The rapid growth of UAV-enabled low-altitude networks (LANs) increases the demand for secure data sharing to support mission-critical applications, yet existing solutions struggle with LANs dynamics, quantum vulnerabilities of traditional cryptography, and unbalanced accountability-privacy. To address these gaps, a blockchain-based privacy-preserving (BCPP) model has been introduced for UAV data sharing in LANs, with three key components: 1) a consortium blockchain optimized for UAV mobility, which replaces centralized trust with distributed consensus to ensure data integrity without single-point dependencies; 2) a novel lattice-based certificateless undeniable signature (CL-US) scheme built on the Ring-Learning With Errors (Ring- LWE) problem—this scheme binds UAV senders/receivers to data transmission for accountability while using pseudonymous identifiers to protect identity privacy. Formal security analysis under the random oracle model (ROM) proves that the proposed CL-US scheme achieves soundness and unforgeability against adaptive chosen-message attacks under the hardness assumption of the Ring-LWE problem. The performance evaluations of the key size and time consumption show that this CL-US scheme is efficient and storage-saving to similar schemes. This work provides a quantum-resilient solution balancing non-repudiation, privacy, and efficiency for dynamic LANs, laying a foundation for secure post-quantum LANs deployment in mission-critical scenarios.

This paper presents MARVEL, a mobile augmented reality (MAR) system which provides a notation display service with imperceptible latency (<100 ms) and low energy consumption on regular mobile devices. In contrast to conventional MAR systems, which recognize objects using image-based computations performed in the cloud, MARVEL mainly utilizes a mobile device's local inertial sensors for recognizing and tracking multiple objects, while computing local optical flow and offloading images only when necessary. We propose a system architecture which uses local inertial tracking, local optical flow, and visual tracking in the cloud synergistically. On top of that, we investigate how to minimize the overhead for image computation and offloading. We have implemented and deployed a holistic prototype system in a commercial building and evaluate MARVEL's performance. The efficient use of a mobile device's capabilities lowers latency and energy consumption without sacrificing accuracy.

The emergence of low-power 32-bit Systems-on-Chip (SoCs), which integrate a 32-bit MCU, radio, and flash, presents an opportunity to re-examine design points and trade-offs at all levels of the system architecture of networked sensors. To this end, we develop a post-SoC/32-bit design point called Hamilton, showing that using integrated components enables a ~$7 core and shifts hardware modularity to design time. We study the interaction between hardware and embedded operating systems, identifying that (1) post-SoC motes provide lower idle current (5.9 μA) than traditional 16-bit motes, (2) 32-bit MCUs are a major energy consumer (e.g., tick increases idle current >50 times), comparable to radios, and (3) thread-based concurrency is viable, requiring only 8.3 μs of context switch time. We design a system architecture, based on a tickless multithreading operating system, with cooperative/adaptive clocking, advanced sensor abstraction, and preemptive packet processing. Its efficient MCU control improves concurrency with ~30% less energy consumption. Together, these developments set the system architecture for networked sensors in a new direction.

Operating systems and applications in the built environment have relied upon central authorization and management mechanisms that restrict their scalability, especially with respect to administrative overhead. We propose a new set of primitives encompassing syndication, security, and service execution that unifies the management of applications and services across the built environment, while enabling participants to individually delegate privilege across multiple administrative domains with no loss of security or manageability. We show how to leverage a decentralized authorization syndication platform to extend the design of building operating systems beyond the single administrative domain of a building. The authorization system leveraged is based on blockchain smart contracts to permit decentralized and democratized delegation of authorization without central trust. Upon this, a publish/subscribe syndication tier and a containerized service execution environment are constructed. Combined, these mechanisms solve problems of delegation, federation, device protection and service execution that arise throughout the built environment. We leverage a high-fidelity city-scale emulation to verify the scalability of the authorization tier, and briefly describe a prototypical democratized operating system for the built environment using this foundation. This is an extension of work presented in Ref. [3].

Network traffic prioritization is gaining attention in the WSN community, as more and more features are being integrated into sensor networks. Real-world deployment experience suggests that WSN brings new challenges to existing problems, such as resource constraints, low data-rate radios, and diverse application scenarios. We present the RushNet framework that prioritizes two common traffic patterns in multi-hop sensor networks: low-priority (LP) traffic that is large-volume but delay-tolerant, and high-priority (HP) traffic that is sporadic but latency-sensitive. RushNet achieves schedule-free and coordination-free delivery differentiations with the following features. First, RushNet works with most data collection protocols to deliver LP traffic. Second, RushNet leverages transmission power difference and radio capture effect to implement on-demand HP packet delivery with low overhead. Third, RushNet proposes a retrodiction technique to help nodes minimize the overhead of recovering LP packet loss due to concurrent HP traffic. We evaluate RushNet performance with micro-benchmarks and a crowdsourced office comfort monitoring deployment. The deployment results suggest RushNet can achieve a throughput close to network capacity, and deliver 98% of the HP packets with a latency of less than four seconds.

Many indoor sensing applications leverage knowledge of relative proximity among physical objects and humans, such as the notion of "within arm's reach". In this paper, we quantify this notion using "proximity zone", and propose a methodology that empirically and systematically compare the proximity zones created by various wireless technologies. We find that existing technologies such as 802.15.4, Bluetooth Low Energy (BLE), and RFID fall short on metrics such as boundary sharpness, robustness against interference, and obstacle penetration. We then present the design and evaluation of a wireless proximity detection platform based on magnetic induction - LiveSynergy. LiveSynergy provides sweet spot for indoor applications that require reliable and precise proximity detection. Finally, we present the design and evaluation of an end-to-end system, deployed inside a large food court to offer context-aware and personalized advertisements and diet suggestions at a per-counter granularity.

The maturity and availability of network protocols have enabled wireless sensor networks (WSN) designers to build heterogeneous applications by composing different protocols. A common heterogeneous application combines data collection and dissemination for environmental monitoring with node retasking. While these co-located protocols on the same node have different goals, many of them share requirements and characteristics. Examples of commonalities include the use of bi-directional traffic for reliable transmissions and tree for packet routing. This work explores how the MAC layer can reduce the network transmission overhead of heterogeneous applications by taking advantage of protocol commonalities to aggregate outgoing packets. In other words, this aggregation creates a train of packets destined to the same receiver. Finally, we discuss a strawman implementation of packet train and how our data center monitoring deployment leverages it.

Future ubiquitous home environments can contain 10s or 100s of devices. Ubiquitous services running on these devices (i.e. localizing users, routing, security algorithms) will commonly require an accurate location of each device. In order to obtain these locations, existing techniques require either a manual survey, active sound sources, or estimation using wireless radios. These techniques, however, need additional hardware capabilities and are intrusive to the user. Non-intrusive, automatic localization of ubiquitous computing devices in the home has the potential to greatly facilitate device deployments.

In this demonstration, we present the architecture, implementation, and applications of LiveSynergy --- a system that provides reliable proximity sensing and open interactive abstractions for physical spaces and objects, to enable rich interactions between humans and their environment.