ZYXEL Modem, model# MAX206M2 compatability

[tking]

Hi,

We can only get one bar in our house with the modem supplied by Clear, Motorola CPE25150. I have seen the Zyxel model above with an external antenna jack for sale. Would this modem work in the Clear network?

Thanks!

[thuor]

Yes this will work. The network is uniform across the country.

[pyropete]

Clear and the Zyxel MAX206M2

I just wanted to comment that I was excited initially about the possibility for an external antenna solution to be used with Clear's new Wimax system in North Seattle. Reception and transmission suck at 2.5 Ghz (trees and rain ) even though I'm 1/3 a mile from the tower. I purchased an Xohm (ZyXel's MAX-206M2) modem and some Yagi antenna's figuring the added gain would fix it . Two antennas an extra 16 dbi , full MIMO , kick ass right ? Upon asking , Clear informed me that the Zyxel Xohm modem could not be used on their system. I believe the equipment is compatible but according to Clear, they are not allowing anyone to use it (even if it is compatible). They told me the only equipment I would be allowed to use was equipment they listed on their site. ;( Heck, If the Motorola Modem worked I would'nt be asking these questions but at my location it hasn't worked well since the switch to wimax and a new Motorola Wimax modem.

I guess I'll be sending the Xohm modem back huh... I'm thinking of keeping the Yagis and using the inductive link that Rwel sells on my Motorola modem. Hope that works . Otherwise it's Hello DSL and More $$$$$$$$$
whadya do right ?

[thuor]

Thanks pyropete for this update yes we have heard similar issues with other customers since posting this. This doesn't really make sense to us! The whole idea of 4G wimax and all the gazilion dollars Intel, google and the rest poured on Clearwire was in my opinion supposed to ensure vendor neutrality and open access for certified wimax modems ... alas this is not so!

Would very much appreciate any Clearwire support rep to explain why the Zyxel modem is valid for use in some markets and not others. i.e any technical restrictions vs contractual limitations with equipment vendor.

Some caveats on the coupled-antenna adapter for use with modems without external antennas:

1) unfortunately you cannot fully exploit MIMO antenna diversity & spatial multiplexing as you would with the Zyxel modem. This is because when you couple to the internal antenna you are unable to segregate the dual integrated internal antennas to allow for path redundancy which is where MIMO obtains its benefits. The solution would reduce to the MIMO case where the different paths were highly correlated (MIMO works best when paths are uncorrelated). Now if you have a clear RF line-of-sight LOS (different from optical line of sight) then this would be no different than the case where you did have 2 directional antennas for the Zyxel oriented in the same direction with LOS to the Clearwire WiMax BTS antennas since the MIMO coding gain would be little to nothing here.

2) beware of the coupling losses which are much higher than the insertion loss through the Zyxel antenna adapter. Could be as high as 1-3dB so when doing RF link budgeting consider that in addition to cable losses.