For streaming 4K videos, here are some steps to optimize your network:

1. Check the upload and download speeds of the network
2. Check for any blocks placed by the provider that might restrict streaming
3. Check if the router's range may be too low or outdoor interference is possible
4. Upgrade the router or purchase a specialized router designed for streaming
5. Check the firewall settings, permissions, content filtering, and virtual LANs status
6. Optimize the wireless network for faster throughput by changing the settings