Emerging farming techniques rely on smart devices such as multi-spectral cameras that collect fine-grained data, and tele-operated robots that perform tasks such as de-weeding, berry-picking, etc. These networked farm applications (requiring 10s of Mbps of throughput per device to the edge servers, with tens to hundreds of devices in a typical farm) must be supported on a wireless mesh network with limited capacity. In this work, we use these networked farm applications as a compelling case-study to design FarmNetes, a centralized traffic engineering (TE) system for wireless mesh networks. FarmNetes leverages explicit control over farm workloads to make centralized TE decisions (temporal flow schedules, sending rates, load-aware routes, and channel configurations) from an edge server, so as to best meet task requirements. FarmNetes' centralized TE decisions enable it to work with commodity devices and control how the network is shared across flows based on the desired policies (prioritization and fairness) irrespective of the underlying MAC layer link sharing mechanisms. This further enables MAC-agnostic reasoning of wireless network behavior when making TE decisions. Our evaluation, using testbeds in a farm and trace-driven simulations, shows how FarmNetes achieves 3 × higher end-end network throughput and better meets application demands, compared to status-quo wireless mesh strategies.

The US Federal Aviation Administration (FAA) has recently mandated that small unmanned aerial vehicles (UAVs) be equipped with a transmitter that broadcasts the UAV's serial number, location, and altitude. The inclusion of a unique identifier in the form of a UAV serial number has stoked fears that the identifier will be used to track UAV operators and has even led some UAV operators to file a lawsuit against the FAA.

In this work, a novel self-powered visible light communication and positioning (SPVLCP) system is constructed, which can realize communication, positioning, and energy harvesting simultaneously. The resource allocation scheme applying orthogonal frequency division multiple (OFDM) modulation and the power splitting (PS) method is proposed for the SPVLCP system. Based on this scheme, a corresponding optimization allocation strategy is provided, aiming to maximize the data rate by optimizing the PS factor and the power allocated to subcarriers while ensuring positioning accuracy, harvested energy, and the LED transmit power. To solve the optimization issue, the successive convex approximation (SCA) algorithm and a series of equivalent substitutions are applied to convert the optimization issue from non-convex to convex. The findings demonstrated that the optimization allocation strategy can solve the trade-off problem among communication, positioning, and energy harvesting better than the uniform allocation strategy. Furthermore, the SCA-based algorithm has an obvious superiority over the conventional heuristic algorithm in solving the optimization issue for the proposed resource allocation scheme of the integrated SPVLCP system.

In order to suppress the nonlinearity impact of light‐emitting diodes (LEDs) on the performance of visible light communication (VLC), the combined method including companding and predistortion was proposed in this work. The modified companding and predistortion based on the LED characteristic analysis were used corresponding to the output current ‐input voltage (I‐V) and light output‐injected current (L‐I) nonlinearity, respectively. Using the combined method, the performances of the DC‐biased optical orthogonal frequency division multiplexing (DCO‐OFDM) VLC system were analysed. It is demonstrated that the non‐linear distortion of OFDM transmitted signal is alleviated, thus the received signal quality is increased. As a result, the bit error rate (BER) performance of VLC system is improved obviously by using the combined method of companding and predistortion. Furthermore, the applicability of this combined method is also verified by analysing the nonlinearity suppression of the VLC system using different LED. The results reveal that both the impact from LED's I‐V and L‐I nonlinearity can be alleviated using the proposed method combining from companding and predistortion for DCO‐OFDM VLC system.