Biblio

Next generation cellular networks will provide users better experiences by densely deploying smaller cells, which results in more complicated interferences environment. In order to coordinate interference, power control for uplink is particularly challenging due to random locations of uplink transmitter and dense deployment. In this paper, we address the uplink fractional power control (FPC) optimization problem from network optimization perspective. The relations between FPC parameters and network KPIs (Key Performance Indicators) are investigated. Rather than considering any single KPI in conventional approaches, multi-KPI optimization problem is formulated and solved. By relaxing the discrete optimization problem to a continuous one, the gradients of multiple KPIs with respect to FPC parameters are derived. The gradient enables efficiently searching for optimized FPC parameters which is particularly desirable for dense deployment of large number of cells. Simulation results show that the proposed scheme greatly outperforms the traditional one, in terms of network mean load, call drop & block ratio, and convergence speed.

LTE-based Device-to-Device (D2D) communications have been envisioned as a new key feature for short range wireless communications in advanced and beyond 4G networks. We propose in this work to exploit this novel concept of D2D as a new alternative for Intelligent Transportation Systems (ITS) Vehicle-to-Vehicle/Infrastructure (V2X) communications in next generation cellular networks. A 3GPP standard architecture has been recently defined to support Proximity Services (ProSe) in the LTE core network. Taking into account the limitations of this latter and the requirements of ITS services and V2X communications, we propose the CVN solution as an enhancement to the ProSe architecture in order to support hyper-local ITS services. CVN provides a reliable and scalable LTE-assisted opportunistic model for V2X communications through a distributed ProSe architecture. Using a hybrid clustering approach, vehicles are organized into dynamic clusters that are formed and managed by ProSe Cluster Heads which are elected centrally by the CVN core network. ITS services are deemed as Proximity Services and benefit from the basic ProSe discovery, authorization and authentication mechanisms. The CVN solution enhances V2V communication delays and overhead by reducing the need for multi-hop geo-routing. Preliminary simulation results show that the CVN solution provides short setup times and improves ITS communication delays.