Performance Evaluation of a Live Multi-Site LTE Network

Abstract

In this paper, to quantify the field performance of a live long term evolution (LTE) network, we design and implement a multi-layered performance monitoring system. This monitoring system delivers an accurate and thorough picture of the network behavior including switching, cellular, transmission, IP, and data networks. The designed system enables measurement results gathered from different network layers and from both user and control planes through a mediation platform, paving the way for the collection of synchronous performance measurement results, including latency, handover ratios, and throughput from network entities. Network performance metrics and the terminal-based measurement are jointly reported to reflect the subscriber perspective. Two field trials are conducted to highlight performance results of LTE networks, in a congested multi-cell with release 12 support, and a sparsely populated cell with release 14 support. Different multiple-input multiple-output (MIMO) configurations, including spatial multiplexing, transmit diversity, beamforming, and <inline-formula> <tex-math notation="LaTeX">$64\times 64$ </tex-math></inline-formula> massive MIMO support, along with a selection of bandwidths and frequency bands are considered. The measurement results show that, without any significant latency cost, using more antenna elements provides higher user throughput, which also affects the overall cell throughput. However, doubling the number of antennas may not necessarily double the average data rates. Additionally, the average intrafrequency and interfrequency handover success ratios are observed to be acceptable, hence the changes among the selected the diversity and multiplexing technique does not have a visible deteriorating effect on the handover performance.