1. IEEE TGac usage models – Preliminary stages
Month Year
doc.: IEEE yy/xxxxr0
January 2009
IEEE TGac usage models – Preliminary stages
Date:
Authors:
P. Chambelin, Thomson R&D France
John Doe, Some Company

2. Month Year
doc.: IEEE yy/xxxxr0
January 2009
Abstract
This submission aims to describe and to recall some definitions and preliminary stages aiming to prepare the completion of the usage models.
P. Chambelin, Thomson R&D France
John Doe, Some Company

3. Contents Context and Introduction Some definitions
January 2009
Contents
Context and Introduction
Some definitions
Process to complete the usage models
Definition of parameters
Definitions of environments
Conclusions
P. Chambelin, Thomson R&D France

4. Some definitions from TGn group
January 2009
Some definitions from TGn group
Application – a source or sink of wireless data that relates to a particular type of user activity.
Examples: Streaming video. VOIP.
Environment – The type of place a WLAN system is deployed in. Initial examples: home, large office.
Use case – A use case is a description of how an end user uses a system that exercises that system’s deployment of WLAN. A use case includes an application in a deployment environment with details regarding the user activity and both sides of the link.
Examples: Watching television remote from the cable or set-top box within the home. Talking on the telephone remote from one’s desk at work.
Usage Model – A specification of one or more applications and environments from which a simulation scenario can be created once the traffic patterns of the applications are known. Usage models are created to "cover" use cases.
Source : doc.: IEEE /802r23 IEEE P Wireless LANs Usage Models
P. Chambelin, Thomson R&D France

5. Some definitions from WFA
January 2009
Some definitions from WFA
Usage Model – A usage model is the combination of all the below things; not to be confused with a use case which is the specific set of steps to accomplish a particular task.
Pre-Conditions – Initial conditions before the use case begins.
Application – A source and/or sink of wireless data that relates to a particular type of user activity. Examples are streaming video and VoIP.
Environment – The type of place in which a network is deployed, such as home, outdoor, hot spot, enterprise, metropolitan area, etc.
Traffic Conditions – General background traffic or interference that is expected while the use case steps are occurring. Overlapping BSSs, existing video streams, and interference from cordless phones are all examples of traffic conditions.
Use case – A use case is task oriented. It describes the specific step by step actions performed by a user or device. One use case example is a user starting and stopping a video stream.
Source : doc.: IEEE /2988r2, March 08, Wi-Fi Alliance (WFA) VHT Study Group Usage Models
P. Chambelin, Thomson R&D France

6. Comparison between TGn and WFA definitions
January 2009
Comparison between TGn and WFA definitions
WFA added :
Pre- conditions
Traffic conditions
TGn’s definitions allowing to specify
The state of the network before describing the use case
What is available for the user for the use case
What are the other applications working in vicinity and able to interfere and coexist.
However WFA did not defined the parameters
some requirements for the network are exposed, but the parameters are not specified !
WFA it does not associate environment with channel model
P. Chambelin, Thomson R&D France

7. Process to complete the usage models
January 2009
Process to complete the usage models
Based on IEEE /1392r0 , Inputs for a VHT Selection Procedure
Usage Models
Channel Models
Functional Requirements*
P. Chambelin, Thomson R&D France

8. Process to complete the usage models
January 2009
Process to complete the usage models
How to define Usage Models ?
A usage model is related to :
A specific environment:
and then a channel model for each frequency band (difference from 11.n Usage models).
Maybe new channel models including elevation plan, wider channel bandwidth, antenna parameters ?
And then a network condition with traffic conditions for each frequency band
Multi environment for a usage model is not allowed / the reality. Isn’t it ?
One or several applications, describe by use cases (scenario of the applications), could be a mix of <6 GHz use case and 60 GHz use case.
Specifying the requirements for the applications and for the related parameters.
A usage model should be able :
To create a simulation scenario
P. Chambelin, Thomson R&D France

9. Process to complete the usage models: proposal
January 2009
Process to complete the usage models: proposal
Usage model
Environment 1:
Channel Model(s)
Network state and traffic conditions
Appli 1
Appli 2
Appli N
Application requirements
Application requirements
Application requirements
Functional requirements :
- payload data rate
- BER or PER
- latency / packet delay
- QoS , prioritization
- …
P. Chambelin, Thomson R&D France

