmetry on TCP Performance, Proceedings of 3rd
    ACM/IEEE MobiCom, Budapest, Hungary, September
    1997.
  • Noble, Satyanarayanan, Nguyen, Katz, Trace-based
    Mobile Network Emulation, Proceedings of ACM
    SIGCOMM'97, Cannes, France, September 1997.
  • Stemm, Katz, Measuring and Reducing Energy
    Consumption of Network Interfaces in Hand-Held
    Devices, IEICE (Institute of Electronics,
    Information and Communication Engineers)
    Transactions on Communications, Special Issue on
    Mobile Computing, V. E 80-B, No. 8, (August
    1997), pp. 1125-1131.

46
Major Recent Research Activities
  • Application Support
  • Extensibility of the Proxy Service model
  • WingMan Browser, MASH MediaBoard/Proxy
    integration, many new aggregation and annotation
    services
  • Overlay Networks
  • Satellite Transport Protocol
  • Multicast over Satellite (Hughes)
  • TCP enhancements support for asymmetric
    connections, integrated congestion control and
    loss recovery, short transaction transport
    connections, session-orientation
  • Application-Network Interaction
  • Shared Passive Network Performance Discovery
  • Mobility Service Architecture and Service
    Discovery in MASH CoLab

47
Wingman Browser
  • Proxy-enabled web browser for thin clients
  • Page layout determined on proxy side
  • Full distillation, refinement support
  • Thin drawing layer on PDA side

48
Satellite TransportProtocol(collaboration with
Hughes)
  • Most of our work done in the concept of TCP, but
  • Satellite links are not like WLANs
  • Very high latency, well protected link, high
    bandwidth
  • Strategies borrowed from ATM SSCOP
  • Poll/Stat handshake
  • Receiver explicitly requests retransmissions
  • Sender polls receiver for successfully received
    packets
  • Performance
  • Throughput about the same as TCP
  • Dramatically lower return link b/w demands
    insensitive to variations in round trip delay
  • Excellent fit with DBS/asymmetric bandwidth

49
Shared PassivePerformance Discovery(Collaboratio
n with IBM)
  • Passive piggy back performance data collection
    on on-going accesses, measure bandwidth, latency,
    packet loss, etc.
  • Shared share collected information with other
    nearby users
  • Enables applications to adapt to network
    performance in advance
  • Running at IBM Watson and Berkeley

50
Service Discovery
  • Adapt device functionality to services in new
    environment
  • Beacon augmentation
  • Adaptive user interfaces
  • Composed behaviors
  • Deployment within Soda classrooms and MASH CoLab
  • Light, video, slide projector, VCR, audio
    receiver, camera, monitor, A/V switcher control
  • Local DNS/NTP/SMTP servers, HTTP proxies,
    RTP/multicast gateways
  • Audited printer access
  • Interactive floor maps, protocols for advertising
    object locations
  • Coarse-grained user tracking

Universal Interaction?
51
Presentation Outline
  • Retreat Purpose and Agenda
  • Project Objectives, Motivation, and Approach
  • Project and Testbed Status
  • Technology Developments
  • Review Project Plan
  • New Directions
  • Summary and Conclusions

52
Six Month Plan (to Dec 97)
  • Documentation
  • Finish Scaled Architecture Document (DRAFT
    available)
  • Draft comprehensive system architecture and
    evaluation paper
  • Implementation for Scalability/Extensibility
  • Scalable Proxy Architecture
  • Demonstrate ease of adding new proxy services
  • Extend proxy support for Pilot PDAs
  • Implement, Test, Evaluate Strategies for Network
    Scaling
  • Link Scheduling
  • New Transport Protocols implemented in
    PR/Wireless Cable
  • Network Connection Monitoring Delivery Classes
  • Extend Testbed
  • With Ericssons assistance, integrate GSM
    wide-area connectivity
  • GloMo-Wide Eye Watering Demo
  • Extensive use of proxies, distribution of VHO code

53
Original Research Plan
9/95 - 8/96
9/96 - 8/97
9/97 - 8/98
54
DARPA GloMo Program Goals
DARPA GloMo FY 96 Adaptive Mobile Internet
Services Location Transparent Computing FY
97 Demo B/W Adaptive MM Node Demo Advanced
Mobile Networking FY 98 Demo Multimedia
Conferencing Demo Continuous Mobility
Daedalus/BARWAN Program Measure/eval overlay
networking tech Design overlay network
architecture Design proxy architecture, API,
toolkit Prototype proxies for image, video,
maps Design Scalable Proxies/Proxy Trans
Mgr Arch for Remote Collaboration by Proxy
Overlay IP and Vertical Handoff Reliable
transport for hetero/asym nets Demo scalable
processing for proxies Demo seamless roaming over
in-building, wide-area wireless overlays
55
Revised Project Schedule
Measure Eval Wireless Ovrly Technologies
Demo in-building ovrlys h/os with dynamic b/w
alloc
Demo wide-area ovrlys low latency h/os w/
scalable performance
Aug 95 Start
Aug 96
Aug 97
Aug 98 End
Early Prototype Proxies (1-10 users)
Proto Scaled Proxies (100-1000 Users)
Scaled Proxies (1000-10000 Users)
Large Scale Scalability Demonstrations
Initial Architectural Specification
Scaled Architectural Specification
on 10 UltraSparc cluster
56
Milestones to End of Contract
  • 3Q97
  • Final Architectural Specification (slipped to
    1Q98)
  • Integrated wireless simulation environment based
    on ns
  • 4Q97
  • Demonstration of network scaling in WLAN
    environment
  • Demonstration of network scaling in PR
    environment
  • 1Q98
  • Demonstration of scalable, extensible TACC
    (Transformation, Aggregation, Customization,
    Caching) Servers
  • 2Q98
  • Integrated demonstration of wireless networking,
    real-time conferencing, proxy adaptation,
    integrated into GloMo Eye Watering Demo

