Internet of Things (IoT) is a system that connects computing devices including phones, sensor, mechanical machines and other items over a network allowing them to exchange data and perform tasks without human interaction. It has altered the means by which connected devices interact and communicate, facilitating smarter and more convenient applications. As a result of their technological specifications, these devices are considered power constrained, as they lack battery sources. Therefore, they require a suitable underlying technology that considers power constraints and fulfills other IoT application requirements including long-range communication and low cost. Low Power Wide Area Network (LPWAN) is a communication technology that is gaining increasing popularity, as it provides low-rate long-range communication suitable for IoT applications. This research uses simulation to evaluate the performance of LoRa and Sigfox as the leading LPWAN technologies. The simulation evaluates collision, packet error rate and spectrum using different values for channel bandwidth. It also examines the impact of the number of IoT devices on network performance. Results reveal that Sigfox has less collisions and packet error rate compared to LoRa. They also show that in general, increasing the number of devices leads to increasing collision and packet error rate. Utilizing larger bandwidth provides more available slots and therefore reducing collision.