Fastest Speeds Ever Seen on WiMax

[iansltx]

Just fired up my Clear Hub with a 2-hour pass to see if lower congestion and potentially improved backhaul (but probably not since this is definitely a redundant site) have boosted the attainable speeds from me to the tower 1000 feet away. The answer is, unfortunately, no. Unless Clearwire is heavily de-prioritizing 2-hour pass folks (which I could buy...I'm getting 1 Mbps up and it appears to be a very-much-throttled 1 Mbps).

 

Tests are all over the map, from 3 Mbps to 8 Mbps, with a modem that I've seen hit 18/1.5 before, with a similar CNR (25+).

 

ne interesting thing I noticed is that the frequency the modem locked onto is quite a bit higher than what I remember it using the last time I tried it (several months ago). 2683.5 MHz to be exact. Not sure about channel size; for all its faults, the Clear Spot Voyager gives a lot more of that info.

 

EDIT: Hit 10 Mbps, with peaks to nearly 12, though things are still wildly inconsistent. But hey, I got my CNR up above 30 by standing the modem on edge. Yeah, I'm close to the tower.

[WiWavelength]

I have been doing some TDD research over the past few days.

 

For mobile WiMAX, the two most common downlink:uplink symbol ratios are 29:18 and 35:12.  In its FCC construction requirement fillings, Clear states that it has utilized the 29:18 ratio.  If we assume 2x2 MIMO and 64-QAM on the downlink but no MIMO and only QPSK on the uplink, then that symbol ratio calculates to a 348:36 bit ratio, which is reasonably close to 10:1.  But that represents a best case scenario on the downlink, worst case scenario on the uplink.

 

So, I suspect that Clear has implemented some throttling beyond just the downlink:uplink ratio to limit the uplink to 1 Mbps or 1.5 Mbps.

 

AJ

[zz1049]

My at home speeds and experiences with uploads

I have no advanced information into the network but I noticed that the internet will not allow me upload any faster than about 150-spikes of 180 but doing the math (and some speed tests) results in basically 187.5KB/s or 1.5 Mbit, HOWEVER, I used a seperate application "LTE SpeedTest" which seems to estimate immediate traffic capibilities between the tower and the user. I consistently get similar DOWN speeds as I do with other applications, including the common speedtest app. but it always registers that I potentially can get anywhere between 2-5mbit upload; I USED to get 6-12mbit down now I'm lucky to get 4megabits down. So far the REAL ratio I get to output is more like 300-500KB/s down average and 170 up. (This location is based on my house) off Snell/Capitol 95136 area, surrounded by 4-6 clear mapped sites.

My best experiences and what I believe

With that being said, those who experience momentary 200+ speeds; upload I am talking about, close to a tower I can get close to 16Mbit -20 Mbit speeds but I believe that to be calculation error due to the phone clearing its buffer for more than one second's worth of data within less than a second due to some type of software lag, making it look like there was a point where the speed peaked beyond the cap but I (personally) think that's the data it missed in the previous moments to beginning the data transfer.

I PERSONALLY believe that the network is having issues due to the upcoming LTE upgrades; but have not noticed any change in WiMax performance, if anything it has gotten worse. (San Jose, CA)

Why I think that meters/speeds are being reported as "Higher":

To break it down it's somewhat like a mileage meter, it can tell you your mileage based on point A->B (Total transfer/time). Taking it to the car explanation, think you are in a newer car that displays mileage, in which you see the meter refresh every second, and notice that for some point in your trip you are getting 50MPG, and this meter refreshes every second, it simply could just be that the rest of the data is not being incorporated and a simple estimate for that momentary second is being displayed. My belief is having data from the last second be recieved as the data for the current second is registered for that second the meter/display will register it momentarily higher to approximate for each second just like the vehicles' built in meter would display for your mileage for that second. I think of bursts just like letting the car idle at a higher speed, of course the meter will display a high end number but is the estimate correct? One must consider what these measurements are, approximations over time.

[S4GRU]

WiMax performance is completely unrelated to LTE. WiMax network is owned by Clearwire and is separate from Sprint's network in every way. Different sites and different backhaul and different switch centers. Sprint LTE is deployed on their own sites on the Network Vision platform.

 

Robert from Note 2 using Tapatalk 4 Beta

 

 

[WiWavelength]

WiMax performance is completely unrelated to LTE. WiMax network is owned by Clearwire and is separate from Sprint's network in every way. Different sites and different backhaul and different switch centers. Sprint LTE is deployed on their own sites on the Network Vision platform.

 

In my recent TDD reading, one possibility that I came across is a slight degradation to WiMAX performance because of TD-LTE deployment.  If WiMAX and TD-LTE are deployed in adjacent spectrum, then their TDD downlink:uplink ratios and guard periods must be closely synchronized.  Otherwise, the WiMAX base station could be transmitting while the TD-LTE base station is receiving (or vice versa) -- the out of band adjacent channel emissions causing major interference.  To prevent that, syncing up their TDD downlink:uplink ratios and guard periods is relatively doable, but it may require a compromise in which the WiMAX carrier goes prematurely quiet each cycle, thereby cutting down its capacity.

 

AJ

[S4GRU]

 

 

WiMax performance is completely unrelated to LTE. WiMax network is owned by Clearwire and is separate from Sprint's network in every way. Different sites and different backhaul and different switch centers. Sprint LTE is deployed on their own sites on the Network Vision platform.

 

 

In my recent TDD reading, one possibility that I came across is a slight degradation to WiMAX performance because of TD-LTE deployment. If WiMAX and TD-LTE are deployed in adjacent spectrum, then their TDD downlink:uplink ratios and guard periods must be closely synchronized. Otherwise, the WiMAX base station could be transmitting while the TD-LTE base station is receiving (or vice versa) -- the out of band adjacent channel emissions causing major interference. To prevent that, syncing up their TDD downlink:uplink ratios and guard periods is relatively doable, but it may require a compromise in which the WiMAX carrier goes prematurely quiet each cycle, thereby cutting down its capacity.

 

AJ

That's very interesting to consider. To clarify for others reading, my reference was related to Sprint FDD-LTE and WiMax. It will be interesting to monitor WiMax performance in TDD-LTE markets over time.

 

Robert via Nexus 7 using Tapatalk 4 Beta