TY - JOUR
T1 - Throughput-Outage Analysis and Evaluation of Cache-Aided D2D Networks with Measured Popularity Distributions
AU - Lee, Ming Chun
AU - Ji, Mingyue
AU - Molisch, Andreas F.
AU - Sastry, Nishanth
PY - 2019/11/1
Y1 - 2019/11/1
N2 - Caching of video files on user devices, combined with file exchange through device-to-device (D2D) communications is a promising method for increasing the throughput of wireless networks. Previous theoretical investigations showed that throughput can be increased by orders of magnitude, but assumed a Zipf distribution for modeling the popularity distribution, which was based on observations in wired networks. Thus the question whether cache-aided D2D video distribution can provide in practice the benefits promised by existing theoretical literature remains open. To answer this question, we provide new results specifically for popularity distributions of video requests of mobile users. Based on an extensive real-world dataset, we adopt a generalized distribution, known as Mandelbrot-Zipf (MZipf) distribution. We first show that this popularity distribution can fit the practical data well. Using this distribution, we analyze the throughput-outage tradeoff of the cache-aided D2D network and show that the scaling law is identical to the case of Zipf popularity distribution when the MZipf distribution is sufficiently skewed, implying that the benefits previously promised in the literature could indeed be realized in practice. To support the theory, practical evaluations using numerical experiments are provided, and show that the cache-aided D2D can outperform the conventional unicasting from base stations.
AB - Caching of video files on user devices, combined with file exchange through device-to-device (D2D) communications is a promising method for increasing the throughput of wireless networks. Previous theoretical investigations showed that throughput can be increased by orders of magnitude, but assumed a Zipf distribution for modeling the popularity distribution, which was based on observations in wired networks. Thus the question whether cache-aided D2D video distribution can provide in practice the benefits promised by existing theoretical literature remains open. To answer this question, we provide new results specifically for popularity distributions of video requests of mobile users. Based on an extensive real-world dataset, we adopt a generalized distribution, known as Mandelbrot-Zipf (MZipf) distribution. We first show that this popularity distribution can fit the practical data well. Using this distribution, we analyze the throughput-outage tradeoff of the cache-aided D2D network and show that the scaling law is identical to the case of Zipf popularity distribution when the MZipf distribution is sufficiently skewed, implying that the benefits previously promised in the literature could indeed be realized in practice. To support the theory, practical evaluations using numerical experiments are provided, and show that the cache-aided D2D can outperform the conventional unicasting from base stations.
KW - device-to-device (D2D) communications
KW - scaling laws
KW - throughput-outage tradeoff
KW - Wireless caching network
UR - http://www.scopus.com/inward/record.url?scp=85077333580&partnerID=8YFLogxK
U2 - 10.1109/TWC.2019.2935452
DO - 10.1109/TWC.2019.2935452
M3 - Article
AN - SCOPUS:85077333580
SN - 1536-1276
VL - 18
SP - 5316
EP - 5332
JO - IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS
JF - IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS
IS - 11
M1 - 8809411
ER -