【正文】 act ? 3Q97 – Final Architectural Specification (slipped to 1Q98) ? Integrated wireless simulation environment based on ns ? 4Q97 – Demonstration of work scaling in WLAN environment – Demonstration of work scaling in PR environment ? 1Q98 ? Demonstration of scalable, extensible TACC (Transformation, Aggregation, Customization, Caching) Servers ? 2Q98 – Integrated demonstration of wireless working, realtime 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 works – Handoff 187。 Low latency handoff via user tracking 187。 Vertical handoff (power vs. latency) 187。 Policybased VHO – Transport 187。 TCP over high error rate links (snoop) ? Support services for mobile applications – Data type specific pression (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 latencysensitive applications – Link scheduling, classbased queuing – Realtime stream adaptation (RTP gateway) ? Load balancing for scalable mobile processing – Network load balancing across overlay works – Network servers to support processing and storageintensive applications (NOW integration/TranSend) – Uniform architecture for applications support (TACC programming model ) 60 Bonuses Beyond the Proposal ? Research Infrastructure – VINTbased simulation environment – Mobile and home IP trace collection ? Asymmetric Transport – TCP enhancements for bandwidth, latency, error asymmetries in PR, wireless cable, DBS subworks – Satellite Transport Protocol ? Active Services Architecture – RTPGateway’s 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 187。 Distributed to UC Davis, SRI – Wingman Pilot Browser: 8000 downloads Postman Pilot Email: 6000 downloads ? RTP Gateway – 171 downloads in calendar 1997 ? Transport Layer Software – 100 snoop V1 downloads in calendar 1997 187。 Ports to Linux, FreeBSD, NetBSD – 222 SACK downloads 187。 Ports to NetBSD – snoop in daily production use in Reinas wireless work@UCSC ? Wireless, LAN MAC, and Transport simulation modules distributed to VINT munity 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 MASH Collaboration Applications Active Services ProActive Infrastructure Scalable, Secure Services Computation in the Network ―Smart Spaces‖ as an app EventResponse Programmable Access RTPGateway Service Discovery vic, vat, wb TranSend/TACC MASH Toolkit 64 ProActive Infrastructure Units: Client Devices Sensors amp。 Actuators Active Routers: Active work routers Soft state Interchangeable Bases: Scalable, available servers Persistent state Service discovery Publickey infrastructure Databases Home Base User state Email User tracking ―Smart Spaces‖ 65 ProActive Infrastructure (Brewer, PI。 Culler, Joseph, Katz, CoPIs) ? The Challenge – Networkbased applications being 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 187。 Units: diverse end devices, from laptops to sensors amp。 actuators 187。 Active Routers: points of attachment, support for limited capability units, think ―home base station‖ 187。 Bases: large centers of storage amp。 putation shared among many users – Computational Model 187。 Connectors, Objects, Functions, Paths 66 Beyond Third Generation ? Convergence of cellular and Inter technology ? Focus on services in telephony context and beyond: – Mobility, Link Performance Optimization, New Apps and Services Next Generation Inter BSC EIR AUC HLR VLR Corporate Intrawork GW GW BS HA FA Proxy Server GSM Core (IPBased) MSC 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 plete work 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 work connectivity: proxies for audio/video streams and imageful web documents ? New direction: scalable, available, programmable, secure services for heterogeneous devices