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Hi
All,
So I
guess it appears that it is possible to put 4 CDMA carriers in 5 MHz of spectrum
in a 15 MHz block or in a combined 15 MHz+5 MHz block. Then, what are we
debating?
Has
anyone examined the spectrum allocation for the WCS
services?
- WCS should be licensed initially as two
10 MHz channel blocks (with 5 MHz of this spectrum from the lower band paired
with 5 MHz from the upper band) plus two 5 MHz blocks (those immediately
adjacent to the satellite DARS spectrum).
[page 23, FCC 97-05] The
specific channel blocks are as follows [page 24, FCC
97-05]:
·
Channel Block A à 2305 - 2310 and 2350 - 2355 MHz
·
Channel Block B à 2310 - 2315 and 2355 - 2360 MHz
·
Channel Block C à 2315 - 2320 MHz
·
Channel Block D à 2345 - 2350 MHz
- For
out-of-band emissions, the requirement will be that all emissions from
WCS fixed transmitters be attenuated below the transmitter power (p) by at
least 80 + 10log(p) dB and that all emissions from WCS mobile transmitters be
attenuated at least 110 + 10log(p) dB within the 2320 - 2345 MHz band.
This level of attenuation is required in order to adequately protect satellite
DARS reception from WCS transmissions.
[pages 70 - 71, FCC 97-05]
Note
that guard bands are not specified but out-of-band emission requirements are
specified. The needed "guard band" now becomes an implementation
issue.
Joseph
Cleveland
Hi
Anna,
Since 802.20 is intended to be deployed in licensed
bands, the guard band requirements must be understood
and
accounted for in the design of the radio. As I have said, if an
operator has only a 5 MHz block, then it is
possible to deploy only 3 cdma2000 carriers (not 4). If an
operator has a 15 MHz licensed block, then it is possible
to
deploy only 11 carriers (not 12). As you have
noted, if an operator has licenses for two (or more) adjacent
blocks
(such as B and D), then it would be possible to
deploy a total of only 15 carriers in a total licensed block of 20
MHz
( 15
MHz B-block + 5 MHz D block = 20 MHz). Under the Part 24 rules for
PCS, guard bands are not required
between licensed blocks if both blocks are licensed
to the same operator.
Best
regards,
David Shively
Hi
David,
Thanks for the link
to the 3GPP2 web site. In Table 2.1.1.1.2-3 of C.S2002-C v1.0, the CDMA
channel numbers for Band Class 1 (PCS band in the US) and spreading
rate 1 are listed. Using Block B (15 MHz) as an example, it is shown that
the CDMA channel numbers between 425 and 675 are always valid, whereas the
ones between 400 and 424, and those between 676 and 699 are marked
conditionally valid. It is true that there are 11 channels that are always
valid - also listed in Table 2.1.1.1.2-5 as "preferred" channel numbers.
However, the standard didn't seem to exclude the option of deploying 12
channels within the block. Would it be possible to have a scenario in which
an operator owns both adjacent blocks. e.g., Blocks D and B, so that the
operator can decide to use channel number 400 in addition to the 11
preferred channels? In this scenario, it would be possible to deploy 12 CDMA
channels in 15 MHz bandwidth.
Best
regards,
Anna.
-----Original
Message-----
From:
owner-stds-80220-requirements@majordomo.ieee.org
[mailto:owner-stds-80220-requirements@majordomo.ieee.org] On Behalf Of Shively,
David
Sent:
Tuesday, November 25,
2003 12:13
PM
To:
stds-80220-requirements@ieee.org
Subject: RE: stds-80220-requirements:
Spectral Efficiency (4.1.2)
Thank
you for providing this information. You are correct that adjacent
cdma2000 carriers may be
placed
adjacent to one another. This is exactly what I had said in my
previous email below.
