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					2005-5-16                                                                     IEEE C802.20-05/25




Project     IEEE 802.20 Working Group on Mobile Broadband Wireless Access
            <http://grouper.ieee.org/groups/802/20/>

Title       IEEE 802.20 Evaluation Criteria (EC) – Simulation of Common Traffic Types

Date        May-5-2005
Submitted

Source(s)   Dan Gal                                  Voice: 973-428-7734
            67 Whippany Road,                        Fax: 973-386-4555
            Whippany, NJ 07981                       Email: dgal@lucent.com

Re:         MBWA Call for Contributions: Session # 14

Abstract    This contribution proposes a practical approach to the question of Traffic Mix
            simulation and suggests some text changes in section 4 of the Evaluation Criteria
            document (version 15r3).

Purpose     Proposal for section 4 of the 802.20 EC document
            This document has been prepared to assist the IEEE 802.20 Working Group. It is offered as a basis
Notice      for discussion and is not binding on the contributing individual(s) or organization(s). The material in
            this document is subject to change in form and content after further study. The contributor(s)
            reserve(s) the right to add, amend or withdraw material contained herein.
            The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this
Release     contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to
            copyright in the IEEE’s name any IEEE Standards publication even though it may include portions
            of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in
            part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that
            this contribution may be made public by IEEE 802.20.
            The contributor is familiar with IEEE patent policy, as outlined in Section 6.3 of the IEEE-SA
Patent      Standards Board Operations Manual <http://standards.ieee.org/guides/opman/sect6.html#6.3> and in
Policy      Understanding Patent Issues During IEEE Standards Development
            <http://standards.ieee.org/board/pat/guide.html>.




                                                     CP
     2005-5-16                                                              IEEE C802.20-05/25



 1   1.0    Introduction
 2   This contribution builds on the working draft document submitted to the May 3rd, 2005
 3   Evaluation Criteria CG call and includes changes suggested by the participants.

 4   Objectives
 5   The objectives of this proposal are:
 6       Streamline the requirements for the system-level traffic modeling (section 4.3)
 7       Reduce the complexity of the traffic-mix simulations (section 4.4)
 8       Edit some paragraphs to improve clarity
 9
10   Note: All the proposed changes pertain to Section 4 of the Evaluation Criteria Document            Formatted: Font color: Black
11   (Version 15r3.)                                                                                    Formatted: Font: Not Bold, Font color: Black
                                                                                                        Formatted: Font color: Black
12   1


13   2


14   3
15   ======================== Proposed Changes =========================

16   4 Traffic Models for 802.20 System Simulations

17   4.1   Introduction
18
19   The Mobile Broadband Wireless Access (MBWA) systems will be designed to provide a
20   broadband, IP-oriented connection to a wireless user that is comparable to wired broadband
21   connections that are in use today. It is expected that there will be a mix of user applications,
22   not unlike that of such wired systems. Further, the traffic characteristics and system
23   requirements of the various applications can vary widely. The performance of such MBWA
24   systems is thus very much dependant on the details of the applications and their traffic
25   models. This is in contrast to cellular wireless voice systems where the performance studies
26   focused on physical and link layer performance with a relatively simple traffic generation
27   model. The purpose of this section is to provide detailed statistical traffic models that can
28   be used as an input to generate packets in a simulation study of a MBWA system.

29   4.2   Context and Scope

30   4.2.1 User device scenarios
31   [Editor’s Note: It was discussed over the 12/2 conference call if we need to consider all the      Formatted: Highlight
32   user scenarios (Laptop, PDA, Smart phone, machine-to-machine) or only a subset of the
33   user scenarios can be considered. In order to capture different user scenarios, parameters
34   values of some traffic models (e.g. web browsing) would be adapted to the user scenario
35   (e.g. heavy, medium or light web browsing application).]



