Impact of concurrent transmissions on downstream throughput in multihop cellular networks

In this paper, we investigate the impacts of transmission concurrency on the throughput of the downstream channel in multihop cellular networks. In particular, this paper focuses on the tradeoff between the improvement of resource reuse and the increase in radio interference. We evaluate and compare the throughput for various concurrency types of multihop relaying. We also propose a hybrid control strategy, in which we advocate the use of both, the concurrent and the nonconcurrent transmissions. Our results show that the throughput can be increased by allowing transmission concurrency, but the concurrency does not always result in higher throughput, relative to the nonconcurrency case, because of the interference between concurrently transmitting links. In the random topology with shadowing, depending on the particular circumstances, either the concurrent or the nonconcurrent case can be the optimal transmission strategy. Thus, in order to achieve a significant improvement, a hybrid scheme should be employed. Additionally, if concurrency is applied, it should be used among the different downstream paths, rather than between the hops on the same downstream path.