@article{10902/23263,
year = {2021},
month = {11},
url = {http://hdl.handle.net/10902/23263},
abstract = {We study the delay over virtual RAN (vRAN) topologies, entailing base stations that are divided into centralized and distributed units, as well as the packet-switched fronthaul network that connects them. We consider the use of flexible functional split, where the functions that are executed at each of these two entities can be dynamically shifted. We propose a queuing-based model, which is able to precisely mimic the behavior of such nodes, and we validate it by means of extensive simulations. We also exploit Jackson Networks theory to establish the end-to-end delay over the fronthaul network, allowing us to assess the impact of having different networking policies and conditions (for instance, background traffic or heterogeneous technologies). Thanks to the simulator we can also broaden the analysis, by studying the delay variability. In addition, we conduct an in-depth analysis of the performance exhibited by a realistic network setup, whose particular characteristics might hinder the services performance, due to the longer dwell times at each split configuration. The results evince the validity of the proposed model, even under realistic conditions. We show that it might not be enough to guarantee an average stable operation of the centralized/distributed units, but the traffic load should remain below the slowest service rate, to avoid reaching unacceptable delays. An increase of >100× is observed in the delay, using the realistic network setup, when these conditions do not hold.},
organization = {This work was supported in part by the Spanish Government, Ministerio de Economía y Competitividad, Fondo Europeo de Desarrollo Regional (MINECO-FEDER), through the Project FIERCE: Future Internet Enabled Resilient smart CitiEs under Grant RTI2018-093475-AI00; and in part by the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovation Program (FlexNets) under Grant 647158},
publisher = {Institute of Electrical and Electronics Engineers, Inc.},
publisher = {IEEE Access, 2021, 9, 151049-151066},
title = {Flexible functional split and fronthaul delay: a queuing-based model},
author = {Díez Fernández, Luis Francisco and Martínez Alba, Alberto and Kellerer, Wolgang and Agüero Calvo, Ramón},
}