900Mbps!! Fiber to the desktop?
Wireless broadband data speeds (WiFi included) -- depend on the ratio of signal power to noise+interference. Acronym: SINR (signal to interference and noise ratio).
THIS IS TWO-WAY. Most people are unaware that the client-to-router signal strength is important, and rarely made known to the user.
As well, since WiFi is in an unlicensed band, speed is reduced as you and neighbors' WiFi compete for air time. It's like a the parliamentary procedure: One speaker at a time. WiFi is not "managed" so a speaker speaks when he hears silence; there is no moderator. To use a metaphor.
WiFi speeds in marketing and on the box, are the "burst rate bits per second". Data is sent in tiny bursts with 802.11 WiFi. The receiving end has to send an acknowledgement of successful receipt every few bursts. And there are retransmissions to do error correction. If you could see the bursts, you'd see that they are sent rather infrequently (in the world of thousands of bursts per second).
So all this adds up to a rule of thumb: For each step of SINR (signal strength mainly), there's a unique ideal burst bit rate. IEEE 802.11 defines what burst rates can be used so devices can talk across brand names. About 60% of the burst rate is available, presuming no delays for air time access. If you are near the channel of a neighbor that uses a lot of air time, a LOT, like streaming HD video on WiFi (real HD, not the shrunk down speeds like Netflix uses) - then your net speeds are way less than 60% of the ideal burst rate. So you change and try to use a less busy part of the band's channels (channels overlap so you have to separate by about 3 channels). But in unlicensed, what you experience today will differ tomorrow, due to nearby WiFi usage habits of people.
oversimplified, but I hope it helps.