Essential patent portfolios to monitor technology standardization strategies: Case of LTE-A technologies

•This study suggests patent portfolio maps to analyze standardization strategy.•Five maps were designed considering the characteristics of essential patents.•The main focus includes concentration, activities, diversity, and quality of standard.•A case study was conducted on the LTE-A technologies.•Among 10 leading companies, the top three showed distinguishing strategies. Patent portfolio analysis can be a useful approach to understand the characteristics of an industry and competitors in terms of their standard-setting activities. Despite its potential, however, little attention has been given to portfolio analysis, especially for essential patents. Therefore, this study aims to develop five patent portfolio maps that can be used to analyze essential patent strategies from various perspectives: 1) concentration, 2) activities, 3) diversity, 4) quality-breakthrough, and 5) quality-impact. Then, a case study is conducted on LTE-A technologies in the telecommunications sector, where technology standards are essential to establish technology strategies.