A novel software-defined networking approach for vertical handoff in heterogeneous wireless networks

We propose a novel vertical handoff scheme with the support of the software-defined networking technique for heterogeneous wireless networks. The proposed scheme solves two important issues in vertical handoff: network selection and handoff timing. In this paper, the network selection is formulated as a 0-1 integer programming problem, which maximizes the sum of channel capacities that handoff users can obtain from their new access points. After the network selection process is finished, a user will wait for a time period. Only if the new access point is consistently more appropriate than the current access point during this time period, will the user transfer its inter-network connection to the new access point. Our proposed scheme ensures that a user will transfer to the most appropriate access point at the most appropriate time. Comprehensive simulation has been conducted. It is shown that the proposed scheme reduces the number of vertical handoffs, maximizes the total throughput, and user served ratio significantly. Copyright (c) 2016 John Wiley & Sons, Ltd.