@Sam Schrimsher the guys that by the revenue stream from the cell lease will offer a lump sum. As an example, let's say the cell tower pays $1,000/month or $12k/year and there's some term remaining on the lease. They will offer a buy out of the lease of say $200k (12,000/.06; e.g. 6 cap). They pay you 200k today and get whatever revenue the existing lease and renewals generate for the next 50 years. They also take a risk that the tower doesn't shutdown or not renew. It's kind of like a ground lease.
Cell tower owners have caught onto this and added language to their leases to give them the right to buy first or restrict deals like this. So check the lease to be sure there's no limiting language. There's also more value in 3% annual escalations vs 2% and cell towers have really been pushing for lower escalations.
If this is something you're considering engage a lawyer to help you lock it up with an option to purchase. Once under contract you can negotiate a sale of the cell tower income. Just know that any financing you may get will want a portion of whatever payment you get or will change how they underwrite the financing of the purchase.