Replying to: How is the spectrum split up? by wb
Re: How is the spectrum split up?
The wireless licenses are divided into blocks and they have geographical boundaries. For each market in the US, there are six license blocks in the 1900Mhz (PCS) band and two blocks in the 800Mhz (Cellular) band.
The cellular band is at 824-849Mhz and 869-894Mhz. One frequency group is used to transmit and the other to receive. These blocks are each split in two equal parts (12.5Mhz wide) and that's how you get the 2 blocks that compose the cellular band. In these two blocks you can have 2 different wireless carriers. They are called the A and B blocks. So one carrier uses 12.5Mhz from one group to transmit and uses 12.5Mhz from the other group to receive.
The PCS band goes from 1850-1910Mhz and 1930-1990Mhz. As with the cellular band, one frequency group is to transmit and the other to receive. However, these frequency groups are divided into 6 blocks, one for each carrier. The blocks are A, B, C, D, E, and F. A, B and C are 30Mhz wide each (15Mhz to transmit and 15Mhz to receive). The D, E, and F blocks are 10Mhz wide (5Mhz to transmit and 5Mhz to receive).
The FCC had laid out rules to assign these license blocks. Of the two cellular (800Mhz) blocks, the B block was to be assigned to the local phone company and the A block to a competitor. Of the 6 PCS blocks, the A and B were supposed to be acquired by the major national carriers and the C be left for any smaller carrier. The D and E were to be assigned to large carriers who needed extra capacity and the F block for a smaller carrier that needed extra capacity. In this world today, you'll find that it doesn't work out quite that way since carriers have been merging and buying licenses from one another.
Nextel uses the SMR band which are a group of 25Khz channels between 806-821Mhz and 851-866Mhz. Again, one group to transmit, the other to receive. They also own some channels up in the 900Mhz band somewhere.
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