                                                                                                   1
     2005-5-16                                                            IEEE C802.20-05/25

 1   {Leave this section as FYI, based on consensus of CC: April 5, 05}                               Formatted: Highlight
 2   [Editor’s suggestions: Option 1) Leave the section as FYI; Option 2) Specify a traffic mix
 3   in Table 5 and/or 11 that resembles one or more of these user device scenarios.]
 4   There can be various different user scenarios for MBWA systems, some of which we
 5   cannot foresee at this time. For purposes of illustration, we include some candidate
 6   scenarios to frame the context of our work.
 7   [Editor’s note: These descriptions need to be discussed]                                         Formatted: Highlight
 8   [Needs resolution with regard to whether to drop the issue or to continue /Berlin].              Formatted: Highlight
 9
10   In all cases, the MBWA modem can either be built-in or supplied through a card or a
11   peripheral device.
12        a) Laptop user: The large and rich display capabilities can be expected to generate
13           graphics-rich and multimedia-rich applications. In general, laptop users will
14           provide the highest data volume demands due to the storage and battery
15           capabilities of laptops. They can provide a full range of applications with perhaps
16           less emphasis on voice and WAP applications. Except for special cases, they tend
17           to be stationary during use.
18        b) PDA user: The display, battery, and storage capabilities are less than that of
19           laptops, and so they are expected to have somewhat less traffic volume. They can
20           be very portable. They are typically used for Web browsing, e-mail,
21           synchronization, video, and voice applications.
22        c) Smartphone user: These devices are very portable and very constrained display
23           and storage capabilities. It is expected that they will be oriented towards voice,
24           WAP, and light video.
25        d) Machine to machine (telematics, remote cameras etc.): These usage scenarios can
26             have a wide range of characteristics. In some remote monitoring/control
27             applications driven by specific events, the traffic is bursty. For remote
28             surveillance using continuous video feeds, the traffic is more like streaming. This
29             can be a potentially significant usage scenario for 802.20 systems, but the relevant
30             traffic characteristics may not have received as much study as a applications with
31             human users.
32   Since the various devices can have very distinct traffic characteristics, we will create
33   multiple traffic models for different usage scenarios of an application.
34   For example, web browsing is likely to have different statistical characteristics for laptop
35   and PDA scenarios. Rather than tie the models specifically to device types such as laptop
36   and PDA, we will adopt multiple versions of a traffic model with generic names, e.g. Web
37   Browsing A & Web Browsing B, or Web Browsing Heavy & Web Browsing Light. These
38   could have different statistical functions, or different parameters for the same function.

39   4.2.2 Basis for Traffic Models
40   Most traffic modeling work is based on measurements of real traffic, which are analyzed to
41   generate usable statistical descriptions. These are typically used in computer simulations,
42   but and can also be used to generate packet traffic for a real system under test. Since


                                                                                                  2
     2005-5-16                                                               IEEE C802.20-05/25

 1   MBWA is a future service that is similar to some existing wired systems, a lot of the basis
 2   of this section is the traffic modeling work done for wired systems. These provide a
 3   reasonable and realistic description of the potential user. Our approach is to use statistical
 4   models that can be used to generate a stream of packets that need to be transmitted over the
 5   system.
 6   We realize that characteristics of user applications keep changing. At best, one can develop
 7   a reasonable consensus model that is useful for bringing some uniformity in comparisons of
 8   systems. In particular, it is known that user traffic patterns change as the network
 9   performance changes. Traffic modeling work has attempted to adjust to this trend. For
10   example, some of the traffic models such as Web and FTP try to capture the essence of the
11   user applications by describing the amount of data the user is trying to retrieve rather than
12   specifying a packet stream.
13   We specifically do not use the trace-based approach where a real recorded stream of
14   packets is played back for simulation. While traces can capture sophisticated details, such
15   traces have details that are often very dependant on the system from which they were
16   recorded, and do not provide flexibility for computer simulation work.

17   4.2.3 Adaptive applications
18   Certain applications such as audio streaming sense the available bit rate of the channel and
19   then adjust the amount of traffic that is transmitted. Certain multi-media sessions may
20   employ content-adaptation of images or video based on network conditions. This directly
21   changes the amount of data that is transmitted. The adaptive nature of applications can be
22   incorporated into the traffic model. We do not perceive a strong need for the adaptive
23   nature of an application to be incorporated as a dynamic feature of the traffic model. Such
24   adaptive behavior can be addressed by using traffic models with different parameters and
25   switching between them in an appropriate manner. Thus, adaptation of traffic
26   characteristics based on network/device conditions is outside the scope of this modeling.

27   4.3 Traffic Models
28                                                                      4               4
     This section describes the traffic models in detail. Sections 4.3.1‎ .3.1 and 4.3.2‎ .3.2 clarify
29   some aspects of the modeling approach and the remaining sections provide detailed models
30   for traffic types listed in Table 1Table 1.                                                         Formatted: Font: (Default) Times New Roman
                                                                                                         Formatted: Font: (Default) Arial
31                          Table 11 Characteristics of 802.20 Traffic Types
                                                                                                         Formatted: Font: (Default) Arial
32   {D. Gal’s proposed changes: 1. sort the table rows by Traffic-Category 2. reduce the                Formatted: Font: (Default) Arial
33   number of simulated applications (a short-list is shown in bold font) }
                                                                                                         Formatted: Highlight
34
                                                                                                         Formatted: Normal, Left
35   {DG: clean new Table 1}
                                                                                                         Formatted: Font: Bold, Highlight
      #     Application            Traffic        Priority   Availability       Testing Variants
                                   Category       for        of                                          Formatted: Highlight

                                                  Evaluation suitable                                    Formatted: Font: Bold, Highlight
                                                             traffic                                     Formatted: Highlight
                                                             models                                      Formatted: Font: Bold, Highlight
      1      FTP                    Best-effort      High       Medium          Fixed                    Formatted: Highlight
                                                                                /deterministic           Formatted: Highlight
                                                                                Heavy, Light             Formatted: Font: Not Italic



