In the case of point to point licenses for backhaul purposes in the US, obtaining a license is relatively simple and easy.  A service provider would contact a company that acts as a frequency coordinator with the FCC.  This company is responsible to do database searches of existing PTP licenses in a given spectrum in the market to ensure there is not cross-over (to prevent interference).  The typical cost for the license and frequency coordinator services typically will run $2,500 to $4,000.  However, it should be noted that prices will vary.  Spectrum in the 900 MHz and 2.0 GHz range are rarely allotted by the FCC nowadays.  It is much more common to obtain 6 GHz, 11 GHz, 18 GHz or 23 GHz PTP licenses.  The "sweet spot" for PTP based upon cost versus capability seems to be at 18 GHz.  For firms desiring very high bandwidth and short range backhaul companies such as FiberTower Corporation or NextLink sublet frequencies in the 24 and 39 GHz band readily for modest cost.  The rules for similar types of PTP licenses used in other countries vary widely. 

Obtaining a license to deliver multi-point services in the US, especially in the 2.5 GHz range is extremely difficult---largely because there is not much spectrum available.  Most of this spectrum range is controlled by Sprint/Nextel and Clearwire (and soon primarily Clearwire)---leaving only about fifteen percent of either BRS or EBS spectrum obtainable.  The cost is not insignificant.  Typically for a firm attempting to secure spectrum for multi-point use the first step is to identify the market area desired, locate the spectrum holder (by searching the FCC site) or work with a broker who may have local contacts to help obtain control of a license. 

Expect to spend significant funds, even for rural markets.  It is not a process to attempt lightly.  For those with a compelling economic justification and need for a license, the current capabilities of WiMAX technology offer and deliver significant advantages for license holders.