Latency of Concatenating Unlicensed LPWAN with Cellular IoT: An Experimental QoE Study
Latency of Concatenating Unlicensed LPWAN with Cellular IoT: An Experimental QoE Study
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将未经许可的 LPWAN 与蜂窝物联网连接的延迟：实验性 QoE 研究
DOI：
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发表时间：
2021
期刊：
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通讯作者：
Mouhamed Abdulla
中科院分区：
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作者：
A. Ramoutar;Z. Motamedi;Mouhamed Abdulla
开发高效采用、部署和维护的低功耗广域网（LPWAN）解决方案对于智慧城市至关重要。非授权LPWAN的服务质量差，以及LTE-M/NB-IoT的高服务成本是这些技术的关键缺点。将未经许可的LPWAN与许可的LPWAN相结合可以克服这些限制并利用它们的好处。然而，级联LPWAN架构将不可避免地导致可能影响用户体验质量（QoE）的过度延迟。为了评估该系统的实际可行性，我们首先提出了一个级联LPWAN架构，并通过实验测量了端到端（E2 E）延迟的统计数据。级联延迟裕度是通过用不同的LPWAN架构方案（即，用未授权IoT（独立LoRa）、蜂窝IoT（独立LTE-M）和级联IoT（与LTE-M对接的LoRa））来对LPWAN进行基准测试来确定的。通过对30，000个数据点的E2 E延迟的广泛实验测量活动，我们表明，由于LPWAN接口导致的额外延迟平均不到300毫秒。在用户QoE满意度达到95%的情况下，我们还发现级联LPWAN的性能比未授权物联网高出约1.5秒。总的来说，结果表明，级联LPWAN在技术上是可行的，并为现实世界的智慧城市部署提供了一种负担得起的替代方案。
Developing low-power wide-area network (LPWAN) solutions that are efficient to adopt, deploy and maintain are vital for smart cities. The poor quality-of-service of unlicensed LPWAN, and the high service cost of LTE-M/NB-IoT are key disadvantages of these technologies. Concatenating unlicensed with licensed LPWANs can overcome these limitations and harness their benefits. However, a concatenated LPWAN architecture will inevitably result in excess latency which may impact users’ quality-of-experience (QoE). To evaluate the real-life feasibility of this system, we first propose a concatenated LPWAN architecture and experimentally measure the statistics of end-to-end (E2E) latencies. The concatenated delay margin is determined by benchmarking the latencies with different LPWAN architecture schemes, namely with unlicensed IoT (standalone LoRa), cellular IoT (standalone LTE-M), and concatenated IoT (LoRa interfaced with LTE-M). Through extensive experimental measurement campaigns of 30,000 data points of E2E latencies, we show that the excess delay due to LPWAN interfacing introduces on average less than 300 milliseconds. With a users’ QoE satisfaction of 95%, we also found that concatenated LPWAN outperforms unlicensed IoT by roughly 1.5 s. Overall, the result suggests that a concatenated LPWAN is technically feasible and offers an affordable alternative for real-world smart city deployment.