Systems and methods for retransmitting unsuccessfully transmitted data across a communication link. The retransmission mechanism may be applied to point to multipoint networks including wireless networks. Each packet is encapsulated in an ARQ frame and assigned a sequence number for the purpose of coordinating acknowledgments and retransmissions. Information as to which packets require retransmission is communicated in the form of a bitmap where each bit indicates an acknowledgment status for a given packet. Any missing packets in the received sequence are assumed to require retransmission.