RE: stds-802-16-tg4: coexistence with 802.11/802.15
I agree with Ken and Jori that Antenna radiation pattern is one trick often
played in this game, but I want to caution everyone that it's not the only
trick, and probably not the most useful/reliable trick. Call me
conservative or old-fashioned, but I just don't have as much faith in
something that hasn't been widely used and benchmarked. It could be a nice
auxiliary or complementary feature to enhance system performance and reduce
interference, but it should NOT be a cornerstone of the standard, i.e. we
cannot rely on it to achieve coexistence.
--------------------------------------------------------------------------
Minfei Leng
Phone: (716)631-4584; Fax: (716)631-6080
Clearwire Technologies
P.O.Box 850
Buffalo, NY 14225-0850
www.clearwire.com
> -----Original Message-----
> From: Jori.Arrakoski@nokia.com [mailto:Jori.Arrakoski@nokia.com]
> Sent: Tuesday, April 10, 2001 2:11 AM
> To: ken@Malibunetworks.com; stds-802-16-tg4@ieee.org
> Subject: RE: stds-802-16-tg4: coexistence with 802.11/802.15
>
>
> Ken,
>
> Defining antenna radiation pattern limits is one of the
> tools in the co-existence game. The problem is the range
> from our "omni"-approach to John Sydor's 10-15 degree beams,
> with most of you other guys somewhere in between. Thus it
> might be difficult to define reasonable numbers unless it
> is done case by case. Anyhow, we can state that it is in
> the group's interest to minimize any side or backlobe
> radiation of the antennas used (and this is very true since
> we gain too).
>
> Another issue is the vertical radiation pattern. Since FWA
> systems tend to operate in the horizontal plane, we could
> try to set limits on vertical radiation patterns. This would
> have real impact on co-existence with 802.11/802.15 devices
> below and even satellites above!
>
> BR
> Jori
>
> > -----Original Message-----
> > From: ext Ken Peirce [mailto:ken@Malibunetworks.com]
> > Sent: 09 April, 2001 21:11
> > To: 'stds-802-16-tg4@ieee.org'
> > Subject: stds-802-16-tg4: coexistence with 802.11/802.15
> >
> >
> > All,
> > In addressing the coexistence issue where 802.11 and 802.15 are
> > concerned, I would like to know what the PHY team would think
> > of instituting
> > a maximum on power behind the antenna (back
> > lobes/backscatter). I believe
> > that in most cases the antenna for a UNII system will be
> > pointed away from
> > the building it is attached to. It is hardly ideal, but what
> > if we simply
> > required an Xdb signal strength drop in the 180 degrees of
> > the back side of
> > the antenna? I know that there are outdoor capable EM
> > absorbing foams in
> > this frequency band available. There are also a lot of other means
> > available. While smart antennas may be a solution as well, I
> > was looking for
> > a simple, inexpensive option too. Also, I would like to keep
> > the MAC as
> > simple as possible with its coexistence role limited to
> other UNII BWA
> > systems. I am not an expert in this area, but I would like
> to hear the
> > opinions of those who are PRIOR to the next meeting.
> >
> > Thanks,
> > Ken Peirce
> >
> > Disclaimer: The opinions stated here are mine and not
> > necessarily those of
> > Malibu Networks.
> >
>