UHF Expansion Questions
GENERAL QUESTIONS & ANSWERS 1. What is it? From April 2008 to April 2010, the ACMA (Australian Communications and Media Authority) reviewed the arrangements for the radio frequency spectrum in the 400 MHz band, which incorporates the UHF CB band. As a result of the review the ACMA decided to restructure the UHF CB band into eighty 12.5 kHz wide channels from the existing forty 25 kHz wide channels. Summary The UHF CB band is being restructured to increase its capacity from 40 channels to 80 channels (75 for voice communications). The existing 40 channels will continue to operate at their current frequencies, but the width of each channel will be reduced from 25kHz (Wideband) width to 12.5kHz (Narrowband) width which will then allow the additional 40 channels. Users will soon see the terms Wideband and Narrowband being used to describe current radios and newer radios. Current radios that operate on 40 UHF‐CB channels are Wideband radios and newer radios that will operate on 75 UHF‐CB channels are Narrowband radios. For further technical details on the distinction between Wideband and Narrowband radios refer to the Technical Q&A section below. 2. Why is this happening? Refer to opening paragraph of Q1. What is it? User traffic on the current 40 channels is congested, particularly in the main centres. The expansion is expected to eliminate congestion in busy areas and provide greater efficiency in band usage with an eye to the future. 3. Who is behind this? The ACMA (Australian Communications and Media Authority) is the Government regulatory body driving this change. It is supported by industry, who have prepared technical standards to meet the changes. 4. When will this happen? The ACMA have set 1st January 2011 as the date from which new 80 channel Narrowband radios can be sold. 40 channel Wideband radios will continue to be used up to 1st January 2016, a 5 year period, at which time the ACMA are considering to revoke the Radio Communications Class License for Wideband UHF‐CB radio use.
5. I’m a radio user ‐ What does this actually mean? It means you can continue to use your current 40 channel Wideband radio and eventually all Wideband radios will be phased out of use. Newer 75 channel Narrowband radios will start to appear in the market from 1st January 2011. For information on the phase out period; refer to Q4. When will this happen? There may be some disruption and confusion for users as this transition period comes about. 6. I’m a radio dealer – What does this mean? You will be able to sell the newer 75 channel Narrowband radios from 1st January 2011. What about all the stock of current radios I have? You may continue to sell Wideband radios up to a certain date which the ACMA is yet to confirm. Since repeaters will take some time to be updated to the new Narrowband format, it is expected that 40 channel Wideband radio will still be in high circulation and even in demand for some time. Narrowband Handheld radios (in any brand) will not be readily available from 1st January 2011, so stock of Handheld radios will also be in demand. 7. What will happen to my current radio? Nothing changes with your current radio. Can I still use my current radio? Yes. You may continue to use your Wideband radio however the ACMA is considering revoking the user license for older radios in 5 years’ time. 1st January 2016. Does this affect my handheld radios? Yes. All radios using the UHF‐CB band are affected. Does this affect my mobile radios? Yes. All radios using the UHF‐CB band are affected. 8. But I’ve just bought a brand new UHF‐CB radio: Can I still use it? Yes. You may continue to use your Wideband radio however the ACMA is considering revoking the user license for older radios in 5 years’ time. 1st January 2016. How do I tell what kind of radio it is? Newer Narrowband radios will have more than 40 channels. i.e. 41 ‐ 80 9. Can my current radios talk with these newer radios? Yes. The newer Narrowband radios are fully able to use the current 40 channels. The position of these channels (within the band) will not change so both Wideband and Narrowband radios can be used to communicate with each other on the first 40 channels. However, only the Narrowband radios can communicate on additional channels 41 – 80. 10. My radios work fine and there is no congestion around my area: Why should I upgrade? i) The expansion offers greater efficiency within the band – more channels to use. ii) Eventually the ACMA is expected to revoke the Radio Communications Class License for Wideband UHF‐CB radio use.
11. Will the newer radios cost more? Newer Narrowband radios may be more complex in design and the cost may vary. 12. What about AM‐CB radio? There is no change to AM‐CB radio. CHANNEL USAGE QUESTIONS & ANSWERS 13. Repeater Channels: Are they affected by the expansion? The current repeater channels (01‐08) and the guidelines for their use remain unchanged. However, 8 additional repeater channels (41‐48) will become available with the channel expansion. 14. Telemetry Channels 22 & 23: What will happen to them? Channels 22 & 23 and the guidelines for their use remain unchanged and unaffected by the expansion. 15. Emergency Channels 05 & 35: What will happen to them? Emergency channels 05 & 35 and the guidelines for their use, remain unchanged. 16. Other Uses ‐ Calling Channel 11 and Road Channel 40: What will happen to them? Channels 11 & 40 and the guidelines for their use remain unchanged.
