WS1 Piloting Activities - Technical Inter-connection of Existing LDTs

Brief Overview

This Work Strand focuses on connecting and testing existing Local Digital Twins (LDTs) within a European ecosystem. The goal is to demonstrate interoperability, enable data sharing across domains and borders, and unlock new opportunities for smarter and more resilient communities.

Key facts:

6–8 pilots will be selected
Start of the pilots: May 2026
Duration: 18 months
Funding: 50% co-funding required
First Round of open calls: November 2025
Second Round of open calls: February 2026

👉 Second round of open calls now OPEN. Check it out here. Apply by 15/04/2026, 23:59 CET.

What is the goal?

Demonstrate interoperability between existing LDTs
Enable cross-domain and cross-border data sharing
Build the foundations for a European federation of LDTs
Unlock innovation opportunities for cities, communities, and providers

Who Are We Looking For?

Municipalities, groups of municipalities, syndicates, or regions, who have a Local Digital Twin in place, with a description and a functional perimeter, and who are willing to share data, models, and services with:

Other data platforms (LDT, hypervision, etc.)
Data spaces

Municipalities or regions aiming to:

Create a data space to link a batch of existing digital twins
Develop a marketplace of services

Consortium composition:

At least 2 public entities
Plus 1 other partner from the following:
→ Private entity (e.g., service provider)
→ Private association (legal status)
→ Trusted third party
→ Representative of a use-case sector

WS1 Requirements Cheat Sheet:

This is a cheat sheet for Work Strand 1 (Connecting Existing Local Digital Twins). For a complete list of requirements, please refer to the specific Call for Pilots Manual.

🎯 Minimum Conditions

🏛️ 2+ public authorities from 2 different eligible countries, each with a digitally mature LDT (Rq1)
→ Descriptive-level capabilities + dynamic data integration
🤝 At least 1 additional partner (private entity, association, trusted third party, or sector representative)
🔀 2+ cross-sectoral use cases, each with one shared service (Rq2)

📋 Describe in the Application Form

Existing LDTs and their capabilities (dynamic data + services) (Rq3)
→ Include URL/screenshots of platform front-end
Current architectures (technical + functional) for each LDT (Rq4)
→ Include diagrams, tools, standards, data lifecycle
Data governance across all dimensions (Rq5)
current ➜ target (political • technical • legal • organisational)
Project management, incl. resource allocation, team structure, recruitment (Rq6)
→ Each public authority needs technical capacity + political support
AI/XR usage + ethics/legal safeguards (Rq7)
Alignment with EU priorities and LDT4SSC objectives (Rq8)
→ Green Deal, New European Bauhaus, LDT4SSC key challenges
Political endorsement with Letter of Commitment (Rq9)
Engagement of stakeholders from the Quadruple Helix (Rq10)
→ public • private • research • civil society (3 of 4 required)
Relevance and replicability to other EU communities (Rq11)
EU technology stack and infrastructure to be used (Rq12)
→ SIMPL, DSSC, LDT CitiVERSE EDIC, Gaia-X...
Project phases (Rq13)
→ Explore → Validate → Define → Implement
→ Include: data governance, business model, Cost-Benefit analysis, eco-design
Technical interconnection approach (Rq14)
→ Tools, software, standards (data catalogue, IAM, connectors, etc.)
→ Demonstrate usage of SIMPL Governance Authority Agent
Ambition and rationale for interconnecting LDTs (Rq19)
Tangible benefits and long-term impacts (Rq20)
Wider socio-economic and environmental effects (Rq21)
Maintenance and expansion strategy post-pilot (Rq24)

🧱 Provide as complementary material

4 draft diagrams (technical + functional, current + future) per use case (Rq15)
→ Technical: LDT interconnection (current + future) → Functional: data lifecycle (current + future)
Letter of Commitment with political endorsement (Rq9)
Ownership and Control Declaration (OCD)
Financial Form (.xlsx)
Ethics and Data Protection Self-Assessment
Contractual framework guaranteeing sustainability of LDTs (Rq22)

🛠️ Engage during the project

Pilots are expected to engage with:

End-users actively throughout the project lifecycle (Rq10)
Linked Data Ontology (MIM1) for semantic consistency (Rq16)
→ e.g., NGSI-LD, SPARQL
At least 5 foundational MIMs Plus (MIM0, MIM1, MIM2, MIM3, MIM6) (Rq18)
Open data models, to be shared back via open repositories (Rq23)
The LDT Toolbox Marketplace for service sharing (Rq23)
The LDT4SSC Knowledge Hub for regular documentation and updates (Rq23)

✏️ Specify upon application

Data, assets, or services to be shared (Rq17)
Sectors involved, main providers, beneficiaries (Rq17)
MIMs Plus (MIM0–MIM8) the project will engage with (Rq18)
→ Current and planned compliance level (Initial, Partial, Full)
Equivalent open-source solution, in case of proprietary components (Rq23)

⭐ Recommendations

Assess LORDIMAS maturity (Rc1)
→ Pilot Lead: Digitally Optimised
→ Others: ≥ Moderate
Use open-source components and share back enhancements (Rc2)
Include in consortium agreement IP and exploitation rights provisions (Rc3)
Technically establish (Rc4):
→ Data catalogue using DCAT vocabulary
→ Data management system with contextualised metadata (JSON-LD, RDF, NGSI-LD)
→ Identity and access management (OAuth2, OpenID Connect, Verifiable Credentials)
→ ODRL-based data policy
Pursue alignment with upcoming LDT Toolbox (Rc5)
Describe compliance with frameworks (Rc6):
→ Gaia-X, IDSA specification, DSBA recommendation, DSSC Blueprint, DS4SSCC-DEP Blueprint
Record baseline data for meaningful comparisons in Cost-Benefit Analysis (Rc7)
Assess eco-design maturity using the General Policy Framework for Ecodesign of Digital Services (Rc8)
→ At least 30 highest-priority criteria

💰 Financial Rules

Maximum grant per third-party: €500,000
Maximum cumulative grant per consortium: €1,000,000
Co-funding: 50% of total pilot costs from applicants' own resources
Indirect costs: 7% flat rate of direct costs