## 1 Introduction  
During the COVID-19 pandemic, many small and medium-sized enterprises (SMEs) suffered declines in business. Mobile applications and services still drive the growth of the world economy. In 2021, the economic value added by mobile applications and services reached 5% of GDP globally [1]. According to the GSMA (Groupe Speciale Mobile Association), by 2025, the figure will reach nearly 5 trillion US dollars. Broadband mobile applications will continue to improve productivity and efficiency in all economic sectors, especially in the service and manufacturing industries. As a result, enterprises are facing austere challenges caused by new types of clients and new patterns of management [2], people working from home by using various telecommunating tools in the time of the coronavirus outbreak, and merchants, more frequently, communicating with customers by using mobile tools during the transaction process. Conversely, the features of broadband mobile technology such as connectivity, agility, interactivity, and being 'always-on' can deliver various advantages to business. Namely, mobile technologies can be used for increasing business operational efficiency, and to improve responsiveness and competitiveness [3]. Widely deployed broadband mobile networks to date enjoy a favorable environment for leading insto a new era of mobile applications. The rapidly developing broadband mobile technology with more powerful features not only facilitates various types of innovative applications such as telecommunating, digital marketing, cloud computing services, internet of things (IoT), smart home and smart city, augmented reality (AR), and artificial intelligence (AI) manufacturing, but also accelerates the innovation of business models and change the appearance of industries [4]. SMEs play an important role in economic growth and job creation [5; 6], and faced severe business difficulties during the pandemic [7]. The use of innovative ICT and mobile applications is more vital for SMEs, however, few studies have focused on the adoption of broadband mobile applications to expedite the growth and evolution of SMEs. Yet broadband mobile applications will probably be the key to driving the digitalization of enterprises. Hence, the main purpose of this study is to explore the determinants of SMEs' adoption of broadband mobile applications. We hope that the results of this research may be of great help in strengthening the competitiveness and digital transformation of SMEs. Most of the broadband mobile applications must be installed in and operated by personal mobile devices, and the intention of internal users must be accounted for. Thus, this study applied the Technology-Organization-Environment (TOE) framework along with the internal users' point of view and proposed an ITO research model in an attempt to obtain a broader perspective. Qualitative interviews were conducted in the first phase to collect data from 12 SMEs in different industries and in different adoption stages. Subsequently, a questionnaire-based survey was conducted to verify the findings and results from the qualitative interviews and research models. This study was conducted in Taiwan where SMEs account for 98.9% of firms and over 80% of employment [8]. Both percentages are similar to those of other Asia-Pacific countries. The domestic 4G broadband mobile network penetration rate exceeds 94.5% [9], which ranks third amongst the main Asia-Pacific countries. 5G networks have been deployed since 2020, while the penetration rate as well as the implementation and usage by SMEs are still in the initial stages. The results of this study may provide constructive references to SMEs in other Asia-Pacific countries similarly situated. This paper is structured as follows: A literature review of the related issues is presented in the second section. The methods and process of analysis, as well as the results, are described in section three. In the fourth section, there is a discussion based on the findings.