SIST EN 303 681-4 V1.1.2:2020

ETSI EN 303 681-4 V1.1.2 (2020-06)






EUROPEAN STANDARD
Reconfigurable Radio Systems (RRS);
Radio Equipment (RE) information models and protocols
for generalized software reconfiguration architecture;
Part 4: generalized Radio Programming Interface (gRPI)

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2 ETSI EN 303 681-4 V1.1.2 (2020-06)



Reference
REN/RRS-0231
Keywords
architecture, interface, radio, SDR, software,
system

ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: +33 4 92 94 42 00  Fax: +33 4 93 65 47 16

Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88

Important notice
The present document can be downloaded from:
http://www.etsi.org/standards-search
The present document may be made available in electronic versions and/or in print. The content of any electronic and/or
print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any
existing or perceived difference in contents between such versions and/or in print, the prevailing version of an ETSI
deliverable is the one made publicly available in PDF format at www.etsi.org/deliver.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at
https://portal.etsi.org/TB/ETSIDeliverableStatus.aspx
If you find errors in the present document, please send your comment to one of the following services:
https://portal.etsi.org/People/CommiteeSupportStaff.aspx
Copyright Notification
No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying
and microfilm except as authorized by written permission of ETSI.
The content of the PDF version shall not be modified without the written authorization of ETSI.
The copyright and the foregoing restriction extend to reproduction in all media.

© ETSI 2020.
All rights reserved.

DECT™, PLUGTESTS™, UMTS™ and the ETSI logo are trademarks of ETSI registered for the benefit of its Members.

3GPP™ and LTE™ are trademarks of ETSI registered for the benefit of its Members and
of the 3GPP Organizational Partners.
oneM2M™ logo is a trademark of ETSI registered for the benefit of its Members and
of the oneM2M Partners.
®
GSM and the GSM logo are trademarks registered and owned by the GSM Association.
ETSI

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3 ETSI EN 303 681-4 V1.1.2 (2020-06)
Contents
Intellectual Property Rights . 4
Foreword . 4
Modal verbs terminology . 4
1 Scope . 5
2 References . 5
2.1 Normative references . 5
2.2 Informative references . 5
3 Definition of terms, symbols and abbreviations . 6
3.1 Terms . 6
3.2 Symbols . 7
3.3 Abbreviations . 7
4 Introduction . 8
5 System Requirement Mapping . 10
6 Radio Virtual Machine specification . 10
6.1 Concept of RVM . 10
6.2 Elementary RVM (eRVM) . 12
6.3 RVM Hierarchy . 15
6.4 Data types . 17
6.4.1 Types and Values . 17
6.4.2 Run-Time Data . 17
6.5 Arithmetic. 17
6.6 Exceptions . 17
6.7 Control, Synchronization and Execution . 17
6.8 Operations with Memory . 18
6.9 RVM run-time environment . 18
7 Configcodes for RVM . 19
7.1 Introduction . 19
7.2 Configcodes generation . 19
7.3 Binary format for Configcodes . 20
7.4 XML schema for Configcodes . 24
8 Radio Library . 29
8.1 Introduction . 29
8.2 Reference Radio Library . 30
8.3 Native Radio Library . 30
9 Loading, Linking and Initialization . 31
10 Compiling for RVM (Front-End Compilation) . 32
Annex A (informative): Mapping between XML and Binary . 33
Annex B (informative): SFB Candidate . 34
Annex C (informative): Replacement of selected components of an existing RAT . 36
Annex D (informative): Introducing new SFBs . 37
Annex E (informative): Synchronous Approach . 38
History . 42


ETSI

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4 ETSI EN 303 681-4 V1.1.2 (2020-06)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (https://ipr.etsi.org/).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Trademarks
The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.
ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does
not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.
Foreword
This European Standard (EN) has been produced by ETSI Technical Committee Reconfigurable Radio Systems (RRS).
The present document is part 4 of a multi-part deliverable covering the Radio Equipment (RE) information models and
protocols, as identified below:
Part 1: "generalized Multiradio Interface (gMURI)";
Part 2: "generalized Reconfigurable Radio Frequency Interface (gRRFI)";
Part 3: "generalized Unified Radio Application Interface (gURAI)";
Part 4: "generalized Radio Programming Interface (gRPI)".

National transposition dates
Date of adoption of this EN: 22 June 2020
Date of latest announcement of this EN (doa): 30 September 2020
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 31 March 2021
Date of withdrawal of any conflicting National Standard (dow): 31 March 2021

Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
ETSI

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5 ETSI EN 303 681-4 V1.1.2 (2020-06)
1 Scope
The scope of the present document is to define the generalized Radio Programming Interface (gRPI) for radio
equipment reconfiguration except for reconfigurable mobile devices which are covered in [i.4] to [i.9]. The work is
based on the Use Cases defined in ETSI TR 103 585 [i.1], on the system requirements defined in ETSI EN 303 641 [1]
and on the radio reconfiguration related architecture for radio equipment defined in ETSI EN 303 648 [i.2].
The present document will be based on ETSI EN 303 146-4 [i.9] and provide a generalized interface definition for the
generalized Radio Programming Interface (gRPI).
2 References
2.1 Normative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
https://docbox.etsi.org/Reference/.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are necessary for the application of the present document.
[1] ETSI EN 303 641: "Reconfigurable Radio Systems (RRS); Radio Equipment (RE) reconfiguration
requirements".
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] ETSI TR 103 585: "Reconfigurable Radio Systems (RRS); Radio Equipment (RE) reconfiguration
use cases".
[i.2] ETSI EN 303 648: "Reconfigurable Radio Systems (RRS); Radio Equipment (RE) reconfiguration
architecture".
[i.3] Directive 2014/53/EU of the European Parliament and of the Council of 16 April 2014 on the
harmonisation of the laws of the Member States relating to the making available on the market of
Radio Equipment and repealing Directive 1999/5/EC.
[i.4] ETSI EN 302 969: "Reconfigurable Radio Systems (RRS); Radio Reconfiguration related
requirements for Mobile Devices".
[i.5] ETSI EN 303 095: "Reconfigurable Radio Systems (RRS); Radio reconfiguration related
architecture for Mobile Devices (MD)".
[i.6] ETSI EN 303 146-1: "Reconfigurable Radio Systems (RRS); Mobile Device (MD) information
models and protocols; Part 1: Multiradio Interface (MURI)".
ETSI

