How to License Your Private Wireless Radio System

Gaining proper authorization for a radio station and remaining in good standing with the FCC with your current license are crucial aspects to operating a radio system on the government-regulated airwaves. In order to understand the licensing process, it is important to know your radio system (or proposed radio system) and the terms the U.S. government uses to describe your communications system.

The type of system that the user needs to communicate will directly impact the license that the FCC provides to authorize that system. The following is a description of the spectrum choices available, channel spacing, radio systems and FCC licensing terminology.

Spectrum Choices

End users must decide which frequency allocation on which to operate. Exclusive-use channels are popular because they provide clear spectrum for centralized trunked radio systems, but they are also scarce in metro areas. Shared spectrum allows more companies to access the same channel, but it is similar to the old party-line telephone systems where users from different companies can hear each other. While shared has traditionally been used for conventional radio technology, not too long ago, the FCC has begun to allow the licensing of trunked systems, increasing their popularity.

Land mobile users have shared spectrum in the 25-50 MHz (low-band); 150-174 MHz (VHF); 450-470 MHz (UHF) bands. If certain qualifications are met, the FCC may assign spectrum for exclusive use by single entities in the 470-512 MHz, 806-821/851-866 MHz, 821-824/866-869 and 896-901/935-940 MHz bands.

Channel Spacing Choices

Channels should be thought of as lanes on a highway. Like a car, each radio transmission is required to stay between the lines.

The FCC has recently reduced the channel spacing for private wireless systems but migration to narrowband equipment has, so far, been voluntary. In other words, they painted more dotted lines on the highway, creating more possible lanes. The current channel spacing is as follows: Low band, 20 kHz; VHF, 7.5 kHz; UHF, 6.25 kHz; 806-821/851-866 MHz, 25 kHz; 821-824/866-869 and 896-901/935-940 MHz, 12.5 kHz. Equipment is not yet available for 6.25 kHz channel spacing. While new equipment uses dual-mode 12.5/25 kHz channels, existing equipment tends to use 25 kHz and 30 kHz spacing.

Radio System Choices

Conventional
Conventional private wireless systems, which operate on one to two channels, are used widely today. A radio will always transmit on the same channel, unless the user manually changes it to another authorized channel.

• Simplex Operation
  In a simplex radio system, the dispatcher and the mobiles and portable radios in the field communicate back and forth using a single frequency. This system is used primarily for dispatch communications to the field, as the mobiles have limited capability to talk back and forth. (For licensing, see FB/MO below)
• Half-duplex
  A half-duplex system is a variant of the simplex system. It uses two frequencies, but there is no repeater. Therefore, each mobile transmits on channel and receives messages from the dispatcher on the other, but since field conversations are not rebroadcast, no employee hears transmissions from another employee, which is used often in the taxicab industry. (For licensing, see FB, MO)
• Repeaters/Duplex Operation
  A repeater is usually located at a higher elevation or atop a higher building than the base (control) to provide better coverage. The repeater rebroadcasts both the base transmissions to mobile units and the mobiles transmissions to the base station. This system uses two frequencies; the repeater transmits on one frequency, which it received by the mobile units; and the mobiles transmit on another frequency, which is received by the repeater. This system also makes duplex conversations possible and conversations between mobiles. (For licensing, see FB2/MO)

Trunked Radio

Trunked radios are licensed for five to 10 channels. The radio system determines which frequency is free, which is similar to the PBX in an office connecting people to an open outside line. One of the key advantages to trunking is that it increases the spectrum efficiency. Advanced electronics allow the dispatcher to communicate to a single employee, a working group or all the employees at once.

In the late 1990s trunked systems were introduced in the shared bands below 470 MHz. This technology combines a control channel with a protected service area with multiple repeaters on shared spectrum. (For licensing, see FB8, FB6, FB2, MO)

Mobile Only

In situations where crews work closely together (such as a construction site) or do not use a central dispatcher, an antenna transmitting signals across a large area may not be needed to communicate. The answer may be a mobile-only system, where the radios use their own power to transmit signals to each other and require no system to talk over. (For licensing, see MO)

Multiple Address System

A multiple address system consists of a master station and several remotes. The master station uses an omni-directional antenna to transmit data to interrogate the operational fixed remotes, which answer back with data. The utility industry uses these systems to supervise and control its power grid on a remote basis, as well as operating its mobile meter reading systems. (For licensing, see FX1, MO)

Paging

A paging system is simply a single-frequency, one-way radio system used to alert people. It can send a numeric, alphanumeric or voice message. (See FX1)

Classifying Your System Using Station Class Codes

The type of system and what it will be used for directly affects how the Commission licenses it. The applicant communicates this to the FCC through the use of a Station Code.

• FB8-Protected Service Area: If the user wants to implement a centralized trunked system in the channels below 470 MHz, it will need to secure a protected service area, known as an FB8 station class code, for the control channel. To receive an FB8 station class, a user has to show that the system doesn't cause co-channel interference or show letters of consent from the surrounding radio systems. The FB8 channel is for the system's control channel, additional channels will be licensed as repeaters (FB6, FB4 or FB2) and the transmit channel for the mobiles is licensed as an MO.
• FB6-Private Carrier: Community repeaters are used to sell dispatch service to local businesses on shared spectrum. Traditionally, each user on the system had to be licensed as an FB4. Today, the system operator can be licensed as an FB6 Private Carrier and each of the users will be covered under that license. The transmit channel for the mobiles is licensed as an MO.
• FB4-Community Repeater: On some community repeaters all of users on the system are licensed as FB4.
• FB2-Repeater: Any company that sets up a repeater for its internal communications must license the repeater as an FB2 station class and their dispatch center as a Control Station (FX1) station class. The transmit channel for the mobiles is licensed as an MO.
• FX1 Control Station: A transmitter at a dispatch center for either a repeater system or a paging system will be given the station class FX1 Control Station.
• FB-Base Station: A simplex system requires that the FB Base Station (FB) and Mobiles (M0) be authorized on the same frequency.
• MO-Mobile Only: The mobile-only system, even though it doesn't use a fixed transmitter, still must be licensed. The coordinates listed on the license are a point central to the work operations. Except for paging, virtually all types of land mobile equipment can be licensed as MO.

Radio Service Codes Describe Your Radio Equipment

Each applicant must also tell the FCC what type of equipment will be used. For private wireless applicants below 800 MHz, trunking equipment is known as a YG and conventional (non-trunked) equipment is known as an IG. For commercial systems below 800 MHz, the trunked/conventional coding is IK/YK.

In the 800/900 MHz bands, there are two private wireless pools, Business and Industrial/Land Transportation and there are different codes depending on whether it is 800 or 900 MHz. Below is a table giving the private wireless codes, although other codes exist for land mobile. They can be found in the FCC 601 Instructions.

Pool 800 MHz Band 900 MHz Band

Business Conventional GB GU

Business Trunked YB YU

Industrial/LT Conventional GO GI

Industrial/LT Trunked YO YI

Conclusion

The FCC licensing system requires you to know a series of codes, which could be compared to learning a second language. Bewildering at first, it becomes clearer when you realize how your communications system works and how to communicate that to the Commission. As an FCC-certified frequency coordinator, CCSi specializes in providing a liaison between the end-user licensee and the Commission and trying to make the confusing codes just a little more clear.