A method for providing communication in a wireless network comprising one or more simultaneously operating pico networks includes dividing UWB spectrum into a plurality of frequency bands. These bands are formed into band groups. At least one band group is assigned to each one of the pico networks. At least pne time frequency code is assigned to symbols associated with each one of the pico networks on a transmission-by-transmission basis. A system for channelization of the spectrum includes a frequency-synthesized oscillator and a time frequency code generator configured to assign time-frequency codes to successive transmissions of a pico network such that the successive transmissions are transmitted in all frequency bands of a band group assigned to the pico network.