Wondering what type of policies or procedures are out there to refill SCBA bottles on a major High-Rise incident. We have 2nd, 3rd, and 4th due companies bringing spare bottles to the staging area 2 floors below the fire floor along w/ their assigned gear. Also, all companies in multiple alarm responses are rquired to bring spare bottles to staging are upon there arrival. Thus we have nothing in place if it becomes and extended operation in a high rise building espically if it a significant incident were crews are continuously rotated in and out of fire operations. We have talked about assigning a company to taxi bottles via elevator or stairs, but this will still become a problem during a extended operation. Looking for input or ideas of how to possibly deal with this potential problem or if anyone has had this porblem and how they over came it.