RE: stds-80220-requirements: Aggrigate Data rates Requirement, 4.1.7
I noticed a typo in my earlier email below - "b/s/Hz/sector/antenna" (per cell site) in measure 1 should read as "b/s/Hz/antenna". The rationale remains the same i.e. to pick a measure that is independent of how a particular air interface (TDD or FDD) chooses to deploy its multiple antennas across one or more sectors in each cell to optimise performance in the whole cell and consequently in a geographic area.
Regards,
Samir
-----Original Message-----
From: Kapoor Samir
Sent: Friday, September 05, 2003 1:57 PM
To: 'kazuhiro murakami'; 802-20 IEEE requirements list
Subject: RE: stds-80220-requirements: Aggrigate Data rates Requirement,
4.1.7
Dear Murakami-san and all,
Before we propose new specific values for sustained spectral efficiencies and corresponding sustained aggregate data rates for FDD and TDD configurations, I would like to suggest that the group first discuss the current definition of spectral efficiency, namely b/s/Hz/sector that has been using so far. In the evaluation criterion conference call on Wednesday September 3rd, this issue came up and it became clear that
given the various FDD/TDD deployment configurations possible (e.g. single antenna fixed sectors in FDD or multi antennas per sector in FDD, multi-antennas in a single cell in TDD, multi-antennas within fixed sectors in a cell in TDD etc), that the b/s/Hz/sector definition does not always lead to an apples to apples comparsion.
For each case below, universal frequency reuse is assumed (i.e. same carrier frequency in all sectors and cells in the evaluation scenario). The overall issue was not resolved on the call but two possibilities that came out to develop a measure that would capture this plurality of deployment options without penalizing any one configuration are:
1. b/s/Hz/sector/antenna: This normalizes the spectral efficiency to all "degrees of freedom" and allows the proposals to deploy whatever configuration of sectorizaton and antennas they wish for best performance while still resulting in a fair comparison with other proposals that may be used different numbers of antennas or sectors as their optimum configurations.
2. b/s/Hz/cell: This essentially is a measure of the aggregate data rates on the backhaul to the cell site. It has to be taken with some upper bounds on the number of sectors or antennas that can be used for the purpose of evaluation (e.g. no more than 3 sectors and 6 antennas per cell). This does not mean that in actual deployment the numbers cannot be larger in some situations, just that this would be the baseline max values for evaluation purposes (that are also quite typical in actual deployments).
These would apply to all example channel bandwidths (2 x 1.25 FDD, 2 x 5 FDD, 10 TDD, ...) using the method shown by Murakami-san below. Also, regardless of which method is finally adopted, since these numbers correspond to sustained data rates and not peak, the channel and mobility distribution conditions under which these values are expected to be met must be specified, otherwise the numbers are not meaningful or useful for differentiating between various proposals. Therefore, I'm not even sure if a single number for DL and UL respectively will suffice unless only one test scenario is chosen.
Best Regards,
Samir
-----Original Message-----
From: kazuhiro murakami [mailto:kazuhiro_murakami@csg.kyocera.co.jp]
Sent: Friday, September 05, 2003 11:48 AM
To: 802-20 IEEE requirements list
Subject: stds-80220-requirements: Aggrigate Data rates Requirement,
4.1.7
Dear sirs
Kaz@Kyocera
I would like to propose Aggregate data rate description using example chart of
FDD and TDD which Mr.Khurram Sheikh contributed
If precise conditions are described, it become clear.
- Precise bandwidth description for FDD
- Addition of time duty concept for TDD.
Action: Change condition description of the examples of FDD and TDD
with leave two table
The aggregate data rate for downlink and uplink shall be consistent with the
spectral efficiency which is
defined by 4.1.2 Spectral efficiency.
An example of a 10MHz FDD (Downlink 5MHz,Uplink 5MHz) channel is shown in
Table 1 below.
Description Downlink Uplink
Outdoor to Indoor > 10 Mbps/Sector > 5Mbps/Sector
Expected Aggregate Data Rate
As an example of a 10MHz TDD channel with 50% duty of Downlink and Uplink is
shown in Table 2 below.
Description Downlink Uplink
Outdoor to Indoor > 10 Mbps/Sector > 5Mbps/Sector
Expected Aggregate Data Rate
Rationale:
aggregate data rates is related to several specification of the other items.
PAR aggregate data rate, spectral efficiency ratio are one of them.
However, if showing example of FDD and TDD channel using spectral efficiency
definition of 4.1.2 , I can consider example description with specified
condtion.
FDD: 5MHz FDD ---> 10MHz(Downlink 5MHz, Uplink 5MHz)FDD
TDD: 10MHz TDD channel with 50% duty of Downlink and Uplink is shown in
Table 2 below.
When calculating TDD spectral efficency ratio, we must consider time
allocation of Dwonlink
and Uplink.
if Spectoral efficency is Downlink 2 bit/Hz/sec, Uplink 1 bit/Hz/sec
Downlink:Uplink=1:1 Downlink : 10MHz x 1/2 x >2 bit/Hz/sec = >10Mbps
Uplink : 10MHz x 1/2 x >1 bit/Hz/sec = >5Mbps
Downlink:Uplink=5:3 Downlink : 10MHz x 5/8 x >2 bit/Hz/sec = >12.5Mbps
Uplink : 10MHz x 3/8 x >1 bit/Hz/sec = >3.75Mbps
If we describe time allocation ( Duty) of downlink and uplink in TDD example.
above chart can be understood as a example.
Best regards
Kaz
.