  This paper focuses on the design of provably efficient online link scheduling
algorithms for multi-hop wireless networks. We consider single-hop traffic and
the one-hop interference model. The objective is twofold: 1) maximizing the
throughput when the flow sources continuously inject packets into the network,
and 2) minimizing the evacuation time when there are no future packet arrivals.
The prior work mostly employs the link-based approach, which leads to
throughput-efficient algorithms but often does not guarantee satisfactory
evacuation time performance. In this paper, we propose a novel Node-based
Service-Balanced (NSB) online scheduling algorithm. NSB aims to give scheduling
opportunities to heavily congested nodes in a balanced manner, by maximizing
the total weight of the scheduled nodes in each scheduling cycle, where the
weight of a node is determined by its workload and whether the node was
scheduled in the previous scheduling cycle(s). We rigorously prove that NSB
guarantees to achieve an efficiency ratio no worse (or no smaller) than 2/3 for
the throughput and an approximation ratio no worse (or no greater) than 3/2 for
the evacuation time. It is remarkable that NSB is both throughput-optimal and
evacuation-time-optimal if the underlying network graph is bipartite. Further,
we develop a lower-complexity NSB algorithm, called LC-NSB, which provides the
same performance guarantees as NSB. Finally, we conduct numerical experiments
to elucidate our theoretical results.