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6 ETSI EN 303 681-4 V1.1.2 (2020-06)
[i.7] ETSI EN 303 146-2: "Reconfigurable Radio Systems (RRS); Mobile Device (MD) information
models and protocols; Part 2: Reconfigurable Radio Frequency Interface (RRFI)".
[i.8] ETSI EN 303 146-3: "Reconfigurable Radio Systems (RRS); Mobile Device (MD) information
models and protocols; Part 3: Unified Radio Application Interface (URAI)".
[i.9] ETSI EN 303 146-4: "Reconfigurable Radio Systems (RRS); Mobile Device (MD) information
models and protocols; Part 4: Radio Programming Interface (RPI)".
[i.10] ETSI EN 303 681-1: "Reconfigurable Radio Systems (RRS); Radio Equipment (RE) information
models and protocols for generalized software reconfiguration architecture; Part 1: generalized
Multiradio Interface (gMURI)".
[i.11] ETSI EN 303 681-2: "Reconfigurable Radio Systems (RRS); Radio Equipment (RE) information
models and protocols for generalized software reconfiguration architecture; Part 2: generalized
Reconfigurable Radio Frequency Interface (gRRFI)".
[i.12] ETSI EN 303 681-3: "Reconfigurable Radio Systems (RRS); Radio Equipment (RE) information
models and protocols for generalized software reconfiguration architecture; Part 3: generalized
Unified Radio Application Interface (gURAI)".
3 Definition of terms, symbols and abbreviations
3.1 Terms
For the purposes of the present document, the following terms apply:
Abstract Processing Element (APE): abstracts computational resource that executes any computations downloaded
from Radio Library
NOTE: APE is connected with input and output DOs. APE is reactive. Any computations are started if all input
DOs are filled with real data.
basic operations: operations either provided by the Radio Library and/or UDFB Set to eRVM or by the Radio Library
and/or RVM/eRVM Configcodes to RVM
NOTE: Each Basic Operation is mapped to a corresponding APE in the case of eRVM or mapped to a
corresponding APE or RVM/eRVM in the case of RVM.
data flow chart: reactive data flow computational model consisting of data and operators where data are connected
with operators
NOTE: Operators abstract computations. They are triggered by full data. Results of operator computations are
written in connected output data if they are empty.
Data Object (DO): typeless token abstracting any type of data
NOTE: DO provides a container for storing data. It can be empty if no data in the container or it can be full if
there is data in the container. DO is allocated in the infinite and flat memory. Any RVM has access to this
memory. One or a few APEs from RVM can be connected with DO. DO acknowledges connected APEs
about its status whether it empty or full.
dynamic operation: operation that is performed by allocating the computational resources during run-time for each
APE required executing the given operation
NOTE 1: The resources are deallocated upon completion of the corresponding operation.
NOTE 2: Dynamic operation is available only in the case of RERC-7 defined in ETSI EN 303 641 [1]. In other
words, dynamic operation is needed when RA requires the dynamic resource sharing.
native radio library: library providing platform-specific description of each SFB that represents the target platform
hardware
ETSI

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7 ETSI EN 303 681-4 V1.1.2 (2020-06)
port configuration: specification of the number of APEs inputs and outputs
Radio Equipment (RE): "an electrical or electronic product, which intentionally emits and/or receives radio waves for
the purpose of radio communication and/or radiodetermination, or an electrical or electronic product which must be
completed with an accessory, such as antenna, so as to intentionally emit and/or receive radio waves for the purpose of
radio communication and/or radiodetermination".
NOTE: The definition above is as defined in the Radio Equipment Directive, Article 2(1)(1) [i.3].
radio library authority: authority empowered to decide which components can be registered as new SFBs
NOTE: Any suitable organization can take the role of a Radio Library Authority. The choice of the organization
is beyond the scope of the present document.
Radio Virtual Machine (RVM): abstract machine that supports reactive and concurrent executions
NOTE: A RVM may be implemented as a controlled execution environment that allows the selection of a trade-
off between flexibility of base band code development and required (re-)certification efforts.
Radio Virtual Machine Runtime Environment (RVM RE): software that allows running Radio Applications that
might be Configcodes or executable codes
reconfigurable mobile device: mobile device with radio communication capabilities providing support for radio
reconfiguration
NOTE: Reconfigurable mobile devices include but are not limited to: smartphones, feature phones, tablets, and
laptops.
reference radio library: library providing normative definition of each SFB
NOTE: There may be multiple such Reference Radio Libraries. For a given RA, a unique Reference Radio
Library is used.
Software Intermediate Representation (SWIR): RA representation as data flow chart
NOTE: SWIR file contains information on all terminal objects, their parameters (cost, implement function, size,
etc.) and connections (links, access type, source and destination).
terminal operation: operation that will always be executed without any other interruption
NOTE 1: Furthermore, terminal operation cannot be decomposed into smaller operations.
NOTE 2: "Terminal operations" are equivalent to "atomic operations", but additionally it indicates that a hierarchy
is being used in which the "terminal operations" are on the lowest level of hierarchy and they can be part
of another operation.
3.2 Symbols
Void.
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AOT Ahead-Of-Time
APE Abstract Processing Element
ASF Abstract Switch Fabric
CC Configcodes Counter
CSL Communication Services Layer
CU Control Unit
DO Data Object
eRVM elementary RVM
eSFB elementary SFB
ETSI

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8 ETSI EN 303 681-4 V1.1.2 (2020-06)
FB Functional Block
FBRI FB Reusability Index
FFT Fast Fourier Transform
gMURI generalized Multiradio Interface
gRPI generalized Radio Programming Interface
gRRFI generalized Reconfigurable Radio Frequency Interface
gURAI generalized Unified Radio Applications Interface
HD Hardware Dimension
HW Hardware
ID IDentification
IFFT Inverse Fast Fourier Transform
IR Intermediate Representation
JIT Just-In-Time
LCF Last Configuration Flag
NAF Next Address Flag
NAPE Number of Abstract Processing Elements
NCAO Next Configcode Address Offset
NDO Number of Data Objects
NOP No OPeration
RA Radio Application
RAP Radio Application Package
RAT Radio Access Technology
RCF Radio Control Framework
RE Radio Equipment
RF Radio Frequency
RLA Radio Library Authority
ROS Radio Operating System
RPI Radio Programming Interface
RVM Radio Virtual Machine
RVM RE RVM Runtime Environment
SD Software Dimension
SFB Standard Functional Block
SWIR SoftWare Intermediate Representation
UDFB User Defined Functional Block
UML Unified Modelling Language
URA Unified Radio Applications
VDO Virtual Data Object
VHDL Very high speed integrated circuit Hardware Description Language
XML eXtensible Markup Language
XOR eXclusive OR
4 Introduction
A reconfigurable RE is capable of running multiple radios simultaneously, changing the set of radios by loading new
Radio Application Packages (RAP) and setting their parameters. All Radio Applications (RAs) are called Unified Radio
Applications (URAs) when they exhibit a common behaviour from the reconfigurable RE's point of view in ETSI
EN 303 648 [i.2]. In order to run multiple URAs, the reconfigurable RE will include Communication Services Layer
(CSL), Radio Control Frameworks (RCFs), Radio Platforms and 4 sets of interfaces for their interconnection.
ETSI

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9 ETSI EN 303 681-4 V1.1.2 (2020-06)

Figure 4.1: Four sets of interfaces for Reconfigurable RE
Figure 4.1 illustrates the Reconfigurable RE architecture with the 4 sets of interfaces, i.e.:
• gMURI for interfacing CSL and RCF (in ETSI EN 303 681-1 [i.10]).
• gRRFI for interfacing URA and RF Transceiver (in ETSI EN 303 681-2 [i.11]).
• gURAI for interfacing URA and RCF (in ETSI EN 303 681-3 [i.12]).
• gRPI for allowing an independent and uniform production of RAs which is the scope of the present document.
The present document defines gRPI.
<< in t erf ace>>
IgM U R I
<< in t erf ace>>
IgRRFI
Ra di oC ompu te r
<< in t erf ace>>
IgU R AI
<< in t erf ace>>
IgR PI

