The main intent of 802.11j is to add channels in the radio-frequency (RF) band of 4.9 GHz to 5.0 GHz. In addition, certain changes are proposed that will satisfy Japanese legal requirements concerning wireless transmitter output power, operational modes, channel arrangements, and spurious emission levels. (Spurious emissions are transmitted signals at frequencies other than those necessary for the intended communications. All wireless transmitters produce some such signals, but laws in many jurisdictions limit how strong they can be.)
Like 802.11a networks, WLANs using 802.11j will provide for speeds of up to 54 Mbps, and will employ orthogonal frequency division multiplexing (OFDM). The specification will define how Japanese 802.11 family WLANs and other wireless systems, particularly HiperLAN2 networks, can operate in geographic proximity without mutual interference.