Patent ID: 9319331
Filing Date: 2016-04-19
CPC Classification: H04L,H04W

Claim Text:
1. A data transmission rate control method in upward vertical handover by a TCP (transmission control protocol) sender in an overlay network environment, comprising steps of: checking whether or not a retransmission timeout event occurs while communicating with a TCP receiver through a dual interface; storing a sequence number of a packet having the largest sequence number among transmitting packets, and after that, performing congestion control if the retransmission timeout event occurs; checking whether or not an ACK (acknowledge) signal corresponding to a sequence number which is equal to or smaller than the stored sequence number is received after performing the congestion control; determining to execute upward vertical handover if the ACK signal sequence number is received; and calculating and setting a congestion window size of a new network when the TCP sender determines to execute the upward vertical handover, wherein the congestion window size of the new network is set to a product of a maximum congestion window size of an old network and a weighting factor; the weighting factor is set by using a data capacity of a link in the old network and a data capacity of a link in the new network; and the data capacity depends on a BDP (Bandwidth Delay Product) of the link and a buffer size of a relay device.