This read-only floating-point object reports the terminal's cumulative Background Blocks Error Rate, tracking errored blocks measured outside of severely errored seconds, since the link last started up. An engineer monitors this as a subtler long-run quality indicator that can reveal a gradual link degradation even when the link hasn't had any outright severe outages. For example, a steadily rising wvlinkBBER over weeks without any corresponding SES events could be an early sign of an antenna slowly drifting out of alignment.