The correct answers are A. Identify the location of devices that utilize 2.4GHz and D. Map all of the wireless signals in the restaurant. In order to troubleshoot the issue, the technician should first identify the location of devices that utilize the 2.4GHz frequency, as this can cause interference with the wireless signal.
Additionally, the technician should map all of the wireless signals in the restaurant in order to identify any potential sources of interference. Checking to see if the phones are IJTP or STP lines, testing to see if the copper electrical wires are causing interference, verifying T568B is being used in the wiring closet patch panel, and scheduling timed router reboots throughout the day are not necessary steps for troubleshooting this issue.