LTE in unlicensed spectrum: are we there yet?
LTE in unlicensed spectrum: are we there yet?
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DOI：
10.1145/2973750.2973781
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发表时间：
2016-10
期刊：
影响因子：
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通讯作者：
Eugene Chai;K. Sundaresan;M. Khojastepour;S. Rangarajan
中科院分区：
文献类型：
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作者：
Eugene Chai;K. Sundaresan;M. Khojastepour;S. Rangarajan
在这项工作中，我们探讨了未授权LTE在未授权频谱中对WiFi的潜力和影响。我们的实验表明，WiFi和LTE采用的信道接入方法（WiFi中的载波感测/通知，LTE-U中单独的能量感测）的严重不对称可能导致LTE-U完全阻塞WiFi传输，并导致任何一种技术的显着退化。冲突。我们使用Ultron解决了这种关键的感知不对称性，这是一种LTE-WiFi共存解决方案，将WiFi的载波感知和通知机制集成到LTE中，而无需对LTE PHY标准进行任何修改。Ultron在LTE基站处运行，并且由两个关键组件组成：（a）WiFi嵌入，其通过LTE PHY的智能逆向工程将适当的数据嵌入到LTE子帧中，以便直接使用LTE PHY在空中实现WiFi PLCP报头传输;以及（B）可扩展WiFi感测，其采用单个WiFi接口并且使其对在LTE节点处操作的所有未许可信道的载波感测益处最大化。我们的评估表明，Ultron可以将WiFi和LTE的吞吐量分别提高5倍和6倍，这是由于LTE-WiFi干扰的急剧减少。
In this work, we explore the potential and impact of unlicensed LTE on WiFi in unlicensed spectrum. Our experiments demonstrate that the large asymmetry in the channel access methodologies employed by WiFi and LTE (carrier sensing/notification in WiFi, energy sensing alone in LTE-U), can result LTE-U completely blocking WiFi transmissions, and causing significant degradation to either technologies from collisions. We address this critical sensing asymmetry with Ultron, a LTE-WiFi co-existence solution that integrates WiFi's carrier sensing and notification mechanisms into LTE, without any modifications to the LTE PHY standard. Ultron operates at the LTE base station and consists of two key components: (a) WiFi embedding that embeds appropriate data into the LTE-subframes through an intelligent reverse-engineering of the LTE PHY, so as to realize a WiFi PLCP preamble-header transmission over the air directly using the LTE PHY; and (b) scalable WiFi sensing that employs a single WiFi interface and maximizes its carrier sensing benefits to all the unlicensed channels operating at the LTE node. Our evaluations demonstrate that Ultron can increase the WiFi and LTE throughput by 5x and 6x respectively, resulting from a sharp reduction in LTE-WiFi interference.