Virtual network embedding in hybrid data center networks with over-subscription

In this paper, we study virtual network embedding problem in hybrid data center networks (HDCN), where each top-on-rack switch is equipped with a directional antenna. Those antennas can dynamically construct a wireless network in the on-demand way, regarding to the current traffic flow. Hence, HDCN has a great potential to alleviate the over- subscription problem suffered by traditional data centers. However, how to embed virtual networks in HDCN while fully utilizing the benefits introduced by the wireless links remains as an open topic. To this end, we jointly consider virtual network embedding and the antenna scheduling. In particular, in our model, to some extend, over-subscription in links is acceptable. We first abstract the studied problem into an integer programming problem. Then we provide a heuristic algorithm to find sub- optimal solutions to the problem. Extensive simulation based evaluation has shown the great efficiency of the proposed algorithm, which makes it a promising solution for VNE in HDCN.