DL, the receiver selec- tivity of the FDD terminal will have great impact on ACIR. Technical specifications in Ref. [17] recommend for both UP/DL are 33 dB for adjacent carriers with 5 MHz sepa- ration, and 43 dB for the 2nd adjacent carrier with 10 MHz separation. 8.4.1 ACIR Impacts in a Multi-Operator Environment Non-colocated BSs of two different operators can originate near-far effects; in particu- lar, when a MS closer to another operator's BS stays far from its own BS. Despite the usage of different carriers, total interfering signal suppression will not be possible. Thus, the BS receiving the interference cannot control the output power of the interfer- ing MS because it belongs to another operator. As a result there exists a need for Adjacent 7 Channel Protection (ACP), which is the ratio of the transmitted power and the power measured after a receiver filter in the adjacent channel. The ACP results from the combination of out-of-band emission and receiver se- lectivity, where these two quantities need balance, to prevent over-specification. Carrier spacing [MHz] Figure 8.7 ACP as a function of carrier spacing [18]. Adjacent channel may refer to the channel closest to the assigned channel, and the 2nd adjacent channel. Resource and Network Management In [18] measurements have been made on a commercial PA, and a model has been de- rived. Integrating the power spectrum over a receiver filter gives the ACP. For different offsets of the filter, the ACP as a function of carrier spacing was obtained. Assuming a receiver filter matched to the transmitter pulse, Figure 8.7 illustrates the ACP, where the curve gets steep just below 5 MHz, and where it becomes flatter thereafter. This implies that the adjacent channel interference (ACI) increases when the carrier spacing falls below 5 MHz and that the ACI marginally decreases for carrier spacing larger than 5 It also implies that capacity loss depends on ACP, cell radius, and relative location of the BSs. Thus, co-location of BSs will ease the near-far problem, and