(California News Service) Most devices that run on 3G wireless technology will become obsolete this year, some as soon as three weeks.

To clear bandwidth for the new high-speed, fifth-generation networks known as 5G, companies will shut off service to devices that use 3G. That includes older-model flip phones, fire alarms, burglar alarms, personal emergency response necklaces or bracelets, and onboard navigation systems in older cars.

"What we're recommending is that a person really sit down and go through everything in their home and their car that might be connected to a wireless connection," said Tom Kamber, executive director of Older Adults Technology Services from AARP. "Write down what the model number is and call the provider who's giving you service for the device."

AT&T will shut down its 3G network on Feb. 22. T-Mobile shuts down its old Sprint network March 31 and its own 3G offerings at the end of July. Verizon has said it will retire its 3G service at the end of this year. 

Kamber said you may have to replace your device, but you don't have to go with an expensive, top-of-the-line 5G product if you only need a basic model. 

"Begin by saying, 'What is the most compatible new device that would be at the same level of cost as my old device, and can I do this cost-free?' And many companies are trying to offer it for free right now," he said.