10. Definition of parameters from TGn
January 2009
Definition of parameters from TGn
Source : doc.: IEEE /802r23 IEEE P Wireless LANs Usage Models
Parameter
Definition
MSDU size
Packet size at the top of the MAC
Maximum PLR
Maximum packet loss rate at the top of the MAC. This is defined by the loss rate that can be tolerated by the application.
Maximum Delay
Maximum transport delay at the top of the MAC – i.e. between matching MA-UNITDATA.request and .indication.
Protocol
Indicates the network-layer protocol running between the data source and the MAC. It takes one of two values: TCP or UDP.
These two protocols are intended to represent a generic acknowledged and a generic unacknowledged network-layer protocol.
Offered Load
This parameter is interpreted differently according to the Protocol parameter:
Applications identified as being carried by UDP are assumed to generate MSDUs at a fixed rate, as identified in the "Offered load" column. Inability to carry the traffic generated by a UDP application, due to insufficient throughput capability, results in lost MSDUs, which is reported in simulation results as a packet loss rate, or an outage, associated with the application. The comparison criteria include a measure of whether this packet loss rate exceeds the maximum specified for the application in this table.
Traffic carried by TCP is assumed to be served on a best-effort basis, and applications using TCP are assumed to generate MSDUs at rates up to the
value given in the "Offered load" column. Being an acknowledged protocol with a constrained window size, TCP responds to congestion in the BSS by reducing application throughput without losing MSDUs. This effect is reflected in simulation results by reporting achieved throughput for applications using TCP. Note: Acknowledgement traffic is generated by TCP sinks, this is not explicitly specified in the simulation scenarios, but it is included in the count of non-QoS flows and measurement of goodput.
P. Chambelin, Thomson R&D France

11. Definition of environments from TGn
January 2009
Definition of environments from TGn
Source : doc.: IEEE /802r23 IEEE P Wireless LANs Usage Models
Environment
Includes
Applicable Channel Model
Residential, Domestic or Home
Intra-room
Room to room
Indoor to outdoor
Large multi-family dwelling.
Note: one or more PCs in the home may be notebooks or other portable devices that come home with the user. these wireless devices may have more than one wireless technology included. B
House to house
One main house has AP with uplink connection, Another house holds single or multiple STA(s), Guest house, garage or studio. In garage model, STA may be embed inside a car. F
Small Enterprise
Enclosed offices
Meeting room / conference room
Classroom C
Medium/Large Enterprise
Sea of cubes
Multi-story office environment
Campus E
P. Chambelin, Thomson R&D France

12. Definition of environments from TGn
January 2009
Definition of environments from TGn
Source : doc.: IEEE /802r23 IEEE P Wireless LANs Usage Models
Environment
Includes
Applicable Channel Model
Hotspot
Airport
Library
Convention center
Hotel
Shopping mall
Arcade
Train station / bus terminal
Drive-in window F
Outdoor
Outdoor sport event
Campus
City Square
Public park
Amusement park
Industrial
Indoor
Large factory floor
Hospital
Warehouse
Concert hall / auditorium
Movie theatre
Other custom environments
Wireless backhaul
Fixed wireless access:
outside to multiple STA inside
outside to multiple STA outside
Mobile
Train
Bus
Plane
Roadside APs for data-service in-car (fast roaming) C
P. Chambelin, Thomson R&D France

13. Definition of environments from WFA
January 2009
Definition of environments from WFA
Source : doc.: IEEE /2988r2, March 08, Wi-Fi Alliance (WFA) VHT Study Group Usage Models
Home
On desk (short range, line of sight)
Within room (medium range, mostly line of sight)
Entire home (long range, could be no line of sight)
Home Mesh
Enterprise
On desk/cube (short range, line of sight)
Conference room (medium range, mostly line of sight)
Dense deployment
Enterprise Mesh
Small Office
Single BSS with unmanageable interferences with limited number of users
Outdoor
Outdoor mesh backhaul link
Regular bridging between buildings
Airplane docking
Campus (Education Space, Hospital)
Auditorium/lecture halls in the education space for video demos
Video surveillance and conferencing
Hospitals where Remote Medical Assistance for Operations is via Wireless Networks
Airplane/Bus/Train/Ship – Intra-large-vehicle communication. Large vehicle being airplane, bus, train or ship
Factory floor
P. Chambelin, Thomson R&D France

14. Definition of environments Proposal
January 2009
Definition of environments Proposal
No full redundancy between TGn and WFA Definition of environments
9 main environments in TGn
7 main environments in WFA
Hotspots are not considered
Mobility (train, plane, car) is not considered
WFA seems to provide an up to date view of environments except that Hot spot is missing.
Proposal : Keep WFA environments and add Hot spot
P. Chambelin, Thomson R&D France

15. January 2009
Conclusions
The following steps are proposed to be able to specify the Usage Models and to describe the functional requirements.
Keep the environments defined by WFA
Keep the usage models proposed by WFA, and check if the group need more usage models
Then how to define the relevant parameters and requirements ?
List all relevant applications by environment, and describe the associated requirements.
An application defined in a specific environment allows to specify the relative Channel Model.
Define the parameters for the functional requirements
and finally describe the functional requirements and parameters for each usage models.
P. Chambelin, Thomson R&D France

16. January 2009
References
IEEE /802r23 IEEE P Wireless LANs Usage Models
IEEE /2988r2, March 08, Wi-Fi Alliance (WFA) VHT Study Group Usage Models
P. Chambelin, Thomson R&D France