Resources

1. Recognize April 2026 as the Inflection Point for AI 1.13

WP 4C is expected to deliver:

• Mature MSS–IMT sharing and compatibility studies
• Consolidated system definitions and architectures
• Updated working documents and assumptions
• Preliminary CPM text directions
• Liaison responses, especially with WP 5D

Once studies stabilize, conclusions will follow quickly — even if technical uncertainty remains.

Action

• Confirm contribution pathways with your administration or sector member entity, as different contribution types can have a stronger impact if submitted by administrations vs sector members.

2. Shape System Definitions and Architectures Before They Solidify

Many AI 1.13 outcomes hinge on how systems are defined, not just how they perform.

Key issues include:

• Definitions of DC-MSS–IMT architectures
• Operational parameters (duty cycle, beam behavior, user density)
• Satellite and terminal antenna modeling
• Beam management and handover assumptions
• Cross-border and adjacent-band (unwanted emissions)  interference scenarios

Much of the text remains bracketed — meaning influence is still possible. Ensuring that the systems are allowed the flexibility in meeting the regulatory provisions that will be drafted in the CPM text will allow NGSO system operators wishing to implement DC-MSS-IMT and their MNO partners more operational discretion.

Action
Assess whether proposed definitions:

• Accurately reflect your system
• Implicitly favor or disadvantage certain architectures
• Lock in assumptions that distort future deployments

Support contributions that anchor definitions in technically accurate, operationally realistic descriptions which are aligned with your system architecture and operations.

3. Prepare Band-by-Band Arguments Early

Sharing feasibility under AI 1.13 will vary significantly by band. April meetings will begin sorting:

• Feasible vs infeasible bands
• Candidate regulatory approaches
• Modeling assumptions for compatibility
• Cross-border coordination expectations

Action
For each band of interest, prepare contributions addressing:

• Incumbent usage
• Propagation characteristics
• Link-budget sensitivity
• Sharing constraints
• Realistic deployment scenarios

Early inclusion greatly increases the likelihood these arguments persist into CPM text. Current contributions mostly show that compatibility can be achieved, with cross-border compatibility through the application of mitigation techniques. In this context, beam separation from the border remains a key factor where the distance between beam center and the adjacent country border is being heavily scrutinized.

4. Address Cross-Border Interference Head-On

Administrations are increasingly concerned about:

• Spillover from satellite beams
• Roaming terminals near borders
• Aggregate effects in dense deployments

Avoiding this topic will not make it disappear.

Action

• Propose realistic cross-border modeling assumptions
• Explain technical limits of control mechanisms
• Highlight mitigation techniques already in use or planned

Developing reasonable border beam back-off distances which achieve incumbent service protection will be a key negotiation point in April 2026.

5. Manage WP 4C–WP 5D Interface Risks

The interface between WP 4C and WP 5D is becoming more strained, particularly around IMT assumptions and protection criteria.

Action

• Monitor WP 5D positions closely
• Anticipate where IMT assumptions may harden
• Prepare liaison-aware contributions that bridge technical language between groups

In particular, the issue of aggregation factor (“Beta”) has seen several proposals in both WP 4C and WP 5D with wildly varying ranges and should be aligned to a realistic aggregation while not unduly constraining the DC-MSS-IMT with scenarios that have a low probability of occurring in reality.

6. Coordinate Positions for Hybrid and Multi-Service Systems

Systems combining MSS for NGSO and GSO or terrestrial components face elevated scrutiny.

Action

• Align internal technical narratives across services
• Ensure consistent parameters across contributions
• Clarify operational boundaries to avoid mischaracterization

Ensuring that solutions which leverage hybrid or multi-service systems are properly reflected in sharing studies. This would be essential to show compatibility for systems which might not be able to share if they were not integrated due to high-level, low probability interference.

7. Ensure Visibility in CPM Development

By May 2026, CPM text directions will begin to narrow.

Action
Confirm your positions appear in:

• Working documents
• Study summaries
• Annexes
• Liaison statements

If an idea is absent by April, it may not survive into CPM text. Building strong consensus with reliable partners with similar interests in developing this allocation framework will also yield a pivotal role in this consensus-based regulatory process. As such, the identification and alignment of positions with these partners will play an outsized role in obtaining favourable outcomes in this arena.