Adaptive load balancing for 60GHz wireless LAN with rof-based distributed antennas

60 GHz millimeter-wave wireless LAN (WLAN) has been attracting much interest of industry because of its very high capacity. However, it needs many antennas to cover a wide space on account of the strong atmospheric extinction and directivity of 60 GHz RF signal. If an access point (AP) is deployed for each of many antennas in a 60 GHz WLAN, the total cost of APs becomes very high. For reducing the cost of many APs in such a network with many antennas, in this paper, we focus on using radio over fiber (RoF)-based distributed antenna technology that connects multiple remote antennas to a centralized AP. If the density of active users in the WLAN is not geographically uniform and changes with time, using a fixed relation of connection between APs and antennas is not efficient because traffic may concentrate at a portion of APs. In this paper, we propose a new architecture of 60 GHz WLAN with RoF-based densely distributed antennas. It adaptively changes the relation of connection between APs and antennas to balance the load on APs. In addition, we propose algorithms for assigning an AP/channel to each antenna so that the load on APs can be balanced and the frequency of handovers can be reduced. Simulation results show that the proposed algorithms achieve sufficiently high fairness of user throughput and low likeliness of handovers compared with naive AP/channel assignment algorithms.