One document matched: draft-ietf-rmcat-wireless-tests-00.xml
<?xml version="1.0" encoding="US-ASCII"?>
<!-- This template is for creating an Internet Draft using xml2rfc,
which is available here: http://xml.resource.org. -->
<!DOCTYPE rfc SYSTEM "rfc2629.dtd" [
<!-- One method to get references from the online citation libraries.
There has to be one entity for each item to be referenced.
An alternate method (rfc include) is described in the references. -->
<!ENTITY RFC2119 SYSTEM "http://xml.resource.org/public/rfc/bibxml/reference.RFC.2119.xml">
<!ENTITY RFC2629 SYSTEM "http://xml.resource.org/public/rfc/bibxml/reference.RFC.2629.xml">
<!ENTITY RFC3552 SYSTEM "http://xml.resource.org/public/rfc/bibxml/reference.RFC.3552.xml">
<!ENTITY I-D.narten-iana-considerations-rfc2434bis SYSTEM "http://xml.resource.org/public/rfc/bibxml3/reference.I-D.narten-iana-considerations-rfc2434bis.xml">
<!ENTITY I-D.draft-sarker-rmcat-eval-test SYSTEM "http://xml.resource.org/public/rfc/bibxml3/reference.I-D.draft-sarker-rmcat-eval-test-01.xml">
]>
<?xml-stylesheet type='text/xsl' href='rfc2629.xslt' ?>
<!-- used by XSLT processors -->
<!-- For a complete list and description of processing instructions (PIs),
please see http://xml.resource.org/authoring/README.html. -->
<!-- Below are generally applicable Processing Instructions (PIs) that most I-Ds might want to use.
(Here they are set differently than their defaults in xml2rfc v1.32) -->
<?rfc strict="yes" ?>
<!-- give errors regarding ID-nits and DTD validation -->
<!-- control the table of contents (ToC) -->
<?rfc toc="yes"?>
<!-- generate a ToC -->
<?rfc tocdepth="4"?>
<!-- the number of levels of subsections in ToC. default: 3 -->
<!-- control references -->
<?rfc symrefs="yes"?>
<!-- use symbolic references tags, i.e, [RFC2119] instead of [1] -->
<?rfc sortrefs="yes" ?>
<!-- sort the reference entries alphabetically -->
<!-- control vertical white space
(using these PIs as follows is recommended by the RFC Editor) -->
<?rfc compact="yes" ?>
<!-- do not start each main section on a new page -->
<?rfc subcompact="no" ?>
<!-- keep one blank line between list items -->
<!-- end of list of popular I-D processing instructions -->
<rfc category="info" docName="draft-ietf-rmcat-wireless-tests-00"
ipr="trust200902">
<!-- category values: std, bcp, info, exp, and historic
ipr values: full3667, noModification3667, noDerivatives3667
you can add the attributes updates="NNNN" and obsoletes="NNNN"
they will automatically be output with "(if approved)" -->
<!-- ***** FRONT MATTER ***** -->
<front>
<!-- The abbreviated title is used in the page header - it is only necessary if the
full title is longer than 39 characters -->
<title abbrev="RMCAT Wireless Test Cases">Evaluation Test Cases for
Interactive Real-Time Media over Wireless Networks</title>
<author fullname="Zaheduzzaman Sarker" initials="Z." surname="Sarker">
<organization>Ericsson AB</organization>
<address>
<postal>
<street>Laboratoriegränd 11</street>
<city>Luleå</city>
<region></region>
<code>97753</code>
<country>Sweden</country>
</postal>
<phone>+46 107173743</phone>
<email>zaheduzzaman.sarker@ericsson.com</email>
</address>
</author>
<author fullname="Ingemar Johansson" initials="I." surname="Johansson">
<organization>Ericsson AB</organization>
<address>
<postal>
<street>Laboratoriegränd 11</street>
<city>Luleå</city>
<region></region>
<code>97753</code>
<country>Sweden</country>
</postal>
<phone>+46 10 7143042</phone>
<email>ingemar.s.johansson@ericsson.com</email>
</address>
</author>
<date day="11" month="June" year="2015" />
