Teleoperated service robots can perform more complex and precise tasks as they combine robot skills and human expertise. Communication between the operator and the robot is essential for remote operation and strongly affects system efficiency. Immersive interfaces are being used to enhance teleoperation experience. However, latency or time delay can impair the performance of the robot operation. Since remote visualization involves transmitting a large amount of video data, the challenge is to decrease communication instability. Then, an efficient teleoperation system must have a suitable operation interface capable of visualizing the remote environment, controlling the robot, and having a fast response time. This work presents the development of a service robot teleoperation system with an immersive mixed reality operation interface where the operator can visualize the real remote environment or a virtual 3D environment representing it. The virtual environment aims to reduce the latency on communication by reducing the amount of information sent over the network and improve user experience. The robot can perform navigation and simple tasks autonomously or change to the teleoperated mode for more complex tasks. The system was developed using ROS, UNITY 3D, and sockets to be exported with ease to different platforms. The experiments suggest that having an immersive operation interface provides improved usability for the operator. The latency appears to improve when using the virtual environment. The user experience seems to benefit from the use of mixed reality techniques; this may lead to the broader use of teleoperated service robot systems.