5G networks are supposed to offer a high flexibility in a several ways. In this regard, a twofold split of the processing in the radio access network is under discussion: A control plane / user plane split to support the software defined networking principle and a radio protocol stack layer based split to allow a flexible placement of processing functions between a central and distributed units. In this work, the motivation and state of the art for both splits are described including a discussion of the advantages and disadvantages. It is followed by a description of a network architecture allowing a flexible implementation of these splits. This especially focuses on the required interfaces between control and user plane.

Although the range expansion and inter-cell interference coordination (ICIC) have been shown to successfully enhance the capacity and load balancing in the Heterogeneous Network, their impacts on the handover (HO) performance are not fully understood in existing studies. In this paper, a novel measurement-based approach is adopted to investigate these issues, where the real measured data of the reference signal received power in a macro-pico co-channel deployment are collected. Then the mobility performance in terms of the HO failure rate and ping-pong rate is simulated with various ICIC schemes in the same reality environment. This has been made possible by modeling the possible HO failure events based on evaluating the downlink received signal-to-interference-plus-noise ratio from reference signal received power. The simulation results indicate that range expansion together with ICIC can have positive or negative influences on macro-to-pico, pico-to-macro, pico-to-pico and macro-to-macro HOs in the Heterogeneous Network. The existing static ICIC or mobility-based ICIC cannot handle the intra-layer (pico-to-pico and macro-to-macro) interference, thus limiting their abilities to improve the mobility performance. Motivated by this, a dynamic-ICIC-aided HO procedure is proposed. The proposed HO enhancement method is more flexible and effective in mitigating both the inter-layer and intra-layer interference, outperforming the existing methods significantly.

No abstract

No abstract

No abstract