Rohde & Schwarz R&S CMW-KM300 User manual

R&S®CMW-KM300/-KS300
NB-IoT Firmware Applications
User Manual
User Manual
Version 06
1178568902
(;ÜÆç2)
深圳德标仪器 135-1095-0799

This user manual describes the following R&S®CMW options:
●R&S®CMW-KM300 (NB-IoT R13/14, TX measurement, uplink)
●R&S®CMW-KM012 (TX measurement, multi-evaluation list mode)
●R&S®CMW-KS300 (NB-IoT R13/14, generic signaling)
●R&S®CMW-KE100 (basic fading support: AWGN generator)
●R&S®CMW-KE500 (LTE fading profiles TS 36.521, excerpts)
© 2019 Rohde & Schwarz GmbH & Co. KG
Mühldorfstr. 15, 81671 München, Germany
Phone: [phone] - 0
Fax: [phone]
Email: [email protected]
Internet: www.rohde-schwarz.com
Subject to change – Data without tolerance limits is not binding.
R&S® is a registered trademark of Rohde & Schwarz GmbH & Co. KG.
Trade names are trademarks of the owners.
1178.5689.02 | Version 06 | R&S®CMW-KM300/-KS300
The following abbreviations are used throughout this manual: R&S®CMW is abbreviated as R&S CMW.
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Contents
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Contents
1 Preface.................................................................................................... 9
1.1 Documentation Overview............................................................................................. 9
1.1.1 Getting Started Manual / Quick Start Guide....................................................................9
1.1.2 User Manual and Help.................................................................................................... 9
1.1.3 Features & Functions...................................................................................................... 9
1.1.4 Basic Safety Instructions...............................................................................................10
1.1.5 Data Sheet and Brochure..............................................................................................10
1.1.6 Release Notes and Open-Source Acknowledgment (OSA)..........................................10
1.1.7 Application Notes, Application Cards, White Papers, etc..............................................10
1.2 R&S CMW Models....................................................................................................... 10
1.3 How to Read Firmware Application Chapters.......................................................... 11
1.3.1 General Description.......................................................................................................11
1.3.2 Application Sheets.........................................................................................................11
1.3.3 GUI Reference...............................................................................................................11
1.3.4 Programming Examples................................................................................................ 11
1.3.5 Command Reference.................................................................................................... 12
2 NB-IoT Signaling.................................................................................. 13
2.1 What's New in This Version........................................................................................13
2.2 General Description.................................................................................................... 13
2.2.1 Test Setup..................................................................................................................... 14
2.2.2 Initiating Signaling Tests................................................................................................14
2.2.3 Internal Fading.............................................................................................................. 15
2.2.4 Connection States.........................................................................................................16
2.2.5 Operation Modes...........................................................................................................18
2.2.6 Physical DL Channels and Signals............................................................................... 20
2.2.7 UL Resources in Time and Frequency Domain............................................................ 21
2.2.8 Scheduling Type UL RMC.............................................................................................23
2.2.9 Scheduling Type DL RMC.............................................................................................24
2.2.10 User-Defined Scheduling.............................................................................................. 24
2.2.11 Operating Bands........................................................................................................... 27
2.2.12 Data Tests..................................................................................................................... 30
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2.2.13 Trigger Signals.............................................................................................................. 30
2.2.14 Cell Reselection Setup..................................................................................................31
2.3 GUI Reference............................................................................................................. 32
2.3.1 Main View......................................................................................................................33
2.3.2 Signaling Control...........................................................................................................42
2.3.3 Using the Shortcut Softkeys..........................................................................................43
2.3.4 General Settings........................................................................................................... 44
2.3.5 RF Settings................................................................................................................... 45
2.3.6 Internal Fading.............................................................................................................. 50
2.3.7 Downlink Power Levels................................................................................................. 54
2.3.8 Uplink Power Control.................................................................................................... 56
2.3.9 Physical Cell Setup....................................................................................................... 58
2.3.10 Network Settings........................................................................................................... 63
2.3.11 Connection Configuration..............................................................................................72
2.3.12 Messaging (SMS) Parameters...................................................................................... 82
2.3.13 Message Monitoring Settings........................................................................................87
2.3.14 Shortcut Configuration.................................................................................................. 88
2.3.15 Debug Configuration..................................................................................................... 88
2.3.16 BLER Measurement......................................................................................................90
2.4 Programming...............................................................................................................93
2.4.1 General Configuration................................................................................................... 93
2.4.2 BLER Tests................................................................................................................. 104
2.5 Command Reference................................................................................................ 105
2.5.1 Conventions and General Information........................................................................ 105
2.5.2 Connection Control and States....................................................................................111
2.5.3 Event Log.................................................................................................................... 113
2.5.4 UE Info.........................................................................................................................114
2.5.5 UE Capabilities............................................................................................................116
2.5.6 Routing Settings..........................................................................................................123
2.5.7 Internal Fading............................................................................................................ 133
2.5.8 Downlink Power Levels............................................................................................... 140
2.5.9 Uplink Power Control.................................................................................................. 141