Figure 4.2: UMLclass diagram for Radio Computer interfaces
ETSI

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10 ETSI EN 303 681-4 V1.1.2 (2020-06)
Figure 4.2 illustrates UML class diagram for Radio Computer interfaces. The reconfigurable RE may be seen as a set of
multiple Radio Computers where individual URAs are engineered as software entities in ETSI EN 303 648 [i.2].
The present document is organized as follows:
• Clause 5 describes the system requirement mapping.
• Clause 6 describes the radio virtual machine specification.
• Clause 7 describes the Configcodes for RVM.
• Clause 8 describes the radio library structure.
• Clause 9 describes the loading, linking and initialization.
• Clause 10 describes the compiling for RVM.
• Annex A describes the mapping between Binary and XML.
• Annex B describes SFB Candidates.
• Annex C describes the replacement of selected components of an existing RAT.
While UML is used for defining the information model and protocol related to gRPI, other modelling languages could
be used as well.
5 System Requirement Mapping
The Radio Programming Interface and its related components described in the present document shall support the
system requirements shown in table 5.1 referring to clause 6 of ETSI EN 303 641 [1]. This is achieved by introducing
st
the entities/components/units given in the 1 column of table 5.1.
Table 5.1: Mapping of Radio Programming Interface and its related components to
the system requirements described in ETSI EN 303 641 [1]
Entity/Component/Unit System Requirements [1] Comments
Radio Programming R-FUNC-RER-04 The requirement shall be as described in clause 6.4.4 of [1].
Interface
Radio Virtual Machine R-FUNC-RER-13 The requirement shall be as described in clause 6.4.13 of [1].
R-FUNC-RER-14 The requirement shall be as described in clause 6.4.14 of [1].
R-FUNC-RER-15 The requirement shall be as described in clause 6.4.15 of [1].
Radio Library R-FUNC-FB-06 A library extension shall be supported. The requirement shall
be as described in clause 6.3.6 of [1].

6 Radio Virtual Machine specification
6.1 Concept of RVM
As introduced in ETSI EN 303 648 [i.2], the Radio Virtual Machine (RVM) is an Abstract Machine which is capable of
executing Configcodes and it is independent of the hardware. The implementation of a RVM is target Radio Computer
specific and it shall have access to the Back-end Compiler (on the platform itself or externally as described in ETSI
EN 303 648 [i.2], clause 4.4.1) for Just-In-Time (JIT) or Ahead-Of-Time (AOT) compilation of Configcodes.
This clause describes the concept of RVM. As mentioned above, the RVM is an abstract machine, which executes a
particular algorithm presented as a data flow chart. In other words, the RVM is the result of replacing all operators and
tokens in the particular data flow chart with Abstract Processing Elements (APEs) and Data Objects (DOs),
respectively. Each APE executes computations marked by the replaced operator identifier. These computations are
taken from the Radio Library.
ETSI

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11 ETSI EN 303 681-4 V1.1.2 (2020-06)
Figure 6.1 illustrates a conceptual view of RVM processing. This process requires APE, DO and Radio Library, of
which the definitions are as follows:
• APE abstracts a computational resource corresponding to the operation in a particular data flow chart.
• DO abstracts a memory resource. In other words, DO is an abstracted memory for storing data used during the
procedure of Radio processing.
• Reference/Native Radio Library includes normative definitions/native implementation of all Standard
Functional Blocks (SFBs) [i.5] for front-end/back-end compilation. Note that the computations included in the
Radio Library are represented in terms of normative definitions or native implementations of SFBs depending
upon whether the Radio Library is used for front-end or back-end compilation, respectively.
NOTE 1: User Defined Functional Blocks (UDFBs) will be created through combination of SFBs and represented
as a data flow chart to be executed in the RVM. Alternatively, a UDFB is implemented as a stand-alone
module/function which can be mapped:
i) into one APE (i.e. this UDFB can be considered atomic); or
ii) into an eRVM/RVM (i.e. not atomic). UDFBs are not in general included into the Radio Library,
but they are part of the Radio Application Package.
The RVM begins to work immediately after some DOs initialization. All APEs shall execute computations
asynchronously and concurrently. An individual APE shall execute the allocated operator if all the corresponding input
DOs are full. APEs shall access DOs with operations "read", "read-erase", or "write". After reading input data from
DOs, the APE shall execute the allocated operator and, if output DOs are empty, then the APE shall write processed
data. Any full output DO shall block the corresponding writing operation. The RVM shall execute computations until
reaching the state when all APEs become inactive. In this state, there are not enough full DOs, which can activate the
inactive operators. The result of computations are full DOs, which cannot activate the inactive operators.
NOTE 2: An Output DO can become an Input DO for a subsequent operator. Then, this input DO can activate the
subsequent operator.
NOTE 3: The state or operation of a given APE is independent on the state of other APEs. I.e. each APE is atomic.

Figure 6.1: Conceptual Diagram of Radio Virtual Machine Processing
ETSI

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12 ETSI EN 303 681-4 V1.1.2 (2020-06)
6.2 Elementary RVM (eRVM)
This clause describes the eRVM which shall consist of components of Basic Operations, Program memory, Control
Unit (CU), Abstract Switch Fabric (ASF) as well as APEs and DOs, of which the definitions are as follows. eRVM shall
not contain another eRVM or RVM:
• Basic Operations shall include operators either provided:
i) from Radio Library as SFBs and/or;
ii) from UDFB set as UDFBs, each of which is mapped onto one
...

Draft ETSI EN 303 681-4 V1.1.2 (2020-03)






EUROPEAN STANDARD
Reconfigurable Radio Systems (RRS);
Radio Equipment (RE) information models and protocols
for generalized software reconfiguration architecture;
Part 4: generalized Radio Programming Interface (gRPI)

---------------------- Page: 1 ----------------------
2 Draft ETSI EN 303 681-4 V1.1.2 (2020-03)



Reference
REN/RRS-0231
Keywords
architecture, interface, radio, SDR, software,
system

ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: +33 4 92 94 42 00  Fax: +33 4 93 65 47 16

Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88

Important notice
The present document can be downloaded from:
http://www.etsi.org/standards-search
The present document may be made available in electronic versions and/or in print. The content of any electronic and/or
print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any
existing or perceived difference in contents between such versions and/or in print, the prevailing version of an ETSI
deliverable is the one made publicly available in PDF format at www.etsi.org/deliver.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at
https://portal.etsi.org/TB/ETSIDeliverableStatus.aspx
If you find errors in the present document, please send your comment to one of the following services:
https://portal.etsi.org/People/CommiteeSupportStaff.aspx
Copyright Notification
No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying
and microfilm except as authorized by written permission of ETSI.
The content of the PDF version shall not be modified without the written authorization of ETSI.
The copyright and the foregoing restriction extend to reproduction in all media.

© ETSI 2020.
All rights reserved.

DECT™, PLUGTESTS™, UMTS™ and the ETSI logo are trademarks of ETSI registered for the benefit of its Members.

