The PSTN works with a simple corded phone into a landline, & continues to work even when a powercut occurs. Digital broadband & Voice over Internet Protocol services are often disrupted.

During a powercut, with mobile reception poor due to severe weather conditions, the PSTN can still work fine, providing a communication option for elderly and vulnerable people to stay in contact with friends and family.

Digital systems often won't work, and mobiles can be out of credit/charge.