<!-- Meta-data Declarations -->
<area>TSV</area>
<keyword>Cellular Network</keyword>
<keyword>Congestion Control</keyword>
<keyword>RTP</keyword>
<abstract>
<t>It is evident that to ensure seamless and robust user experience
across all type of access networks multimedia communication suits should
adapt to the changing network conditions. There is an ongoing effort in
IETF RMCAT working group to standardize rate adaptive algorithm(s) to be
used in the real-time interactive communication. In this document test
cases are described to evaluate the performances of the proposed
endpoint adaptation solutions in LTE networks and Wi-Fi networks. It is
aimed that the proposed solutions should be evaluated using the test
cases defined in this document to select most optimal solutions.</t>
</abstract>
</front>
<middle>
<section title="Introduction">
<t>Wireless networks (both cellular and Wi-Fi <xref
target="IEEE802.11"></xref> local area network) are an integral part of
the Internet. Mobile devices connected to the wireless networks produces
huge amount of media traffic in the Internet. They covers the scenarios
of having a video call in the bus to media consumption sitting on a
couch in a living room. It is a well known fact that the characteristic
and challenges for offering service over wireless network are very
different than providing the same over a wired network. Even though
RMCAT basic test cases defines number of test cases that covers lots of
effects of the impairments visible in the wireless networks but there
are characteristics and dynamics those are unique to particular wireless
environment. For example, in the LTE the base station maintains queues
per radio bearer per user hence it gives different interaction when all
traffic from user share the same queue. Again, the user mobility in a
cellular network is different than the user mobility in a Wi-Fi network.
Thus, It is important to evaluate the performance of the proposed RMCAT
candidates separately in the cellular mobile networks and Wi-Fi local
networks (IEEE 802.11xx protocol family ).</t>
<t>RMCAT evaluation criteria <xref
target="I-D.ietf-rmcat-eval-criteria"></xref> document provides the
guideline to perform the evaluation on candidate algorithms and
recognizes wireless networks to be important access link. However, it
does not provides particular test cases to evaluate the performance of
the candidate algorithm. In this document we device test cases
specifically targeting cellular networks such as LTE networks and Wi-Fi
local networks.</t>
</section>
<section title="Terminologies">
<t>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in <xref
target="RFC2119">RFC2119</xref></t>
</section>
<section title="Cellular Network Specific Test Cases">
<t>A cellular environment is more complicated than a wireline ditto
since it seeks to provide services in the context of variable available
bandwidth, location dependencies and user mobilities at different
speeds. In a cellular network the user may reach the cell edge which may
lead to a significant amount of retransmissions to deliver the data from
the base station to the destination and vice versa. These network links
or radio links will often act as a bottleneck for the rest of the
network which will eventually lead to excessive delays or packet drops.
An efficient retransmission or link adaptation mechanism can reduce the
packet loss probability but there will still be some packet losses and
delay variations. Moreover, with increased cell load or handover to a
congested cell, congestion in transport network will become even worse.