3GPP™ and LTE™ are trademarks of ETSI registered for the benefit of its Members and
of the 3GPP Organizational Partners.
oneM2M™ logo is a trademark of ETSI registered for the benefit of its Members and
of the oneM2M Partners.
®
GSM and the GSM logo are trademarks registered and owned by the GSM Association.
ETSI

---------------------- Page: 2 ----------------------
3 Draft ETSI EN 303 681-4 V1.1.2 (2020-03)
Contents
Intellectual Property Rights . 4
Foreword . 4
Modal verbs terminology . 4
1 Scope . 5
2 References . 5
2.1 Normative references . 5
2.2 Informative references . 5
3 Definition of terms, symbols and abbreviations . 6
3.1 Terms . 6
3.2 Symbols . 7
3.3 Abbreviations . 7
4 Introduction . 8
5 System Requirement Mapping . 10
6 Radio Virtual Machine specification . 10
6.1 Concept of RVM . 10
6.2 Elementary RVM (eRVM) . 12
6.3 RVM Hierarchy . 15
6.4 Data types . 17
6.4.1 Types and Values . 17
6.4.2 Run-Time Data . 17
6.5 Arithmetic. 17
6.6 Exceptions . 17
6.7 Control, Synchronization and Execution . 17
6.8 Operations with Memory . 18
6.9 RVM run-time environment . 18
7 Configcodes for RVM . 19
7.1 Introduction . 19
7.2 Configcodes generation . 19
7.3 Binary format for Configcodes . 20
7.4 XML schema for Configcodes . 24
8 Radio Library . 29
8.1 Introduction . 29
8.2 Reference Radio Library . 30
8.3 Native Radio Library . 30
9 Loading, Linking and Initialization . 31
10 Compiling for RVM (Front-End Compilation) . 32
Annex A (informative): Mapping between XML and Binary . 33
Annex B (informative): SFB Candidate . 34
Annex C (informative): Replacement of selected components of an existing RAT . 36
Annex D (informative): Introducing new SFBs . 37
Annex E (informative): Synchronous Approach . 38
History . 42


ETSI

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4 Draft ETSI EN 303 681-4 V1.1.2 (2020-03)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (https://ipr.etsi.org/).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Trademarks
The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.
ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does
not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.
Foreword
This draft European Standard (EN) has been produced by ETSI Technical Committee Reconfigurable Radio Systems
(RRS), and is now submitted for the combined Public Enquiry and Vote phase of the ETSI standards EN Approval
Procedure.
The present document is part 4 of a multi-part deliverable covering the Radio Equipment (RE) information models and
protocols, as identified below:
Part 1: "generalized Multiradio Interface (gMURI)";
Part 2: "generalized Reconfigurable Radio Frequency Interface (gRRFI)";
Part 3: "generalized Unified Radio Application Interface (gURAI)";
Part 4: "generalized Radio Programming Interface (gRPI)".

Proposed national transposition dates
Date of latest announcement of this EN (doa): 3 months after ETSI publication
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 6 months after doa
Date of withdrawal of any conflicting National Standard (dow): 6 months after doa

Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
ETSI

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5 Draft ETSI EN 303 681-4 V1.1.2 (2020-03)
1 Scope
The scope of the present document is to define the generalized Radio Programming Interface (gRPI) for radio
equipment reconfiguration except for reconfigurable mobile devices which are covered in [i.4] to [i.9]. The work is
based on the Use Cases defined in ETSI TR 103 585 [i.1], on the system requirements defined in ETSI EN 303 641 [1]
and on the radio reconfiguration related architecture for radio equipment defined in ETSI EN 303 648 [i.2].
The present document will be based on ETSI EN 303 146-4 [i.9] and provide a generalized interface definition for the
generalized Radio Programming Interface (gRPI).
2 References
2.1 Normative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
https://docbox.etsi.org/Reference/.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
[1] ETSI EN 303 641: "Reconfigurable Radio Systems (RRS); Radio Equipment (RE) reconfiguration
requirements".
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] ETSI TR 103 585: "Reconfigurable Radio Systems (RRS); Radio Equipment (RE) reconfiguration
use cases".
[i.2] ETSI EN 303 648: "Reconfigurable Radio Systems (RRS); Radio Equipment (RE) reconfiguration
architecture".
[i.3] Directive 2014/53/EU of the European Parliament and of the Council of 16 April 2014 on the
harmonisation of the laws of the Member States relating to the making available on the market of
Radio Equipment and repealing Directive 1999/5/EC.
[i.4] ETSI EN 302 969: "Reconfigurable Radio Systems (RRS); Radio Reconfiguration related
requirements for Mobile Devices".
[i.5] ETSI EN 303 095: "Reconfigurable Radio Systems (RRS); Radio reconfiguration related
architecture for Mobile Devices (MD)".
[i.6] ETSI EN 303 146-1: "Reconfigurable Radio Systems (RRS); Mobile Device (MD) information
models and protocols; Part 1: Multiradio Interface (MURI)".
[i.7] ETSI EN 303 146-2: "Reconfigurable Radio Systems (RRS); Mobile Device (MD) information
models and protocols; Part 2: Reconfigurable Radio Frequency Interface (RRFI)".
ETSI

