Figure 4-3: Baseband versus broadband Transmission, Continued Broadband transmission L Modulated Signa Radio channel Source Radio Tuner The radio tuner modulates the signal to a higher frequency The transceiver then sends the signal in a radio channel Expensive but needed for radio-based networks Not used in Ethernet, but is used in wireless LANs(discussed in Chapter 5) 4-84-8 Figure 4-3: Baseband Versus Broadband Transmission, Continued Broadband Transmission Source Radio Tuner Modulated Signal Radio Channel The radio tuner modulates the signal to a higher frequency. The transceiver then sends the signal in a radio channel. Expensive but needed for radio-based networks. Not used in Ethernet, but is used in wireless LANs (discussed in Chapter 5)