Road vehicles -- Media Oriented Systems Transport (MOST)

This document specifies the conformance test plan (CTP) for the transport layer and network layer for MOST, a synchronous time-division-multiplexing network, as specified in ISO 21806-4. This document specifies conformance test cases (CTCs) in the following categories: — network layer services; — data transport mechanism; — dynamic behaviour of a node. Interoperability testing is not in the scope of this document.

Véhicules routiers -- Système de transport axé sur les médias

General Information

Status
Published
Publication Date
17-Sep-2020
Current Stage
5060 - Close of voting Proof returned by Secretariat
Start Date
31-Jul-2020
Completion Date
31-Jul-2020
Ref Project

Buy Standard

Standard
ISO 21806-5:2020 - Road vehicles -- Media Oriented Systems Transport (MOST)
English language
31 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 21806-5
First edition
2020-09
Road vehicles — Media Oriented
Systems Transport (MOST) —
Part 5:
Transport layer and network layer
conformance test plan
Véhicules routiers — Système de transport axé sur les médias —
Partie 5: Plan d'essais de conformité de la couche transport et de la
couche réseau
Reference number
ISO 21806-5:2020(E)
ISO 2020
---------------------- Page: 1 ----------------------
ISO 21806-5:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 21806-5:2020(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Symbols and abbreviated terms ........................................................................................................................................................... 2

4.1 Symbols ......................................................................................................................................................................................................... 2

4.2 Abbreviated terms ............................................................................................................................................................................... 2

5 Conventions ............................................................................................................................................................................................................... 2

6 CTP overview ............................................................................................................................................................................................................ 2

6.1 Test set-up ................................................................................................................................................................................................... 2

6.2 CTP organisation ................................................................................................................................................................................... 4

7 CTP general information .............................................................................................................................................................................. 4

7.1 CTC remarks .............................................................................................................................................................................................. 4

7.1.1 Timer naming ..................................................................................................................................................................... 4

7.1.2 Deadlock prevention .................................................................................................................................................... 4

7.1.3 Un-initialised logical node address .................................................................................................................. 5

7.1.4 Addresses of MOST nodes in the LT ................................................................................................................ 5

7.1.5 Device manufacturer information list ........................................................................................................... 5

7.1.6 States of the node that contains the IUT ..................................................................................................... 6

7.1.7 Procedures ............................................................................................................................................................................ 7

7.1.8 Violation of prerequisites of the CTC ............................................................................................................. 8

7.2 CTC items ..................................................................................................................................................................................................... 8

7.2.1 FBlock EnhancedTestability (ET) ...................................................................................................................... 8

7.2.2 Multi-node devices ......................................................................................................................................................... 8

7.2.3 Node kinds excluded from conformance testing .................................................................................. 8

8 CTC specification .................................................................................................................................................................................................. 9

8.1 Wake-up ........................................................................................................................................................................................................ 9

8.1.1 TimingMaster wake-up .............................................................................................................................................. 9

8.1.2 CTC_2.1.3-1 – TimingSlave wake-up test .................................................................................................12

8.2 s_NetInterface_Normal_Operation – Unlock ...............................................................................................................15

8.2.1 CTC_2.2.1-3 – Short unlock test .......................................................................................................................15

8.2.2 CTC_2.2.1-6 – Sudden signal off test ............................................................................................................17

8.2.3 CTC_2.2.1-7 – Shutdown flag present test ...............................................................................................19

8.3 Segmented transfer ..........................................................................................................................................................................21

8.3.1 CTC_2.8.4-1 – Segmented transfer rejection test ..............................................................................21

8.3.2 CTC_2.8.4-2 – Segmented transfer sending test .................................................................................22

8.3.3 CTC_2.8.4-3 – Segmentation error test ......................................................................................................23

8.3.4 CTC_2.8.4-7 – Segmented transfer buffer test .....................................................................................26

8.3.5 CTC_2.8.4-8 – Parallel segmented transfer reception test ........................................................28

Annex A (normative) Measurement uncertainty for individual CTCs.............................................................................30

Bibliography .............................................................................................................................................................................................................................31

© ISO 2020 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 21806-5:2020(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/ patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/

iso/ foreword .html.

