Characterization of 300 GHz Wireless Channels for Rack-to-Rack Communications in Data Centers
Characterization of 300 GHz Wireless Channels for Rack-to-Rack Communications in Data Centers
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DOI：
10.1109/pimrc.2018.8581042
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发表时间：
2018-09
期刊：
影响因子：
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通讯作者：
Chia-Lin Cheng;A. Zajić
中科院分区：
文献类型：
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作者：
Chia-Lin Cheng;A. Zajić
本文介绍了300 GHz信道的表征与光学透镜的无线机架到机架的数据中心通信。测量是在视线（LoS），阻塞LoS（OLoS），反射非LoS（RNLoS）和阻塞RNLoS（ORNLoS）场景中进行的，这些场景评估了诸如电缆等障碍物对THz传播的影响，以及使用现有金属物体作为反射器的可能性，这些反射器为数据中心中普遍存在的非LoS类型的链路引导波。由于需要光学透镜来将通信范围扩展到1 m以上，因此我们评估了此类环境中的路径损耗并估计了路径损耗模型参数。结果表明，光学透镜创建了一个类似波导的环境，在LoS链路中的PLE为1.54，在RNLoS链路中为1.36。当使用透镜来延长距离时，在PDP中观察到多次反射，但是它们随着距离的增加而衰减。此外，RNLoS链路中的反射器比传统LoS链路更长地保留多次反射，因此限制了相干带宽B_{c}。最后，当存在障碍物时，ORNLoS链路在超过130 cm的距离处具有较低的路径损耗，并且与OLoS链路相比具有较少的多径。如果电缆造成的障碍不可避免，则ORNLoS链路的性能优于OLoS链路。
This paper presents characterization of 300 GHz channel with optical lenses for wireless rack-to-rack data center communications. Measurements are conducted in line-of-sight (LoS), obstructed-LoS (OLoS), reflected-non-LoS (RNLoS), and obstructed-RNLoS (ORNLoS) scenarios, which evaluate the impact of obstructions such as cables on THz propagation as well as possibility of using existing metal objects as reflectors that guide waves for non-LoS type of links that are prevalent in data centers. Since optical lenses are needed to extend the communication range beyond 1m, we have evaluated path loss in such an environment and estimated path loss model parameters. The results indicate that optical lenses create a waveguide-like environment with PLEs of 1.54 in the LoS link and 1.36 in the RNLoS link. Multiple reflections are observed in PDPs when lenses are used to extend the distance but they decay as the distance increases. Additionally, reflector in the RNLoS link preserves multiple reflections longer than traditional LoS link and thus limit the coherence bandwidth $B_{c}$. Finally, when obstructions are present, the ORNLoS link has lower pathloss at distance beyond 130 cm and has less multipath compared to the OLoS link. If obstructions caused by cables are unavoidable, ORNLoS link performs better than OLoS link.