Besides, there are certain characteristics which make the cellular
network different and challenging than other types of access network
such as Wi-Fi and wired network. In a cellular network -</t>
<t><list style="symbols">
<t>The bottleneck is often a shared link with relatively few
users.<list style="symbols">
<t>The cost per bit over the shared link varies over time and is
different for different users.</t>
<t>Left over/ unused resource can be grabbed by other greedy
users.</t>
</list></t>
<t>Queues are always per radio bearer hence each user can have many
of such queues.</t>
<t>Users can experience both Inter and Intra Radio Access Technology
(RAT) handovers ("handover" definition in <xref
target="HO-def-3GPP"></xref> ).</t>
<t>Handover between cells, or change of serving cells (see in <xref
target="HO-LTE-3GPP"></xref> and <xref target="HO-UMTS-3GPP"></xref>
) might cause user plane interruptions which can lead to bursts of
packet losses, delay and/or jitter. The exact behavior depends on
the type of radio bearer. Typically, the default best effort bearers
do not generate packet loss, instead packets are queued up and
transmitted once the handover is completed.</t>
<t>The network part decides how much the user can transmit.</t>
<t>The cellular network has variable link capacity per user<list
style="symbols">
<t>Can vary as fast as a period of milliseconds.</t>
<t>Depends on lots of facts (such as distance, speed,
interference, different flows).</t>
<t>Uses complex and smart link adaptation which makes the link
behavior ever more dynamic.</t>
<t>The scheduling priority depends on the estimated
throughput.</t>
</list></t>
<t>Both Quality of Service (QoS) and non-QoS radio bearers can be
used.</t>
</list>Hence, a real-time communication application operating in such
a cellular network need to cope with shared bottleneck link and variable
link capacity, event likes handover, non-congestion related loss, abrupt
change in bandwidth (both short term and long term) due to handover,
network load and bad radio coverage. Even though 3GPP define QoS bearers
<xref target="QoS-3GPP"></xref> to ensure high quality user experience,
adaptive real-time applications are desired.</t>
<t>Different mobile operators deploy their own cellular network with
their own set of network functionalities and policies. Usually, a mobile
operator network includes 2G, EDGE, 3G and 4G radio access technologies.
Looking at the specifications of such radio technologies it is evident
that only 3G and 4G radio technologies can support the high bandwidth
requirements from real-time interactive video applications. The future
real-time interactive application will impose even greater demand on
cellular network performance which makes 4G (and beyond radio
technologies) more suitable access technology for such genre of
application.</t>
<t>The key factors to define test cases for cellular network are</t>
<t><list style="symbols">
<t>Shared and varying link capacity</t>
<t>Mobility</t>
<t>Handover</t>
</list>However, for cellular network it is very hard to separate such
events from one another as these events are heavily related. Hence
instead of devising separate test cases for all those important events
we have divided the test case in two categories. It should be noted that
in the following test cases the goal is to evaluate the performance of
candidate algorithms over radio interface of the cellular network. Hence
it is assumed that the radio interface is the bottleneck link between
the communicating peers and that the core network does not add any extra
congestion in the path. Also the combination of multiple access
technologies such as one user has LTE connection and another has Wi-Fi
connection is kept out of the scope of this document. However, later
those additional scenarios can also be added in this list of test cases.
While defining the test cases we assumed a typical real-time telephony
scenario over cellular networks where one real-time session consists of
one voice stream and one video stream. We recommend that an LTE network
simulator is used for the test cases defined in this document, for
example-NS-3 LTE simulator <xref target="LTE-simulator"></xref>.</t>
<section anchor="VNL" title="Varying Network Load">
<t>The goal of this test is to evaluate the performance of the
candidate congestion control algorithm under varying network load. The
network load variation is created by adding and removing network users
a.k.a. User Equipments (UEs) during the simulation. In this test case,
each of the user/UE in the media session is an RMCAT compliant
endpoint. The arrival of users follows a Poisson distribution, which
is proportional to the length of the call, so that the number of users
per cell is kept fairly constant during the evaluation period. At the
beginning of the simulation there should be enough amount of time to
warm-up the network. This is to avoid running the evaluation in an
empty network where network nodes are having empty buffers, low
interference at the beginning of the simulation. This network
initialization period is therefore excluded from the evaluation
period.</t>
<t>This test case also includes user mobility and competing traffic.
