ARQ Optimization for UMTS Networks
Eduardo Rodrigues Vale, Julio Cesar R. Dal Bello · IOSR Journal of Electronics and Communication Engineering · 2014
Initially developed for use in fixed networks, the ARQ (Automatic Repeat Request) technique was adopted in UMTS systems aiming the QoS improvement for data transmission.However, real time services like VoIP cannot benefits of ARQ, because of the related delay problems in WCDMA systems.With the advent of HSPA (High Speed Packet Access) and the LTE (Long Term Evolution) networks, there was a consequent redefinition of the ARQ functionalities, aiming to become possible to use it for real time services.Delay problems were minimized as a consequence of the facilities introduced for the new methods of ARQ generation.The main objective of this work is the definition of a methodology toward ARQ optimization relatively to the mean power required to transfer the information from the origin to the destination, accordingly to a given error probability.To reduce the amount of the power transfer in the uplink direction is of paramount importance for the minimization of interference levels as well as to economize battery of cellular equipment.Though the treatment here presented is focused to E-DCH (Enhanced Uplink Dedicated Channel) of HSPA systems, the results obtained are applicable to other related networks using ARQ techniques.