Priority Go-Back-N ARQ schemes

The go-back-N scheme is one of the error control methods in the satellite link. Various improvements have been made on this scheme, and the resulting throughput characteristics and packet delay characteristics have been described. However, in those methods, the priority of the class of the packet to be transmitted is not considered. This paper discusses the go-back-N scheme where priority rules are useful when several packets with different priority classes are to be transmitted on the satellite link are introduced. Two priority rules are introduced: nonpreemptive priority queueing and preemptive priority queueing. The go-back-N ARQ scheme with those priority rules can easily be realized by adding the packet sort function to the transmitter buffer in the conventional basic go-back-N ARQ scheme. The traffic analysis is made of the go-back-N ARQ scheme with those two priority rules for an arbitrary number of priority classes, and the packet delay expression is derived for each class. Then by numerical calculation examples, the average packet transmission delay characteristics in the two methods are examined.