This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 31,

Data communication.
A list of all parts in the ISO 21806 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2020 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 21806-5:2020(E)
Introduction

The Media Oriented Systems Transport (MOST) communication technology was initially developed at

the end of the 1990s in order to support complex audio applications in cars. The MOST Cooperation was

founded in 1998 with the goal to develop and enable the technology for the automotive industry. Today,

MOST enables the transport of high quality of service (QoS) audio and video together with packet data

and real-time control to support modern automotive multimedia and similar applications. MOST is a

function-oriented communication technology to network a variety of multimedia devices comprising

one or more MOST nodes.
Figure 1 shows a MOST network example.
Figure 1 — MOST network example
The MOST communication technology provides:
— synchronous and isochronous streaming,
— small overhead for administrative communication control,
— a functional and hierarchical system model,
— API standardization through a function block (FBlock) framework,
— free partitioning of functionality to real devices,
— service discovery and notification, and
[2]

— flexibly scalable automotive-ready Ethernet communication according to ISO/IEC/IEEE 8802-3 .

MOST is a synchronous time-division-multiplexing (TDM) network that transports different data types

on separate channels at low latency. MOST supports different bit rates and physical layers. The network

clock is provided with a continuous data signal.

1) MOST is the registered trademark of Microchip Technology Inc. This information is given for the convenience

of users of this document and does not constitute an endorsement by ISO.
© ISO 2020 – All rights reserved v
---------------------- Page: 5 ----------------------
ISO 21806-5:2020(E)

Within the synchronous base data signal, the content of multiple streaming connections and control

data is transported. For streaming data connections, bandwidth is reserved to avoid interruptions,

collisions, or delays in the transport of the data stream.

MOST specifies mechanisms for sending anisochronous, packet-based data in addition to control data

and streaming data. The transmission of packet-based data is separated from the transmission of

control data and streaming data. None of them interfere with each other.

A MOST network consists of devices that are connected to one common control channel and packet

channel.

In summary, MOST is a network that has mechanisms to transport the various signals and data streams

that occur in multimedia and infotainment systems.

The ISO standards maintenance portal (https:// standards .iso .org/ iso/ ) provides references to MOST

specifications implemented in today's road vehicles because easy access via hyperlinks to these

specifications is necessary. It references documents that are normative or informative for the MOST

versions 4V0, 3V1, 3V0, and 2V5.

The ISO 21806 series has been established in order to specify requirements and recommendations

for implementing the MOST communication technology into multimedia devices and to provide

conformance test plans for implementing related test tools and test procedures.

To achieve this, the ISO 21806 series is based on the open systems interconnection (OSI) basic reference

[1] [3]

model in accordance with ISO/IEC 7498-1 and ISO/IEC 10731 , which structures communication

systems into seven layers as shown in Figure 2. Stream transmission applications use a direct stream

data interface (transparent) to the data link layer.
vi © ISO 2020 – All rights reserved
---------------------- Page: 6 ----------------------
ISO 21806-5:2020(E)
Figure 2 — The ISO 21806 series reference according to the OSI model

The International Organization for Standardization (ISO) draws attention to the fact that it is claimed

that compliance with this document may involve the use of a patent.

ISO takes no position concerning the evidence, validity and scope of this patent right.

The holder of this patent right has assured ISO that he/she is willing to negotiate licences under

reasonable and non-discriminatory terms and conditions with applicants throughout the world. In

this respect, the statement of the holder of this patent right is registered with ISO. Information may be

obtained from the patent database available at www .iso .org/ patents.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights other than those in the patent database. ISO shall not be held responsible for identifying

any or all such patent rights.
© ISO 2020 – All rights reserved vii
---------------------- Page: 7 ----------------------
INTERNATIONAL STANDARD ISO 21806-5:2020(E)
Road vehicles — Media Oriented Systems Transport
(MOST) —
Part 5:
Transport layer and network layer conformance test plan
1 Scope

This document specifies the conformance test plan (CTP) for the transport layer and network layer for

MOST, a synchronous time-division-multiplexing network, as specified in ISO 21806-4.