2.5.10 Physical Cell Setup..................................................................................................... 145
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2.5.11 Network Settings......................................................................................................... 150
2.5.12 Connection Configuration............................................................................................163
2.5.13 Messaging (SMS)........................................................................................................179
2.5.14 Message Monitoring Settings......................................................................................187
2.5.15 BLER Measurement....................................................................................................188
2.6 List of Commands.....................................................................................................194
3 NB-IoT Multi-Evaluation Measurement............................................ 199
3.1 What's New in This Version......................................................................................199
3.2 General Description.................................................................................................. 199
3.2.1 Test Setup................................................................................................................... 200
3.2.2 How to Measure an Uplink NB-IoT Signal...................................................................200
3.2.3 Scope of the Measurement......................................................................................... 200
3.2.4 Parallel Signaling and Measurement.......................................................................... 202
3.2.5 List Mode.....................................................................................................................202
3.2.6 NB-IoT UL Signal Properties.......................................................................................207
3.3 GUI Reference............................................................................................................211
3.3.1 Measurement Control..................................................................................................211
3.3.2 Measurement Results................................................................................................. 212
3.3.3 Signal Routing and Analyzer Settings.........................................................................226
3.3.4 Measurement Control Settings....................................................................................229
3.3.5 Trigger Settings...........................................................................................................236
3.3.6 Limit Settings...............................................................................................................239
3.3.7 Shortcut Configuration................................................................................................ 246
3.3.8 Additional Softkeys and Hotkeys.................................................................................246
3.4 Programming.............................................................................................................248
3.4.1 General Examples.......................................................................................................248
3.4.2 Using the List Mode.................................................................................................... 252
3.5 Command Reference................................................................................................ 255
3.5.1 Conventions and General Information........................................................................ 256
3.5.2 General Measurement Settings.................................................................................. 262
3.5.3 Multi-Evaluation Measurement Commands................................................................ 267
3.5.4 Combined Signal Path Commands............................................................................. 322
3.6 List of Commands.....................................................................................................323
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4NB-IoT NPRACH Measurement.........................................................328
4.1 What's New in This Version......................................................................................328
4.2 General Description.................................................................................................. 328
4.2.1 Test Setup................................................................................................................... 328
4.2.2 How to Measure an Uplink NPRACH Signal...............................................................328
4.2.3 Defining the Scope of the Measurement.....................................................................329
4.2.4 Parallel Signaling and Measurement.......................................................................... 330
4.2.5 Calculation of Modulation Results...............................................................................330
4.2.6 NB-IoT Preamble Structure.........................................................................................331
4.3 GUI Reference........................................................................................................... 333
4.3.1 Measurement Control..................................................................................................333
4.3.2 Measurement Results................................................................................................. 333
4.3.3 Signal Routing and Analyzer Settings.........................................................................342
4.3.4 Measurement Control Settings....................................................................................342
4.3.5 Trigger Settings...........................................................................................................346
4.3.6 Limit Settings...............................................................................................................348
4.3.7 Shortcut Configuration................................................................................................ 350
4.3.8 Additional Softkeys and Hotkeys.................................................................................350
4.4 Programming.............................................................................................................350
4.4.1 Key Features...............................................................................................................351
4.4.2 Specifying General and Common Measurement Settings.......................................... 351
4.4.3 Specifying Required NPRACH Settings......................................................................352
4.4.4 Specifying Measurement-Specific Settings.................................................................352
4.4.5 Configuring the Trigger System...................................................................................352
4.4.6 Specifying Limits......................................................................................................... 352
4.4.7 Performing Single-Shot Measurements...................................................................... 353
4.4.8 Single-Shot and Continuous Measurements...............................................................354
4.5 Command Reference................................................................................................ 354
4.5.1 Conventions and General Information........................................................................ 355
4.5.2 General Measurement Settings.................................................................................. 360
4.5.3 NPRACH Measurement Commands...........................................................................360
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4.5.4 Combined Signal Path Commands............................................................................. 383
4.6 List of Commands.....................................................................................................383
Index....................................................................................................386
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Preface
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1 Preface
●Documentation Overview..........................................................................................9
●R&S CMW Models.................................................................................................. 10
●How to Read Firmware Application Chapters......................................................... 11
1.1 Documentation Overview
This chapter provides an overview of the R&S CMW user documentation. Most docu-
ments are available in PDF format on the CMW customer web.