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    2005-5-16                                                        IEEE C802.20-05/25


     2    PDA remote          Best-effort      Low            Low
          synch
     3    File-sharing        Best-effort      Low            Low
     4    Broadcast /         Best-effort      Low            Low        High-rate, low-
          Multicast                                                      rate
     5    Telematics          Best-effort/     Low            Low
                               Real-time
     6    E-mail              Interactive/    Medium          Low        Heavy, Medium,
                              Best-effort                                Light,
                                                                         Non-interactive
                                                                         mode
     7    Web Browsing        Interactive      High          High        Heavy, Medium,
                                                                         Light
     8    WAP                 Interactive      High          High
     9    Multimedia          Interactive     Medium        Medium
          Messaging
     10   Instant             Interactive     Medium        Medium
          Messaging
     11   Gaming              Interactive     Medium          Low
     12   Audio Streaming     Streaming       Medium          Low        High-rate, low-
                                                                         rate                  Formatted: Normal, Left
     13   Video Streaming     Streaming       Medium        Medium       High-rate, low-       Formatted: Highlight
                                                                         rate                  Formatted Table
     14   VoIP                Real-time        High          High        High-rate, low-       Formatted: Font: Bold, Font color: Light Blue
                                                                         rate                  Formatted: Font color: Black
     15   Video Telephony     Real-time       Medium         High        Heavy, Light          Formatted: Left
1                                                                                              Formatted: Left
2                                                                                              Formatted: Font color: Light Blue
3   {DG: proposed changes to Table 1}
                                                                                               Formatted: Font: Bold, Font color: Light Blue
     #    Application         Traffic        Priority     Availability   Different
                                                                                               Formatted: Left
                              Category       for          of             versionsTesting
                                                                                               Formatted: Font color: Black
                                             Evaluation   suitable       Variants
                                             valn.        traffic        needed                Formatted: Left

                                             Group        model(s)s                            Formatted: Left

     1    FTP                 Best-effort       High         Medium      Fixed                 Formatted: Font color: Black
          (File transfer)                                                /deterministic        Formatted: Left
                                                                         (for testing),        Formatted: Font: Bold, Font color: Light Blue
                                                                         Heavy, Light          Formatted: Left
     2    PDA remote          Best-effort    MediumL          Low                              Formatted: Font color: Black
          synch                                ow                                              Formatted: Font color: Black
     3    File-sharing        Best-effort     Low             Low                              Formatted: Left
     4    Broadcast /         Best-effort     Low             Low        High-rate, low-
                                                                                               Formatted: Font color: Black
          Multicast                                                      rate
                                                                                               Formatted: Left
     5    Telematics          Best-effort/     Low            Low
                                                                                               Formatted: Font color: Black
                               Real-time
                                                                                               Formatted: Left



                                                                                           4
                                                                                      Formatted         ...
                                                                                      Formatted         ...
2005-5-16                                                  IEEE C802.20-05/25         Formatted         ...
                                                                                      Formatted         ...
                                                                                      Formatted         ...
 6    E-mail              Interactive/   Medium    Low       Heavy, Medium,
                                                                                      Formatted         ...
                          Best-effort                        Light,
                                                                                      Formatted         ...
                                                             Non-interactive
                                                                                      Formatted         ...
                                                             mode
                                                                                      Formatted         ...
 7    Web Browsing        Interactive     High     High      Heavy, Medium,
                                                             Light                    Formatted         ...
 8    WAP                 Interactive     High     High                               Formatted         ...
 9    Multimedia          Interactive    Medium   Medium                              Formatted         ...
      Messaging                                                                       Formatted         ...
 10   Instant             Interactive    Medium   Medium                              Formatted         ...
      Messaging                                                                       Formatted         ...
 11   Gaming              Interactive    Medium    Low                                Formatted         ...
 12   Audio Streaming     Streaming      Medium    Low       High-rate, low-          Formatted         ...
                                                             rate                     Formatted         ...
 13   Video Streaming     Streaming      Medium   Medium     High-rate, low-          Formatted         ...
                                                             rate                     Formatted         ...
 14   VoIP                Real-time       High     High      High-rate, low-          Formatted         ...
                                                             rate
                                                                                      Formatted         ...
 15   Video Telephony      Real-time     Medium    High      Heavy, Light
                                                                                      Formatted         ...
      Web Browsing        Interactive     High     High      Heavy, Medium,
                                                                                      Formatted         ...
                                                             Light
                                                                                      Formatted         ...
      WAP                 Interactive     High     High
                                                                                      Formatted         ...
      FTP (File           Best-effort     High    Medium     Fixed/deterministi
      transfer)                                              c                        Formatted         ...
                                                             (for testing),           Formatted         ...
                                                             Heavy, Light             Formatted         ...
      Video-conference     Real-time     Medium    High      Heavy, Light             Formatted         ...
      E-mail              Interactive/   Medium    Low       Heavy, Medium,           Formatted         ...
                          Best-effort                        Light,                   Formatted         ...
                                                             Non-interactive          Formatted         ...
                                                             mode                     Formatted         ...
      Multimedia          Interactive    Medium   Medium                              Formatted         ...
      Messaging
                                                                                      Formatted         ...
      Instant Messaging   Interactive    Medium   Medium
                                                                                      Formatted         ...
      Gaming              Interactive    Medium    Low
                                                                                      Formatted         ...
      Audio streaming     Streaming      Medium    Low       High-rate, low-
                                                                                      Formatted         ...
                                                             rate
                                                                                      Formatted         ...
      Video streaming     Streaming      Medium   Medium     High-rate, low-
                                                             rate                     Formatted Table   ...
      PDA remote          Best-effort    Medium    Low                                Formatted         ...
      synch                                                                           Formatted         ...
      File-sharing        Best-effort     Low      Low                                Formatted         ...
      Broadcast/multica   Best-effort     Low      Low       High-rate, low-          Formatted         ...
      st                                                     rate                     Formatted         ...
      Telematics          Best-effort/    Low      Low                                Formatted         ...
                                                                                      Formatted         ...
                                                                                      Formatted         ...
                                                                                  5
                                                                                      Formatted         ...
                                                                                      Formatted         ...
                                                                                      Formatted Table   ...
                                                                                      Formatted         ...
                                                                                      Formatted         ...
                                                                                      Formatted         ...
                                                                                      Formatted         ...
                                                                                      Formatted         ...
                                                                                      Formatted         ...
     2005-5-16                                                              IEEE C802.20-05/25


