RE: stds-80220-requirements: Spectral Efficiency (4.1.2)

["Shively, David" <david.shively@cingular.com>]

Title: Message

Joseph,

 

I'm afraid I have to disagree and this is actually an example of the point I have tried

to clarify.

 

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

rather than 4. 

 

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.

 

David Shively

-----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)

David,

 

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.

 

Joseph Cleveland

-----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