The CMW customer web is a section of GLORIS, the global Rohde & Schwarz infor-
mation system, see https://gloris.rohde-schwarz.com. A registration is required.
1.1.1 Getting Started Manual / Quick Start Guide
Depending on your instrument model, there is either a getting started manual or a
quick start guide.
The document introduces the R&S CMW and describes how to set up and start work-
ing with the product.
A PDF file is available on the CMW customer web.
1.1.2 User Manual and Help
Separate user manuals are provided for the base unit and the firmware applications:
●The base unit manual describes the base software and common features of the
firmware applications. It also describes basic principles for manual operation and
remote control. The manual includes the contents of the getting started manual or
quick start guide.
●Additional documents, like this one, describe the firmware applications, including
the graphical user interface of each application and the remote control commands.
All user manuals are available on the CMW customer web.
The contents of the user manuals are also available as help in the R&S CMW. The
help offers quick, context-sensitive access to the information needed for operation and
programming. If you perform a software update, the help is also updated.
1.1.3 Features & Functions
The features & functions documents list the available software options and the related
features, settings and measurement results. The documents are available on the CMW
customer web.
Documentation Overview
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1.1.4 Basic Safety Instructions
Contains safety instructions, operating conditions and further important information.
The printed document is delivered with the instrument.
1.1.5 Data Sheet and Brochure
The data sheet contains the technical specifications of the R&S CMW. It also lists the
options and their order numbers and optional accessories.
The brochure provides an overview of the instrument and deals with the specific char-
acteristics.
For download, refer to the internet page of your instrument model, for example
www.rohde-schwarz.com/brochure-datasheet/CMW500.
1.1.6 Release Notes and Open-Source Acknowledgment (OSA)
The release notes list new features, improvements and known issues per software ver-
sion and installation package.
The open-source acknowledgment provides verbatim license texts of the used open-
source software.
The documents are available on the CMW customer web.
1.1.7 Application Notes, Application Cards, White Papers, etc.
These documents deal with special applications or background information on particu-
lar topics.
See www.rohde-schwarz.com/appnotes.
1.2 R&S CMW Models
The R&S CMW software supports several instrument models. Depending on the
model, only a subset of the software packages and software options is allowed.
To check whether this document is relevant for your instrument model and which soft-
ware options are supported, refer to the preface of your model-specific base unit man-
ual. The PDF filename of this manual starts with CMW<Model>_UserManual, for
example CMW500_UserManual.
R&S CMW Models
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1.3 How to Read Firmware Application Chapters
Each firmware application is described in a separate chapter. These chapters can be
read independently of each other. However, they are all organized as follows:
1. General description
2. Application sheets (optional)
3. GUI reference
4. Programming examples
5. Command reference
1.3.1 General Description
This chapter provides a general description of the firmware application, independent of
a specific operation mode (manual or remote control). Background information related
to the network standard is given as far as it is directly related to configurable parame-
ters.
1.3.2 Application Sheets
This optional chapter provides short application examples for selected issues and rela-
ted background information.
1.3.3 GUI Reference
The GUI reference describes the manual operation of the firmware application via the
graphical user interface (GUI).
The description of a configuration dialog usually starts with a screenshot presenting the
preset values of the parameters. Sometimes, preset values are modified to enable hid-
den parts of a dialog. Below the screenshot, all shown parameters are described. For
each single parameter, a link to the corresponding command description in the com-
mand reference is provided. Ranges for numeric parameters and reset values are
given there.
