Abstract: A special-purpose mobile communication device using low-bandwidth cellular technology designed for IoT applications, such Narrowband LTE for IoT, is used to securely exchange voice messages in real-time or near real-time with another user. The voice messages are short duration voice messages, also referred to as voice clips, that are capable of being compressed using file compression algorithms instead of stream compression methods ordinarily used for real-time audio. A general-purpose mobile communication device activates the special-purpose devices and creates a private network for securely exchanging the voice messages between the devices. The general-purpose device also operates a mobile application that interfaces with a cloud-based mobile voice communication and location tracking system to manage the voice messages and track the location of the special-purpose device using Observed Time Difference of Arrival measurements.