                                    Real-time
 1

 2   4.3.1 User/Traffic Modeling Approach
 3           {DG: clean edited text}                                                                    Formatted: Normal
 4   One of the objectives of a modeling and simulation exercise is to determine the number of
 5   users a MBWA system can support. The proposed approach here is to model traffic for
 6   active users that maintain a session with transmission activity. Such traffic models can be
 7   used to determine the number of active users that can be supported. The proposed models
 8   do not address the traffic arrival process.
 9   {DG: proposal – open the following statements for discussion. In section 4.4 we attempt to
10   define requirements for the simulation of system-wide traffic mix in conjunction with user
11   distribution - in the cells – and fairness criteria. We also attempt to determine the maximum
12   throughput available from the system under those constrains. Hence, the following
13   paragraph needs to be revised or deleted}
14   Modeling of an aggregated traffic load, generated by a number of active users for
15   background loading purposes, may not be feasible for a wireless network. Such modeling is
16   particularly difficult for systems that employ adaptive antenna technologies and for systems
17   that have complex channel dependencies. Therefore, our traffic models shall apply to a
18   single user terminal.
19                                                                                                      Formatted: Pattern: Clear (Gray-5%)
20
21           {DG: editorial changes}                                                                    Formatted: Normal
22   One of the objectives of a modeling and simulation exercise is to determine the number of          Formatted: Font: Not Bold
23   users a MBWA system can support. The proposed approach here is to model have traffic
24   models for a useractive users who that is maintaining a session with transmission activity.
25   These Such traffic models can be used to determine the number of such registered active
26   users that can be supported. The proposed is document models does not address the traffic
27   arrival process. of such registered users traffic.
28   Modeling of an aggregated traffic load, generated from by a number of active users nodes
29   for background loading purposes, may not be feasible for a wireless network. Such an
30   abstractionmodeling is particularly difficult for systems that employ with adaptive antenna
31   technologies and for systems with that have complex channel dependencies. Therefore, So,
32   our traffic models shall apply to a single one user terminal.
33                                                                                                      Formatted: Normal


34   4.3.2 Packet Generation
35   {DG: clean edited text}                                                                            Formatted: Highlight
36   In some of the traffic models, there is a statistical description of the workload or the content   Formatted: Highlight
37   of the application rather than the actual packet stream. This is consistent with the state of
38   the art of evaluation techniques of multi-service data systems. For example, the Web
39   browsing model describes the Web pages and the timing between the Web pages.
40   Depending on the details of the underlying TCP model (e.g. MTU size, max receive
41   window) and the HTTP protocol version (HTTP v1.0 v. HTTPv1.1), the actual stream of
42   packets will vary. In other applications, such as VoIP, the traffic models may describe the
43   packet stream more specifically.


