Cellular Radio Relay Placement for Optimized Capacity
Author(s): Sambale,K.
Chair of Communication Networks (ComNets), Faculty 6, RWTH Aachen University
Contact: publications@comnets.rwth-aachen.de
Ph. D. Dissertation
, ABMT
71
,
p.
200
, ISBN: 978-3-86130-475-3
Wissenschaftsverlag Mainz,
Year: 2013
On page(s):200
ISBN: 978-3-86130-475-3
Abstract Data traffic in mobile cellular radio networks is increasing, continuously. The success of smartphones still intensifies this development. To meet these increasing demands for capacity, different extensions to the mobile cellular network concept have to be applied in combination, one of them is relaying. In this work relaying scenarios to increase Cell Spectral Efficiency (CSE) under rate fair scheduling are investigated and an optimized number and placement of Relay Stations (RSs) per radio cell is derived based on a Capacity Model (CM) developed for that purpose. The impact of various system parameters such as RS transmit power, resource allocation scheme, down tilt of Base Station (BS) antennas and backhaul link conditions is assessed allowing to formulate basic rules to follow to maximize CSE. It is assumed that rate fair scheduling is the ultimate goal of network operators to guarantee an ubiquitous Quality of Service (QoS) experience independent of the user’s current location. The new CM is based on the broadly accepted International Mobile Telecommunications - Advanced (IMT-A) channel model and applies simulated annealing to determine maximum CSE and optimized RS positions in an urban environment. Impact of the channel model on RS placement and CSE increase is assessed by comparison to results based on the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) channel model. Results are validated by stochastic event-driven simulation with the open Wireless Network Simulator (openWNS) at a very high level of detail of the protocol stack confirming the correctness of the CM. The results show that already three low-power Layer-2 Decode-and-Forward (DF)-RSs per cell almost double CSE when properly placed thereby serving up to 60% of the cell area. An additional pico BS placed at the BS site increases CSE furthermore, thereby doubling CSE compared to a BS only scenario. RSs should be mounted below roof-top at about 5-6m to minimize mutual interference if operating on the same radio resources. Reusing radio resources across RSs, even within the same cell, clearly maximizes CSE. Additionally, it is essential that the links between RSs and their serving BSs are Line-of-Sight (LoS) whereas propagation conditions to interfering BS sites should be Non-Line-of-Sight (NLoS) if possible.
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@PHDTHESIS{DissSambale2013
AUTHOR = {Sambale,K.} ,
TITLE = {Cellular Radio Relay Placement for Optimized Capacity} ,
YEAR = {2013} ,
MONTH = {Dec} ,
VOLUME = {71},
PAGES = {200},
PUBLISHER = {Wissenschaftsverlag Mainz},
ADDRESS = {Communication Networks (ComNets) Research Group @ RWTH Aachen University},
SERIES = {ABMT},
AFFILIATION = {Chair of Communication Networks (ComNets), Faculty 6, RWTH Aachen University},
ISBN = {978-3-86130-475-3 },
URL = {https://www.comnets.rwth-aachen.de}