A Hybrid Algorithm for Changepoint Aware Long-Term Seasonality Detection of Mobile Network Base Stations

Year 2021, Issue: 27, 370 - 385, 30.11.2021

Yakup Kranda , Rüya Şamlı

https://doi.org/10.31590/ejosat.931099

Abstract

Automated capacity planning for mobile networks requires long-term forecasting of traffic demand by using historical patterns.
To decide the correct time of investment and correct capacity expansion size or to improve the accuracy of forecasting algorithms with exogenous features, both seasonal decomposition, and seasonal period identification improves decision accuracy. We design a hybrid algorithm to calculate these features on live network data with improved accuracy which uses piecewise Seasonality Trend Decomposition with Loess (STL) decomposition and Prophet library’s regression with Laplace prior under the hood. Combining both methods with the awareness of their weak and strong parts and leveraging overall output with changepoint and similarity analysis help us to improve our accuracy around 18.6% comparing the average of single usage of these methods. We also provide and present some special cases that increase problem complexity and decrease decomposition accuracy.

Keywords

Mobile Network Seasonality Detection, Changepoint Awareness, Network Capacity Planning, Piece-wise Regression, Time Series Decomposition

Thanks

A part of this work has been conducted under the frame of the Celtic-Next AI4Green project where efficient and risk-aware energy saving algorithms are studied in collaboration. Calculating high season start and end dates next to the multiplicative impact of seasons is significant for risk minimization of RAN energy saving algorithms since contemporary solutions rely on short-term predictions over limited history.

Mobil Ağ Baz İstasyonlarının Değişim Noktalarının Uzun Dönem Sezonsallık Tespiti için Hibrid Bir Algoritma

Abstract

Mobil ağlar için otomatik kapasite planlaması, geçmiş kalıpları kullanarak trafik talebinin uzun vadeli tahminini gerektirir.
Doğru yatırım zamanına, doğru kapasite genişletme boyutuna karar vermede veya dışsal etkilere sahip tahmin algoritmalarının doğruluğunu iyileştirmede hem mevsimsel ayrıştırma hem de mevsimsel dönem tanımlama işlemleri karar doğruluğunu artırır.
Bu çalışmada bu işlemleri, altyapısında parçalı Loess ile Mevsimsel Trend Ayrışımı (Seasonality Trend Decomposition with Loess – STL) ayrıştırması ve Prophet Kütüphanesi’nin Laplace önsele sahip regresyon yaklaşımını kullanan ve canlı ağ örnekleri üzerinde daha yüksek doğrulukla gerçekleştiren hibrid bir algoritma tasarlanmıştır. Her iki yöntemi de zayıf ve güçlü parçalarının farkındalığıyla birleştirmek ve değişim noktalarının benzerlik analizi ile tespit edilmesi üzerine geliştirilen çözüm, bu yöntemlerin tek başlarına elde ettiği ortalama başarımı yaklaşık %18,6 oranında artırmaktadır. Ayrıca çalışma kapsamında, problemin karmaşıklığını artıran ve ayrıştırma doğruluğunu azaltan bazı özel durumlar da sunulmuştur.

Keywords

Mobil Ağ Sezonsallık Tespiti, Değişim Noktası Farkındalığı, Mobil Ağ Kapasite Planlama, Parçalı Regresyon Analizi, Zaman Serisi Bileşenlerine Ayırma

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