The competing traffics includes both same kind of flows (with same
adaptation algorithms) and different kind of flows (with different
service and congestion control). The investigated congestion control
algorithms should show maximum possible network utilization and
stability in terms of rate variations, lowest possible end to end
frame latency, network latency and Packet Loss Rate (PLR) at different
cell load level.</t>
<section anchor="NC-VNL" title="Network Connection">
<t>Each mobile user is connected to a fixed user. The connection
between the mobile user and fixed user consists of a LTE radio
access, an Evolved Packet Core (EPC) and an Internet connection. The
mobile user is connected to the EPC using LTE radio access
technology which is further connected to the Internet. The fixed
user is connected to the Internet via wired connection with no
bottleneck (practically infinite bandwidth). The Internet and wired
connection in this setup does not add any network impairments to the
test, it only adds 10ms of one-way transport propagation delay.</t>
<t>The path from the fixed user to mobile user is defines as
"Downlink" and the path from mobile user to the fixed user is
defined as "Uplink". We assume that only uplink or downlink is
congested for the mobile users. Hence, we recommend that the uplink
and downlink simulations are run separately. <figure align="center"
anchor="fig-siml-topology" title="Simulation Topology">
<artwork align="center" name="Simulation Topology"><![CDATA[ uplink
++))) +-------------------------->
++-+ ((o))
| | / \ +-------+ +------+ +---+
+--+ / \----+ +-----+ +----+ |
/ \ +-------+ +------+ +---+
UE BS EPC Internet fixed
<--------------------------+
downlink
]]></artwork>
</figure></t>
</section>
<section anchor="SS-VNL" title="Simulation Setup">
<t>The values enclosed within " [ ] " for the following simulation
attributes follow the notion set in <xref
target="I-D.ietf-rmcat-eval-test"></xref>. The desired simulation
setup as follows-<list style="numbers">
<t>Radio environment <list style="letters">
<t>Deployment and propagation model : 3GPP case 1<xref
target="Deployment"></xref></t>
<t>Antenna: Multiple-Input and Multiple-Output (MIMO), [2D,
3D]</t>
<t>Mobility: [3km/h, 30km/h]</t>
<t>Transmission bandwidth: 10Mhz</t>
<t>Number of cells: multi cell deployment (3 Cells per Base
Station (BS) * 7 BS) = 21 cells</t>
<t>Cell radius: 166.666 Meters</t>
<t>Scheduler: Proportional fair with no priority</t>
<t>Bearer: Default bearer for all traffic.</t>
<t>Active Queue Management (AQM) settings: AQM [on,off]</t>
</list></t>
<t>End to end Round Trip Time (RTT): [ 40, 150]</t>
<t>User arrival model: Poisson arrival model</t>
<t>User intensity:<list style="symbols">
<t>Downlink user intensity: {0.7, 1.4, 2.1, 2.8, 3.5, 4.2,
4.9, 5.6, 6.3, 7.0, 7.7, 8.4, 9,1, 9.8, 10.5}</t>
<t>Uplink user intercity : {0.7, 1.4, 2.1, 2.8, 3.5, 4.2,
4.9, 5.6, 6.3, 7.0}</t>
</list></t>
<t>Simulation duration: 91s</t>
<t>Evaluation period : 30s-60s</t>
<t>Media traffic <list counter="reqs" style="numbers">
<t>Media type: Video<list style="letters">
<t>Media direction: [Uplink, Downlink]</t>
<t>Number of Media source per user: One (1)</t>
<t>Media duration per user: 30s</t>
<t>Media source: same as define in section 4.3 of <xref
target="I-D.ietf-rmcat-eval-test"></xref></t>
</list></t>
<t>Media Type : Audio <list style="letters">
<t>Media direction: Uplink and Downlink</t>
<t>Number of Media source per user: One (1)</t>
<t>Media duration per user: 30s</t>
<t>Media codec: Constant BitRate (CBR)</t>
<t>Media bitrate : 20 Kbps</t>
<t>Adaptation: off</t>
</list></t>
</list></t>
<t>Other traffic model:<list style="symbols">
<t>Downlink simulation: Maximum of 4Mbps/cell (web browsing
or FTP traffic)</t>
<t>Unlink simulation: Maximum of 2Mbps/cell (web browsing or
FTP traffic)</t>
</list></t>
</list></t>
</section>
</section>
<section title="Bad Radio Coverage">
<t>The goal of this test is to evaluate the performance of candidate
congestion control algorithm when users visit part of the network with
bad radio coverage. The scenario is created by using larger cell
radius than previous test case. In this test case each of the user/UE
in the media session is an RMCAT compliant endpoint. The arrival of
users follows a Poisson distribution, which is proportional to the
length of the call, so that the number of users per cell is kept
fairly constant during the evaluation period. At the beginning of the
simulation there should be enough amount of time to warm-up the
network. This is to avoid running the evaluation in an empty network
where network nodes are having empty buffers, low interference at the
beginning of the simulation. This network initialization period is
therefore excluded from the evaluation period.</t>
<t>This test case also includes user mobility and competing traffic.
