Rumor Control Headquarters

The purpose of this page is to assist in understanding the facts about 3650 and eliminate as much as possible the rumors, misunderstandings, etc.

 

Rumor Control Help Center

 

Rumor # 1	I can not use 3650 because I am within 150km from an FSS Station?
Rumor # 2	DFS is a Contention-Based Protocol
Rumor # 3	If the equipment I am deploying is FCC certified with a 24dB grid, and I change that to an 18dB grid?
Rumor # 4	Do I have to list each CPE in the FCC's ULS?
Rumor # 5	What is the difference between using the lower 25MHz and the full 50MHz
Rumor # 6	I was there first, so I get some sort of priority over interference issues.

Rumor # 1 - I can not use 3650 because I am within 150km from an FSS Station?:

FACT: You can use 3650 within the 150km Protection Zone with proper coordination with the FSS Station. See diagram below. Trying to operation within 50km of an FSS Station may be impossible or at a minimum very difficult.

Rumor # 2 - DFS is a Contention-Based Protocol 

FACT: The FCC has NOT approved or classified DFS as a Contention-Based Protocol. They may very well approve or classify it later but as of 05052008, they have not yet done so.  

Rumor # 3 -  If the equipment I am deploying is FCC certified with a 24dB grid, and I change that to an 18dB grid?

FACT: YES,

Rumor # 4 - Do I have to list each CPE in the FCC's ULS?

FACT: NO, only radios that produce more than 1 watt EIRP for every 25 MHz of bandwidth need be registered.

Rumor # 5 - What is the difference between using the lower 25MHz and the full 50MHz

FACT: Under the FCC’s rules, contention-based protocols can be broadly categorized as either “unrestricted” or “restricted.” Unrestricted protocols are broadly compatible and function to prevent interference even with other, dissimilar contention technologies on the market. Restricted contention protocols can prevent interference only with other devices incorporating the same protocol. The Commission, through the equipment certification process, retains the authority to determine whether equipment that operators seek to deploy in the band meets the requirements established for contention-based protocols.

Rumor # 6 - I was there first, so I get some sort of priority over interference issues.

FACT: NO YOUR DON'T. Non-exclusive licensing means just that! The FCC specifically declines to give interference priority to licensees who are the first to deploy in an area.

The above figure is an example of how to compute the actual protection zone of an FSS Station. Basically, it shows that as long as the WISP is NOT inside the blue areas, then the WISP should be allowed to operate his/her 3650 equipment