This document specifies conformance test cases (CTCs) in the following categories:

— network layer services;
— data transport mechanism;
— dynamic behaviour of a node.
Interoperability testing is not in the scope of this document.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO/IEC 9646-1:1994, Information technology — Open Systems Interconnection — Conformance testing

methodology and framework — Part 1: General concepts

ISO 21806-1, Road vehicles — Media Oriented Systems Transport (MOST) — Part 1: General information

and definitions

ISO 21806-2, Road vehicles — Media Oriented Systems Transport (MOST) — Part 2: Application layer

ISO 21806-4, Road vehicles — Media Oriented Systems Transport (MOST) — Part 4: Transport layer and

network layer
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 21806-1, ISO 21806-2,

ISO 21806-4, ISO/IEC 9646-1, and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
REPEAT
pseudo code command for an iteration
© ISO 2020 – All rights reserved 1
---------------------- Page: 8 ----------------------
ISO 21806-5:2020(E)
3.2
REPEAT END
pseudo code command for ending an iteration
4 Symbols and abbreviated terms
4.1 Symbols
--- empty cell/undefined
4.2 Abbreviated terms
CTC conformance test case
CTP conformance test plan
ET EnhancedTestability
FBlock function block
IUT implementation under test
LT lower tester
MPI maximum position information
NCE network change event
OSI Open Systems Interconnection
UT upper tester
5 Conventions
[3]

This document is based on OSI service conventions as specified in ISO/IEC 10731 and ISO/IEC 9646-1

for conformance test system setup.
6 CTP overview
6.1 Test set-up

All CTCs are based on the same test set-up with an upper tester (UT) and a lower tester (LT). The LT

contains the lower tester pre-IUT (LT pre-IUT) and the lower tester post-IUT (LT post-IUT).

Figure 3 specifies the test set-up.
2 © ISO 2020 – All rights reserved
---------------------- Page: 9 ----------------------
ISO 21806-5:2020(E)
Figure 3 — Test set-up

The LT pre-IUT and the LT post-IUT implement the application layer services and the lower layer

services of a MOST node in accordance with the ISO 21806 series. They also contain a listen-only

node in front of the MOST node to log the whole communication. The MOST node is able to operate as

TimingMaster or TimingSlave; alternatively, it can be physically disconnected from the MOST network.

If it is disconnected, the associated LT pre-IUT or LT post-IUT serves as listen-only node.

Every CTC specifies the roles of the LT pre-IUT and the LT post-IUT.

During testing of the MOST device that implements the IUT, avoid over-temperature by following the

manufacturer recommendations regarding cooling.

The power supply of the MOST device that contains the IUT is adjustable and the power consumption

can be monitored by the UT. This is necessary to determine whether a node has entered s_

NetInterface_Sleep.

A MOST device contains one or more nodes, which are connected to an external MOST physical interface.

One of the nodes contains the implementation under test (IUT). All tests and timings, specified by the

CTP, are related to the external MOST physical interface.
Figure 4 shows a MOST device with one node and a MOST device with three nodes.
© ISO 2020 – All rights reserved 3
---------------------- Page: 10 ----------------------
ISO 21806-5:2020(E)
1 external MOST physical interface
2 internal MOST physical interface
Figure 4 — MOST device with one node and MOST device with three nodes
6.2 CTP organisation

CTCs are independent of one another. Each CTC checks the behaviour of the IUT for requirements stated

in ISO 21806-4. Within CTCs, which require variations of individual parameters, each specified value of

the parameter is iterated.
The measurement uncertainty for each CTC shall be in accordance with Annex A.
7 CTP general information
7.1 CTC remarks
7.1.1 Timer naming

For conformance testing of the IUT, the UT and LT need minimum and maximum timers. The names of

the timers used by this document are based on ISO 21806-2 and ISO 21806-4. To obtain the timer name,

for minimum and maximum, “ ” and “ ” are appended, respectively. Table 1 shows a timer naming

