d/or transmit in uplink while in those cells. It is also expected that in some cases, that is, not in hidden-node cases where the two cells with the same PCI are hidden from each other but are heard by the UEs, the network can detect PCI collision by listening to carriers and avoid the collision by changing the PCI values of their cells. PCI confusion and PCI collision can be avoided completely if Operation in Unlicensed and Shared Spectrum 905 operators coordinate the PCI values for their LAA cells. Otherwise, the probability of occur- rence would be scenario dependent. In LWA, the UE mobility is transparent to the eNB while in a Wi-Fi mobility set, that is, a group of Wi-Fi access points that are controlled by one WT logical entity. As long as the UE moves between APs of the same mobility set, it does not need to inform the eNB about its movement. When the UE leaves the mobility set, the eNB may change the access point based on the Wi-Fi measurements, thus it informs the UE of its decision. Coexistence with other technologies is very important for LAA, and therefore accessing and using already congested frequencies/channels that are used by Wi-Fi access points and cli- ents should be avoided. Because efficient radio resource management is critical for the overall performance of LAA scheme, LTE defines signal quality criteria such as reference signal received power [RSRP (dBm)] and reference signal received quality [RSRQ (dB)] metrics to effectively quantify the [shared] channel conditions. The RSSI serves as the key performance indicator for interference on a given carrier. To measure RSSI, the DRS needs to be present. However, because DRS is subject to LBT, any RSSI measurement report of an LAA-capable UE needs to include a time stamp indicating when the measurements were conducted. Therefore, higher layers configure an RSSI measurement time configuration (RMTC) with a measurement period [40, 80, 160, 320, or 640 ms], a subframe offset [0,...,639] and a measurement duration [1, 14, 28, 42, or 70 OFDM symbols].