Traffic steering by self-tuning controllers in enterprise LTE femtocells

Abstract

Femtocells have been suggested as a promising solution for the provision of indoor coverage and capacity. This article investigates the problem of re-distributing traffic demand between long-term evolution (LTE) femtocells with open access in an enterprise scenario. Several traffic sharing algorithms based on automatic tuning of femtocell parameters are considered. The proposed algorithms are implemented by fuzzy logic controllers. Performance assessment is carried out in a dynamic system-level simulator. Results show that localized congestion problems in these scenarios can be solved without impairing connection quality by jointly tuning handover margins and cell transmit power.

Improving load balancing techniques by location awareness at indoor femtocell networks

“…The proposed MLB algorithm is compared with the non-optimized network (baseline) and the power traffic sharing (PTS) algorithm presented in reference [19] which tunes femtocell transmission power based on comparing the call blocking ratio of a cell to the average call blocking ratio of its neighboring cells. To quantify the advantages and disadvantages of the MLB algorithm, the indicators described in Section 3 are assessed: UDR and UHR.…”

“…The authors in [18], proposed a method to adjust hysteresis margins depending on an estimation of the distance from the base station to the user equipment (UE), reduces the number of redundant handovers (HOs) while keeping the throughput of femtocells as high as possible. The work shown in [19] studied the persistent congestion problems on traffic distribution in LTE femtocell enterprise scenario. That work implemented and compared several traffic sharing algorithms that tune femtocell transmission power and handover margins, following a fuzzy logic controller (FLC) scheme in order to automatically adjust femtocell parameters.…”

“…The PTS algorithm reduces the average UDR, as expected. However, with PTS, the temporary network congestions are not rapidly optimized because of its long convergence period (further details in [19]). Conversely, the yellow bar represents the proposed mechanism supported by the MRs.…”

“…It is interpreted as a combination of CBR and CDR [19], which is also an important parameter from the operator point of view because the users' QoE is important to keep clients.…”

A femtocell location strategy for improving adaptive traffic sharing in heterogeneous LTE networks

“…Initial studies on load sharing are focused on macrocellular scenarios in different radio access technologies (e.g., time division multiple access/frequency division multiple access -TDMA/FDMA [10], wideband code division multiple access -WCDMA [11], and orthogonal frequency division multiple access -OFDMA [12,13]). Recently, the analysis has been extended to heterogeneous office scenarios with open-access femtocells [14]. Results presented there showed that traffic sharing in OFDMA femtocell networks is a challenging task due to the full frequency reuse currently used by operators.…”