Title
Fundamental Limits of Memory-Latency Tradeoff in Fog Radio Access Networks Under Arbitrary Demands
Abstract
We consider a fog radio access network (F-RAN) with multiple transmitters and receivers, where each transmitter is connected to the cloud via a fronthaul link. Each network node has a finite cache, where it fills its cache with portions of the library files in the off-peak hours. In the delivery phase, receivers request each library files according to an arbitrary popularity distribution. The cloud and the transmitters are responsible for satisfying the requests. This paper aims to design content placement and coded delivery schemes for minimizing both the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">expected</italic> normalized delivery time (NDT) and the peak NDT which measures the transmission latency. We propose achievable transmission policies, and derive an information-theoretic bound on the expected NDT under uniform popularity distribution. The analytical results show that the proposed scheme is within a gap of 2.58 from the derived bound for both the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">expected</italic> NDT under uniform popularity distribution and the peak NDT. Next, we investigate the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">expected</italic> NDT under an arbitrary popularity distribution for an F-RAN with transmitter-side caches only. The achievable and information-theoretic bounds on the expected NDT are derived, where we analytically prove that our proposed scheme is optimal within a gap of two independent of the popularity distribution.
Year
DOI
Venue
2019
10.1109/TWC.2019.2919028
IEEE Transactions on Wireless Communications
Keywords
Field
DocType
Receivers,Wireless communication,Interference,Radio transmitters,Libraries,Cache memory
Transmitter,Wireless,Cache,CPU cache,Computer network,Node (networking),Radio access network,CAS latency,Mathematics,Cloud computing
Journal
Volume
Issue
ISSN
18
8
1536-1276
Citations 
PageRank 
References 
0
0.34
0
Authors
4
Name
Order
Citations
PageRank
Antonious M. Girgis101.69
Özgür Erçetin214622.96
Mohamed Nafie325342.26
Tamer A. Elbatt460764.37