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6 Draft ETSI EN 303 681-4 V1.1.2 (2020-03)
[i.8] ETSI EN 303 146-3: "Reconfigurable Radio Systems (RRS); Mobile Device (MD) information
models and protocols; Part 3: Unified Radio Application Interface (URAI)".
[i.9] ETSI EN 303 146-4: "Reconfigurable Radio Systems (RRS); Mobile Device (MD) information
models and protocols; Part 4: Radio Programming Interface (RPI)".
[i.10] ETSI EN 303 681-1: "Reconfigurable Radio Systems (RRS); Radio Equipment (RE) information
models and protocols for generalized software reconfiguration architecture; Part 1: generalized
Multiradio Interface (gMURI)".
[i.11] ETSI EN 303 681-2: "Reconfigurable Radio Systems (RRS); Radio Equipment (RE) information
models and protocols for generalized software reconfiguration architecture; Part 2: generalized
Reconfigurable Radio Frequency Interface (gRRFI)".
[i.12] ETSI EN 303 681-3: "Reconfigurable Radio Systems (RRS); Radio Equipment (RE) information
models and protocols for generalized software reconfiguration architecture; Part 3: generalized
Unified Radio Application Interface (gURAI)".
3 Definition of terms, symbols and abbreviations
3.1 Terms
For the purposes of the present document, the following terms apply:
Abstract Processing Element (APE): abstracts computational resource that executes any computations downloaded
from Radio Library
NOTE: APE is connected with input and output DOs. APE is reactive. Any computations are started if all input
DOs are filled with real data.
basic operations: operations either provided by the Radio Library and/or UDFB Set to eRVM or by the Radio Library
and/or RVM/eRVM Configcodes to RVM
NOTE: Each Basic Operation is mapped to a corresponding APE in the case of eRVM or mapped to a
corresponding APE or RVM/eRVM in the case of RVM.
data flow chart: reactive data flow computational model consisting of data and operators where data are connected
with operators
NOTE: Operators abstract computations. They are triggered by full data. Results of operator computations are
written in connected output data if they are empty.
Data Object (DO): typeless token abstracting any type of data
NOTE: DO provides a container for storing data. It can be empty if no data in the container or it can be full if
there is data in the container. DO is allocated in the infinite and flat memory. Any RVM has access to this
memory. One or a few APEs from RVM can be connected with DO. DO acknowledges connected APEs
about its status whether it empty or full.
dynamic operation: operation that is performed by allocating the computational resources during run-time for each
APE required executing the given operation
NOTE 1: The resources are deallocated upon completion of the corresponding operation.
NOTE 2: Dynamic operation is available only in the case of RERC-7 defined in ETSI EN 303 641 [1]. In other
words, dynamic operation is needed when RA requires the dynamic resource sharing.
native radio library: library providing platform-specific description of each SFB that represents the target platform
hardware
port configuration: specification of the number of APEs inputs and outputs
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7 Draft ETSI EN 303 681-4 V1.1.2 (2020-03)
Radio Equipment (RE): "an electrical or electronic product, which intentionally emits and/or receives radio waves for
the purpose of radio communication and/or radiodetermination, or an electrical or electronic product which must be
completed with an accessory, such as antenna, so as to intentionally emit and/or receive radio waves for the purpose of
radio communication and/or radiodetermination".
NOTE: The definition above is as defined in the Radio Equipment Directive, Article 2(1)(1) [i.3].
radio library authority: authority empowered to decide which components can be registered as new SFBs
NOTE: Any suitable organization can take the role of a Radio Library Authority. The choice of the organization
is beyond the scope of the present document.
Radio Virtual Machine (RVM): abstract machine that supports reactive and concurrent executions
NOTE: A RVM may be implemented as a controlled execution environment that allows the selection of a trade-
off between flexibility of base band code development and required (re-)certification efforts.
Radio Virtual Machine Runtime Environment (RVM RE): software that allows running Radio Applications that
might be Configcodes or executable codes
reconfigurable mobile device: mobile device with radio communication capabilities providing support for radio
reconfiguration
NOTE: Reconfigurable mobile devices include but are not limited to: smartphones, feature phones, tablets, and
laptops.
reference radio library: library providing normative definition of each SFB
NOTE: There may be multiple such Reference Radio Libraries. For a given RA, a unique Reference Radio
Library is used.
Software Intermediate Representation (SWIR): RA representation as data flow chart
NOTE: SWIR file contains information on all terminal objects, their parameters (cost, implement function, size,
etc.) and connections (links, access type, source and destination).
terminal operation: operation that will always be executed without any other interruption
NOTE 1: Furthermore, terminal operation cannot be decomposed into smaller operations.
NOTE 2: "Terminal operations" are equivalent to "atomic operations", but additionally it indicates that a hierarchy
is being used in which the "terminal operations" are on the lowest level of hierarchy and they can be part
of another operation.
3.2 Symbols
Void.
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AOT Ahead-Of-Time
APE Abstract Processing Element
ASF Abstract Switch Fabric
CC Configcodes Counter
CSL Communication Services Layer
CU Control Unit
DO Data Object
eRVM elementary RVM
eSFB elementary SFB
FB Functional Block
FBRI FB Reusability Index
ETSI

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8 Draft ETSI EN 303 681-4 V1.1.2 (2020-03)
FFT Fast Fourier Transform
gMURI generalized Multiradio Interface
gRPI generalized Radio Programming Interface
gRRFI generalized Reconfigurable Radio Frequency Interface
gURAI generalized Unified Radio Applications Interface
HD Hardware Dimension
HW Hardware
ID IDentification
IFFT Inverse Fast Fourier Transform
IR Intermediate Representation
JIT Just-In-Time
LCF Last Configuration Flag
NAF Next Address Flag
NAPE Number of Abstract Processing Elements
NCAO Next Configcode Address Offset
NDO Number of Data Objects
NOP No OPeration
RA Radio Application
RAP Radio Application Package
RAT Radio Access Technology
RCF Radio Control Framework
RE Radio Equipment
RF Radio Frequency
RLA Radio Library Authority
ROS Radio Operating System
RPI Radio Programming Interface
RVM RE RVM Runtime Environment
RVM Radio Virtual Machine
SD Software Dimension
SFB Standard Functional Block
SWIR SoftWare Intermediate Representation
UDFB User Defined Functional Block
UML Unified Modelling Language
URA Unified Radio Applications
VDO Virtual Data Object
VHDL Very high speed integrated circuit Hardware Description Language
XML eXtensible Markup Language
XOR eXclusive OR
4 Introduction
A reconfigurable RE is capable of running multiple radios simultaneously, changing the set of radios by loading new
Radio Application Packages (RAP) and setting their parameters. All Radio Applications (RAs) are called Unified Radio
Applications (URAs) when they exhibit a common behaviour from the reconfigurable RE's point of view in ETSI
EN 303 648 [i.2]. In order to run multiple URAs, the reconfigurable RE will include Communication Services Layer
(CSL), Radio Control Frameworks (RCFs), Radio Platforms and 4 sets of interfaces for their interconnection.
ETSI

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9 Draft ETSI EN 303 681-4 V1.1.2 (2020-03)

Figure 4.1: Four sets of interfaces for Reconfigurable RE
Figure 4.1 illustrates the Reconfigurable RE architecture with the 4 sets of interfaces, i.e.:
• gMURI for interfacing CSL and RCF (in ETSI EN 303 681-1 [i.10]).
• gRRFI for interfacing URA and RF Transceiver (in ETSI EN 303 681-2 [i.11]).
• gURAI for interfacing URA and RCF (in ETSI EN 303 681-3 [i.12]).
• gRPI for allowing an independent and uniform production of RAs which is the scope of the present document.
The present document defines gRPI.
<< in t erf a ce>>
IgM U R I
<< in t erf a ce>>
IgR R F I
Ra di oC ompute r
<< in t erf a ce>>
IgU R AI
<< in t erf a ce>>
IgR PI

Figure 4.2: UMLclass diagram for Radio Computer interfaces
ETSI

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10 Draft ETSI EN 303 681-4 V1.1.2 (2020-03)
Figure 4.2 illustrates UML class diagram for Radio Computer interfaces. The reconfigurable RE may be seen as a set of
multiple Radio Computers where individual URAs are engineered as software entities in ETSI EN 303 648 [i.2].
The present document is organized as follows:
• Clause 5 describes the system requirement mapping.
• Clause 6 describes the radio virtual machine specification.
• Clause 7 describes the Configcodes for RVM.
• Clause 8 describes the radio library structure.
• Clause 9 describes the loading, linking and initialization.
• Clause 10 describes the compiling for RVM.
• Annex A describes the mapping between Binary and XML.
• Annex B describes SFB Candidates.
• Annex C describes the replacement of selected components of an existing RAT.
While UML is used for defining the information model and protocol related to gRPI, other modelling languages could
be used as well.
5 System Requirement Mapping
The Radio Programming Interface and its related components described in the present document shall support the
system requirements shown in table 5.1 referring to clause 6 of ETSI EN 303 641 [1]. This is achieved by introducing
st
the entities/components/units given in the 1 column of table 5.1.
Table 5.1: Mapping of Radio Programming Interface and its related components to
the system requirements described in ETSI EN 303 641 [1]
Entity/Component/Unit System Requirements [1] Comments
Radio Programming R-FUNC-RER-04 The requirement shall be as described in clause 6.4.4 of [1].
Interface
Radio Virtual Machine R-FUNC-RER-13 The requirement shall be as described in clause 6.4.13 of [1].
R-FUNC-RER-14 The requirement shall be as described in clause 6.4.14 of [1].
R-FUNC-RER-15 The requirement shall be as described in clause 6.4.15 of [1].
Radio Library R-FUNC-FB-06 A library extension shall be supported. The requirement shall
be as described in clause 6.3.6 of [1].

