Question: In a UTRAN Iub interface (NBAP), for the Radio Link Reconfiguration procedure in FDD mode, how is the Capacity Credit updated when changing the spreading factor?
Option 1: The new consumption cost for the spreading factor is credited to the Capacity Credit.
Option 2: The difference between the new and old spreading factor consumption costs is debited from (or credited to, if negative) the Capacity Credit.
Option 3: The entire Capacity Credit is reset based on the new spreading factor's consumption cost.
Option 4: No update to the Capacity Credit occurs for spreading factor changes in Reconfiguration.
Explanation: During a Radio Link Reconfiguration in FDD mode, the capacity consumption law dictates that the difference in costs between the new and old spreading factors should be applied to the Capacity Credit. This means if the new configuration is more resource-intensive, the credit is debited; if less intensive, it's credited (when the difference is negative). This approach ensures accurate tracking of resource utilization within the Node B.