[Retracted] An XGB-Based Reliable Transmission Method in the mMTC Scenarios

Algorithm 1

UDP-XGB algorithm.

	Input: The four features with the highest correlation, RSRQ, RSRP, SINR, and RSSI, are taken as input . is the target output . is the predicted by the model. is a regression tree, a function of mapped to . Set the target function to . Set the number of trees for model integration to  = 150. represents the deviation between and real RTT. is a smooth factor for , which is 0.25.
	Output: Model is the mapping relationship between features and RTT, which integrated all of . Use the model to predict RTT. is obtained by and .
(1)	Model is empty
(2)	for t = 1 todo
(3)	Divide by to find all the regression trees
(4)	Choose a tree to satisfy
(5)	Model add
(6)	end for
(7)	while send data do
(8)	if Retransmit then
(9)
(10)	else
(11)	= Model Predict(X)
(12)
(13)	end if
(14)
(15)	if Send SUCCESS then
(16)
(17)	end if
(18)	end while