[SC4] Communications direction

Outgoing relations

• [SC4] Communications direction is subconcept of [SC] Satellite Communication

Incoming relations

• [SC4-1] Up-link is subconcept of [SC4] Communications direction
• [SC4-2] Down-link is subconcept of [SC4] Communications direction
• [SC4-3] Cross-link is subconcept of [SC4] Communications direction