6 Radio Virtual Machine specification
6.1 Concept of RVM
As introduced in ETSI EN 303 648 [i.2], the Radio Virtual Machine (RVM) is an Abstract Machine which is capable of
executing Configcodes and it is independent of the hardware. The implementation of a RVM is target Radio Computer
specific and it shall have access to the Back-end Compiler (on the platform itself or externally as described in ETSI
EN 303 648 [i.2], clause 4.4.1) for Just-in-Time (JIT) or Ahead-of-Time (AOT) compilation of Configcodes.
This clause describes the concept of RVM. As mentioned above, the RVM is an abstract machine, which executes a
particular algorithm presented as a data flow chart. In other words, the RVM is the result of replacing all operators and
tokens in the particular data flow chart with Abstract Processing Elements (APEs) and Data Objects (DOs),
respectively. Each APE executes computations marked by the replaced operator identifier. These computations are
taken from the Radio Library.
ETSI

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11 Draft ETSI EN 303 681-4 V1.1.2 (2020-03)
Figure 6.1 illustrates a conceptual view of RVM processing. This process requires APE, DO and Radio Library, of
which the definitions are as follows:
• APE abstracts a computational resource corresponding to the operation in a particular data flow chart.
• DO abstracts a memory resource. In other words, DO is an abstracted memory for storing data used during the
procedure of Radio processing.
• Reference/Native Radio Library includes normative definitions/native implementation of all Standard
Functional Blocks (SFBs) [i.5] for front-end/back-end compilation. Note that the computations included in the
Radio Library are represented in terms of normative definitions or native implementations of SFBs depending
upon whether the Radio Library is used for front-end or back-end compilation, respectively.
NOTE 1: User Defined Functional Blocks (UDFBs) will be created through combination of SFBs and represented
as a data flow chart to be executed in the RVM. Alternatively, a UDFB is implemented as a stand-alone
module/function which can be mapped:
i) into one APE (i.e. this UDFB can be considered atomic); or
ii) into an eRVM/RVM (i.e. not atomic). UDFBs are not in general included into the Radio Library,
but they are part of the Radio Application Package.
The RVM begins to work immediately after some DOs initialization. All APEs shall execute computations
asynchronously and concurrently. An individual APE shall execute the allocated operator if all the corresponding input
DOs are full. APEs shall access DOs with operations "read", "read-erase", or "write". After reading input data from
DOs, the APE shall execute the allocated operator and, if output DOs are empty, then the APE shall write processed
data. Any full output DO shall block the corresponding writing operation. The RVM shall execute computations until
reaching the state when all APEs become inactive. In this state, there are not enough full DOs, which can activate the
inactive operators. The result of computations are full DOs, which cannot activate the inactive operators.
NOTE 2: An Output DO can become an Input DO for a subsequent operator. Then, this input DO can activate the
subsequent operator.
NOTE 3: The state or operation of a given APE is independent on the state of other APEs. I.e. each APE is atomic.

Figure 6.1: Conceptual Diagram of Radio Virtual Machine Processing
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12 Draft ETSI EN 303 681-4 V1.1.2 (2020-03)
6.2 Elementary RVM (eRVM)
This clause describes the eRVM which shall consist of components of Basic Operations, Program memory, Control
Unit (CU), Abstract Switch Fabric (ASF) as well as APEs and DOs, of which the definitions are as follows. eRVM shall
not contain another eRVM or RVM:
• Basic Operations shall include operators either provided:
i) from Radio
...

SLOVENSKI STANDARD
oSIST prEN 303 681-4 V1.1.2:2020
01-julij-2020
Radijski sistemi z možnostjo preoblikovanja (RRS) - Informacijski modeli in
protokoli za radijsko opremo (RE) za splošno arhitekturo preoblikovanja
programske opreme - 4. del: Splošni radijski programski vmesnik (gRPI)
Reconfigurable Radio Systems (RRS) - Radio Equipment (RE) information models and
protocols for generalized software reconfiguration architecture - Part 4: generalized
Radio Programming Interface (gRPI)
Ta slovenski standard je istoveten z: ETSI EN 303 681-4 V1.1.2 (2020-03)
ICS:
33.060.01 Radijske komunikacije na Radiocommunications in
splošno general
35.200 Vmesniška in povezovalna Interface and interconnection
oprema equipment
oSIST prEN 303 681-4 V1.1.2:2020 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 303 681-4 V1.1.2:2020

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oSIST prEN 303 681-4 V1.1.2:2020
Draft ETSI EN 303 681-4 V1.1.2 (2020-03)






EUROPEAN STANDARD
Reconfigurable Radio Systems (RRS);
Radio Equipment (RE) information models and protocols
for generalized software reconfiguration architecture;
Part 4: generalized Radio Programming Interface (gRPI)

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oSIST prEN 303 681-4 V1.1.2:2020

2 Draft ETSI EN 303 681-4 V1.1.2 (2020-03)



Reference
REN/RRS-0231
Keywords
architecture, interface, radio, SDR, software,
system

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ETSI

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3 Draft ETSI EN 303 681-4 V1.1.2 (2020-03)
Contents
Intellectual Property Rights . 4
Foreword . 4
Modal verbs terminology . 4
1 Scope . 5
2 References . 5
2.1 Normative references . 5
2.2 Informative references . 5
3 Definition of terms, symbols and abbreviations . 6
3.1 Terms . 6
3.2 Symbols . 7
3.3 Abbreviations . 7
4 Introduction . 8
5 System Requirement Mapping . 10
6 Radio Virtual Machine specification . 10
6.1 Concept of RVM . 10
6.2 Elementary RVM (eRVM) . 12
6.3 RVM Hierarchy . 15
6.4 Data types . 17
6.4.1 Types and Values . 17
6.4.2 Run-Time Data . 17
6.5 Arithmetic. 17
6.6 Exceptions . 17
6.7 Control, Synchronization and Execution . 17
6.8 Operations with Memory . 18
6.9 RVM run-time environment . 18
7 Configcodes for RVM . 19
7.1 Introduction . 19
7.2 Configcodes generation . 19
7.3 Binary format for Configcodes . 20
7.4 XML schema for Configcodes . 24
8 Radio Library . 29
8.1 Introduction . 29
8.2 Reference Radio Library . 30
8.3 Native Radio Library . 30
9 Loading, Linking and Initialization . 31
10 Compiling for RVM (Front-End Compilation) . 32
Annex A (informative): Mapping between XML and Binary . 33
Annex B (informative): SFB Candidate . 34
Annex C (informative): Replacement of selected components of an existing RAT . 36
Annex D (informative): Introducing new SFBs . 37
Annex E (informative): Synchronous Approach . 38
History . 42


ETSI

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4 Draft ETSI EN 303 681-4 V1.1.2 (2020-03)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (https://ipr.etsi.org/).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Trademarks
The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.
ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does
not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.
Foreword
This draft European Standard (EN) has been produced by ETSI Technical Committee Reconfigurable Radio Systems
(RRS), and is now submitted for the combined Public Enquiry and Vote phase of the ETSI standards EN Approval
Procedure.
The present document is part 4 of a multi-part deliverable covering the Radio Equipment (RE) information models and
protocols, as identified below:
Part 1: "generalized Multiradio Interface (gMURI)";
Part 2: "generalized Reconfigurable Radio Frequency Interface (gRRFI)";
Part 3: "generalized Unified Radio Application Interface (gURAI)";
Part 4: "generalized Radio Programming Interface (gRPI)".

