5G Access Slices with Native TCP
The 5G system integrates a variety of disruptive innovations in wireless access: new air interfaces, split link architectures that separate base-band processing and radio heads, virtualization of functions in general-purpose processors, and flexible chaining of virtualized functions in network slices tailored to the specific needs of diverse services. Besides new use cases and market verticals, 5G should open the mobile broadband network to throughput-intensive interactive (TII) applications, which present the most challenging combination of requirements on throughput (very high) and queuing delay (very low). TII applications rely on TCP for end-to-end transport, but TCP congestion control is not ready to meet their requirements in 5G. It suffers already from the bandwidth variations of LTE and Wi-Fi links, which 5G links will likely exacerbate. Many years of research on TCP optimization have produced consensus on the benefits of bringing the data source in close proximity of the wireless link, but not a conclusive solution for flawless performance. Leveraging the flexibility of the mobile edge cloud we rethink congestion control over the wireless link and conceive a native TCP for 5G where flow control alone is sufficient to lock the transmission rate of the data source to the available bandwidth. Network slicing makes our solution scalable: the native TCP function only needs to be chained in premium access slices for TII applications.