Decoupling Uplink-Downlink Associations in 5G Cellular
In existing 3G and 4G cellular networks, mobile devices associate with the same base station(BS) in the downlink(DL) and uplink(UL) directions. A key reason for this is that the overhead and control channels in each direction help inform communication in the other direction. For example, in LTE, the resource block assignments for both the DL and UL are given in DL control messages.
