The use of unlicensed bands is one of the most promising features envisaged to increase capacity in cellular networks. However, this poses multiple challenges associated to the operation of LTE based standards with coexisting networks, such as WiFi. Previous coexistence analyses have been focused on the user-plane data-related transmissions and mainly based on abstract models. Meanwhile, the effects of the in-band signaling defined by the standards have been mainly disregarded, particularly for ultra-dense scenarios. This paper performs an assessment of how the different in-band signaling mechanisms influence the performance of the coexisting technologies. Based on this analyzed, an optimized signaling solution is envisaged to additionally enhance the service provision in these scenarios.