I'm no LTE expert, but I'm pretty sure that it handles overlap: you can run LTE diagnostic apps on Android that will display all the visible base stations - often many are visible, sometimes 3 or more on the same band. Your phone looks at what's available and picks a combination with the best signal strength (sometimes it will connect on 2 or 3 different bands simultaneously with carrier aggregation).
But even then, most carriers have many bands/channels (EARFCNs) available - and presumably only a small slice of bandwidth is needed for this service considering it's (initially) only for text messages. Finding 5 Mhz on one of the higher LTE frequencies wouldn't be so hard for many carriers, even if it does need an exclusive channel.
But even then, most carriers have many bands/channels (EARFCNs) available - and presumably only a small slice of bandwidth is needed for this service considering it's (initially) only for text messages. Finding 5 Mhz on one of the higher LTE frequencies wouldn't be so hard for many carriers, even if it does need an exclusive channel.