Emergency officials will conduct another test of the country's new wireless alert system later this month, after an initial test in May failed to reach some mobile users.

The alert will be sent out in all provinces and territories at 1:55 p.m. local time on Nov. 28 except for Quebec, where the alert will go out an hour later at 2:55 p.m.

Canadian Radio-television and Telecommunications Commission (CRTC) requires that all wireless carriers be capable of warning their subscribers of imminent safety threats, such as tornadoes, floods, Amber Alerts or terrorism.

Since the wireless alert system was implemented in April, "close to 100 alerts and updates have been successfully delivered to warn Canadians of imminent threats," according to the CRTC, Canada's telecommunications regulator.

On a smartphone, users should hear a tone similar to an ambulance siren, feel their device vibrate and see a notification displayed on-screen.

Alerts will also go out across radio and television stations at the same time. The system, called Alert Ready, is operated by Pelmorex, which is the parent company of The Weather Network.

The CRTC says that the additional testing is being conducted to raise awareness and "to address any outstanding issues that could reduce the system's effectiveness," after the first test failed to reach some mobile phone users across the country — and in Quebec, failed to work at all.

To receive the alert, users must have a relatively modern device that is connected to their carrier's LTE network, as well as have the latest software updates and support for wireless public alerts.

The CRTC expects that by April 2019 all new devices sold in Canada will be able to receive emergency alerts, but is encouraging Canadians to contact their wireless carriers if they have a supported device that isn't receiving alerts.

Canadians can also check to see if their devices is compatible on the Alert Ready website.