In a world driven by data, cities are increasingly interested in deploying networks of smart city devices for urban and environmental monitoring. To be successful, these networks must be reliable, scalable, real-time, low-cost, and easy to install and maintain -- criteria that are all significantly affected by the design choices around connectivity and power. LTE networks and solar energy can seemingly both satisfy the necessary criteria and are often used in real-world sensor network deployments. However, there have not been extensive real-world studies to examine how well such networks perform and the challenges they encounter in urban settings over long periods. In this work, we analyze the performance of a stationary 118-node LTE-connected, solar-powered sensor network over one year in Chicago. Results show the promise of LTE networks and solar panels for city-wide IoT deployments, but also reveal areas for improvement. Notably, we find 11 sites with inadequate RSS to support sensing nodes and over 33,000 hours of data loss due to solar energy availability issues between October and March. Furthermore, we discover that the neighborhoods most affected by connectivity and charging issues are socioeconomically disadvantaged areas with a majority Black and Latine residents. This work presents observations from a networking and powering perspective of the urban sensor network to help drive reliable, scalable future smart city deployments. The work also analyzes the impact of land use, adaptive energy harvesting management strategies, and shortcomings of open data, to support the need for increased real-world deployments that ensure the design of equitable smart city networks.

翻译：在数据驱动的世界中，城市对部署用于城市和环境监测的智慧城市设备网络兴趣日益浓厚。这些网络必须满足可靠性、可扩展性、实时性、低成本以及易于安装和维护等标准——而这些标准均受到连接性与供电设计选择的显著影响。LTE网络与太阳能看似都能满足上述必要条件，且常被应用于实际传感器网络部署中。然而，目前尚缺乏针对此类网络在长期城市环境中的性能表现及所遇挑战的大规模实地研究。本研究分析了一个由118个节点组成的固定式LTE连接太阳能供电传感器网络在芝加哥地区为期一年的运行表现。结果表明，LTE网络与太阳能板在城市级物联网部署中具有潜力，但也揭示了需要改进的领域。值得注意的是，我们发现有11个站点的RSS值不足以支持传感节点运行，且因10月至3月间太阳能可用性问题导致超过33,000小时的数据丢失。此外，我们发现受连接性与充电问题影响最严重的街区，正是以黑人和拉美裔居民为主的 socioeconomically disadvantaged 区域。本研究从网络与供电角度分析城市传感器网络的现状，以推动未来智慧城市部署的可靠性与可扩展性。工作还分析了土地利用的影响、自适应能量采集管理策略以及开放数据的不足，从而论证增加真实环境部署的必要性，以确保设计出公平的智慧城市网络。