For weeks we've reported how many Clearwire customers are seeing their service throttled back to speeds around 256 kbps, without Clearwire being clear about how, why or when this occurs. Customers have been told different things depending on who they talk to at the company, which has repeatedly encouraged users to fully utilize the "unlimited" service. Our recent conversations with Clearwire haven't clarified things much, the company simply saying they take a "hands off" approach to managing the network.

"If we experience network congestion, we are committed to dealing with everyone fairly and we do not target specific applications," company spokesman Mike DiGioia tells Broadband Reports. "The heaviest of users may give up a small amount of bandwidth so that everybody has a good experience."

In follow up conversations we've tried to get Clearwire to be more specific, but haven't had a lot of luck.

"Regarding the system, during September we made some enhancements to the customer experience optimization system that we utilize across our networks," confirms DiGioia. "We implemented this system to help ensure that our customers continue to get the level of service they expect from us as we grow, and as data consumption continues to expand," he says. "The system was designed with a singular purpose: to provide the maximum number of customers the maximum amount of bandwidth, in the times when they demand it most."

That still doesn't explain what specifically causes the throttling, how long customers are throttled, and to what speed they're throttle back to. But an employee posting to the Clear forums offers up substantially more detail, noting that the throttling is imposed on a per tower and rolling invisible quota basis:According to the post (which still fails to give users hard usage lines to avoid), the system is "theoretically" only supposed to throttle users for fifteen minute increments, but Clearwire confirms "a very small percentage of users are being set at very low D/L speeds for hours at a time." Clearwire says they're collecting data on the system and will make adjustments so that throttled user connections will "become more usable."

Hopefully they'll take some time to adjust the way they inform consumers as well. While some level of congestion management on a wireless network is expected, consumers have a right to know precisely what kind of connection they're paying for. That said, it sounds like even Clearwire doesn't know when their throttling system will kick in, given some of their towers likely struggle with backhaul capacity.