%0 Journal Article %T Optimal Relay Placement in Cellular Networks %+ Nanayang Technological University (NTU) %+ Réseaux, Mobilité et Services (RMS) %+ Département Informatique et Réseaux (INFRES) %+ Orange Labs [Lannion] %+ Laboratoire Traitement et Communication de l'Information (LTCI) %A Minelli, Mattia %A Ma, Maode %A Coupechoux, Marceau %A Kélif, Jean-Marc %A Sigelle, Marc %A Godlewski, Philippe %< avec comité de lecture %Z MMCKSG:TWC-14 %@ 1536-1276 %J IEEE Transactions on Wireless Communications %I Institute of Electrical and Electronics Engineers %V 13 %N 2 %P 998-1009 %8 2014-02 %D 2014 %R 10.1109/TWC.2013.010214.130814 %Z Computer Science [cs]/Networking and Internet Architecture [cs.NI]Journal articles %X In this paper, we address the problem of optimally placing relay nodes in a cellular network with the aim of maximizing cell capacity. In order to accurately model interference, we use a dynamic framework, in which users arrive at random time instants and locations, download a file and leave the system. A fixed point equation is solved to account for the interactions between stations. We also propose an extension of a fluid model to relay based cellular networks. This allows us to obtain quick approximations of the Signal to Interference plus Noise Ratio (SINR) that are very close to 3GPP LTE-A guideline results in terms of SINR distribution.We then use these formulas to develop a dedicated Simulated Annealing (SA) algorithm, which adapts dynamically the temperature to energy variations and uses a combination of coarse and fine grids to accelerate the search for an optimized solution. Simulations results are provided for both in-band and out-of-band relays. They show how relays should be placed in a cell in order to increase the capacity in case of uniform and non-uniform traffic. The crucial impact of the backhaul link is analyzed for in-band relays. Insights are given on the influence of shadowing. %G English %2 https://hal-imt.archives-ouvertes.fr/hal-00958679/document %2 https://hal-imt.archives-ouvertes.fr/hal-00958679/file/relayplacementjournal_final_doublecolumn.pdf %L hal-00958679 %U https://hal-imt.archives-ouvertes.fr/hal-00958679 %~ INSTITUT-TELECOM %~ CNRS %~ ENST %~ TELECOM-PARISTECH %~ PARISTECH %~ LTCI %~ INFRES %~ RMS %~ INSTITUTS-TELECOM