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     2005-5-16                                                              IEEE C802.20-05/25

 1
 2   {DG: editorial changes}
 3   In some of the traffic models, there is a statistical description of the workload or the content
 4   of the application rather than the actual packet stream. This is consistent with the state of
 5   the art in of evaluation techniques of multi-service data systems. For example, the Web
 6   browsing model describes the Web pages and the timing between the Web pages.
 7   Depending on the details of the underlying TCP model (e.g. MTU size, max receive
 8   window) and the HTTP protocol version (HTTP v1.0 v. HTTPv1.1), the actual stream of
 9   packets will changevary. In other some applicationscases, as insuch as the Voice VoIP, the
10   traffic models, the model may describe the packet stream more specifically.directly.
11

12   4.3.3 Web Browsing
13   Web browsing is the dominant application for broadband data systems, and has been
14   studied extensively. See references […..]
15   The parameters for the web browsing traffic are as follows:
16   SM: Size of the main object in a page
17   SE: Size of an embedded object in a page
18   Nd: Number of embedded objects in a page
19   Dpc: Reading time
20   Tp: Parsing time for the main page
21
                                                                                                        Formatted: Font: (Default) Arial
22   Table 22 HTTP Traffic Model Parameters




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     Component        Distribution     Parameters                PDF


     Main object      Truncated        Mean = 10710 bytes                 1  ln x   2 
     size (SM)        Lognormal        Std. dev. = 25032         fx                exp    , x  0
                                                                  2x      2 2
                                                                                           
                                                                                            
                                       bytes
                                       Minimum = 100 bytes   1.37,   8.35
                                       Maximum = 2 Mbytes
     Embedded         Truncated        Mean = 7758 bytes                  1       ln x   2 
     object size      Lognormal        Std. dev. = 126168        fx                exp         , x  0
     (SE)
                                                                        2x     2 2
                                                                                                
                                                                                                 
                                       bytes
                                       Minimum = 50 bytes          2.36,   6.17
                                       Maximum = 2 Mbytes
                                                                           
     Number of        Truncated        Mean = 5.64                     k
     embedded         Pareto           Max. = 53                  f x   1 , k  x  m
     objects per                                                        x
                                                                              
     page (Nd)
                                                                         
                                                                          k
                                                                  fx         ,x  m
                                                                         
                                                                          m
                                                                   1.1, k  2, m  55


                                                                 Note: Subtract k from the
                                                                 generated random value to
                                                                 obtain Nd
     Reading time     Exponential      Mean = 30 sec                        x
                                                                  f x  e      ,x  0
     (Dpc)
                                                                   0.033


     Parsing time     Exponential      Mean = 0.13 sec                        x
                                                                  f x  e          ,x  0
     (Tp)
                                                                   7.69

 1
 2   Note: When generating a random sample from a truncated distribution, discard the random
 3   sample when it is outside the valid interval and regenerate another random sample.
 4

 5   4.3.4 FTP
 6   In FTP applications, a session consists of a sequence of file transfers, separated by reading
 7   times. The two main parameters of an FTP session are:
 8    S : the size of a file to be transferred
 9    D pc : reading time, i.e., the time interval between end of download of the previous file and
10   the user request for the next file.



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 1   The underlying transport protocol for FTP is TCP. The parameters for the FTP application
 2   session are described in Table 3Table 3.                                                                 Formatted: Font: (Default) Times New Roman
                                                                                                              Formatted: Font: (Default) Arial
 3                               Table 33 FTP Traffic Model Parameters
                                                                                                              Formatted: Font: (Default) Arial
     Component        Distribution       Parameters            PDF                                            Formatted: Font: (Default) Arial
                                                                                                              Formatted: Centered
     File size (S)    Truncated          Mean = 2Mbytes
                                                                      1         ln x   2 
                      Lognormal          Std. Dev. = 0.722     fx         exp                , x  0
                                                                     2 x     2 2           
                                         Mbytes                                               
                                         Maximum = 5             0.35,   14.45
                                         Mbytes


     Reading time     Exponential        Mean = 180 sec.                   x
                                                                f x  e         ,x  0
     (Dpc)
                                                                 0.006

 4
                                                                                                              Formatted: Not Highlight
 5   4.3.5 Voice (VoIP)
 6   {DG: clean edited text}
 7   The voice traffic model will be implemented as voice over IP (VoIP). Voice data traffic
 8   will, in general, follow a Markov source model with different encoding rates (full rate, half
 9   rate, etc) and corresponding rate-transition probabilities.
10
11   {DG: proposed editorial changes}
12   The voice traffic model will be implemented as voice over IP (VoIP). Voice data traffic
13   will, in general, follow a Markov source model with different encoding rates (full rate, half
14   rate, etc) and with a corresponding set of rate-transition probabilities. between different
15   rates.
                                                                                                              Formatted: Not Highlight
16   4.3.6 Video (Video telephony / Video conferencing)                                                       Formatted: Not Highlight
17   [Needs contribution/Berlin]                                                                              Formatted: Not Highlight
                                                                                                              Formatted: Not Highlight
18   4.3.7 Audio streaming                                                                                    Formatted: Not Highlight
19   This can be an important class of traffic. It has received relatively less attention in the              Formatted: Highlight
20   modeling community. (See [Error! Reference source not found.Error! Reference                             Formatted: Not Highlight
21   source not found.])
22   [Further contribution on Audio Streaming is needed/Berlin]                                               Formatted: Highlight
                                                                                                              Formatted: Not Highlight
23   4.3.8 Video streaming
24   The following section describes a model for streaming video traffic on the forward link.
25   Figure 1Figure 1 describes the steady state of video streaming traffic from the network as               Formatted: Font: (Default) Times New Roman
26   seen by the base station. Latency of starting up the call is not considered in this steady
27   state model.



