There was this frenetic period of dual calling...
We categorize these calls into (1) new calls including dual access calls blocked in the WLAN, (2) horizontal handoff, and (3) vertical handoff calls from the WLAN to the cellular networks.
Let λ w c c be the arrival rate of the dual access call in the cell, which includes new calls, horizontal calls, and vertical handoff calls from the cell to join the WLAN.
Dual Video Call: While video-chatting with someone, you can show them both your face and the view from your rear camera while you chat.
In some primate species, close calls appear to have a dual function: calls addressed at a broad class of targets serve to maintain group cohesion, whereas the same calls directed at a specific target serve to regulate subsequent social interactions.
On the other hand, in the cellular network, dual access calls in the cellular-only area, cellular-only calls, horizontal handoff calls, and upward vertical handoff calls all compete for the same resource in the cellular network.
Dual access calls in the cellular-only area, cellular-only calls, and dual access calls blocked in the WLAN are eventually blocked if they are blocked in the cellular networks.
Hence, we refer to the calls from dual-interfaced MSs as dual access calls.
From Figure 8, it can be seen that the blocking probability of the WLAN-only calls is unfairly higher than that of dual access calls.
Moreover, with the increase of the arrival rates of the dual access calls, the blocking probability of the WLAN-only callsignificantlyly increases.
