Open source software is expected to play a major role in future 5G systems. The main applications are as follows:
i. Adaptation of generic equipment platforms to a multitude of use cases
White papers issued by relevant interest groups, such as [ 26 ] , indicate that a wide variety of use cases will need to be addressed by future 5G systems. These comprise not only mass market products but also applications for specific (niche) markets with specific requirements. A typical example of the latter is Remote Object Manipulation:
Remote Surgery, which requires devices of specific form factors and ultra-high reliability.
It is therefore expected that major manufacturers may not be able to provide products suitable for all possible use cases, because of their sheer number. Instead, specialized companies, such as SMEs (Small and Medium Entrepreneurs), will build on generic underlying hardware platforms, which will be parameterized through open source software interfaces and integrated into specialized target form factors. Without open source software interfaces, many of the identified 5G use cases may never be supported.
Figure 4-17. Opportunistic resource aggregation in the backhaul network
ii. Enable modification of radio parameters through an evolution of Smartphone apps to RadioApps
The European Commission revised the Radio and Telecommunications Terminal Equipment Directive (R&TTED) and adopted the new Radio Equipment Directive (RED) [ 27 ] in 2014. This Directive establishes a regulatory framework in the European Union for making radio equipment available on the market and putting it into service. One of the key novelties introduced by the RED is the possibility of introducing new radio equipment features through software. The concerned RED paragraphs are as follows [ 27 ] :
“Article 3 - Essential requirements
3. Radio equipment within certain categories or classes shall be so constructed that it complies with the following essential requirements:
(i) radio equipment supports certain features in order to ensure that software can only be loaded into the radio equipment where the compliance of the combination of the radio equipment and software has been demonstrated.”
And
“Article 4 - Provision of information on the compliance of combinations of radio equipment and software
1. Manufacturers of radio equipment and of software allowing radio equipment to be used as intended shall provide the Member States and the Commission with information on the compliance of intended combinations of radio equipment and software with the essential requirements set out in Article 3. Such information shall result from a conformity assessment carried out in accordance with Article 17, and shall be given in the form of a statement of compliance which includes the elements set out in Annex VI. Depending on the specific combinations of radio equipment and software, the information shall precisely identify the radio equipment and the software which have been assessed, and it shall be continuously updated.
2. The Commission shall be empowered to adopt delegated acts in accordance with Article 44 specifying which categories or classes of radio equipment are concerned by the requirement set out in paragraph 1 of this Article.
3. The Commission shall adopt implementing acts laying down the operational rules for making the information on compliance available for the categories and classes specified by the delegated acts adopted pursuant to paragraph 2 of this Article. Those implementing acts shall be adopted in accordance with the examination procedure referred to in Article 45(3).”
In this context, ETSI has developed technical solutions for enabling the reconfiguration of mobile devices through so-called RadioApps . Those are similar to existing Smartphone apps, with the difference that the modification of radio parameters is made possible. It should be noted that a substantially different approach to software reconfiguration is taken by ETSI compared to past efforts in the context of Software Defined Radio (SDR). Existing SDR approaches typically rely on a complex computation platform allowing the execution of entire air interfaces or wave forms. Because of the inherent complexity, those solutions have led to poor acceptance in the mass market.
The current ETSI approach instead addresses the problem from the other end, building on existing Smartphone apps. It is indeed proposed that an equipment manufacturer can gradually open up its platform to defined internal Application Programming Interfaces (API). Corresponding code is executed in a secure environment called the Radio Virtual Machine (RVM). The platform is thus not fully opened to a third-party software manufacturer but allows access only to clearly identified features. To give a specific example, a manufacturer may choose to provide access to antenna selection APIs to third-party software manufacturers. Then, new RadioApps can be created, providing optimized antenna-selection solutions for a specific context.
The basic system architecture for mobile device reconfiguration is defined in [ 28 ] and shown in Figure 4-18 .
Figure 4-18. System architecture for Radio Computer, where Radio Library and Back End (BE) compiler are included within the Radio Computer [ 28 ]
ETSI TR 102 967 [ 29 ] analyzes requirements related to the issuance of a Declaration of Conformity and its handling in the context of software reconfiguration affecting radio parameters. Such a Declaration of Conformity is required by regulation administrations in Europe before the concerned equipment can be introduced into the single European market.
The ETSI document discusses two potential scenarios for a Declaration of
Conformity in the context of a revision of TR 102 967 as of a global application, depending on the applicable legal framework:
Potential Scenario 1 : An update of the applicable Declaration of Conformity for the joint operation of Hardware in combination with a new Software Component (RadioApp).
In the European context, it is proposed to build on Radio Equipment Directive, Annex VII: SIMPLIFIED EU DECLARATION OF CONFORMITY;
Initially, the Original Equipment Manufacturer
declares that the radio equipment type [designation of type of radio equipment] is in compliance with Directive 2014/53/EU. The full text of the EU declaration of conformity Declaration of Conformity is available at the following internet address:___
In order to enable joint operation of the available Hardware in combination with a new Software Component (RadioApp), the Declaration of Conformity available at the given Internet Address is updated to include the new configuration.
Potential Scenario 2 : Initially, a DoC is issued for available hardware components in combination with Software Components (RadioApps) to be developed in the future.
A future software component is typically made available together with a “Conformity Statement” by the Original Equipment Manufacturer, indicating that the combination of concerned hardware and software complies with the appropriate requirements.
The initial DoC will be not modified, as the Conformity Statement is related to the features enabled by RVM, which limits software components’ access to radio parameters as defined by the EN 303 095 concept of “RVM protection classes“ [ 28 ] .
In Scenario 2, the Declaration of Conformity together with the appropriate Conformity Statement is expected to be equivalent to a Scenario 1—the overall responsibility is taken by a single entity, that is, the Original Equipment Manufacturer (OEM), as illustrated in Figure 4-19 .
These two scenarios for the Declaration of Conformity were presented to the European Telecommunications Conformity Assessment and Market Surveillance Committee (TCAM) in October, 2015. It is expected that regulation issues will be studied further before related products can be introduced into the market.
We’ve looked here at the European context of software reconfiguration. Other regions may apply different mechanisms, and correspondingly adapted methodologies need to be defined in order to allow the modification of radio parameters through third-party software developers.