Maintaining Data Freshness in Multi-channel Multi-hop Wireless Networks

Age of Information (AoI) has emerged as a new metric to quantify the freshness of data and has attracted extensive interests recently. In this paper, we investigate the first work of optimizing average AoI for data collection in a sink-based wireless networks. The problem of optimizing the average AoI of the entire network by allocating channels in an OFDM-based network is formulated. Secondly, the average AoI under the line topology is theoretically analyzed, which takes channel allocation, multi-hop routing, and queuing models into account, and the corresponding channel allocation scheduling algorithm under such a topology is studied. Then, the AoI aware channel allocation algorithm with a theoretical bound for the network with tree topology is proposed. Finally, the numerical results show that the proposed algorithm can achieve high performance in terms of AoI.