Project
IEEE 802.20 Working Group on Mobile Broadband Wireless Access
<http://grouper.ieee.org/groups/802/20/>
Title
Evaluation Criteria and Traffic Models Update
Date
Submitted
2004-03-15
Source(s)
Farooq Khan
67 Whippany Road
Whippany, NJ 07981
Re:
802.20 Call for Contributions: Session # 7 – March 15-19, 2004
Abstract
This contribution provides update of 802.20 evaluation criteria and Traffic modeling groups activities.
Purpose
Review
Voice: +1 973 386 5434
Fax: +1 973 386 4555
Email: fkhan1@lucent.com
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Notice
802.20 Evaluation Criteria and
Traffic Models Update
Farooq Khan
IEEE 802.20 Plenary Meeting
Orlando, FL, USA
March 15-19, 2004
Evaluation Criteria Status
C802.20-04/038
• Four conference calls (1/27, 2/10, 2/24 and 3/9)
since Vancouver Interim.
• No activity on Traffic Modeling
• Evaluation criteria discussed the following items:
– Simulation of various channel bandwidths, spectral
mask, Phased approach for technology evaluation and
Link budget template
• Open issues not discussed:
– Interface between link and system simulations,
application specific fairness/outage criteria and system
simulation calibration
• Plan for a joint meeting with the channel models
group
-3-
Various channel bandwidths
C802.20-04/038
Specify a small number (preferably one) of spectrum allocations[1] (over which the results are
quoted). The individual technology proposals may then split the total spectrum into a given number of
carriers and specify their reuse factor and channel bandwidth[2]. For example, if XMHz (TBD) is
specified as the spectrum allocation to be used for the evaluation process, then individual technology
proposals can perform simulations and then scale the simulation output data to that spectrum
allocation (XMHz). For proposals with channel bandwidths that are smaller than that spectrum
allocation, it would also be possible to simulate multiple carriers per sector and to collect data from all
the carriers that can be supported within that spectrum allocation.
[1] See definition of spectrum allocation from the Terminology Annex of Requirements Document.
[2] See definition of channel bandwidths from the Terminology Annex of Requirements Document.
• Issues requiring further consideration:
– How the spectral mask requirement would apply
spectrum allocation used for the evaluation process.
to
the
• One possibility is that proposals specify both its channel bandwidth
and its "necessary bandwidth” and justify the ability to support their
specified number of carriers within the spectrum allocation specified.
• proposals with multiple carriers within the spectrum allocation used
for the evaluation process may have to simulate the inter-carrier
leakage in order to justify the number of carriers used within the
allocation.
– A value for the spectrum allocation used for the evaluation
process.
-4-
Phased Approach
C802.20-04/038
The 802.20 evaluation will be structured with multiple phases with each phase
progressively adding more complexity. The evaluation work for each proposal may then
be compared at each phase to ensure a progressive "apples to apples" comparison of
proposals. This structured approach will also provide performance metrics for the physical
and link layer performance early rather than later in the evaluation process.
Phase 1 of the evaluation will consist of:
- Items/issues/criteria that are required for the calibration of simulations
- Items/issues/criteria that will draw out the important differences between the
various proposals that cannot be otherwise inferred.
The goals at the end of phase 1 are, first, to achieve confidence that different simulation
models are calibrated and, two, to present fundamental performance metrics for the
physical and link layer of various proposals.
• The details of phase 1 are currently being discussed in the
evaluation criteria:
– Agreed to use 19-cells 3-sector wrap-around configuration, Full
buffers (hungry) traffic, simulation calibration, link-system
interface etc.
• The issues that need further consideration:
– Channel model(s) used, Full-duplex simulation, and handoff
modeling etc.
-5-
Link Budget
C802.20-04/038
• Discussion on Link budget over the last 2 conference calls (2/24
and 3/9):
• Multiple proposals for the link budget parameters (need
convergence on a single set of parameter values):
– Antenna gain for BS and MS
– Cable, connector, and combiner losses
– Body Losses
– Building/vehicle penetration Loss
– Receiver noise figure at BS and MS
– Max Transmitter power at the base station (BS) and mobile
station (MS) – How to account for power amplifier back-off?
• Plan to meet in an Ad Hoc group for further discussion on
link budget parameters.
• Open issue: Should maximum range (link budget) be used as a
performance metric for proposal comparison or not?
-6-
Link-system Interface (LSI)
C802.20-04/038
• The evaluation criteria agreed to specify an
acceptable interface between link and system
simulations.
– This is needed because the link and system simulations
are performed separately (the simulation complexity
would be very high if joint link and system simulations
are required).
• Two potential solutions to the link-system
interface:
– Use actual link curves
– Specify an LSI methodology
• Contributions are invited on this topic
-7-
Application specific criteria
C802.20-04/038
In the evaluation of spectral efficiency and in order to make a fair comparison of
different proposals, it is important that all mobile users be provided with a
minimal level of throughput. The fairness for best effort traffic (HTTP, FTP and full
buffers) is evaluated by determining the normalized cumulative distribution
function (CDF) of the user throughput, which meets a predetermined function. For
applications other than best effort, application specific outage criteria are defined.
The proposals will also provide additional fairness metrics. The details of the
additional fairness metrics are TBD (see for example IEEE C802.20-04/05).
• A fairness criteria is defined for the best effort data
traffic:
– application specific outage and QoS (FER, delay etc.)
criteria need to be defined for other applications!
• Contributions are also invited on additional fairness
metrics
-8-
System simulation calibration
C802.20-04/038
• The evaluation criteria would specify a system
simulation calibration process.
– Calibration would be done as part of phase 1 of
simulations
• However, it is not clear, at this stage, to what
level of detail different simulations need to be
calibrated.
• The group is open to proposals to nail down
the calibration specifications.
-9-
Traffic Models
C802.20-04/038
• Items requiring further consideration:
– Specification of traffic mix
• Currently only a list of traffic types is provided, Issue of
percentage of various traffic types in a mixed scenario is
still open.
• Contributions invited on possible traffic mix scenarios.
– FTP traffic model
• Contributions invited on whether we need to modify the
“think time” behavior in the existing FTP traffic model.
– VoIP Traffic and Wireless multi-party Gaming traffic
models
• Overview of possible VoIP traffic models during the
Vancouver Interim
• Contributions invited on possible VoIP and gaming traffic
models to be used in system simulations.
-10-