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     2005-5-16                                                                      IEEE C802.20-05/25


                                      Video Streaming Session (= simulation time)




                                                                                                                time

          0                            T                            2T     (K-1)T                          KT
              TB (Buffering Window)

                                                 DC (Packet                         Packet Size
                                                Coding Delay)
 1
 2
                                                                                                                 Formatted: Font: (Default) Arial
 3                           Figure 11 Near Real-Time Video Traffic Model
 4   A video streaming session is defined as the entire video and associated audio streaming call
 5   time, which is equal to the simulation time for this model.
 6   Each frame of video data arrives at a regular interval T determined by the number of
 7   frames per second (fps). Each frame is decomposed into a fixed number of slices, each
 8   transmitted as a single packet. The size of these packets/slices is distributed as a truncated
 9   Pareto. Encoding delay, Dc, at the video encoder introduces delay intervals between the
10   packets of a frame. These intervals are modeled by a truncated Pareto distribution. The
11   parameter TB is the length (in seconds) of the de-jitter buffer window in the mobile station
12   used to guarantee a continuous display of video streaming data. This parameter is not
13   relevant for generating the traffic distribution but is useful for identifying periods when the
14   real-time constraint of this service is not met. At the beginning of the simulation, it is
15   assumed that the mobile station de-jitter buffer is full with (TB x source video data rate) bits
16   of data. Over the simulation time, data is “leaked” out of this buffer at the source video
17   data rate and “filled” as forward link traffic reaches the mobile station. As a performance
18   criterion, the simulation shall record the length of time, if any, during which the de-jitter
19   buffer runs dry. Option 1: The de-jitter buffer window for the video streaming service is 5
20   seconds.
21   Option 2:                                                                                                   Formatted: Font: Bold
22   The de-jitter buffer window for the video streaming service is a maximum of 5 seconds.
23    [need to confirm if the de-jitter buffer window size of 5 seconds needs to be changed for                  Formatted: Highlight
24   the higher data rate]
25   Using a source rate of 64 kbps, the video traffic model parameters are defined Table 4Table                 Formatted: Font: (Default) Times New Roman
26   4.
27
                                                                                                                 Formatted: Font: (Default) Arial
28                     Table 44 Near Real-Time Video Traffic Model Parameters

        Information      Inter-arrival Number of       Packet (slice)                Inter-arrival time
        types            time between packets (slices) size                          between packets
                         the beginning in a frame                                    (slices) in a frame



                                                                                                           10
     2005-5-16                                                                              IEEE C802.20-05/25


                           of each frame
        Distribution       Deterministic Deterministic        Truncated                      Truncated Pareto
                           (Based on                          Pareto                         (Mean= 6ms,
                           10fps)                             (Mean=                         Max= 12.5ms)
                                                              50bytes, Max=
                                                              125bytes)
        Distribution       100ms             8                K = 20bytes                    K = 2.5ms
        Parameters                                             = 1.2                         = 1.2
 1

 2   4.3.9 Wireless Multi-Party Gaming Traffic
 3   [Note: It was noted over the 12/2 conference call that wireless gaming is an important                          Formatted: Highlight
 4   application that needs to be considered in 802.20 system evaluation. Input required on
 5   mobile wireless gaming models.]
 6   [Note 1: Options from contribution C802.20-04/86 and C802.20-05/06 are included                                 Formatted: Highlight
 7   below:]
 8   Some types of multi-player games may have demanding requirements on response times.
 9   Option 1: Modify 3GPP2 model, to include DL characteristics as in Faber [2002]:                                 Formatted: Font: Bold
10   This section describes a model for mobile network gaming traffic on the forward link and
11   reverse link. This model is a combination of a standardized reverse link model (see
12   cdma2000 Evaluation Methodology, C.P1002, Version 0.3, July 2004) and a forward link
13   model developed from the research literature.