For measurement results, links to the corresponding command descriptions are provi-
ded (commands to retrieve the results).
1.3.4 Programming Examples
The programming examples show how to control and configure the firmware applica-
tion via a remote-control program and how to retrieve measurement results. The exam-
ples consist of comprehensive command sequences. You can check just a single com-
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mand of a sequence to get an example for the syntax of this single command. But you
can also consider an entire sequence showing the commands in the context of a com-
mand script, under consideration of dependencies and required orders of the com-
mands.
The command sequences are written with the intention to list most commands of the
firmware application. They do not show the fastest way for a given configuration task.
The fastest way would use many reset values and omit the corresponding commands.
The examples are referenced by the command descriptions of the command refer-
ence.
1.3.5 Command Reference
The command reference provides information on the remote commands of the firm-
ware application. The commands are grouped according to their function.
Each command description indicates the syntax of the command header and of the
parameters. For input parameters, the allowed ranges, reset values and default units
are listed. Most commands have a command form and a query form. Exceptions are
marked by "Setting only", "Query only" or "Event". Furthermore, a link to the program-
ming examples is provided and the first software version supporting the command is
indicated.
How to Read Firmware Application Chapters
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NB-IoT Signaling
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2 NB-IoT Signaling
The NB-IoT signaling firmware application is available as option R&S CMW-KS300. It
emulates an NB-IoT cell and communicates with the UE under test. The UE can syn-
chronize to the downlink signal and attach to the PS domain. A connection can be set
up.
The application requires an SUA as signaling unit. The SUW is not supported.
Tests can be performed using the NB-IoT multi-evaluation measurement (option
R&S CMW-KM300).
Data transfer tests can be performed using the data application unit (DAU, option
R&S CMW-B450x and R&S CMW-KM050).
The NB-IoT signaling application provides also RX measurements, see Chapter 2.3.16,
"BLER Measurement", on page 90.
2.1 What's New in This Version
This documentation describes version 3.7.60 and later of the NB-IoT signaling applica-
tion. Compared to version 3.7.50, it provides the following new features and changes:
●Fading added, see:
–Scenario
–Internal Fading - description
–Internal Fading - configuration
●SMS, see Messaging (SMS) Parameters
●Continuous DL 95 kbps pattern for user-defined scheduling, see Pattern
●Two HARQ processes configurable, see No. of HARQ Processes
●Message Monitoring Settings
2.2 General Description
The following sections describe how to use the R&S CMW for NB-IoT signaling tests
and provide background information.
●Test Setup............................................................................................................... 14
●Initiating Signaling Tests..........................................................................................14
●Internal Fading........................................................................................................ 15
●Connection States...................................................................................................16
●Operation Modes.....................................................................................................18
●Physical DL Channels and Signals......................................................................... 20
●UL Resources in Time and Frequency Domain...................................................... 21
●Scheduling Type UL RMC.......................................................................................23
●Scheduling Type DL RMC.......................................................................................24
General Description
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●User-Defined Scheduling........................................................................................ 24
●Operating Bands..................................................................................................... 27
●Data Tests............................................................................................................... 30
●Trigger Signals........................................................................................................ 30
●Cell Reselection Setup............................................................................................31
2.2.1 Test Setup
The basic test setup uses a bidirectional RF connection between the tester and the
device under test (DUT). It carries both the downlink and the uplink signal:
●The R&S CMW transmits the downlink signal to which the DUT can synchronize to
perform an attach. The downlink signal is used to transfer signaling messages and
user data to the DUT.
●The DUT transmits an uplink signal that the R&S CMW can receive, decode and
analyze.
For this setup, the DUT is connected to one of the bidirectional RF COM connectors at
the front panel of the R&S CMW. No additional cabling and no external trigger are nee-
ded. The input level ranges of all RF COM connectors are identical.
Figure 2-1: Test setup
2.2.2 Initiating Signaling Tests
The required settings vary depending on the measurement to be performed. However,
the following general procedure is applicable to most measurements.
1. Connect your UE to the R&S CMW (see Chapter 2.2.1, "Test Setup", on page 14).
2. Open the "NB-IoT signaling" firmware application.
3. Configure the signaling application according to your test case.
You can modify the most important settings directly in the main view. The "Config"
hotkey provides access to the configuration dialog box.
4. To turn on the DL signal, press ON | OFF. Alternatively, right-click the "NB-IoT Sig-
naling" softkey and click ON.
