Mine Site Technologies’ MinePhone, a Voice over Internet Protocol (VoIP) telephone handset for underground two-way communications, has received MSHA approval for use in US coal mines. This completes the approval of the last component for our tracking & communication system to meet the of the MINER Act 2006. Already deployed in hard rock mines, the MinePhone uses the ImPact Wi-Fi network as the communication backbone to provide two-way voice and texting along the primary and secondary escapeways underground. The MinePhone is a VoIP telephone handset which allows private dialling between other phones in the network and the mine’s outside telephone system. Additionally, the MinePhone has 24 channels, Push-to-Talk functionality and Emergency Calling. The Wireless Network Switches (WNS) that form a key part of the underground digital backbone also act as readers for Wi-Fi RFID Tags that are carried by miners underground, meaning a single communication network provides both communication and tracking underground.