to the available spectral resources and the restriction due to the support of the legacy system. If the two adjacent component carriers are used to deploy a mixed-mode system, the overlapped sub-carriers may not be aligned. If the MS cannot support carrier aggregation due to hardware restriction under a sub-carrier misalignment configuration, it is required to inform the 11.2 Sub-carrier alignment and use of guard sub-carriers Table 11-1 Multi-Carrier Configurations and Component Carrier Offset Values [2] Index Multi-Carrier Configuration (MHz) Frequency Offset (kHz) (8.75) (10, 10) (0, -3.1248) Other values are reserved serving BS about the component carriers that it can simultaneously process through an AAI_MC-REQ MAC control message. During network entry, the serving BS will notify the MS of the frequency offset to be applied to each component carrier for the purpose of sub-carrier alignment through the AAI_MC-ADV message. According to the multi-carrier configuration index and the physical carrier index of the current component carrier that is broadcast by the BS, the MS can derive the center frequency of the available component carriers by the associated frequency offset Afoffset using Table 11-1. The frequency offset Afoffset specified in Table 11-1 is calculated as follows: |fc2-fc1|mod Af Af2/fc2-f1modAf (11-1) where fc2 is the center frequency of the component carrier before applying frequency offset Afoffset and fc1 denotes the center frequency of the reference component carrier in each carrier group. Note that the frequency offset is calculated relative to the center frequency of the reference component carrier. The center frequency of the reference component carrier in each carrier group is always located on the channel raster grid. The center frequency of the offset component carrier is given as: fa= fc2 fc2<fc1 fc1 (11-2) Note that the absolute value of the frequency offset foffset is less than the OFDMA sub-carrier spacing Af. Table 11-1 is used to identify the permissible configurations for a group