Wait until the "NB-IoT Signaling" softkey indicates the "ON" state and the hour
glass symbol has disappeared.
5. Switch on the UE.
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The UE synchronizes to the DL signal and attaches. Note the connection states
displayed in the main view.
6. If the RRC state is "Idle", press the "Connect" hotkey.
Whether this step is required depends on the setting "Keep RRC Connection".
7. To switch to the measurement application, press the "NB-IoT TX Meas" or "NB-IoT
RX Meas" softkey. The NB-IoT RX measurements are part of the "NB-IoT Signal-
ing" firmware application. The NB-IoT TX measurements are available as option
R&S CMW-KM300.
8. Configure and start the measurement.
If the UE fails to attach
Check the following R&S CMW settings:
●The "Frequency" of the generated DL signal must be within the frequency band
supported by the UE.
●The configured "NRS EPRE" must be sufficient so that the UE under test can
receive the DL signal.
●The "Uplink Power Control" settings must be appropriate so that the UL signal is
strong enough to be received and decoded by the R&S CMW.
●The UE capabilities must be in accordance with the security settings in the "Net-
work" section of the configuration dialog.
●For data application tests, the configured C-IoT optimization type must be suppor-
ted by the UE.
●The configured uplink subcarrier spacing must be supported by the UE.
If the measurement does not start
If the measurement does not start at all while the signaling application generates a
downlink signal, verify that the combined signal path scenario is selected in the mea-
surement.
2.2.3 Internal Fading
Testing under realistic air interface conditions is important in order to verify the receiver
performance and the correct operation of the protocol stack implementation. For exam-
ple, block error rates can be evaluated.
The fading uses one SUA partition. The SUA comes with a fading simulator. It manipu-
lates the generated downlink I/Q data stream to emulate typical signal conditions at the
receiver.
The following options are required to use the internal fading simulator:
●Option R&S CMW-KE100 for basic fading support and AWGN generator.
●Option R&S CMW-KE500 for LTE fading profiles TS 36.521
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2.2.3.1 Fading Simulator
Multi-path fading is an effect which occurs in real world situations. A signal sent from
the base station follows the direct line of sight and/or takes routes with reflections. The
phase-shifted signals sum up at the receiving antenna. If the receiver is moving, there
are also frequency-shifted signals.
The internal fading simulator supports multipath propagation conditions defined in
annex B.2 of 3GPP TS 36.101.
A faded signal has a higher crest factor than an unfaded one. To avoid distortion, the
baseband signal must be attenuated before entering the fading module. The necessary
attenuation (insertion loss) depends on the selected fading profile.
In NB-IoT signaling, the insertion loss at the baseband level can be calculated auto-
matically or set manually. It is automatically compensated on the HF level. The com-
pensation implies a shift of the allowed DL power range to the same extent, but in
opposite direction.
2.2.3.2 AWGN Generator
Additional white Gaussian noise (AWGN) is typically modeled in receiver tests,
because it can lead to a decrease of throughput. The quality of the received signal is
affected by the ratio of the signal power to the surrounding traffic noise level (signal to
noise ratio). The modulated signals from neighbor cells simply appear as noise. This
effect is simulated by adding AWGN to the signal.
The internal fading module supports AWGN insertion with configurable bandwidth and
signal to noise ratio. Insertion loss at the baseband level is calculated and compensa-
ted automatically at the HF.
AWGN insertion via the signaling unit is disabled for fading scenarios (see "AWGN"
on page 55).
2.2.4 Connection States
An NB-IoT connection is always a packet-switched connection. The main connection
states are described in the following table. The states are displayed in the main view
as "Packet Switched" (PS) state.
PS state Description
"(Cell) Off" No downlink signal transmission
"(Cell) On" The R&S CMW emulates an NB-IoT cell, transmitting an NB-IoT signal to which the UE
can synchronize. After synchronization, the UE can initiate an attach towards the instru-
ment.
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PS state Description
"Attached" Synchronization and attach have been performed.
There is no radio resource control (RRC) connection (RRC state = idle).
"Connection
Established"
An RRC connection has been established (RRC state = connected).
User data can be exchanged. The R&S CMW can vary connection parameters and per-
form transmitter or receiver tests.
Note that short RRC idle periods are possible without a PS state change, for example, for
redirection.
