Narrowband/Wideband VHF frequencies, and Digital/Analog Radios

1. Narrowband/Wideband VHF frequencies, and Digital/Analog Radios Current and future Impacts to TNC’s fire programs Sam Lindblom, TNC Fire Initiative

2. The Issue • Increased radio frequency usage (more users) • Limited bandwidth available on the VHF spectrum • Much more conflict between users • Getting “walked” on… • Potential increased regulation by the FCC

3. The Solution • Convert to Narrow Band radio frequencies and equipment • More on equipment later.... • First, let’s look at the technology and the issue in more detail

4. What is Narrow Band? • Narrow band frequencies use ½ the bandwidth of wide-band • Normal wideband spacing is 25 Khz • Narrowband spacing is 12.5 Khz • For example, the TNCFIRE frequency is 151.625. Normally, the next frequency up would be 151.650. In narrow band, the next frequency is 151.6375 • Narrow banding essentially doubles the number of available frequencies in the VHF “Business” spectrum (148-174 Mhz)

5. Sounds Great, right? • PROS of Narrowband • Less traffic on currently “shared” frequencies • Reduces the need to use tone/code guards • CONS of Narrowband • Operating wideband in a narrowband environment can cause problems • Requires specific radio equipment • Could be costly (more on that in a minute) • It’s likely to be a long time before the general public will be forced to use narrowband and all wideband radios are obsolete

7. Why would I want to convert to Narrowband radios? • If you regularly burn with federal partners, you will likely have to convert sooner than most • If you experience significant radio traffic where you work, narrowband could help (but only if everyone converts) • If you intend to participate on large wildland fire incidents of any kind

8. The FCC and Narrowbanding • The Federal Communications Commission mandated that all federal agencies convert by 2005. This mandate was lifted until further notice… • FCC does not currently have a time schedule in place to change the general licenses that we have now.

9. Equipment • Some existing radios that we have can be programmed to narrowband (most likely so if they were purchased in the last few years) • Bendix King EPH and GPH radios are OK • At this point, you should avoid radios that will not work on narrowband frequencies • Most radios require programming each individual frequency/channel as narrow or wide • Narrowband radios alone don’t significantly increase costs

10. What about Digital? • The problem with Analog and Narrowband frequencies • Analog radios have a harder time sending and receiving narrowband frequencies, reducing their effective radiated power. • Certain analog radios can lose up to ½ of their transmit distance.

11. What about Digital? • Digital radios overcome this problem with a better capacity to process narrowband frequencies • They don’t typically suffer from the same loss in effective radiated power as analog. • Some digital radios using narrowband can theoretically transmit further than their analog counterparts using wideband • Digital radios are expensive • GPH Bendix King (Analog) is ~$500 • DPH Bendix King (Digital) is ~$1200

12. Recommendations • Continue to purchase analog radios unless you have a big budget • Do not purchase radios that cannot process narrowband frequencies • Know how to program your radios • Know if you are working in a narrowband environment • Ask all of your local cooperators • Establish a communications plan if you contribute to local emergency response.