BW REQ Header requests refer to the mechanism that SSs use to indicate to the BS that they need uplink BW allocation. Because the uplink burst profile can change dynamically, all requests for BW shall be made in terms of the number of bytes needed to carry the MAC Header and payload but not the PHY overhead. BW REQ message may be transmitted during any uplink allocation, except during any initial ranging interval. BW is always requested on a CID basis and BW is allocated on an SS basis.