A method of assessment of LTE coverage holes

Ana Gómez-Andrades,Inmaculada Serrano,Raquel Barco

doi:10.1186/s13638-016-0733-y

Ana Gómez-Andrades, Inmaculada Serrano + Show 1 more

Open Access

https://doi.org/10.1186/s13638-016-0733-y

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Abstract

Analyzing coverage holes in mobile networks is still an important problem that needs to be addressed, mainly in Long-Term Evolution (LTE) networks, which have been recently deployed. However, each type of coverage hole has to be handled depending on the effect they have on the users. In particular, they are characterized by causing abnormal disconnections or inter-Radio Access Technology (RAT) handovers when there is an underlying RAT available to maintain the connection released by the LTE network at the cost of reducing the service performance. Therefore, in this paper, an approach to detect cells with coverage holes and diagnose their type and severity is proposed. Furthermore, this paper proposes a method capable of analyzing the impact each coverage hole has on the users both in LTE and in the underlying RAT at the same time. To that end, it performs an inter-technology follow-up of those users that leave LTE technology to continue their services in the underlying RAT and then quantifies the effect of the coverage hole by means of a new inter-technology indicator estimated from the mobile traces of both RATs. The proposed system has been validated using data from a live LTE network and its co-located 3G network, showing its effectiveness in detecting coverage holes and diagnosing their type.

Highlights

In the context of mobile networks, it is important to ensure that end-user services are properly provided, i.e., they are neither interrupted nor ended abnormally
The considered urban area is a section of the whole network, consisting of 120 Long-Term Evolution (LTE) cells that are located in the same area as all the 3G cells of a particular Radio Network Controller (RNC); LTE and 3G coverage areas are overlapped
The ATOLaverage metric is estimated based on the group of users that performed an Inter-RAT HO rate (IRAT HO), which may be small

Summary

Introduction

In the context of mobile networks, it is important to ensure that end-user services are properly provided, i.e., they are neither interrupted nor ended abnormally. The main difference of the proposed solution with the approaches available in the literature is that the presented diagnosis system does detect cells with coverage holes (as in the previous references) and diagnoses their type and severity This is achieved through the use of both traditional statistics indicators (obtained from the Operation, Administration and Maintenance (OAM) system) and the user information obtained from the mobile traces gathered both in LTE and in the co-existing uRAT. In the constant struggle to deal with coverage holes, operators have to use theoretical propagation models in the coverage planning of LTE networks, manually analyze statistics performance indicators and extensively collect user measurements through the traditional drive test It is, a time-consuming task that has a great impact in CAPEX and OPEX. Areas with LTE coverage holes present high number of customer complaints regarding frequent call drops, service gaps, or downgraded performance

System model

Results and discussion

Conclusions