Radical changes driven by overseas smartphone might weaken mobile network operators' presence in the domestic market, but they are still active innovators in the market. The trend of convergence between devices, services and technologies within and across industries has offered a breakthrough for the Korean mobile network operators to continuously create new service products in the saturated domestic market. This study explores the mobile network operator's dynamic capabilities for innovation by structuring innovation models of service design and delivery in Korea's business-to-business (B2B) mobile service sector. We observed 151 network solutions services which are mainstream services of mobile network operator's B2B service products. The findings of this research reveal that mobile network operators, as service providers, play a dynamic role in achieving innovation by recombining the existing technologies and components in service design or by delivering customized services for specific customers at the user/provider interface. Such capabilities of mobile network operators are represented as ‘recombinative innovation’ and ‘customized innovation’, respectively. These modes of innovation may not be achieved through long-term technological advancement, but can be drawn from existing resources by utilizing them creatively in modification or combination with new ones to develop a uniquely different service product.