Handover Parameter Optimisation in LTE

1. Introduction Handover (HO) is key procedure for ensuring that users can move freely within a network being connected to high quality services [1]. In currently deployed mobile networks, handover optimization is performed manually over a long time period-days or weeks. This approach is both time consuming and can not be carried out as often as needed. By introducing an online self-optimising algorithm that can tune the parameters of the HO process, we aim at improving overall network performance and user QoS. The main goals are reducing the number of HOs that are initiated but not carried out until completion (HO failures), repeated back and forth HOs between two base stations ('ping-pong' HOs) and dropped calls. One of the most important directions of LTE expertise evolution is comprehension of Self-Organizing Network (SON) functionality [2]. Every wireless telecom service provider needs infrastructure that is self-configuring, self-operating and self-optimizing. Ideal infrastructure deploys quickly without any special expertise, automatically discovers the neighbors, automatically reconfigures around network failures and automatically optimizes radio parameters. In addition, backhaul and interconnect should be automatically configured and QoS should be self-established and autonomously optimized. These capabilities, along with many others, are the vision of the SON. SON is defined as a set of use cases that covers the entire network lifecycle: planning, deployment, operation and optimization. Hence, SON is designed to be a multi-vendor solution. The key SON subjects are network planning, network deployment and network optimization. The goal of SON at the stage of network planning is to eliminate as much pre-planning of network configuration as possible. SON does allow pre-planned network configuration, but it strongly encourages that as much of network configuration as possible should be generated/discovered automatically. The goal of SON at the stage of network deployment is to radically decrease deployment time and procedures, especially in the deployment of eNBs. The goal of SON at the stage of network optimization is to maintain the desired performance level over the life of the network as new equipment is deployed, usage patterns change, etc. In particular SON optimization should provide automatic handoff optimization, including monitoring KPIs (key performance indicators) to optimize handoff by iteratively adjusting target C/I (carrier-to-interference) and RSSI (received-signal strength indication). Self-optimization of future radio access networks is one of the main topics for MERA research group. MERA has developed an LTE system-level Matlab-based simulator. It allows evaluating and optimizing the system performance. This …