Integration of Multi-path Optimized Link State Protocol with Max-weight Scheduling

Backpressure-based Max-Weight Scheduling (MWS) algorithms are theoretically proven to be optimal with respect to wireless multi-hop networks throughput maximization. On the other hand, Optimized Link State Protocol (OLSR) is the leading proactive protocol for wireless ad-hoc networks. However, in its standard implementation, OLSR is a single-path protocol, whereas it is widely known that wireless network performance can be improved by allowing multiple routes from a given source to a given destination. Moreover, MWS algorithms provide higher throughput when used in multi-path routing scenarios. We designed a light-weight multi-path modification of the OLSR algorithm that is dedicated to work in cooperation with backpressure-based scheduling. The proposed routing algorithm preserves all features of proactive protocols. We tested our joint routing and scheduling scheme in a wireless network serving TCP flows. Since performance of multi-path TCP can suffer from packet reordering, we implemented a delayed reordering algorithm. In order to keep 802.11 MAC unmodified, we deployed a mechanism for the estimation of number of packets in the MAC sub-layer.