On Improving the Radio Resource Control Signaling Reliability in LTE Uplink

In this article we study and analyze the problems related to power limitation in Long Term Evolution (LTE) uplink (UL). Power control (PC) has been specified for LTE UL to account for pathloss and slow fading variations and minimize the interference. The maximum transmission power has been limited to 23 dBm. Especially in sparse networks, this can lead to so called power limitation, where the terminals at the cell edge are forced to use less power per Physical Resource Block (PRB) than needed. Power limitation could clearly increase the packet error probability and transmission delay due to increased number of retransmissions. This may be especially problematic for Radio Resource Control (RRC) messages, e.g. handover signaling, since their reliability affects evidently on user Quality of Service (QoS). In this article we have concentrated on power boosting to improve the RRC message reliability and the performance is evaluated by means of dynamic system level simulations. It may be concluded that power boosting notably reduces the power limitation probability and thus also improves the RRC signaling reliability.