14   4.3.9.1 Reverse Link Model
15   Table 5Table 5 describes the parameters for the mobile network gaming traffic on the
16   reverse link.
17               Table 5 Mobile Reverse Link network gaming traffic model parameters
             Component        Distribution       PDF and generation method



             Initial          Uniform (a=0,                  1
                                                 f ( x)          a xb
             packet           b=40ms)                       ba
             arrival
             Packet           Deterministic
             arrival          (40ms)
             Packet size      Extreme                             xa            
                                                                                     xa
                                                          1                e
                                                  f ( x)  e                               ,b  0
                                                                                      b
                              (a=45 bytes, b                       b
                                                                        e
                              = 5.7)                      b
                                                  X  a  b ln  ln Y  , Y  U (0,1)
                                                 Because packet size has to be integer
                                                 number of bytes, the largest integer less
                                                 than or equal to X is used as the actual
                                                 packet size.
             UDP header       Deterministic


                                                                                                                11
     2005-5-16                                                                           IEEE C802.20-05/25


                              (2bytes)
 1   This model uses Largest Extreme Value distribution for the packet size. For cellular system
 2   simulation, 2-byte UDP header (after header compression) should be added to the packet
 3   size X . Because the packet size has to be an integer number of bytes, the largest integer
 4   less than or equal to X is used as the actual packet size. To simulate the random timing
 5   relationship between client traffic packet arrival and reverse link frame boundary, the
 6   starting time of a network gaming mobile is uniformly distributed within [0, 40ms].
 7   A maximum delay of 160ms is applied to all reverse link packets, i.e., a packet is dropped
 8   by the mobile station if any part of the packet have not started physical layer transmission,
 9   including HARQ operation, 160ms after entering the mobile station buffer.. A packet can
10   start physical layer transmission at the 160ms time instant. Packet dropping should be the
11   last operation of mobile station buffer management, if any, at any time instant. The packet
12   delay of a dropped packet is counted as 180ms.
13   A mobile network gaming user is in outage if the average packet delay is greater than
14   60ms. The average delay is the average of the delay of all packets, including the delay of
15   packets delivered and the delay of packets dropped.

16   4.3.9.2 Forward Link Model
17   Table 6Table 6 describes the parameters for the mobile network gaming traffic on the
18   forward link.
19                  Table 6 Forward Link network gaming traffic model parameters
             Component      Distribution      PDF and generation method



             Initial        Uniform (a=0,                 1
                                              f ( x)          a xb
             packet         b=40ms)                      ba
             arrival
             Packet         Extreme
             arrival        (a=55, b=6)
             Packet size    Extreme                            xa            
                                                                                  xa
                                                       1                e
                                               f ( x)  e                               ,b  0
                                                                                   b
                            (a=120 bytes,                       b
                                                                     e
                            b = 36)                    b
                                               X  a  b ln  ln Y  , Y  U (0,1)
                                              Because packet size has to be integer
                                              number of bytes, the largest integer less
                                              than or equal to X is used as the actual
                                              packet size.
             UDP header     Deterministic
                            (2bytes)
20
21   This model uses Largest Extreme Value distribution for the packet size. For cellular system
22   simulation, a 2-byte UDP header (after header compression) should be added to the packet
23   size X . Because the packet size has to be an integer number of bytes, the largest integer
24   less than or equal to X is used as the actual packet size. To simulate the random timing



                                                                                                          12
     2005-5-16                                                             IEEE C802.20-05/25

 1   relationship between client traffic packet arrival and reverse link frame boundary, the
 2   starting time of a network gaming mobile is uniformly distributed within [0, 40ms].
 3   A maximum delay of 160ms is applied to all reverse link packets, i.e., a packet is dropped
 4   by the mobile station if any part of the packet have not started physical layer transmission,
 5   including HARQ operation, 160ms after entering the mobile station buffer.. A packet can
 6   start physical layer transmission at the 160ms time instant. Packet dropping should be the
 7   last operation of base station buffer management, if any, at any time instant. The packet
 8   delay of a dropped packet is counted as 180ms.
 9   A mobile network gaming user is in outage if the average packet delay is greater than
10   60ms. The average delay is the average of the delay of all packets, including the delay of
11   packets delivered and the delay of packets dropped.
12
13   Option 2: Adopt or modify 3GPP model                                                            Formatted: Font color: Black, Highlight
14   Option 3: Combine the best of the two models
15   Option 4: Develop an 802.20 model based on more recent literature                               Formatted: Font color: Black
                                                                                                     Formatted: Not Highlight
16   4.3.10 Full buffers (Infinite backlog) model
17   In the full buffers (Infinite backlog) user traffic model, all the users in the system always
18   have data to send or receive. In other words, there is always a constant amount of data that
19   needs to be transferred, in contrast to bursts of data that follow an arrival process. This
20   model allows the assessment of the spectral efficiency of the system independent of actual
21   user traffic distribution type.
                                                                                                     Formatted: Not Highlight