The competing traffics includes same kind of flows (with same
adaptation algorithms) . The investigated congestion control
algorithms should show maximum possible network utilization and
stability in terms of rate variations, lowest possible end to end
frame latency, network latency and Packet Loss Rate (PLR) at different
cell load level.</t>
<section title="Network connection">
<t>Same as defined in <xref target="NC-VNL"></xref></t>
</section>
<section title="Simulation Setup">
<t>The desired simulation setup is same as Varying Network Load test
case defined in <xref target="VNL"></xref> except following
changes-<list style="numbers">
<t>Radio environment : Same as defined in <xref
target="SS-VNL"></xref> except followings<list style="letters">
<t>Deployment and propagation model : 3GPP case 3<xref
target="Deployment"></xref></t>
<t>Cell radius: 577.3333 Meters</t>
<t>Mobility: 3km/h</t>
</list></t>
<t>User intensity = {0.7, 1.4, 2.1, 2.8, 3.5, 4.2, 4.9, 5.6,
6.3, 7.0}</t>
<t>Media traffic model: Same as defined in <xref
target="SS-VNL"></xref></t>
<t>Other traffic model: None</t>
</list></t>
</section>
</section>
<section title="Desired Evaluation Metrics for cellular test cases">
<t>RMCAT evaluation criteria document <xref
target="I-D.ietf-rmcat-eval-criteria"></xref> defines metrics to be
used to evaluate candidate algorithms. However, looking at the nature
and distinction of cellular networks we recommend at minimum following
metrics to be used to evaluate the performance of the candidate
algorithms for the test cases defined in this document.</t>
<t>The desired metrics are-</t>
<t><list style="symbols">
<t>Average cell throughput (for all cells), shows cell
utilizations.</t>
<t>Application sending and receiving bitrate, goodput.</t>
<t>Packet Loss Rate (PLR).</t>
<t>End to end Media frame delay. For video, this means the delay
from capture to display.</t>
<t>Transport delay.</t>
<t>Algorithm stability in terms of rate variation.</t>
</list></t>
</section>
</section>
<section title="Wi-Fi Networks Specific Test Cases">
<t>TBD</t>
</section>
<section title="Conclusion">
<t>This document defines two test cases that are considered important
for cellular networks. Moreover, this document also provides a framework
to define more additional test cases for cellular network.</t>
</section>
<!-- This PI places the pagebreak correctly (before the section title) in the text output. -->
<?rfc needLines="8" ?>
<section anchor="Acknowledgements" title="Acknowledgements">
<t>We would like to thank Tomas Frankkila, Magnus Westerlund, Kristofer
Sandlund for their valuable comments while writing this draft.</t>
</section>
<section anchor="IANA" title="IANA Considerations">
<t>This memo includes no request to IANA.</t>
<t></t>
</section>
<section anchor="Security" title="Security Considerations">
<t>Security issues have not been discussed in this memo.</t>
</section>
</middle>
<!-- *****BACK MATTER ***** -->
<back>
<!-- References split into informative and normative -->
<!-- There are 2 ways to insert reference entries from the citation libraries:
1. define an ENTITY at the top, and use "ampersand character"RFC2629; here (as shown)
2. simply use a PI "less than character"?rfc include="reference.RFC.2119.xml"?> here
(for I-Ds: include="reference.I-D.narten-iana-considerations-rfc2434bis.xml")
Both are cited textually in the same manner: by using xref elements.
