Stochastic Delay Guarantees for Devices with Dual Connectivity

Dual connectivity (DC) is a feature that allows dual-wireless interface devices to concurrently utilize radio resources from two different wireless network technologies. The aggregate data rate achievable using DC is expected to enhance application performance and user experience if the radio resources of contributing wireless networks are efficiently allocated. Moreover, with the current 5G deployment stage, DC is envisioned as a promising solution to address the 5G coverage holes using the existing 4G long-term evolution (LTE) infrastructure. This article presents an approach to provide statistical delay guarantees for delay-sensitive applications running on devices with DC. We propose a stochastic delay-based DC analytical model using the effective bandwidth concept. The model is applied to two case studies, namely, LTE-WiFi connectivity (licensed with nonlicensed) and 5G-LTE connectivity (intergeneration). The proposed model is used as a tool for effective resource allocation by obtaining the optimal uplink traffic share for each network that minimizes the delay violation probability or data transmission cost. Furthermore, using the analytical model, an algorithm for node admission control (NAC) is developed for DC networks. Our simulation results demonstrate that the proposed model and the NAC algorithm can efficiently allocate resources with stochastic delay guarantees for DC networks.