At the
edge of a 5 MHz licensed frequency block, there is typically a guard band of
625 kHz. As you
have
noted, this is to avoid interference to an operator in an adjacent frequency
block. With a guard band
of 625
kHz on each end of a 5 MHz block, this leaves only 3.75 MHz of spectrum,
e.g. this will allow
the
deployment of 3 cdma2000 carriers where each carrier is 1.25 MHz.
In the
case of a 15 MHz licensed spectrum block, it is possible to deploy a total
of 11 cdma2000
Additional details
can be found in: Physical Layer Standard for cdma2000 Spread Spectrum
Systems
Also,
again as I had indicated in my previous email, if an operator
had a licensed allocation of only
1.25
MHz then there is no realistic way to deploy this type of system since the
necessary guard bands
would
fall out of this block and onto the adjacent operators.
-----Original
Message-----
From: Lai-King
Tee [mailto:a.tee@samsung.com]
Sent: Tuesday, November
25, 2003 2:03
PM
To: 'Joseph Cleveland';
'Shively,
David'; stds-80220-requirements@ieee.org
Subject: RE: stds-80220-requirements:
Spectral Efficiency (4.1.2)
Hello
David,
Based on what I
found from the reference material*, the guard band is used in the CDMA
(IS-95) system when the adjacent frequency channel may have high power
signal transmissions. However, there is no need for guard bands between
adjacent CDMA channels.
The
reason that the first CDMA 2000 channel is usually deployed further away
from the edge of the licensed band is probably to avoid high interference
power from the adjacent frequency channel that has been used for other
high power wireless systems.
*Reference:
"Jerry D. Gibson, The Mobile Communications Handbook, Chapter 27, IEEE
press, 1996.
Best
regards,
Anna.
-----Original
Message-----
From:
owner-stds-80220-requirements@majordomo.ieee.org
[mailto:owner-stds-80220-requirements@majordomo.ieee.org] On Behalf Of Joseph
Cleveland
Sent:
Tuesday, November 25,
2003 8:53
AM
To: 'Shively, David';
'stds-80220-requirements@ieee.org'
Subject: RE: stds-80220-requirements:
Spectral Efficiency (4.1.2)
I
disagree with your analysis. For example, PCS
D/E/F-Block (5 MHz) operators currently use carriers
separated by 1.25 MHz with all channels assigned. If an
operator has a 15 MHz block (e.g., A/B/C-Block), the operator can use
the entire spectrum with carriers placed 1.25 MHz apart across
the entire block - for a total of 12 carriers, not 9. It is realistic
to deploy a system with a chip rate of 1.2288 Mcps in a 1.25 MHz
bandwidth!
-----Original
Message-----
From:
owner-stds-80220-requirements@majordomo.ieee.org
[mailto:owner-stds-80220-requirements@majordomo.ieee.org] On Behalf Of Shively,
David
Sent: Tuesday,
November 25, 2003 10:00 AM
To:
'stds-80220-requirements@ieee.org'
Subject: RE: stds-80220-requirements:
Spectral Efficiency (4.1.2)
I'm afraid I
have to disagree and this is actually an example of the point I
have tried
In
some cases, yes, cdma2000 carriers can be placed directly adjacent to
one another,
although there
is some degradation in overall capacity when this is done.
However, in
most
deployments the first cdma2000 channel that is used is 1.25 MHz away
from the
edge of the
licensed band. This means that there is a guard band of
approx. 625 kHz
between the
first cdma2000 carrier and the edge of a licensees spectrum
allocation.
This
is why an operator can use 3 cdma2000 carriers in a 5 MHz block of
licensed spectrum
If an
operator had a license for only a 1.25 MHz block of spectrum, then I do
not think it would
realistic to
deploy a system with a chip rate of 1.2288 Mcps.
