Adoption of Push-to-Talk over Cellular and Wi-Fi networks is growing in the security market due to the wide area coverage, low cost, the bandwidth to accommodate voice and video communications, and integration with dispatching applications. This article reviews the different types of Push to Talk network deployments, how they work, the devices used, and the benefits to users.  The types of Push-to-Talk networks include Push to Talk over Cellular (PoC), Push-to-Talk over Wi-Fi, and unified PoC, Wi-Fi and LMR radio networks.