A Queueing Analysis of Two ARQ Protocols

In every data communication system, a procedure must be provided to allow for the retransmission of data when errors are detected. The receiving node is required to make a (positive/negative) acknowledgment (ACK/NACK) to the sending node. Until an acknowledgment is received, a "copy" of the message must be retained at the sending node. If an ACK is received, the space assigned to the "copy" is released. If either a NACK or no acknowledgment is received in a suitable interval of time, retransmission is required. Different protocols specifying how the nodes recover from a transmission error can be defined. In this paper, we present a queueing analysis of the two ARQ (automatic repeat request) protocols-block and select ARQ-for a (slotted) concentrator network node.