State transitions can be initiated by the instrument or by the UE. The transitions
between "Cell On" and "Connection Established" depend on whether the setting "Keep
RRC Connection" is enabled, or not. The following figure provides an overview.
Cell On
Connection
Established
Connect
Detach Attached
Cell On
Cell Off
Connection
Established
Detach
ON
Attached
OFF
Disconnect
Cell Off
ON
OFF
Keep RRC Connection Keep RRC Connection
Connect
SMS
SMS
SMS
SMS
Disconnect
Figure 2-2: PS state transitions with and without Keep RRC Connection
Dotted line = Action initiated by instrument
Dashed line = Action initiated by UE
In addition to the main states shown in the table and the figure, the instrument indi-
cates the following transitory states:
●"Signaling in Progress"
For example, displayed during the attach procedure.
●"Connection in Progress"
Displayed during connection setup.
●"Sending Message"
Displayed while an SMS message is sent to the MS.
●"Receiving Message"
Displayed while an SMS message is received from the MS. To check the received
message, see Chapter 2.3.12.2, "Incoming SMS", on page 86.
●"Disconnect in Progress"
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Additional transitions
The list of transitions in Figure 2-2 is not complete. The "Off" state can be reached from
any state by turning off the cell signal. Moreover, incidents like a loss of the radio link
cause additional transitions.
2.2.5 Operation Modes
There are three NB-IoT operation modes defined by 3GPP. All three modes are sup-
ported by the signaling application.
This section provides background information for the three operation modes.
●Standalone Operation............................................................................................. 18
●Guard-Band Operation............................................................................................18
●In-Band Operation...................................................................................................19
2.2.5.1 Standalone Operation
In the standalone operation mode, the used spectrum is dedicated to NB-IoT only. So
the frequencies are not shared with another technology.
One possible deployment scenario is, to use no longer needed GSM spectrum for NB-
IoT. An NB-IoT carrier fits perfectly into a no longer used GSM channel.
Another scenario is, to use new spectrum for NB-IoT.
2.2.5.2 Guard-Band Operation
In the guard-band operation mode, the NB-IoT carrier is located in the guard band of
an LTE carrier. So the NB-IoT carrier uses already available LTE spectrum, without
reducing the capacity of the LTE carrier. But there can be interference between NB-IoT
and LTE.
The NB-IoT signaling application generates an NB-IoT cell signal and an LTE cell sig-
nal. The LTE signal contains no synchronization signals and no broadcast information.
So the UE cannot synchronize to the LTE cell signal. But the LTE signal contains cell-
specific reference signal (CRS) symbols. The other LTE OFDM symbols contain QPSK
modulated uncorrelated pseudo-random data. All LTE OFDM symbols have the same
power level.
Carrier frequency and channel raster offset
To maintain the orthogonality to the LTE carrier, the NB-IoT center frequency must fol-
low the subcarrier raster. So the possible NB-IoT frequencies in each guard band have
a spacing of 15 kHz, the downlink subcarrier spacing.
Another aspect is, that the UE uses the 100-kHz channel raster for cell search. For that
reason, 3GPP allows only NB-IoT DL frequencies with the smallest possible offset from
the 100-kHz channel raster. For cell BWs with an even total number of RBs, a DL
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channel raster offset of 2.5 kHz is allowed. For cell BWs with an odd total number of
RBs, a DL channel raster offset of 7.5 kHz is allowed.
The UL/DL separation for the guard-band mode and the in-band mode differs from the
UL/DL separation for the standalone mode by 7.5 kHz. In the lower guard band, the
spacing is greater. In the upper guard band, it is smaller. The UL channel raster offset
differs by 7.5 kHz from the DL channel raster offset.
The following tables list the used NB-IoT carrier position in the upper guard band
depending on the LTE cell BW. For the lower guard band, all values have the opposite
sign.
Table 2-1: NB-IoT carrier positions in the upper guard band
5 MHz 10 MHz 15 MHz 20 MHz
Downlink Frequency offset to LTE 2400 kHz 4600 kHz 7200 kHz 9100 kHz
Channel raster offset 7.5 kHz -2.5 kHz 7.5 kHz -2.5 kHz
Uplink Frequency offset to LTE 2400 kHz 4600 kHz 7200 kHz 9100 kHz
Channel raster offset 0 kHz -10 kHz 0 kHz -10 kHz
The NB-IoT signaling application takes care of all the dependencies. You configure the
NB-IoT RF frequency as for the standalone mode, for example via a channel number.
