Abstract - The Internet of Things (IoT) is transforming industries and our daily lives. Industries are utilizing wide-area commercial Long-Term Evolution (LTE) networks to serve immediate and urgent IoT applications today. LTE was designed, however, for broadband service, while IoT is traditionally dominated by low-rate, low-power, and infrequent short-burst data. It is crucial to differentiate the IoT applications from broadband data services to ensure adequate coverage, efficiency, and reliability. In this paper, we present the first field trial performance results of IoT applications using LTE Category 1 devices. The field results show that the sector throughput impact on existing broadband service is less than 2% with 8 simultaneous IoT devices intensively transmitting 250 bytes. The low-cost single radio receiver device could reduce the coverage by 2-5 dB based on field measurements. Increasing control channel power and the number of HARQ retransmissions can compensate for the coverage loss. Signaling overhead and capacity were also studied by incorporating field measurement and network statistics into our system simulator to identify the critical limiting factors. We investigated the positive feedback effect of excessive signaling bearer traffic to ensure network stability. Various new access technologies, such as eMTC, NB-IoT, and 5G, are under development to further improve network performance and efficiency to serve varieties of IoT applications.