-----Original
Message-----
From:
Joseph Cleveland [mailto:JClevela@sta.samsung.com]
Sent: Tuesday, November 25, 2003
9:51 AM
To: 'Shively,
David'; 'stds-80220-requirements@ieee.org'
Subject: RE:
stds-80220-requirements: Spectral Efficiency (4.1.2)
I believe
that if you look at the spectrum allocation scheme and spectrum
emission mask for CDMA2000 you will find that 1.25 MHz does
include the guard bands. The CDMA2000 channel spacing is
1.25 MHz.
-----Original
Message-----
From:
owner-stds-80220-requirements@majordomo.ieee.org
[mailto:owner-stds-80220-requirements@majordomo.ieee.org] On Behalf Of Shively,
David
Sent: Monday,
November 17, 2003 3:06 PM
To:
stds-80220-requirements@ieee.org
Subject: RE:
stds-80220-requirements: Spectral Efficiency
(4.1.2)
Regarding these definitions, it
should be clearly understood whether
or not guard bands are
accounted for in the calculation of spectral
efficiency. For UMTS
(W-CDMA), the channel is usually quoted as being
5 MHz wide. In
this case the guard bands have been included. However,
for
cdma2000 1X (and IS-95) the channel is usually quoted as being
1.25
MHz wide which does not include the necessary guard
bands.
I propose the
following:
Network Wide Bandwidth:
The network wide bandwidth is the total spectrum in
use by
the unique carriers deployed in the network, including any
required guard bands.
Best regards,
David
Shively
-----------------------------------------------------------
Dr. David
Shively
Cingular Wireless
5565 Glenridge Connector, Mail
Stop 950
Atlanta, GA 30342
Phone: 404 236
5909
Mobile: 404 285 5731
FAX: 404 236
5949
email:
david.shively@cingular.com
pager:
dshively@imcingular.com
-----Original
Message-----
From: Humbert, John J [NTWK SVCS] [mailto:JHumbe01@sprintspectrum.com]
Sent: Monday,
November 17, 2003 12:08 PM
To:
stds-80220-requirements@ieee.org
Cc:
mike@arraycomm.com
Subject: stds-80220-requirements: Spectral
Efficiency (4.1.2)
Below is the latest version of
the text that was developed at the Plenary in Albuquerque along with
a list of the open issues for this section.
*
4.1.2 System Spectral Efficiency (b/s/Hz/sector)
* The
system spectral efficiency of the 802.20 air interface shall be
quoted for the case of a three sector baseline configuration
[Footnote 1]. It shall be computed in a loaded multi-cellular
network setting, which shall be simulated based on the methodology
established by the 802.20 evaluation criteria group. It shall
consider among other factors a minimum expected data rate/user
and/or other fairness criteria, and percentage of throughput due to
duplicated information flow. The values shall be quoted on a
b/s/Hz/sector basis. The system spectral efficiency of the 802.20
air interface shall be greater than X b/s/Hz/sector.
*
Footnote 1: Since the base configuration is only required for the
purpose of comparing system spectral efficiency, proposals may
submit deployment models over and beyond the base
configuration.
*
Definition:
* System
spectral efficiency - System spectral efficiency is defined as the
ratio of the aggregate throughput (bits/sec) to all users in the
system divided by the network wide bandwidth (Hz) and divided by the
number of sectors in the system.
*
Aggregate Throughput: Aggregate throughput is defined as the total
throughput to all users in the system (user payload only).
*
Network Wide Bandwidth:The network wide bandwidth is the total
spectrum in use by the unique carriers deployed in the
network.
* Open
items
- Single
value vs. multiple for uplink and downlink
- X
bits/sec/Hz [note 1 b/s/Hz -or- downlink > 2 b/s/Hz/(cell or
sector?) @ 3km/hr ;uplink > 1 b/s/Hz/(cell or sector?) @ 3
km/hr].
- Actual
values of spectral efficiency at higher speeds
-
TDD/FDD
John J. Humbert
6220 Sprint
Parkway
Mailstop KSOPHD0504 - 5D276
Overland Park, KS
66251-6118
PCS (816) 210-9611
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