TCP performance evaluation over backpressure-based routing strategies for wireless mesh backhaul in LTE networks

Wireless redundant networks are expected to play a fundamental role to backhaul dense LTE networks. In these scenarios, backpressure-based routing strategies such as BP-MR can exploit the network redundancy. In this paper, we perform an exhaustive performance evaluation of different TCP variants over an LTE access network, backhauled by various routing protocols (including per-packet and per-flow BP-MR variants and a static alternative, OLSR) over two different wireless topologies: a regular mesh and an irregular ring-tree topology. We compare the performance of different TCP congestion control algorithms based on loss (NewReno, Cubic, Highspeed, Westwood, Hybla, and Scalable) and delay (Vegas) under different workloads. Our extensive analysis with ns-3 on throughput, fairness, scalability and latency reveals that the underlying backhaul routing scheme seems irrelevant for delay-based TCPs, whereas per-flow variant offers the best performance irrespective of any loss-based TCP congestion control, the most used in the current Internet. We show that BP-MR per-flow highly reduces the download finish time, if compared with OLSR and BP-MR per-packet, despite showing higher round-trip-time.