22   4.4 Traffic Mix
23   {DG: clean edited text}
24   A MBWA system is expected to support a mix of simultaneous traffic types. There can be          Formatted: Pattern: Clear (Gray-5%)
25   different types of usage scenarios (multi-service v. single-type), different types of devices
26   (laptops v. PDAs), different usage levels (intense v. light) and different delay/latency
27   requirements (real-time v. best-effort).
28   The previous sections are primarily concerned with the traffic models for each of the
29   potential traffic types. As discussed in the previous section, these models are based on
30   statistical analysis of measured traffic that yielded some invariant patterns that are not      Formatted: Font: Bold
31   very dependant on the specific system. It is more difficult to describe a similar invariant     Formatted: Font: Bold
32   mix of traffic types since these tend to depend more heavily on the type of system and the
33   actual deployment mix of user device types.                                                     Formatted: Pattern: Clear (Gray-5%)
34   In the context of system performance evaluation, using traffic models, the specific traffic-    Formatted: Font: Not Bold, Pattern: Clear
35   mix should emphasize different aspects of the system performance, e.g. sustained                (Gray-5%)

36   throughput for file downloads v. faster response times for interactive applications.            Formatted: Pattern: Clear (Gray-5%)
37
38   {DG: proposed NEW text}
39   A short list of representative applications and their corresponding percentage in a simulated
40   system-wide traffic mix is shown in Table 7.
41
42   {DG: revised Table 7 with proposed traffic mix percentages}
43
44                     Table 7 Traffic mix: percentage of different Traffic Types


                                                                                                13
     2005-5-16                                                              IEEE C802.20-05/25


             Traffic Category       Application                         Percentage ( % )                 Formatted: Font: 11 pt
             Best Effort            FTP                                         10                       Formatted: Left
                                    E-mail                                      10
             Interactive            Web browsing                                20
                                    Instant Messaging                           5
                                    Gaming                                      5
             Streaming              Video streaming                             10
             Real-time              VoIP                                        25
                                    Video Telephony                             15
 1
 2
 3   {DG: proposed changes}
 4   A MBWA system is expected to support have a mix of simultaneous traffic types. There
 5   can be different types of usage scenarios (multi-service v. single-type), different types of
 6   devices (laptops v. PDAs), different usage levels of use (intense v. light)., and different
 7   delay/latency demands on response timesrequirements (real-time v. best-effort).
 8
 9   The previous sections are primarily concerned with the traffic models for each of the
10   potential traffic types. As discussed in the previous section, these models are based on
11   statistical analysis of measured traffic to extractthat yielded some invariant patterns that are
12   not very dependant on the specific system. It is more difficult to describe a similar invariant
13   mix of traffic types since these tend to depend more heavily on the type of system and the
14   actual deployment mix of user device/user types.
15                                                                                                       Formatted: Font: Not Bold
16   In the context of a system performance evaluation, using traffic models, the specific mix of
                                                                                                         Formatted: Font: Not Bold
17   traffic-mix types will should emphasize different aspects of the system performance, e.g.
                                                                                                         Formatted: Highlight
18   sustained throughput for file downloads v. faster response times for interactive applications.
                                                                                                         Formatted Table
19   [Editor’s note: This needs to be discussed] [Note from CC on April 19: Dan Gal has
20   agreed to submit a contribution to clarify this section]                                            Formatted: Font: (Default) Arial, Bold

21                                                                                                       Formatted: Font: (Default) Arial, Bold
                                                                                                         Formatted: Left
22                     Table 87 Traffic mix: percentage of different Traffic Types
                                                                                                         Formatted: Left
             Traffic Category                Application               Percentage ( % )                  Formatted: Left
             Best Effort            FTP                                      10                          Formatted: Left
                                    E-mail                                   10                          Formatted: Left
             Interactive            Web browsing                             20                          Formatted: Centered
                                    Instant Messaging                         5                          Formatted: Left
                                    Gaming                                    5                          Formatted: Left
             Streaming              Video streaming                          10
                                                                                                         Formatted: Left
             Real-time              VoIP                                     25
                                                                                                         Formatted: Font: Bold
                                    Video Telephony                          15
                                                                                                         Formatted: Left
                                    Web Browsing
                                                                                                         Formatted: Left
                                    WAP
                                                                                                         Formatted: Font: Bold
                                    FTP (File transfer)
                                                                                                         Formatted: Left
                                    Video-
                                                                                                         Formatted: Font: Bold



                                                                                                    14
    2005-5-16                                                       IEEE C802.20-05/25


                                   telephony/conference                                   Formatted: Font: Bold
                                   E-mail                                                 Formatted: Font: Bold
                                   Multimedia Messaging                                   Formatted: Left
                                   Instant Messaging                                      Formatted: Left
                                   Gaming                                                 Formatted: Left
                                   Audio streaming                                        Formatted: Font: Bold
                                   Video streaming                                        Formatted: Font: Bold
                                   PDA remote synch                                       Formatted: Left
                                   File-sharing                                           Formatted: Left
                                   Broadcast/multicast                                    Formatted: Left
                                   Telematics
                                                                                          Formatted: Font: Bold
1
                                                                                          Formatted: Left
2   [Editor’s note: Table 7 needs to be filled with table/Berlin]
                                                                                          Formatted: Left
                                                                                          Formatted: Left
                                                                                          Formatted: Left




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