Recent years have seen the advent of new RF-localization systems that demonstrate tens centimeters accuracy. However, such require either deployment infrastructure, or extensive fingerprinting environment through training crowdsourcing, impeding their wide-scale adoption.

We present joint multi-user beamforming (JMB), a system that enables independent access points (APs) to beamform their signals, and communicate with clients on the same channel as if they were one large MIMO transmitter. The key enabling technology behind JMB is new low-overhead technique for synchronizing phase of multiple transmitters in distributed manner. design allows wireless LAN scale its throughput by continually adding more APs channel. implemented tested both software radio...

Low-Power Wide Area Networks (LP-WANs) are an attractive emerging platform to connect the Internet-of-things. LP-WANs enable low-cost devices with a 10-year battery communicate at few kbps base station, kilometers away. But deploying in large urban environments is challenging, given sheer density of nodes that causes interference, coupled attenuation from buildings limits signal range. Yet, state-of-the-art techniques address these limitations demand inordinate hardware complexity stations...

Despite the rapid growth of next-generation cellular networks, researchers and end-users today have limited visibility into performance problems these networks. As LTE deployments move towards femto pico cells, even operators struggle to fully understand propagation interference patterns affecting their service, particularly indoors. This paper introduces LTEye, first open platform monitor analyze radio at a fine temporal spatial granularity. LTEye accesses PHY layer without requiring...

This paper focuses on a simple, yet fundamental question: ``Can node infer the wireless channels one frequency band by observing different band?'' question arises in cellular networks, where uplink and downlink operate frequencies. Addressing this is critical for deployment of key 5G solutions such as massive MIMO, multi-user distributed which require channel state information.

Despite the rapid growth of next-generation cellular networks, researchers and end-users today have limited visibility into performance problems these networks. As LTE deployments move towards femto pico cells, even operators struggle to fully understand propagation interference patterns affecting their service, particularly indoors. This paper introduces LTEye, first open platform monitor analyze radio at a fine temporal spatial granularity. LTEye accesses PHY layer without requiring...

Low-Power Wide-Area Networks (LPWANs) are an emerging wireless platform which can support battery-powered devices lasting 10-years while communicating at low data-rates to gateways several kilometers away. Not all such will experience the promised 10 year battery life despite high density of LPWAN expected in cities. Transmission from located deep within buildings or remote neighborhoods suffer severe attenuation forcing use slow reach even closest gateway, thus resulting drain. This paper...

Adaptive HTTP video streaming over LTE has been gaining popularity due to LTE's high capacity. Quality of adaptive depends highly on the accuracy client's estimation end-to-end network bandwidth, which is challenging link dynamics. In this paper, we present piStream, that allows a client efficiently monitor basestation's PHY-layer resource allocation, and then map such information an available bandwidth. Given PHY-informed bandwidth estimation, piStream uses probabilistic algorithm balance...

At its peak, the Internet-of-Things will largely be composed of low-power devices with wireless radios attached. Yet, secure authentication these amidst adversaries much higher power and computational capability remains a challenge, even for advanced cryptographic security protocols. For instance, high-power software radio could simply replay chunks signals from device to emulate it. This paper presents deep-learning classifier that learns hardware imperfections are challenging emulate,...

This paper presents Millimetro, an ultra-low-power tag that can be localized at high accuracy over extended distances. We develop Millimetro in the context of autonomous driving to efficiently localize roadside infrastructure such as lane markers and road signs, even if obscured from view, where visual sensing fails. While RF-based localization offers a natural solution, current systems struggle operate accurately ranges under strict latency requirements. addresses this challenge by re-using...

This paper explores a machine learning approach on data from single-chip mmWave radar for generating high resolution point clouds – key sensing primitive robotic applications such as mapping, odometry and localization. Unlike lidar vision-based systems, can operate in harsh environments see through occlusions like smoke, fog, dust. Unfortunately, current processing techniques offer poor spatial compared to clouds. presents RadarHD, an end-to-end neural network that constructs lidar-like low...

