Cellular is always on when you need it. Devices can transfer data in real time so there’s no need for massive storage as data is stored in the cloud or transmitted to another device for storage. Software updates and troubleshooting can also be done remotely.
Some of today's older devices use either PSTN landlines or SD cards that patients are tasked with mailing back to their hospital or healthcare provider. Some also use a PC-based solution that is connected to the Internet. As technology advances and the world goes mobile, these older devices are becoming obsolete.