Recent study predicts that by 2020 up to 50 billion IoT devices will be connected to the Internet, straining the capacity of wireless network that has already been overloaded with data-hungry mobile applications, such as high-definition video streaming and virtual reality(VR)/augmented reality(AR). How to accommodate the demand for both massive scale of IoT devices and high-speed cellular services in the physically limited spectrum without significantly increasing the operational and infrastructure costs is one of the main challenges for operators. In this article, we introduce a new multi-operator network sharing framework that supports the coexistence of IoT and high-speed cellular services. Our framework is based on the radio access network (RAN) sharing architecture recently introduced by 3GPP as a promising solution for operators to improve their resource utilization and reduce the system roll-out cost. We evaluate the performance of our proposed framework using the real base station location data in the city of Dublin collected from two major operators in Ireland. Numerical results show that our proposed framework can almost double the total number of IoT devices that can be supported and coexist with other cellular services compared with the case without network sharing.