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Phil,
All,
Thanks for
comments. I agree that "Dynamic Channel Selection" should be part of the
solution. However, only this will not resolve the problem.
I have a
point to make:
It is
possible PHY independent signaling, at least between 802.16 SCa, OFDM, OFDMA
systems and 802.11a systems.
Al these
standards have a common point: use FFT receivers (for channel
equalization).
In my
understanding, as long as we use messages embedded in PHY
signaling, based on having energy in different zones of the channel
(lets say using FFT 16 or FFT 32 in 10MHz, FFT 32 or FFT 64 in 20MHz), all these
standards are able to detect it.
You can
create simple messages by using "carrier position modulation", as shown in
C802.16/04-30.
Be aware, I
am NOT talking about MAC MESSAGES.
I am talking
about markers of frame start and simple messages based on PHY
signaling.
Regards,
Marianna
It is now more common for operators in licensed
frequency use, for mobile and fixed operation, to co-exist on the same
tower. As Brian identifies, this change is a function of the increased
cost of tower deployment and the need to maximize per tower revenue
streams. Indeed, the existence of the three major independent tower
owner/operator companies in the US owes itself to licensed operators
divestiture of tower assets that had been requiring ever more capital and
management allocations, diverting resources from core business growth and
operations, all supported with single source revenue streams.
However, I think Gordon's point is very valid for
competitors in licensed operation. The nature of licensed use dictates
that while there may be adjacent channel operators on the same tower,
there are not co-channel operators.
Un-licensed tower tenancy is another
matter. It is typical for tower owner/operators to only allow a single
un-licensed band service operator on a given tower (both by contract and in
practice; i.e. in the US, one ISM and one UNII operator per tower).
However, this practice is not universal and is far less prevalent with less
sophisticated tower operators.
For our purposes, I do not think we can assume on
a given tower the unique presence of RF equipment in a given band (ISM, UNII,
etc...) for unlicensed use. So co-band/same site operators must be
considered in our deployment environment modeling. And absent a mandated
mechanism like DFS, co-channel/same site operators cannot be ruled
out.
On another matter, it will not be possible to do
direct PHY mode synchronization in the absence of a common backbone
connection. So for differing operators, negotiated PHY mode
synchronization is NOT possible. Indirect PHY mode
synchronization IS possible.
Thanks,
Phil
----- Original Message -----
Sent: Friday, March 26, 2004 3:48
PM
Subject: Re: [STDS-802-16] LE Ad-hoc -
BS-BS Interference - Call for solut ions
Yes, and they have a frequency plans that allows this to happen plus
they operate in licensed bands where operators have different parts of the
band set out specifically for this to happen.
Agreed - as long as 15 years and more
ago a significant percentage of masts in the UK had both Vodafone and
Cellnet antennas on - even if one or other owned the actual site. 2G
and 3G infrastructure sharing has considered and in some cases implemented
all manner of other scenarios (antenna and feeder sharing etc etc through
to MVNO).
Doug
----
Dr Doug Pulley
Chief Technical
Officer
picoChip
Kiernan, Brian G. wrote:
I agree with everything Gordon says except his last point regarding
competing operators on the same tower.
Towers are very expensive real estate and with the increased
restrictions on tower siting due to various environmental and aesthetic
considerations, it is getting even more difficult and more expensive to
find and construct suitable tower sites, especially in urban and
suburban areas. The mobile industry found this out a number of years
ago and it is now very common to find competing operators using the same
tower, often just leasing space from the tower owner (who may not even
be an operator).
Brian
-----Original Message-----
From: Gordon Antonello [mailto:GAntonello@WI-LAN.COM]
Sent: Friday, March 26, 2004 11:45 AM
To: STDS-802-16@listserv.ieee.org
Subject: Re: [STDS-802-16] LE Ad-hoc - BS-BS Interference - Call for
solut ions
Usually 802.11 systems are indoors and the likelihood of having an
802.11 AP
antenna in close proximity to an 802.16 BS antenna is quite low, if not
zero. 802.11 systems operate in un-licensed bands, typically 5.8 and/or
2.4
GHz, and there are rules established, at least in Europe, for
co-existence.
I would suggest the group investigate the co-existence rules currently
established for Europe as a starting point, it may prove useful. Also,
in
my opinion it is highly unlikely there would be two competing operators
sharing the same tower, even in un-licensed bands.
Gordon
-----Original Message-----
From: Itzik Kitroser [mailto:itzikk@runcom.co.il]
Sent: Thursday, March 25, 2004 11:57 AM
To: STDS-802-16@listserv.ieee.org
Subject: Re: [STDS-802-16] LE Ad-hoc - BS-BS Interference - Call for
solutions
Marianna,
I understand that from your calculations, a feasible 802.16
solution will be realistic only by BS coordination.
What if you have several 802.11 APs, or any other technology
using same bands, close to your BS, with no apparent means of
coordination?
Itzik.
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