Analysis of essential patent portfolios via bibliometric mapping: an illustration of leading firms in the 4G era

This study aims to analyse the essential patent portfolios of individual firms via bibliometric mapping. Based on the maps drawn via this method, important clusters of each company are analysed and two interpretations are made. As an illustration, the mobile phone industry is selected because standardisation is highly important for firms in this industry. Among others, long-term evolution (LTE) of the 4G era is chosen as a standard and Qualcomm, Nokia, Ericsson, and NTT DOCOMO are included as leading firms. As a result, firm-wise LTE essential patent portfolios were visualised. Based on the information given in these maps, two important clusters (i.e. the clusters composed of frequently emerging words and their periphery and the clusters including particularly noticeable terms) were analysed. In addition, two interpretations were made as follows. First, specialised and expandable technological clusters for each company (14 specialised/expandable clusters for Qualcomm, 8 for Nokia, 11 for Ericsson, and 10 for NTT DOCOMO) were identified. Second, appropriate cooperative strategies were devised according to the ownership patterns of technologies as follows. To begin with, if the technologies were owned by one company (e.g. multi-carriers, duplex channel, error correction), a non-cooperative strategy, such as non-exclusive licensing, was advised. Next, when the technology was owned by two companies (i.e. OFDM (orthogonal frequency-division multiplexing)), a cooperative strategy, such as cross-licensing, was recommended. Finally, if the technologies were owned by multiple companies (i.e. MIMO (multi-input and multi-output) and data transmission), then a cooperative strategy, such as a patent pool, was proposed.