That is, if the sender receives three duplicate acknowledgements, it retransmits the last unacknowledged packet. In telecommunications, a repeater is an electronic device that receives a signal and retransmits it. MTP2 provides flow control, error detection and sequence checking, and retransmits unacknowledged messages. The sender individually retransmits frames that have timed out. Using the prior round-trip time estimate, TCP computes a timeout and retransmits a segment. In a variety of circumstances the sender automatically retransmits the data using the retained copy. KGVL also retransmits its signal on 105.9 FM K290AP, which is licensed to Commerce. WSHS (91.7) retransmits the WHID signal during non-school hours in the Sheboygan area. The relay agent then retransmits the response on the local network. Both facilities are owned by WUNC, which WBUX now retransmits. The channel retransmits programmes of RU.TV from Russia.