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Joanne,
Thanks for your
input.
Item 1: I generally agree with
you that guidance out of 802.20 would help specially the service providers. The
issue, however, is that providing guidance on " how to address potential coexistence issues that may arise in the
deployment of an 802.20 system" actually depends on the
bands we pick. I believe there are globally harmonized bands below 3.5
GHz allocated to the mobile service that the group could pick for analysis later
on. Are there such bands for both TDD and FDD?
Item 2:
Agreed.
Item 3: The reason I suggested
discussion on this topic was that Jim's contributions in SF meeting suggested
that Coexistence issues need to be resolved before work on the air interface
could begin. I am trying to see what are these issues that need to be resolved
that are prerequisite to drafting the PHY and the MAC. I don't know of any
standard work dealing with licensed bands that has put coexistence analyses in
advance of the air interface specifications. Typically, Coexistence is either
done after the air interface drafting or in parallel to it because it needs
input from the air interface specifications. Jim? Any input?
Item 4: I also think that
802.20 TDD-FDD interference would be the most problematic, specially the
Base-to-Base and Mobile-to-Mobile cases. This is also, as you
know, what ITU-R studies found for the IMT-2000 TDD-FDD
systems.
Reza
Reza,
Please see my answers below
to the questions you posed:
- Given the fact that 802.20 will be
deployed in licensed bands, does 802.20 WG need to address coexistence or
should the matter be left to the regulatory regime in each
country? ANSWER:
Regulatory
approaches to spectrum management, as well as the specific bands that the
802.20 systems may be used in is likely to vary from country to country. It would
therefore be useful for 802.20 to provide guidance to both operators and
regulators on how address potential coexistence issues that may arise in the
deployment of an 802.20 system.
- In case the WG chooses to take up
the task, should it create a "Recommended Practice" (one containing the word
"should") or a "Guideline" (one containing the word "may")? ANSWER: I believe a
"Recommended Practice" would be most useful. Even though neither would
be mandatory, I believe a Recommended Practice would carry more weight and
would be more likely to be implemented.
- What are coexistence related issues that need to be resolved
before the work on the air interface could begin? ANSWER: None, off
hand come to mind. Any suggestions?
- Should the coexistence work focus on the coexistence of 802.20
TDD and FDD variants as the primary source of interference problems? Or
should it focus on coexistence with other systems? ANSWER: I believe the most
likely scenario would be that 802.20 TDD and FDD systems could occupy
adjacent bands in the same geographic area. It may also be possible
(though, personnally I hope it would be avoided) that a TDD system could
operate co-channel with either a FDD uplink or an FDD downlink band in
an adjacent geographic area. This could be the case either in
neighboring markets in the same country or could be a cross border situation
between two countries. These are the scenarios that I believe should
be the highest priority for the Coexistence
CG.
Best
regards,
Joanne Wilson
ArrayComm, Inc.
(202)669-4006
(Direct)
Resubmission of the
previous message so that it gets into the archives.
Reza
Dear Coexistence CG
participants,
In its July meeting, 802.20 WG chose
to form a Coexistence Correspondence Group to "study and create a
consensus recommendation on how to address the issues of coexistence of
future 802.20 systems with other wireless technologies deployed in the
licensed bands below 3.5 GHz."
There were two contributions on the
issue of coexistence presented to the WG.
-
C802.20-03/72, by Reza Arefi
-
C802.20-03/61r1, by Jim Tomcik, Ayman Naguib, and
Arak Sutivong
The above two contributions, while
consistent on acknowledging the challenges of the task, presented
different views on how to address the issue within 802.20. While document
72 asked for a Coexistence Task Group within 802.20 to deal exclusively
with the issue in parallel to the air interface work, document 61r1
suggested that the matter should be studied by the entire body in series
prior to the air interface work.
The goal of the CG is to come up with
a recommendation on the best way to address coexistence within the WG. The
coexistence analyses themselves are outside the scope of the CG and are
left to a Coexistence document that 802.20 is likely to produce.
Therefore, I see the output of this CG as a concise document (probably one
page) that includes a clear recommendation to the WG and the rationale
behind that recommendation.
The way I propose to go forward is to
have open discussions on the reflector for a while so that we get a sense
of the range of opinions and the amount of interest in the subject. I will
submit to the group a compilation of all views prior to our first
conference call on August 15. I propose the following four specific topics
for discussion on the reflector so that we stay focused on what we are
chartered to do. Please feel free to choose from the list or suggest other
related topics I might have missed.
- Given the fact that 802.20 will be
deployed in licensed bands, does 802.20 WG need to address coexistence
or should the matter be left to the regulatory regime in each
country?
- In case the WG chooses to take up
the task, should it create a "Recommended Practice" (one containing the
word "should") or a "Guideline" (one containing the word "may")?
- What are coexistence related issues
that need to be resolved before the work on the air interface could
begin?
- Should the coexistence work focus
on the coexistence of 802.20 TDD and FDD variants as the primary source
of interference problems? Or should it focus on coexistence with other
systems?
Looking forward to your
participation.
Regards, Reza
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