DeepAI AI Chat
Log In Sign Up

Fundamental Limits of Wireless Caching Under Mixed Cacheable and Uncacheable Traffic

02/18/2020
by   Hamdi Joudeh, et al.
EURECOM
Berlin Institute of Technology (Technische Universität Berlin)
0

We consider cache-aided wireless communication scenarios where each user requests both a file from an a-priori generated cacheable library (referred to as 'content'), and an uncacheable 'non-content' message generated at the start of the wireless transmission session. This scenario is easily found in real-world wireless networks, where the two types of traffic coexist and share limited radio resources. We focus on single-transmitter, single-antenna wireless networks with cache-aided receivers, where the wireless channel is modelled by a degraded Gaussian broadcast channel (GBC). For this setting, we study the delay-rate trade-off, which characterizes the content delivery time and non-content communication rates that can be achieved simultaneously. We propose a scheme based on the separation principle, which isolates the coded caching and multicasting problem from the physical layer transmission problem. We show that this separation-based scheme is sufficient for achieving an information-theoretically order optimal performance, up to a multiplicative factor of 2.01 for the content delivery time, when working in the generalized degrees of freedom (GDoF) limit. We further show that the achievable performance is near-optimal after relaxing the GDoF limit, up to an additional additive factor of 2 bits per dimension for the non-content rates. A key insight emerging from our scheme is that in some scenarios considerable amounts of non-content traffic can be communicated while maintaining the minimum content delivery time, achieved in the absence of non-content messages; compliments of 'topological holes' arising from asymmetries in wireless channel gains.

READ FULL TEXT

page 1

page 2

page 3

page 4

08/12/2019

Fundamental Limits of Wireless Caching under Uneven-Capacity Channels

This work identifies the fundamental limits of cache-aided coded multica...
12/12/2017

Fundamental Limits of Cloud and Cache-Aided Interference Management with Multi-antenna Base Stations

In cellular systems, content delivery latency can be minimized by jointl...
03/20/2018

On Multi-Server Coded Caching in the Low Memory Regime

In this paper we determine the delivery time for a multi-server coded ca...
12/14/2017

Generalized Degrees of Freedom of the Symmetric Cache-Aided MISO Broadcast Channel with Partial CSIT

We consider a wireless network in which K transmitters, each equipped wi...
03/11/2018

Cache-Assisted Broadcast-Relay Wireless Networks: A Delivery-Time Cache-Memory Tradeoff

An emerging trend of next generation communication systems is to provide...