_min _max
definition example for t .
Config
Table 1 — Timer naming example
Name Minimum Typical Maximum Unit Purpose
value name value name value name
t t t t ms Time before ev_Init_Error_Shutdown or delay
Config Config_min Config Config_max
for RBD result.
7.1.2 Deadlock prevention
This document specifies the timeouts t , t , and t to prevent deadlock
DeadLockShort DeadLockMid DeadLockLong
situations during conformance testing. These are the default values:
— t : 1 s;
DeadLockShort
— t : 20 s;
DeadLockMid
— t : 5 min.
DeadLockLong
These timeouts are only relevant for conformance testing and may be extended.
4 © ISO 2020 – All rights reserved
---------------------- Page: 11 ----------------------
ISO 21806-5:2020(E)
7.1.3 Un-initialised logical node address

The variable uninitialised_node_address is defined as the address of an un-initialised node, which is

specified in ISO 21806-2.
7.1.4 Addresses of MOST nodes in the LT

The address of a MOST node in the LT is the default logical node address corresponding to the node

position.

If this address is in conflict with the address of a node that contains the IUT (e.g. if a supplier uses

static addresses in the dynamic address range), the affected MOST node in the LT shall use a valid free

address.
7.1.5 Device manufacturer information list

This list contains all information that is provided by the device manufacturer for conformance testing.

It also includes remarks and references to corresponding CTCs.

Table 2 shows the device manufacturer information list, which does not include information stored in

FBlock EnhancedTestability.
Table 2 — Device manufacturer information list
Category Item/property Description Reference
to CTC

MOST network IUT in the TimingMaster Determines whether the IUT is part of the All CTCs

configuration TimingMaster.
IUT in the NetworkMaster Determines whether the IUT is part of the All CTCs
NetworkMaster.
IUT in the PowerMaster Determines whether the IUT is part of the All CTCs
PowerMaster.
Multi-node device If the IUT is part of a MOST device that contains All CTCs
more than one node, the following information is
provided:
— number of nodes in the MOST device;
— topology of the MOST device (position
of PowerMaster and TimingMaster/
NetworkMaster);
— position of the node that contains the IUT.
IUT sample frequency If the IUT is not part of the TimingMaster, the All CTCs
LT provides the correct network frame rate
(44,1 kHz or 48,0 kHz).
Required value of boundary Value of the boundary descriptor All CTCs
descriptor (if the Timing-
Unless otherwise stated, all CTCs are performed
Master is in the LT)
with this value of the boundary descriptor.
Power Node that contains the IUT --- CTC_2.1.1-6a,
management is capable of waking via net- CTC_2.1.3-1
work startup (i.e. switching
on its MOST output)

Delay between connection Potentially, the UT (see Figure 3) waits for a short All CTCs

to power (of the MOST de- period of time between connecting the MOST de-
vice that contains the IUT) vice that contains the IUT to power and switching
and the ability of the node on the MOST output to wake up the node that con-
that contains the IUT to tains the IUT. Otherwise, the node that contains
detect wake-up events the IUT does not detect a wake-up event.
© ISO 2020 – All rights reserved 5
---------------------- Page: 12 ----------------------
ISO 21806-5:2020(E)
Table 2 (continued)
Category Item/property Description Reference
to CTC
General t Limit for responding to a command that reads a CTC_2.8.4-3
Property
communication property.
Physical U At this voltage level, the MOST device that con- All CTCs
IUT_Operating
parameter tains the IUT operates normally.
(voltage levels)
Unless otherwise stated, all CTCs are performed
at this voltage level.

Messaging Node that contains the The IUT can send and receive segmented trans- CTC_2.8.4-2,

IUT supports segmented fers. CTC_2.8.4-3,
transfers CTC_2.8.4-7,
CTC_2.8.4-8
7.1.6 States of the node that contains the IUT

