The coexistence of visible light communication (VLC) and WiFi elevates indoor wireless communications beyond 4G, by utilizing VLC for high-rate transmission and ensuring reliable mobile connectivity through WiFi. Nevertheless, the high susceptibility of VLC-line-of-sight (VLC-LoS) channel to blocking can result in excessive number of handovers between VLC and WiFi networks leading to huge signaling cost and degradation in overall system performance. Therefore, an efficient inter-system handover scheme is required for a successful integration of the two access technologies. To this end, a channel adaptive dwell vertical handover (CAD-VHO) scheme is presented, in this article, as an improvement on static D-VHO scheme. The width of the dwell timer employed in our scheme is altered based on the rate of blocking and recovery of VLC-LoS channel. As a result, the proposed CAD-VHO scheme is adaptive to the rate and extent of obstruction of VLC-LoS link due to user mobility and surrounding objects. Simulation scenario was set up as a dynamic network environment in an indoor setting with restless and stationary mobile terminals and surrounding mobile object. Based on the simulation results obtained, the CAD-VHO scheme can reduce the number of VHOs by as much as 80% whiles achieving a higher average data rate in most cases. Consequently, the proposed CAD-VHO scheme is highly efficient in minimizing VHO signaling cost and enabling a superior broadband service.

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Visible light communication (VLC), not only provides indoor illumination, but also offers broadband connection. It has the benefits of huge bandwidth, high security, low cost, and health safety. However, duplex communication, user mobility, and seamless coverage are becoming challenging tasks in VLC networks. A VLC heterogeneous network (VLC-HetNet) that combines VLC and existing radio networks, in which a good vertical handover (VHO) scheme is critical to guarantee continuous transmission, has been proposed to solve these problems. In this paper, we propose a new VHO scheme to maximize the quality of experience (QoE) of a user. When a user makes a handover between VLC and the RF network, the influence on the user's QoE may be positive (defined as the QoE profit) or negative (the reduced QoE value is defined as the handover cost). The handover decision is made in order to enhance the QoE and reduce the handover cost of the user, by formulating the problem as a Markov decision process (MDP). The simulation results show that the proposed VHO scheme is adaptive to user movement and achieves a relatively high average QoE, low handover failure probability, and few handover times.

Customer Relations Management (CRM) is an essential marketing approach which telecommunication companies use to interact with current and prospective customers. In recent years, researchers and practitioners have investigated customer churn prediction (CCP) as a CRM approach to differentiate churn from non-churn customers. CCP helps businesses to design better retention measures to retain and attract customers. However, a review of the telecommunication sector revealed little to no research works on appetency (i.e. customers likely to purchase new product) and up-selling (i.e. customers likely to buy upgrades) customers. In this paper, a novel up-selling and appetency prediction scheme is presented based on support vector machine (SVM) algorithm using linear and polynomial kernel functions. This study also investigated how using different sample sizes (i.e. training to test sets) impacted the classification performance. Our findings demonstrated that the polynomial kernel function obtained the highest accuracy and the least minimum error in the first three sample sizes (i.e. 80:20, 77:23, 75:25) %. The proposed model is effective in predicting appetency and up-sell customers from a publicly available dataset.

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