We demonstrate the phase locking of a 2.7 THz metal-metal waveguide quantum cascade laser (QCL) to an external microwave signal. The reference is 15th harmonic, generated by semiconductor superlattice nonlinear device, signal at 182 GHz, which itself multiplier chain (×12) from synthesizer ~15 GHz. Both and radiations are coupled into bolometer mixer, resulting in beat signal, fed phase-lock loop. spectral analysis confirms that QCL locked. This result opens possibility extend heterodyne...

Recent years have seen major innovations in cross-layer wireless designs. Despite demonstrating significant throughput gains, hardly any of these technologies made it into real networks. Deploying requires adoption from Wi-Fi chip manufacturers. Yet, manufacturers hesitate to undertake investments without a better understanding how designs interact with networks and applications.

This paper presents Carcel, a cloud-assisted system for autonomous driving. Carcel enables the cloud to have access sensor data from vehicles as well roadside infrastructure. The assists that use this avoid obstacles such pedestrians and other may not be directly detected by sensors on vehicle. Further, plan efficient paths account unexpected events road-work or accidents.

This paper introduces CarSpeak, a communication system for autonomous driving. CarSpeak enables car to query and access sensory information captured by other cars in manner similar how it accesses from its local sensors. adopts content-centric approach where objects -- i.e., regions along the road are first class citizens. It names using multi-resolution system, which allows scale amount of transmitted data with available bandwidth. also changes MAC protocol so that, instead having nodes...

We introduce RF-Wear, an accurate and wearable solution to track movements of a user's body using passive RFIDs embedded in their clothing. RF-Wear processes wireless signals reflected off these tags compact single-antenna RFID reader the pocket. In doing so, enables first-of-its-kind body-frame tracking mechanism that is lightweight convenient for day-to-day use, without relying on external infrastructure. At heart novel primitive computes angles between different parts attached them....

This paper introduces CarSpeak, a communication system for autonomous driving. CarSpeak enables car to query and access sensory information captured by other cars in manner similar how it accesses from its local sensors. adopts content-centric approach where objects -- i.e., regions along the road are first class citizens. It names using multi-resolution system, which allows scale amount of transmitted data with available bandwidth. also changes MAC protocol so that, instead having nodes...

We consider the problem of satisfying communication demands in a multi-agent system where several robots cooperate on task and fixed subset agents act as mobile routers. Our goal is to position team robotic routers provide coverage remaining client robots. allow for dynamic environments variable demands, thus necessitating an adaptive solution. present innovative method that calculates mapping between robot’s current signal strength it receives along each spatial direction, its wireless...

This paper presents WiSh, a solution that makes ordinary surfaces shape-aware, relaying their real-time geometry directly to user's handheld device. WiSh achieves this using inexpensive, light-weight and battery-free RFID tags attached these tracked from compact single-antenna reader. In doing so, enables several novel applications: shape-aware clothing can detect posture, interactive toys or even bridges report structural health.

Wireless sensing has demonstrated the potential of using Wi-Fi signals to track people and objects, even behind walls.Yet, prior work in this space aims merely detect presence objects around corners, rather than their type. In paper, we explore feasibility following re-search question: ?Can commodity radios both location type moving them?". We present IntuWition, a complementary system that can sense material environment, including those out line-of-sight. It achieves by wireless reflected...

Innovations in healthcare, diagnostics, sensors and data analysis with Artificial Intelligence (AI) learning / recommendations offer opportunities for improved personalized lower costs benefits to the medical industry. The age of human health monitoring has begun. Human using fluidic diagnostic monitoring, non-invasive sensors, wearables (electronic sensors), implanted sound, visual images, combinations these trends individuals healthcare guidance. data, analytics from solutions are...

Robust, wide-area sensing of human environments has been a long-standing research goal. We present Sozu, new low-cost system that can detect wide range events wirelessly, through walls and without line sight, at whole-building scale. To achieve this in battery-free manner, Sozu tags convert energy from activities they sense into RF broadcasts, acting like miniature self-powered radio stations. describe the results series iterative studies, culminating deployment study with 30 instrumented...

This paper presents an RF-based assistive technology for voice impairments (i.e., dysphonia), which occurs in estimated 1% of the global population. We specifically focus on acquired disorders where users continue to be able make facial and lip gestures associated with speech. Despite rich literature technologies this space, there remains a gap solution that neither requires external infrastructure environment, battery-powered sensors skin or body-worn manual input devices. present RFTattoo,...