Table 3 specifies how the NetInterface state s_NetInterface_Normal_Operation is effectuated and

detected in the node that contains the IUT.
Table 3 — Effectuate and detect s_NetInterface_Normal_Operation
Effectuate state Detect state
a) The IUT is contained in a NetworkSlave: a) The IUT is contained in a
NetworkSlave:
The UT shall:
the node that contains the
IUT responds to NetBlock.
— start the network,
FBlockIDs.Get
— wait for the node that contains the IUT to open its bypass (MPI is
nominal ),
— send NetworkMaster.Configuration.Status(NotOK),
— perform an FBlock scan (including retries if the address of the node
that contains the IUT is invalid),
— send NetworkMaster.Configuration.Status(OK), and
— wait for t .
WaitForApplication
b) The IUT is contained in the NetworkMaster: b) The IUT is contained in the
NetworkMaster:
— the UT shall behave like a NetworkSlave. It shall process and
the node that contains the
respond to all requests from the node that contains the IUT so that
IUT responds to NetBlock.
the node can enter central registry state OK;
FBlockIDs.Get
— the UT shall respond to an FBlock scan by the node that contains
the IUT. Additionally, the UT shall wait for the node to open its
bypass (MPI is nominal ) if the node is part of a multi-node device;
— finally, the UT shall wait for t .
WaitForApplication

The nominal MPI is the total number of nodes in the test set-up, based on the device manufacturer information and the

test equipment.

Table 4 specifies how the NetInterface state s_NetInterface_Off is effectuated and detected in the

node that contains the IUT.
Table 4 — Effectuate and detect s_NetInterface_Off
Effectuate state Detect state
The LT shall switch off the MOST output. No network activity
6 © ISO 2020 – All rights reserved
---------------------- Page: 13 ----------------------
ISO 21806-5:2020(E)
7.1.7 Procedures
Table 5 specifies the procedures of the LT.
Table 5 — Procedures of the LT
Purpose Description

Perform wake-up a) If the LT contains the TimingMaster, it shall execute this sequence to perform a

wake-up:
1. switch on the MOST output;
2. wait for network activity (timeout t );
DeadLockShort
3. wait for stable lock (timeout t ).
DeadLockMid

b) If the LT does not contain the TimingMaster, it shall execute this sequence to

perform a wake-up:
1. generate a wake-up event;
2. wait for network activity;
3. switch on the MOST output;
4. wait for stable lock;
5. wait for the lock flag to evaluate to true.

If the LT does not generate a wake-up event and detects network activity, it shall switch

on the MOST output.

In some cases, the node that contains the IUT needs some preconditions for wake-up.

These preconditions are established before testing is started. The preconditions depend

on the device manufacturer.

If EnhancedTestability.AutoWakeup is triggered, the node that contains the IUT does

not enter s_NetInterface_Sleep before creating the corresponding wake-up event.

The node enters s_NetInterface_Off. This state is not detectable by monitoring the

power consumption of the MOST device that contains IUT. With entering

s_NetInterface_Off, the node that contains the IUT switches off the MOST output.

Perform shutdown a) If the IUT is part of the PowerMaster, the LT shall execute this sequence to perform

shutdown:
— trigger shutdown by means of FBlock EnhancedTestability;

— if no network activity is detected, the node that contains the IUT has performed

shutdown;
— if t expires after triggering shutdown and the LT still detects network
DeadLockMid
activity, it shall switch off the MOST output.

b) If the IUT is part of a PowerSlave, the LT shall switch off the MOST output to perform

shutdown.

If the IUT is part of the PowerMaster, no preconditions are established that prevent the

node that contains the IUT from performing shutdown.
Generate unlock To generate an unlock event of predictable duration, the LT

— shall invalidate or delay the preamble at the beginning of at least every third network

frame during the period of unlock (see ISO 21806-6), and
— shall avoid a PLL unlock.
MOST output on The LT shall switch on the MOST output.
MOST output off The LT shall switch off the MOST output.
© ISO 2020 – All rights reserved 7
---------------------- Page: 14 ----------------------
ISO 21806-5:2020(E)
Table 5 (continued)
Purpose Description

Network change The NCE shall be generated between the TimingMaster and the node that contains the IUT.

event with unlock

Network change The NCE shall be generated between the node that contains the IUT and the TimingMaster.

event without unlock
7.1.8 Violation of prerequisites of the CTC

If the node that contains the IUT does not meet the prerequisites of the CTC (such as network activity,

lock, FBlock scan perfo
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.