TECHNICAL QUESTIONS & ANSWERS 17. How is the UHF CB band being restructured? The current UHF CB band ranges from 476.425MHz ‐ 477.400MHz. This range allows for 40 evenly spaced channels that are 25kHz apart. By reducing the channel width from 25kHz to 12.5kHz room is created to fit an extra 12.5kHz width channel in‐between each of the existing channels*. (The upper range will be extended to 477.4125MHz to accommodate the last additional 12.5kHz channel) *NOTE: Telemetry Channels 22 & 23 remain as 25kHz Wideband channels ‐ they are unchanged by the expansion. The 12.5kHz Narrowband channels below, between and above Channels 22 & 23 are designated a guard channels and are not available for use. This makes a total of 75 channels available for voice communications. 18. I have a Wideband radio: What are the performance issues when I talk with a Narrowband radio? When an older wideband radio receives a signal from a new narrowband radio the speech may sound quiet ‐ the wideband radio user simply adjusts their radio volume for best performance.
19. I have a Narrowband radio: What are the performance issues when I talk with a Wideband radio? When a new narrowband radio receives a signal from an older wideband radio the speech may sound loud ‐ however the Uniden’s built‐in AVS (Automatic Volume Stabilizer) circuitry will detect and manage incoming audio to comparable levels. 20. What about adjacent channel interference? Narrowband radios operating on CH41 ‐ CH80 may encounter interference (noise burst or breaking squelch) from a nearby wideband radios transmitting on high power on an adjacent channel (frequency). NOTE: The above situations are not a fault of the radio but a symptom of mixed wideband and narrowband radios in current use. It is expected that as older wideband radios are phased out this issue will be eliminated.
Carrier frequency
Channel
Channel
MHz
01*
476.4250 41*
476.4375
42*
476.4625
43*
476.4875
44*
476.5125
02*
476.4500
03*
476.4750
04*
476.5000
05*
476.5250 45*
06* 46*
476.5625
47*
476.5750 476.5875 476.6000
07* 08* 48* 09 49 10 50 11 12 13 53 54 55 16 56 17 18 19 20 60
476.9125
477.0875 477.1000
68
477.1125
69
477.1375
477.1250 477.1500
31*
477.1625 477.1750
71* 32*
477.1875 477.2000
72* 33*
477.2125 477.2250
73* 34*
477.2375 477.2500
74* 35*
477.2625 477.2750
75* 36*
477.2875 477.3000
76* 37*
477.3125 477.3250
77* 38*
477.3375 477.3500
78* 39
476.8875
477.0625 477.0750
70
476.8625
477.0375 477.0500
67
476.8375
476.9000
477.0250
28
476.8125
476.8750 59
477.0000
66
476.7875
476.8500 58
477.0125
27
476.7625
476.8250 57
64 65
476.7375
476.8000
—
26
476.7125
476.7750
476.9750
25
476.6875
—
63‡ 24
30
476.7500
15
23†
476.6625
476.9250 — 476.9500
62‡
476.6500
476.7250
14
22†
29
476.7000 52
61‡
476.6125 476.6250 476.6375
476.6750 51
MHz
21
476.5375 476.5500
Carrier frequency
477.3625 477.3750
79 40
477.3875 477.4000
80
477.4125
*The primary use for these channels is repeater operation using 750 kHz offset. Channels 1‐8 inclusive are used for mobile reception and channels 31‐38 for mobile transmission. Note that additional channels 41‐48 and 71‐78 may also become available for repeater operation to supplement channels 1‐8 and 31‐38 respectively as approved by ACMA CBRS Class Licence in Australia and Ministry of Economic Development GURL in NZ. In addition, any designated repeater channel may be used for simplex operation in areas where it is not used for repeater operation. † Speech telephony shall be inhibited on these channels. ‡ These channels are for possible future use and shall not be activated until approved by the ACMA CBRS Class Licence in Australia or the Ministry of Economic Development GURL in NZ.