Videos
Peter Lee Address to Summer School 2014 Attendees
Peter Lee Address to Summer School 2014 Attendees
Peter Lee
00:44:10 · 1 July 2014

Software defined radios are a powerful tool for experimenting with wireless PHY and MAC layers. At the same time, they are a challenging programming environment, given tight timing constraints imposed. A student who wants to venture in this area of research needs to master computer architecture and hardware, as well as numerous algorithms for signal processing and communication. In this lecture we will talk about Ziria, a programming language and a compiler that we have recently developed to simplify this task. Ziria is a high-level language, specialized for PHY design, that delegates most of the burdensome hardware optimization to the compiler and allows us to keep the code design clean and simple. We will walk through various building blocks of Wifi PHY design and show how to implement them in Ziria. At the end of the talk you should be able to understand the signal processing foundations of WiFi as well as to quickly implement and deploy your own PHY using Ziria. Ziria compiler is open sourced so you will be able to download it and play with the code yourselves. It currently supports Sora SDR platform but could be easily adapted to other similar platforms.

Ziria: Wireless Programming for Hardware Dummies - Part 3
Ziria: Wireless Programming for Hardware Dummies - Part 3
Bozidar Radunovic
00:58:21 · 1 July 2014

Software defined radios are a powerful tool for experimenting with wireless PHY and MAC layers. At the same time, they are a challenging programming environment, given tight timing constraints imposed. A student who wants to venture in this area of research needs to master computer architecture and hardware, as well as numerous algorithms for signal processing and communication. In this lecture we will talk about Ziria, a programming language and a compiler that we have recently developed to simplify this task. Ziria is a high-level language, specialized for PHY design, that delegates most of the burdensome hardware optimization to the compiler and allows us to keep the code design clean and simple. We will walk through various building blocks of Wifi PHY design and show how to implement them in Ziria. At the end of the talk you should be able to understand the signal processing foundations of WiFi as well as to quickly implement and deploy your own PHY using Ziria. Ziria compiler is open sourced so you will be able to download it and play with the code yourselves. It currently supports Sora SDR platform but could be easily adapted to other similar platforms.

White Space Networking and Spectrum Sharing
White Space Networking and Spectrum Sharing
Sumit Roy
02:07:18 · 30 June 2014

The evolution of cognitive (secondary) networks to enable more efficient spectrum usage will rely on fast and accurate spectrum sensing/mapping, supported by a suitable architecture for data integration and model building. In the first part of the talk, fundamental aspects of the wide-area RF mapping problem as a grand challenge will be highlighted; and some recent work at UW that clarifies sub-system level trade-offs (between scan latency and channel status estimation accuracy, for example) will be described. Next, the evolution of a hybrid architecture - decentralized client-side sensing assisted database updating - is explored. Within this, model-based answers to fundamental questions such as 'how much white space capacity is available' as a function of location for U.S. TV bands are developed. The talk will conclude with a description of current efforts for spectrum sharing (co-existence) just underway in the 3 GHz band (broadly) between different primaries (largely government operated communications such as military and non-military radars) and commercial networks (802.11 and 4G LTE).

Ziria: Wireless Programming for Hardware Dummies - Part 2
Ziria: Wireless Programming for Hardware Dummies - Part 2
Bozidar Radunovic
00:55:52 · 30 June 2014

Software defined radios are a powerful tool for experimenting with wireless PHY and MAC layers. At the same time, they are a challenging programming environment, given tight timing constraints imposed. A student who wants to venture in this area of research needs to master computer architecture and hardware, as well as numerous algorithms for signal processing and communication. In this lecture we will talk about Ziria, a programming language and a compiler that we have recently developed to simplify this task. Ziria is a high-level language, specialized for PHY design, that delegates most of the burdensome hardware optimization to the compiler and allows us to keep the code design clean and simple. We will walk through various building blocks of Wifi PHY design and show how to implement them in Ziria. At the end of the talk you should be able to understand the signal processing foundations of WiFi as well as to quickly implement and deploy your own PHY using Ziria. Ziria compiler is open sourced so you will be able to download it and play with the code yourselves. It currently supports Sora SDR platform but could be easily adapted to other similar platforms.

Ziria: Wireless Programming for Hardware Dummies - Part 1
Ziria: Wireless Programming for Hardware Dummies - Part 1
Bozidar Radunovic
01:06:21 · 30 June 2014

Software defined radios are a powerful tool for experimenting with wireless PHY and MAC layers. At the same time, they are a challenging programming environment, given tight timing constraints imposed. A student who wants to venture in this area of research needs to master computer architecture and hardware, as well as numerous algorithms for signal processing and communication. In this lecture we will talk about Ziria, a programming language and a compiler that we have recently developed to simplify this task. Ziria is a high-level language, specialized for PHY design, that delegates most of the burdensome hardware optimization to the compiler and allows us to keep the code design clean and simple. We will walk through various building blocks of Wifi PHY design and show how to implement them in Ziria. At the end of the talk you should be able to understand the signal processing foundations of WiFi as well as to quickly implement and deploy your own PHY using Ziria. Ziria compiler is open sourced so you will be able to download it and play with the code yourselves. It currently supports Sora SDR platform but could be easily adapted to other similar platforms.

