Flexible bandwidth in LTE 511 channel bandwidths, but only if the same two channel bandwidths are used for defining all three parameters ACIR, ACLR, and ACS used in the equation. The ACLR limits for LTE are derived based on extensive coexistence analysis [133] between LTE and potential LTE or other systems on adjacent carriers. Requirements on ACLR and operating band unwanted emissions both cover the OOB domain, but the operating band unwanted emission limits are set slightly more relaxed compared to the ACLR, since they are defined in a much narrower measurement bandwidth of 100 kHz. This allows for some variations in the unwanted emissions due to intermodulation products from varying power allo- cation between resource blocks within the channel. For an LTE BS, there are ACLR requirements both for an adjacent channel with a UTRA receiver and with an LTE receiver of the same channel bandwidth. 20.4.3.3 Spurious emissions The limits for spurious emissions are taken from international recommendations [134], but are only defined in the region outside the frequency range of operat-