On the Split-TCP Performance over Real 4G LTE and 3G Wireless Networks

The global mobile traffic is growing exponentially, and currently more than 90 percent of the internet traffic depends on TCP for reliable transmission. However, it is well known that TCP performs quite poorly over unreliable wireless networks, while its dynamic TCP flow control is sensitive to congestion events and tends to underutilize the available network capacity. Despite these known limitations, the industry believes that significant network performance enhancement can be achieved through TCP optimization, and in particular through solutions centered on Split-TCP. In this article we share a sample of TCP throughput performance measurements after implementing Split-TCP on commercial 4G LTE and 3G networks. Experimental results show that Split-TCP provides average TCP throughput gains on the order of 60 percent over a 4G LTE network and on the order of 5 percent over a 3G network. Furthermore, TCP throughput gains superior to 200 percent were measured for individual TCP connections over the 4G LTE network. We expect such throughput gains to be even greater when advanced radio technologies, such as 5G, are deployed. For these reasons, Split-TCP has the potential to be widely deployed in both current and next generation networks.