Automated lab assistant and automated grading tools are commonly used to help manage student work in Computer Science lab sections. These tools can ease routine grading tasks and provide rapid and consistent feedback to inform student progress. However, we found their application lacking in our mid-level systems courses. To address this, we present a command-line interface (CLI) driven lab assistant and assessment tool designed specifically for this environment. We provide insights into our design choices and provide context and comparison of this system to other similar tools. Then we present results from using the tool since 2019. By easing routine tasks and common challenges, students and instructors both report uniformly positive reviews. At the same time, grading time is consistently lower than other similar courses while maintaining a humanized and personal student connection.

The Internet of Things (IoT) promises to allow everyday objects to connect to the Internet and seamlessly interact with users and other machines. For this vital Internet connection, most current IoT devices use a personal gateway device such as a smartphone or a home WiFi access point. The necessity of configuring and maintaining these gateways presents an additional burden for both users and developers of IoT applications. Our vision for IoT connectivity is to eliminate the need for the personal gateway by developing crowdsourced low-power wide area networks (csLPWAN). Recent technologies such as RPMA, LoRa, and R-FDMA enable links to reach 15km using ISM-band transceivers, making csLPWANs an attractive option. In this paper, we investigate the practicality of csLPWANs and develop the first csLPWAN planning tool, PlanIt, which combines topography-aware RF signal analysis with demographic data to predict LPWAN coverage in specific geographic areas. Using PlanIt, we find that most cities achieve 99% coverage by deploying a single LPWAN base station within the city. To provide better service on the csLPWAN, we propose and evaluate D-QN, a near-optimal MAC protocol to enable efficient bandwidth sharing in highly utilized networks. In the future, csLPWANs could accommodate a heterogeneous set of IoT applications, simplifying the IoT application development cycle, reducing total system cost, improving application reliability, and enhancing the user experience.

In the world of water resource management, commercially available hydroclimatic monitoring systems are large, expensive, and disconnected. The current technology is inaccessible to smaller community groups, citizen scientists, teachers, and even university researchers needing to collect real time or high density data. The HydroSense project aims to build an open-source hardware and software framework to enable hydroclimatic monitoring in a more cost effective manner. At present, several prototype system components have been designed, fabricated, and tested. Our design demonstrates that a complete hydroclimatic monitoring system can be deployed at 1/8th the cost of modern commercially available systems. Furthermore, we demonstrate the ability to interface with existing water quality sensors, allowing stakeholders the ability to use instruments they may already own.

Energy is a precious resource and as electronic devices (e.g., tablets, smart phones, Internet-connected appliances) and electric cars become ubiquitous, the demand for energy will continue to increase. To meet this demand and enable the integration of renewable resources, electrical distribution networks are beginning to adopt smart-grid technologies by providing bidirectional communication between the distribution grid and the electric meter. The question of how appliances within the home will interface with the smart-grid is still an open question. We propose to use wireless sensor networks as a platform to enable detailed household monitoring, demand response, load scheduling, occupancy-based control, intelligent lighting, and other general-purpose control strategies. In this vision, the smart-grid interface is a single input to the building control system which consists of a wide variety of other sensors and supports many applications that greatly extend the capabilities of the smart-grid. To explore this concept we have: developed efficient and accurate energy disaggregation algorithms, developed reliable multicast and broadcast network protocols, evaluated 10 strategies for energy savings, designed a WSN-based building monitoring and control platform, and evaluated this approach in both offices and a residential home.

We present PIM-WSN, a protocol independent multicast (PIM) protocol tailored for IPv6 wireless sensor networks (WSNs). Existing solutions for multicast in WSNs are limited because they either support multicast only from a single source node (usually the root node) or they limit the multicast group size to constrain memory usage. Our design allows any node to be a mulitcast source with an unlimited number of subscribers. We constrain the memory usage by approximating multicast group membership using a fixed sized Bloom filter. The efficiency of the protocol degrades as the false positive rate of the Bloom filter increases; however, correct operation is always maintained. Using detailed simulations we show that PIM-WSN achieves 1) high packet delivery rate (over 97%), 2) low latency per hop (less than 5 ms), and 3) lower radio utilization than all other comparable protocols (by more than 50%). Using a ten-hop testbed of TelosB motes we have verified our implementation of PIM-WSN for TinyOS 2.× with the Blip IPv6 networking stack which uses only 5,978 bytes of ROM and 235 bytes of RAM.