If you use the PI option, xml2rfc will, by default, try to find included files in the same
directory as the including file. You can also define the XML_LIBRARY environment variable
with a value containing a set of directories to search. These can be either in the local
filing system or remote ones accessed by http (http://domain/dir/... ).-->
<references title="Normative References">
<!--?rfc include="http://xml.resource.org/public/rfc/bibxml/reference.RFC.2119.xml"?-->
<?rfc include='reference.RFC.2119.xml'?>
<?rfc include='reference.I-D.ietf-rmcat-eval-criteria.xml'?>
<reference anchor="Deployment"
target="http://www.3gpp.org/ftp/specs/archive/25_series/25.814/25814-710.zip">
<front>
<title>Physical layer aspects for evolved Universal Terrestrial
Radio Access (UTRA)</title>
<author fullname="3GPP R1" initials="3GPP" surname="TS 25.814">
<organization></organization>
</author>
<date month="October" year="2006" />
</front>
</reference>
<reference anchor="QoS-3GPP"
target="http://www.3gpp.org/ftp/specs/archive/23_series/23.203/23203-990.zip">
<front>
<title>Policy and charging control architecture</title>
<author fullname="3GPP S2" initials="3GPP" surname="TS 23.203">
<organization></organization>
</author>
<date month="June" year="2011" />
</front>
</reference>
<reference anchor="HO-def-3GPP"
target="http://www.3gpp.org/ftp/specs/archive/21_series/21.905/21905-940.zip">
<front>
<title>Vocabulary for 3GPP Specifications</title>
<author fullname="3GPP SA" initials="3GPP" surname="TR 21.905">
<organization>3GPP</organization>
</author>
<date month="December" year="2009" />
</front>
</reference>
<reference anchor="HO-LTE-3GPP"
target="http://www.3gpp.org/ftp/specs/archive/36_series/36.331/36331-990.zip">
<front>
<title>E-UTRA- Radio Resource Control (RRC); Protocol
specification</title>
<author fullname="3GPP R2" initials="3GPP" surname="TS 36.331">
<organization>3GPP</organization>
</author>
<date month="December" year="2011" />
</front>
</reference>
<reference anchor="HO-UMTS-3GPP"
target="http://www.3gpp.org/ftp/specs/archive/25_series/25.331/25331-990.zip">
<front>
<title>Radio Resource Control (RRC); Protocol specification</title>
<author fullname="3GPP R2" initials="3GPP" surname="TS 25.331">
<organization>3GPP</organization>
</author>
<date month="December" year="2011" />
</front>
</reference>
</references>
<references title="Informative References">
<!-- Here we use entities that we defined at the beginning. -->
<!-- A reference written by by an organization not a person. -->
<?rfc include='reference.I-D.ietf-rmcat-cc-requirements.xml'?>
<?rfc include='reference.I-D.ietf-rmcat-eval-test.xml'?>
<reference anchor="IEEE802.11">
<front>
<title>Standard for Information technology--Telecommunications and
information exchange between systems Local and metropolitan area
networks--Specific requirements Part 11: Wireless LAN Medium Access
Control (MAC) and Physical Layer (PHY) Specifications</title>
<author fullname="IEEE">
<organization></organization>
</author>
<date year="2012" />
</front>
</reference>
<reference anchor="LTE-simulator"
target="https://www.nsnam.org/docs/release/3.23/manual/html/index.html">
<front>
<title>NS-3, A discrete-Event Network Simulator</title>
<author>
<organization></organization>
</author>
<date />
</front>
</reference>
</references>
<!-- -->
</back>
</rfc>
| PAFTECH AB 2003-2026 | 2026-04-23 20:36:10 |