Delay Gain Analysis of Wireless Multicasting for Content Distribution
Delay Gain Analysis of Wireless Multicasting for Content Distribution
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DOI：
10.1109/tnet.2020.3039634
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发表时间：
2021-04
期刊：
影响因子：
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通讯作者：
B. Abolhassani;John Tadrous;A. Eryilmaz
中科院分区：
文献类型：
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作者：
B. Abolhassani;John Tadrous;A. Eryilmaz
在这项工作中，我们提供了一个全面的分析的稳定性和延迟增益，无线多播功能，而不是更传统的单播传输，可以提供移动的网络中的内容分发。特别是，我们提出了一个模型和特点的平均带宽长度（因此平均延迟）性能的单播和各种多播策略，在无线边缘的动态用户群服务。首先，我们表明，优化的静态随机多播（我们称之为“盲多播”）导致稳定无处不在的操作，而不管网络负载因素（由需求率的比率服务率）和内容流行度分布。相比之下，传统的单播遭受不稳定的操作时，负载因子接近一，虽然它优于盲多播在小负载因子水平。这促使我们研究“工作保存多播”的政策，总是优于单播，同时仍然提供稳定的无处不在的操作。然后，在最坏的情况下，均匀分布的内容流行度，我们明确地表征的缩放的平均队列长度（因此延迟）下的先来先服务的组播策略作为数据库的大小和负载因子的函数。因此，这项工作提供了基本的限制，以及指导方针，设计和性能分析的有效的多播策略的无线内容分发。
In this work, we provide a comprehensive analysis of stability properties and delay gains that wireless multicasting capabilities, as opposed to more traditional unicast transmissions, can provide for content distribution in mobile networks. In particular, we propose a model and characterize the average queue-length (and hence average delay) performance of unicasting and various multicasting strategies for serving a dynamic user population at the wireless edge. First, we show that optimized static randomized multicasting (we call it ‘blind multicasting’) leads to stable-everywhere operation irrespective of the network loading factor (given by the ratio of the demand rate to the service rate) and the content popularity distribution. In contrast, traditional unicasting suffers from unstable operation when the loading factor approaches one, although it outperforms blind multicasting at small loading factor levels. This motivates us to study ‘work-conserving multicast’ policies next that always outperform unicasting while still offering stable-everywhere operation. Then, in the worst-case of uniformly-distributed content popularity, we explicitly characterize the scaling of the average queue-length (and hence delay) under a first-come-first-serve multicast strategy as a function of the database size and the loading factor. Consequently, this work provides the fundamental limits, as well as the guidelines, for the design and performance analysis of efficient multicasting strategies for wireless content distribution.