There is no network that needs to be joined. The eligibility criteria means the proposal needs to align with some SNS JU Stream B phase 1 or phase 2 topic, e.g. System Architecture (HORIZON-JU-SNS-2022-STREAM-B-01-01), Wireless Communication Technologies and Signal Processing (HORIZON-JU-SNS-2022-STREAM- B-01-02), Communication Infrastructure Technologies and Devices (HORIZON-JU-SNS-2022-STREAM-B-01- 03), Secure Service development and Smart Security (HORIZON-JU-SNS-2022-STREAM-B-01-04), 6G Holistic System (HORIZON-JU-SNS-2022-STREAM-B-01-05), etc. The proposal does need to come out of any funded project within the Stream B portfolio, but any novel proposal on a thematic is possible.