Antennas: Near and Far - Part 2
Antennas: Near and Far - Part 2
Ashutosh Sabharwal
01:18:32 · 27 June 2014

In this short course, we will take a closer look at antennas and their diverse methods of use in wireless networks. We will first review the traditional viewpoint of using antennas 1) antennas which are near-by, like in MIMO systems, are good and 2) antennas which are far-away, like in multiuser systems, cause interference and are problematic. Then we will review the ideas which have emerged in last decade 1') antennas which are near-by, like in full-duplex, are problematic, and 2') antennas which are far-away, like in cooperatively coded systems, are good. The contrasting viewpoints will help us appreciate that our understanding of wireless systems is far from complete, and wireless continues to be an active and vibrant area of research.

Course Lab: While the lectures will focus on concepts and pointers to ongoing research, the course has a lab component. Using a custom developed WARPCloud, each student will be conducting brief experiments to appreciate the basic concepts in MIMO, Interference, Cooperation and Full-duplex.

Acknowledgement: The WARPCloud was developed and provided by Mango Communications, especially for the Microsoft Summer School attendees. Special thanks to Dr. Patrick Murphy, Dr. Christopher Hunter and Mr. Erik Welsh of Mango Communications, who took time off their busy work schedules and contributed towards the important mission of free educational tools for all.

Spinal Codes
Spinal Codes
Kyle Jamieson
01:23:11 · 24 June 2014

Spinal codes ?(ACM SIGCOMM 2012) ?are a new class of rateless codes that enable wireless ?networks to cope with time-varying channel conditions in a natural way, without requiring any explicit bit rate selection. The key idea in the code is the sequential application of a pseudo-random hash function to the message bits to produce a sequence of coded symbols for transmission.

This encoding ensures that two input messages that differ in even one bit lead to very different coded sequences after the point at which they differ, providing good resilience to noise and bit errors. To decode spinal codes, this paper develops an ap- proximate maximum-likelihood decoder, called the bubble decoder, which runs in time polynomial in the message size and achieves the Shannon capacity over both additive white Gaussian noise (AWGN) and binary symmetric channel (BSC) models. Experimental results obtained from a software implementation of a linear-time decoder show that spinal codes achieve higher throughput than fixed-rate LDPC codes, rateless Raptor codes, and the layered rateless coding approach of Strider, across a range of channel conditions and message sizes.

Practical Partial Packet Recovery for 802.11: Maranello
Practical Partial Packet Recovery for 802.11: Maranello
Kyle Jamieson
01:04:00 · 24 June 2014

Phased array signal processing has long been employed outdoors in radar, underwater in sonar, and underground in seismic monitoring. But it has only recently made inroads indoors in the context of WiFi networks, where it must cope with strong multipath reflections, packetized data transmissions, and commodity hardware. I will begin by describing two systems my students and I have worked on: ArrayTrack (published at USENIX NSDI 2013), one of the first fine-grained indoor location systems, and SecureArray (published at ACM MobiCom 2013), one of the most effective physical-layer based security mechanisms for WiFi networks.

Bringing Phased Array Signal Processing Indoors to WiFi Networks
Bringing Phased Array Signal Processing Indoors to WiFi Networks
Kyle Jamieson
01:06:54 · 23 June 2014

Phased array signal processing has long been employed outdoors in radar, underwater in sonar, and underground in seismic monitoring. But it has only recently made inroads indoors in the context of WiFi networks, where it must cope with strong multipath reflections, packetized data transmissions, and commodity hardware. I will begin by describing two systems my students and I have worked on: ArrayTrack (published at USENIX NSDI 2013), one of the first fine-grained indoor location systems, and SecureArray (published at ACM MobiCom 2013), one of the most effective physical-layer based security mechanisms for WiFi networks.

Outpost: Creating Secure Execution Environments Without Secure Hardware
Outpost: Creating Secure Execution Environments Without Secure Hardware
Arvind Seshadri
01:06:36 · 15 June 2014

In this talk I present Outpost, a software-based primitive for attestable establishment of a root-of-trust-for-computing. Outpost creates an execution environment that guarantees untampered code execution even when the entire software stack of system (including the BIOS) is compromised, without requiring secure hardware support.

In contrast to Pioneer (our earlier work on the problem), which uses an adhoc attack-defense design strategy specific to the x86 architecture, Outpost uses a design strategy based on an architecture-portable hardware operational model. We use the insights obtained from a deep understanding of hardware architecture and operation across platforms to define the operational model. This design strategy ensures that Outpost is architecture-portable, is not vulnerable to any of the low-level attacks that Pioneer is vulnerable to, has a 15x higher attacker time overhead, and is amenable to formal reasoning about its security.

I conclude by sharing some thoughts on the important systems security problems in the era of cloud and mobile. I will also discuss how intelligently-defined hardware operational models in combination with creative retrofitting of the design and implementation of commodity systems might enable us to build commodity systems which are amenable to formal reasoning about their security properties.

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