57
What We Proposed to Do
58
What We Proposed to Do
  • Seamless integration of overlay networks
  • Handoff
  • Low latency handoff via user tracking
  • Vertical handoff (power vs. latency)
  • Policy-based VHO
  • Transport
  • TCP over high error rate links (snoop)
  • Support services for mobile applications
  • Data type specific compression (proxy
    distillation) and progressive transmission
  • Dynamic applications partitioning across wireless
    links (service discovery and adaptation wingman
    browser)
  • Integration of multimedia and web applications
    with wireless environment (vic/vat, browser)

59
What We Proposed to Do
  • Managing mobile connections to support
    latency-sensitive applications
  • Link scheduling, class-based queuing
  • Real-time stream adaptation (RTP gateway)
  • Load balancing for scalable mobile processing
  • Network load balancing across overlay networks
  • Network servers to support processing and
    storage-intensive applications (NOW
    integration/TranSend)
  • Uniform architecture for applications support
    (TACC programming model )

60
Bonuses Beyond the Proposal
  • Research Infrastructure
  • VINT-based simulation environment
  • Mobile and home IP trace collection
  • Asymmetric Transport
  • TCP enhancements for bandwidth, latency, error
    asymmetries in PR, wireless cable, DBS
    subnetworks
  • Satellite Transport Protocol
  • Active Services Architecture
  • RTPGateways evolution into MediaGateway
  • Service discovery and adaptation
  • Scalable, Composible Service Architecture
  • TACC model
  • PalmPilot WingMan Browser

61
Technology Transfer Activities
  • Proxy Software
  • Beta TranSend binary distribution available
  • Distributed to UC Davis, SRI
  • Wingman Pilot Browser 8000 downloadsPostman
    Pilot E-mail 6000 downloads
  • RTP Gateway
  • 171 downloads in calendar 1997
  • Transport Layer Software
  • 100 snoop V1 downloads in calendar 1997
  • Ports to Linux, FreeBSD, NetBSD
  • 222 SACK downloads
  • Ports to NetBSD
  • snoop in daily production use in Reinas wireless
    network_at_UCSC
  • Wireless, LAN MAC, and Transport simulation
    modules distributed to VINT community

62
Presentation Outline
  • Retreat Purpose and Agenda
  • Project Objectives, Motivation, and Approach
  • Project and Testbed Status
  • Technology Developments
  • Review Project Plan
  • New Directions
  • Summary and Conclusions

63
Project Synergies
BARWAN Wireless Overlay Networks Scalable Proxies
TranSend/TACC
ProActive Infrastructure Scalable, Secure
Services Computation in the Network Smart
Spaces as an app Event-Response Programmable
Access
RTPGateway Service Discovery
vic, vat, wb
MASH Collaboration Applications Active Services
MASH Toolkit
64
ProActive Infrastructure
Smart Spaces
Active Routers Active network routers Soft
state Interchangeable
Bases Scalable, available servers Persistent
state Service discovery Public-key
infrastructure Databases
Home Base User state E-mail User tracking
Units Client Devices Sensors Actuators
65
ProActive Infrastructure(Brewer, PI Culler,
Joseph, Katz, Co-PIs)
  • The Challenge
  • Network-based applications becoming increasingly
    service intensive
  • Computational resources embedded in the switching
    fabric
  • Dealing with heterogeneity, true utility
    functionality, security, service discovery
  • The Approach
  • Build on BARWAN Proxies and MASH Active Services
  • Computational Elements
  • Units diverse end devices, from laptops to
    sensors actuators
  • Active Routers points of attachment, support for
    limited capability units, think home base
    station
  • Bases large centers of storage computation
    shared among many users
  • Computational Model
  • Connectors, Objects, Functions, Paths

66
Beyond Third Generation
VLR
HLR
AUC
EIR
GSM Core (IP-Based)
HA FA
BS
BSC
GW
GW
Next Generation Internet
Corporate Intranetwork
Proxy Server
  • Convergence of cellular and Internet technology
  • Focus on services in telephony context and
    beyond
  • Mobility, Link Performance Optimization, New Apps
    and Services

67
Presentation Outline
  • Retreat Purpose and Agenda
  • Project Objectives, Motivation, and Approach
  • Project and Testbed Status
  • Technology Developments
  • Review Project Plan
  • New Directions
  • Summary and Conclusions

68
Summary and Conclusions
  • Objective a complete network and application
    support architecture for access across lossy
    links from a wide variety of end devices
  • Access is the killer app
  • Seamless connectivity through wireless overlays
  • Adaptivity through proxy services
  • Dealing with heterogeneity, asymmetry, adaptation
  • Asymmetric bandwidth in satellites, cable modems,
    cellular systems new transport protocol
    techniques
  • High loss links achieving high bandwidth
    utilization through local intelligent
    retransmission
  • Adapt representations to the quality of the end
    device and its network connectivity proxies for
    audio/video streams and imageful web documents
  • New direction scalable, available, programmable,
    secure services for heterogeneous devices
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