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The Venice team and Microsoft Research have developed a mesh monitor and diagnostic tool on the Windows XP platform. The tool comprises two components: a data collection agent and a console. To ease configuration and maintenance, we use peer-to-peer framework for generating and consuming management data in a mesh network. Every mesh node running an agent feeds data into the P2P transport; any mesh node running a console automatically receive data from the different agents to construct a comprehensive view of the network topology and provide network information at various protocol layers. We also demonstrate the capability of detecting network congestion and random packet dropping using the tool.
Presenter: Ananth Rao
Ananth Rao is a PhD student at UC Berkeley, working under the advice of Ion Stoica. His research interests focus on wireless networking.
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Native WiFi is a wireless LAN framework that incorporates the IEEE 802.11 upper MAC functionality, lower MAC and PHY management and additional value adds in the Windows Operating System. The components of Native WiFi include: (1) a Native WiFi Mobile Station (STA), which can either be in infrastructure or ad hoc mode, and (2) a Native WiFi Access Point (AP), which is always in a infrastructure mode.
Native WiFi provides a unified infrastructure that allows for dynamic AP or STA configuration as long as the vendor provided thin miniport driver and hardware supports Native WiFi interfaces. The switching between AP to STA mode and vice-versa is handled via a quick software reset.
Native WiFi is an effort to effectively drive WiFi ubiquity and accelerate WiFi innovation on Windows. Further more it is targeted to improve WiFi end user experience, lower WiFi device and infrastructure deployments costs, and provide richer differentiated functionality in Windows by enhancing features like security, diagnostics, power management, roaming, load balancing, QoS and location awareness.
Presenters: Hui Shen, Jiandong Ruan
Hui Shen has worked with Microsoft since 2001 in networking areas, including Native WiFi, wireless network configuration and security, network diagnostics, and performance. He received a M.S. in Computer Science from Washington University St. Louis in 2001 and a Master in Computer Engineering from Chinese Academy of Sciences in 1999. He received his B.S. in Computer Science from Wuhan University, China in 1996
Jiandong Ruan has worked with Microsoft since 2000 in networking areas, including native WiFi, DHCP, NetBT and IPsec. He received a M.S. in Computer Science from Peking University in 1996 and a B.S in Chemical Engineering from Tsinghua University in 1993.
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There are a number of scenarios where it is desirable to have a wireless device connect to multiple networks simultaneously. Currently, this is possible only by using multiple wireless network cards in the device. Unfortunately, using multiple wireless cards causes excessive energy drain and consequent reduction of lifetime in battery operated devices. In this paper, we propose a software based approach, called MultiNet, which facilitates simultaneous connections to multiple networks by virtualizing a single wireless card. The wireless card is virtualized by introducing an intermediate layer below IP, which continuously switches the card across multiple networks. The goal of the switching algorithm is to be transparent to the user who sees her machine as being connected to multiple networks. Our MultiNet system has been operational for over twelve months, it is agnostic of the upper layer protocols, and works well over popular IEEE 802.11 wireless LAN cards.
Presenter: Ranveer Chandra
Ranveer Chandra is a PhD student in Computer Science at Cornell University. His research interests include wireless networking and distributed systems. He has received his B.Tech. in Computer Science and Engineering from IIT Kharagpur, and his M.S. in Computer Science from Cornell University. During the course of his PhD he has received the Microsoft Research Graduate Fellowship, and the Sage Fellowship for academic excellence at Cornell University.
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Capacity improvement is one of the principal challenges in wireless networking. We present a link-layer protocol called Slotted Seeded Channel Hopping, or SSCH, for increasing the capacity of an IEEE 802.11 network by exploiting frequency diversity. SSCH can be implemented in software over an IEEE 802.11-compliant wireless card. Each node using SSCH switches across channels in such a manner that nodes desiring to communicate overlap, while disjoint communications do not overlap, and hence do not interfere with each other. To achieve this, SSCH uses a novel scheme for distributed rendezvous and synchronization. Simulation results show that SSCH significantly increases network capacity in several multi-hop and single-hop wireless networking scenarios.
