High-Throughput Primary Cell Frequency Switching for Multi-RAT Carrier Aggregation

Wook KIM  Daehee KIM  

IEICE TRANSACTIONS on Information and Systems   Vol.E102-D   No.6   pp.1210-1214
Publication Date: 2019/06/01
Online ISSN: 1745-1361
DOI: 10.1587/transinf.2018EDL8196
Type of Manuscript: LETTER
Category: Information Network
carrier aggregation,  multi-RAT CA,  CA cell coverage mismatch,  PCell inter-frequency handover,  CA mobility,  

Full Text: FreePDF(1.8MB)

Among the five carrier aggregation (CA) deployment scenarios, the most preferred scenario is Scenario 1, which maximizes CA gain by fully overlapping a primary cell (PCell) and one or more secondary cells (SCells). It is possible since the same frequency band is used between component carriers (CCs) so nearly the same coverage is expected. However, Scenario 1 cannot guarantee high throughput in multi-radio access technology carrier aggregation (multi-RAT CA) which is actively being researched. Different carrier frequency characteristics in multi-RAT CA makes it hard to accurately match different frequency ranges. If the ranges of PCell and SCell differ, high throughput may not be obtained despite the CA operation. We found a coverage mismatch of approximately 37% between the PCell and SCell in the deployed network and realized a reduced CA gain in those areas. In this paper, we propose a novel PCell change approach named “PCell frequency switching (PFS)” to guarantee high throughput against cell coverage mismatch in multi-RAT CA deployment scenario 1. The experiment results show that the throughput increased by 9.7% on average and especially by 80.9% around the cell edge area when PFS is applied instead of the legacy CA handover operation.