PMP320 Map Symbol

By chance can some give me an example on why one would change the map symbol from 5 to 7?


The Map Symbol is part of the physical layer which is a pointer to the data burst. The DL MAP and UL MAP messaging handles resource management such as subchannel allocation and burst start times. The data burst comprises the Preamble, Compressed DL Map, Frame Control Header, Compressed UL Map, and the Broadcast Message, such as the Downlink Channel Descriptor. Map Symbol 5 is used as the normal processing case to maximize the downlink sector throughput. Map Symbol 7 is used when the capacity of the number of CSMs supported by Map Symbol 5 has been reached. Using Map Symbol 7 causes about 10 percent reduction in the data resources for the DL sector throughput. Map Symbol 7 can be used when the operator has to configure a large number of CSMs in a given sector with multiple data delivery types provisioned per CSM.