Presenter: Ranveer Chandra, John Dunagan
Ranveer Chandra is a PhD student in Computer Science at Cornell University. (see above)
John Dunagan received both his BS and PhD from MIT. His career at Microsoft Research has spanned the Theory Group, the Systems and Networking Group, and most recently the Systems Management Group. His current research is focused on improving the manageability of today’s deployed systems.
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The Location Platform is a new feature in the future Windows Operating System, code named Longhorn. The platform includes a Windows system service that provides applications with the physical location of the computer. It is built with several levels of extensibility including: (1) a location schema, which can be extended to cover any representation of a physical location, and (2) a plugin layer that IHVs and ISVs can build upon in order to inject location data into the service and thus to extend the capabilities of the location determination process.
We are going to showcase the value of the Location platform in a classic roaming scenario: moving between Home and Office locations.
Presenters: Tracey Yao and Florin Teodorescu
Tracey Yao is a Program Manager in the Windows Networking Product Division. Her current projects include the Longhorn location service and Network location awareness. She recieved a BSc Honors in Mathematics from Victoria University of Wellington, New Zealand in 2001 and a BSc. in Computer Science also from the Victoria University of Wellington, New Zealand in 2000
Florin Teodorescu: Graduated from Politehnical University of Bucharest, Romania in 1993. He received a M.S. from ENSIMAG France (Ecole Nationale Suprieure dInformatique et de Mathmatiques Appliques de Grenoble) in 1994. His research interested include performance evaluation and deterministic re-execution of distributed programs. He has been working for Microsoft since 1998 in various projects including network management, name resolution and more recently wireless networking and location.
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We show an integrated set of features for network QoS on Wireless 802.11 networks to support distributed audio-video scenarios. Our system includes host and client components designed to offer admission control, network monitoring and application adaptation for multiple high definitions streams simultaneously sharing home IP networks, especially wireless IEEE 802.11 networks.
Presenters: Tarek Elabbady
Tarek Elabbady is a lead program manager with Windows Networking group. He received his PhD from Purdue University in 1994 in electrical engineering. Hejoined Microsoft in 2000 to focus on Audio Video Home networking related initiatives. Tarek has co-authored several patents in the content sharing/access over IP home networks. He is currently managing a project to deliver networking technologies supporting distributed AV scenarios in the next release of Windows.
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We present an investigation into the performance of 802.11 when deployed in outdoor long range environments such as found in community network projects. We have studied the performance of the MAC through simulation and have deployed monitors in an outdoor production network in the Cambridge area. Our results highlight the impact of the hidden node problem in these networks when directional antennae are employed to increase range. As a solution we propose a simple modification to the 802.11 DCF protocol that improves throughput and fairness.
Presenter: Neil Stratford
Neil Stratford is a Researcher in the Networks & Performance group at Microsoft Research Cambridge. His research interests are in the area of improving wireless quality of service, bandwidth management and multiservice operating system resource management.
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We consider the threat imposed on network routing in “open” networks such as community wireless networks. The key characteristic of such networks is that it is relatively easy for users (and attackers) to add routers, establish (possibly wireless) links, and advertise routes. We argue that the traditional focus on securing the routing protocol is insufficient to address the threats arising in this environment. It is also important to secure packet forwarding. To this end, we apply a secure traceroute protocol to detect and localize faulty packet forwarding, which can aid problem resolution either via automatic rerouting or via human action. We present a security analysis of the protocol, discuss our implementation of it in a community wireless network testbed, and show that secure traceroute imposes a negligible overhead on performance.
Presenter: Venkat Padmanabhan
Venkat Padmanabhan is a Researcher in the Systems and Networking group at Microsoft Research. His research interests include wide-area and wireless networking, Internet performance, and mobile computing. His recent work has focused on peer-to-peer content distribution, wireless mesh networks, and network measurement & inference. Venkat serves on the editorial boards of the IEEE/ACM ToN and the IEEE TMC journals, is Program Co-Chair for ACM NOSSDAV 2004, was Tutorials Co-Chair for ACM Mobicom 2000, and has served on the program committees of several conferences including Sigcomm, Mobicom, Infocom, and Sigmetrics. He also holds affiliate faculty appointments in the CS and EE departments at the University of Washington, where he has taught and served on student thesis committees.