And you select the upper or lower guard band. The software calculates the resulting
LTE carrier frequencies and the channel raster offsets automatically. The channel ras-
ter offsets are added to the configured NB-IoT RF frequencies.
2.2.5.3 In-Band Operation
In the in-band operation mode, an NB-IoT carrier uses a small part of an LTE carrier.
The resources are flexibly assigned to LTE or to NB-IoT, only to one technology at a
time. So there is no interference between LTE and NB-IoT. But the capacity available
for LTE is reduced by NB-IoT.
As for the guard-band operation mode, the NB-IoT signaling application generates an
NB-IoT cell signal and an LTE cell signal. If both cells share a physical cell ID (mode
"Inband-SamePCI"), the UE can use the LTE CRS OFDM symbols for NB-IoT.
Carrier frequency and channel raster offset
In the in-band operation mode, the NB-IoT carrier uses exactly the frequency span of
an LTE resource block (RB). In the LTE downlink, the center subcarrier is not used. A
resource block covers 180 kHz, a DL subcarrier 15 kHz.
The following figure illustrates the DL frequencies in the center of a 10-MHz LTE chan-
nel.
General Description
深圳德标仪器 135-1095-0799

NB-IoT Signaling
R&S®CMW-KM300/-KS300
20User Manual 1178.5689.02 ─ 06
... ...
RB 25
97.5
-2.5
RB 26
277.5
-22.5
RB 27
457.5
-42.5
RB 28
637.5
37.5
RB 29
817.5
17.5
RB 30
997.5
-2.5
RB 24
-97.5
2.5
RB 23
-277.5
22.5
RB 22
-457.5
42.5
RB 21
-637.5
-37.5
RB 20
-817.5
-17.5
RB 19
-997.5
2.5
LTE DC
carrier
RB index
Offset to DC carrier / kHz
Channel raster offset / kHz
Figure 2-3: Resource block frequencies, DL 10-MHz LTE channel
You can see that the resource blocks have different offsets to the LTE 100-kHz channel
raster, the so-called channel raster offset. For cell BWs with an even total number of
RBs, there are absolute DL channel raster offsets from 2.5 kHz to 42.5 kHz. For cell
BWs with an odd total number of RBs, the absolute DL channel raster offsets range
from 7.5 kHz to 47.5 kHz.
Large DL channel raster offsets are a problem, because the UE uses the 100-kHz
channel raster for cell search. For that reason, 3GPP allows only NB-IoT DL frequen-
cies with the smallest possible offset (2.5 kHz or 7.5 kHz). The RBs around the center
of the LTE channel are also not allowed, because they carry synchronization signals.
The following table lists the RB indices that are allowed for NB-IoT, depending on the
LTE cell BW.
Table 2-2: LTE RB indices allowed for NB-IoT in-band operation, depending on LTE cell BW
3 MHz 5 MHz 10 MHz 15 MHz 20 MHz
RBs 2, 12 2, 7, 17,
22
4, 9, 14, 19,
30, 35, 40, 45
2, 7, 12, 17, 22, 27, 32,
42, 47, 52, 57, 62, 67, 72
4, 9, 14, 19, 24, 29, 34, 39, 44,
55, 60, 65, 70, 75, 80, 85, 90, 95
In contrast to the LTE DL, the LTE UL uses the center subcarrier. As a consequence,
the UL channel raster offset differs by 7.5 kHz from the DL channel raster offset. For
carriers below the LTE DC carrier, the UL offset equals the DL offset plus 7.5 kHz. For
carriers above the LTE DC carrier, the UL offset equals the DL offset minus 7.5 kHz.
The NB-IoT signaling application takes care of all the dependencies. You configure the
NB-IoT RF frequency as for the standalone mode, for example via a channel number.
And you select which allowed resource block you want to use for NB-IoT. The software
calculates the resulting LTE carrier frequencies and the channel raster offsets automat-
ically. The channel raster offsets are added to the configured NB-IoT RF frequencies.
2.2.6 Physical DL Channels and Signals
The NB-IoT downlink uses the physical channels and signals listed in the following
tables.
General Description
深圳德标仪器 135-1095-0799