Proposed national transposition dates
Date of latest announcement of this EN (doa): 3 months after ETSI publication
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 6 months after doa
Date of withdrawal of any conflicting National Standard (dow): 6 months after doa

Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
ETSI

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5 Draft ETSI EN 303 681-4 V1.1.2 (2020-03)
1 Scope
The scope of the present document is to define the generalized Radio Programming Interface (gRPI) for radio
equipment reconfiguration except for reconfigurable mobile devices which are covered in [i.4] to [i.9]. The work is
based on the Use Cases defined in ETSI TR 103 585 [i.1], on the system requirements defined in ETSI EN 303 641 [1]
and on the radio reconfiguration related architecture for radio equipment defined in ETSI EN 303 648 [i.2].
The present document will be based on ETSI EN 303 146-4 [i.9] and provide a generalized interface definition for the
generalized Radio Programming Interface (gRPI).
2 References
2.1 Normative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
https://docbox.etsi.org/Reference/.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
[1] ETSI EN 303 641: "Reconfigurable Radio Systems (RRS); Radio Equipment (RE) reconfiguration
requirements".
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] ETSI TR 103 585: "Reconfigurable Radio Systems (RRS); Radio Equipment (RE) reconfiguration
use cases".
[i.2] ETSI EN 303 648: "Reconfigurable Radio Systems (RRS); Radio Equipment (RE) reconfiguration
architecture".
[i.3] Directive 2014/53/EU of the European Parliament and of the Council of 16 April 2014 on the
harmonisation of the laws of the Member States relating to the making available on the market of
Radio Equipment and repealing Directive 1999/5/EC.
[i.4] ETSI EN 302 969: "Reconfigurable Radio Systems (RRS); Radio Reconfiguration related
requirements for Mobile Devices".
[i.5] ETSI EN 303 095: "Reconfigurable Radio Systems (RRS); Radio reconfiguration related
architecture for Mobile Devices (MD)".
[i.6] ETSI EN 303 146-1: "Reconfigurable Radio Systems (RRS); Mobile Device (MD) information
models and protocols; Part 1: Multiradio Interface (MURI)".
[i.7] ETSI EN 303 146-2: "Reconfigurable Radio Systems (RRS); Mobile Device (MD) information
models and protocols; Part 2: Reconfigurable Radio Frequency Interface (RRFI)".
ETSI

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6 Draft ETSI EN 303 681-4 V1.1.2 (2020-03)
[i.8] ETSI EN 303 146-3: "Reconfigurable Radio Systems (RRS); Mobile Device (MD) information
models and protocols; Part 3: Unified Radio Application Interface (URAI)".
[i.9] ETSI EN 303 146-4: "Reconfigurable Radio Systems (RRS); Mobile Device (MD) information
models and protocols; Part 4: Radio Programming Interface (RPI)".
[i.10] ETSI EN 303 681-1: "Reconfigurable Radio Systems (RRS); Radio Equipment (RE) information
models and protocols for generalized software reconfiguration architecture; Part 1: generalized
Multiradio Interface (gMURI)".
[i.11] ETSI EN 303 681-2: "Reconfigurable Radio Systems (RRS); Radio Equipment (RE) information
models and protocols for generalized software reconfiguration architecture; Part 2: generalized
Reconfigurable Radio Frequency Interface (gRRFI)".
[i.12] ETSI EN 303 681-3: "Reconfigurable Radio Systems (RRS); Radio Equipment (RE) information
models and protocols for generalized software reconfiguration architecture; Part 3: generalized
Unified Radio Application Interface (gURAI)".
3 Definition of terms, symbols and abbreviations
3.1 Terms
For the purposes of the present document, the following terms apply:
Abstract Processing Element (APE): abstracts computational resource that executes any computations downloaded
from Radio Library
NOTE: APE is connected with input and output DOs. APE is reactive. Any computations are started if all input
DOs are filled with real data.
basic operations: operations either provided by the Radio Library and/or UDFB Set to eRVM or by the Radio Library
and/or RVM/eRVM Configcodes to RVM
NOTE: Each Basic Operation is mapped to a corresponding APE in the case of eRVM or mapped to a
corresponding APE or RVM/eRVM in the case of RVM.
data flow chart: reactive data flow computational model consisting of data and operators where data are connected
with operators
NOTE: Operators abstract computations. They are triggered by full data. Results of operator computations are
written in connected output data if they are empty.
Data Object (DO): typeless token abstracting any type of data
NOTE: DO provides a container for storing data. It can be empty if no data in the container or it can be full if
there is data in the container. DO is allocated in the infinite and flat memory. Any RVM has access to this
memory. One or a few APEs from RVM can be connected with DO. DO acknowledges connected APEs
about its status whether it empty or full.
dynamic operation: operation that is performed by allocating the computational resources during run-time for each
APE required executing the given operation
NOTE 1: The resources are deallocated upon completion of the corresponding operation.
NOTE 2: Dynamic operation is available only in the case of RERC-7 defined in ETSI EN 303 641 [1]. In other
words, dynamic operation is needed when RA requires the dynamic resource sharing.
native radio library: library providing platform-specific description of each SFB that represents the target platform
hardware
port configuration: specification of the number of APEs inputs and outputs
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Radio Equipment (RE): "an electrical or electronic product, which intentionally emits and/or receives radio waves for
the purpose of radio communication and/or radiodetermination, or an electrical or electronic product which must be
completed with an accessory, such as antenna, so as to intentionally emit and/or receive radio waves for the purpose of
radio communication and/or radiodetermination".
NOTE: The definition above is as defined in the Radio Equipment Directive, Article 2(1)(1) [i.3].
radio library authority: authority empowered to decide which components can be registered as new SFBs
NOTE: Any suitable organization can take the role of a Radio Library Authority. The choice of the organization
is beyond the scope of the present document.
Radio Virtual Machine (RVM): abstract machine that supports reactive and concurrent executions
NOTE: A RVM may be implemented as a controlled execution environment that allows the selection of a trade-
off between flexibility of base band code development and required (re-)certification efforts.
Radio Virtual Machine Runtime Environment (RVM RE): software that allows running Radio Applications that
might be Configcodes or executable codes
reconfigurable mobile device: mobile device with radio communication capabilities providing support for radio
reconfiguration
NOTE: Reconfigurable mobile devices include but are not limited to: smartphones, feature phones, tablets, and
laptops.
reference radio library: library providing normative definition of each SFB
NOTE: There may be multiple such Reference Radio Libraries. For a given RA, a unique Reference Radio
Library is used.
Software Intermediate Representation (SWIR): RA representation as data flow chart
NOTE: SWIR file contains information on all terminal objects, their parameters (cost, implement function, size,
etc.) and connections (links, access type, source and destination).
terminal operation: operation that will always be executed without any other interruption
NOTE 1: Furthermore, terminal operation cannot be decomposed into smaller operations.
NOTE 2: "Terminal operations" are equivalent to "atomic operations", but additionally it indicates that a hierarchy
is being used in which the "terminal operations" are on the lowest level of hierarchy and they can be part
of another operation.
3.2 Symbols
Void.
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AOT Ahead-Of-Time
APE Abstract Processing Element
ASF Abstract Switch Fabric
CC Configcodes Counter
CSL Communication Services Layer
CU Control Unit
DO Data Object
eRVM elementary RVM
eSFB elementary SFB
FB Functional Block
FBRI FB Reusability Index
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FFT Fast Fourier Transform
gMURI generalized Multiradio Interface
gRPI generalized Radio Programming Interface
gRRFI generalized Reconfigurable Radio Frequency Interface
gURAI generalized Unified Radio Applications Interface
HD Hardware Dimension
HW Hardware
ID IDentification
IFFT Inverse Fast Fourier Transform
IR Intermediate Representation
JIT Just-In-Time
LCF Last Configuration Flag
NAF Next Address Flag
NAPE Number of Abstract Processing Elements
NCAO Next Configcode Address Offset
NDO Number of Data Objects
NOP No OPeration
RA Radio Application
RAP Radio Application Package
RAT Radio Access Technology
RCF Radio Control Framework
RE Radio Equipment
RF Radio Frequency
RLA Radio Library Authority
ROS Radio Operating System
RPI Radio Programming Interface
RVM RE RVM Runtime Environment
RVM Radio Virtual Machine
SD Software Dimension
SFB Standard Functional Block
SWIR SoftWare Intermediate Representation
UDFB User Defined Functional Block
UML Unified Modelling Language
URA Unified Radio Applications
VDO Virtual Data Object
VHDL Very high speed integrated circuit Hardware Description Language
XML eXtensible Markup Language
XOR eXclusive OR
4 Introduction
A reconfigurable RE is capable of running multiple radios simultaneously, changing the set of radios by loading new
Radio Application Packages (RAP) and setting their parameters. All Radio Applications (RAs) are called Unified Radio
Applications (URAs) when they exhibit a common behaviour from the reconfigurable RE's point of view in ETSI
EN 303 648 [i.2]. In order to run multiple URAs, the reconfigurable RE will include Communication Services Layer
(CSL), Radio Control Frameworks (RCFs), Radio Platforms and 4 sets of interfaces for their interconnection.
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Figure 4.1: Four sets of interfaces for Reconfigurable RE
Figure 4.1 illustrates the Reconfigurable RE architecture with the 4 sets of interfaces, i.e.:
• gMURI for interfacing CSL and RCF (in ETSI EN 303 681-1 [i.10]).
• gRRFI for interfacing URA and RF Transceiver (in ETSI EN 303 681-2 [i.11]).
• gURAI for interfacing URA and RCF (in ETSI EN 303 681-3 [i.12]).
• gRPI for allowing an independent and uniform production of RAs which is the scope of the present document.
The present document defines gRPI.
<>
IgMURI
<>
IgRRFI
RadioComputer
<>
IgURAI
<>
IgRPI

