"Clive" <clive@clivesinclair.com> hath wroth:

>I'm looking at buying a Netgear WNR8542 RangeMax Next Router to replace
>an old Edimax.

I think you mean a WNR854T.

>My Edimax has an external antenna which I replaced with a better one.
>How do the latest Rangemax routers and similar types with no external
>antennas have such improved range/coverage?

Here's how beam forming works:
<http://www.ruckuswireless.com/technology/beamflex.php>
You can also request a white paper on how it works:
<http://www.ruckuswireless.com/technology/whitepapers/80211n/>
or watch the video clip. The antenna is an internal circuit board
with about 7 directional antennas. The processor phases these
antennas so that it generates peaks in the desired direction, and
nulls in the direction of interference. It does NOT work standing up
as Netgear has it pictured in all their advertising.

Here's how the various MIMO router compare:
<http://www.smallnetbuilder.com/wireless/wireless-reviews/mimo_face/>
(15 pages). The WNR854T is too new to appear in this review.

--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558