In continuation of the press statement, they said "It is worth noting here that Jio does not offer you fallback option. This means, at a place where 4G coverage is not there, you would not be able to use Jio services. Whereas in Airtel, in case 4G network is weak/ not available in a place or your handset is not 4G compatible, you may still enjoy the services on the 3G/2G network. Would also like to inform that voice services for Jio are experiencing high congestion and since you are a high-value customer this will impact your business. We would also like to reassure you that Airtel has the best network and data speeds across the country." In other words, it means that when you are in an area where the Reliance Jio 4G signals are not strong enough, your SIM may just be useless for that period, until you arrive at a location when the signals come back on. In the case of other operators, if the 4G does not work, you atleast have 3G/2G service to rely back on, but not in the case of Jio.