Figure 4.2: UMLclass diagram for Radio Computer interfaces
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Figure 4.2 illustrates UML class diagram for Radio Computer interfaces. The reconfigurable RE may be seen as a set of
multiple Radio Computers where individual URAs are engineered as software entities in ETSI EN 303 648 [i.2].
The present document is organized as follows:
• Clause 5 describes the system requirement mapping.
• Clause 6 describes the radio virtual machine specification.
• Clause 7 describes the Configcodes for RVM.
• Clause 8 describes the radio library structure.
• Clause 9 describes the loading, linking and initialization.
• Clause 10 describes the compiling for RVM.
• Annex A describes the mapping between Binary and XML.
• Annex B describes SFB Candidates.
• Annex C describes the replacement of selected components of an existing RAT.
While UML is used for defining the information model and protocol related to gRPI, other modelling languages could
be used as well.
5 System Requirement Mapping
The Radio Programming Interface and its related components described in the present document shall support the
system requirements shown in table 5.1 referring to clause 6 of ETSI EN 303 641 [1]. This is achieved by introducing
st
the entities/components/units given in the 1 column of table 5.1.
Table 5.1: Mapping of Radio Programming Interface and its related components to
the system requirements described in ETSI EN 303 641 [1]
Entity/Component/Unit System Requirements [1] Comments
Radio Programming R-FUNC-RER-04 The requirement shall be as described in clause 6.4.4 of [1].
Interface
Radio Virtual Machine R-FUNC-RER-13 The requirement shall be as described in clause 6.4.13 of [1].
R-FUNC-RER-14 The requirement shall be as described in clause 6.4.14 of [1].
R-FUNC-RER-15 The requirement shall be as described in clause 6.4.15 of [1].
Radio Library R-FUNC-FB-06 A library extension shall be supported. The requirement shall
be as described in clause 6.3.6 of [1].

6 Radio Virtual Machine specification
6.1 Concept of RVM
As introduced in ETSI EN 303 648 [i.2], the Radio Virtual Machine (RVM) is an Abstract Machine which is capable of
executing Configcodes and it is independent of the hardware. The implementation of a RVM is target Radio Computer
specific and it shall have access to the Back-end Compiler (on the platform itself or externally as described in ETSI
EN 303 648 [i.2], clause 4.4.1) for Just-in-Time (JIT) or Ahead-of-Time (AOT) compilation of Configcodes.
This clause describes the concept of RVM. As mentioned above, the RVM is an abstract machine, which executes a
particular algorithm presented as a data flow chart. In other words, the RVM is the result of replacing all operators and
tokens in the particular data flow chart with Abstract Processing Elements (APEs) and Data Objects (DOs),
respectively. Each APE executes computations marked by the replaced operator identifier. These computations are
taken from the Radio Library.
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Figure 6.1 illustrates a conceptual view of RVM processing. This process requires APE, DO and Radio Library, of
which the definitions are as follows:
• APE abstracts a computational resource corresponding to the operation in a particular data flow chart.
• DO abstracts a memory resource. In other words, DO is an abstracted memory for storing data used during the
procedure of Radio processing.
• Reference/Native Radio Library includes normative definitions/native implementation of all Standard
Functional Blocks (SFBs) [i.5] for front-end/back-end compilation. Note that the computations included in the
Radio Library are represented in terms of normative definitions or native implementations of SFBs depending
upon whether the Radio Library is used for front-end or back-end compilation, respectively.
NOTE 1: User Defined Functional Blocks (UDFBs) will be created through combination of SFBs and represented
as a data flow chart to be executed in the RVM. Alternatively, a UDFB is implemented as a stand-alone
module/function which can be mapped:
i) into one APE (i.e. this UDFB can be considered atomic); or
ii) into an eRVM/RVM (i.e. not atomic). UDFBs are not in general included into the Radio Library,
but they are part of the Radio Application Package.
The RVM begins to work immediately after some DOs initialization. All APEs shall execute computations
asynchronously and concurrently. An individual APE shall execute the allocated operator if all the corresp
...