In public safety, the radio is the lifeline between the dispatcher and first responders. The importance of calling for help and getting through to dispatch or the other units in the field on the first try really can be a matter of life or death for the personnel trying to get help. The events of Sept. 11, 2001, really brought this point home. The biggest tragedy at an event is that one of your team members didn't come home because the radios do not work properly.

In working on radio systems for more than 40 years each, we have seen firsthand many systems with problems that contribute to the public-safety radio systems not allowing first responders to get the required help when it is needed.

A perfect system will have 100% coverage for the department's jurisdiction. In addition, the department must have the proper FCC authorizations for the radio channels it is using. Finally, the department must have a standard operating procedure that ensures that the radios always are used in a manner that ensures help is available on the first transmission, as sometimes that is the only transmission that is made. In that case, the seconds really do count.

It is very rare that we do not find at least some problems when we are working on a system. Some of the most common problems that we encounter include:

• Short-range system range does not match the jurisdiction.
• Inadequate system engineering.
• Inadequate installations.
• Unforeseen problems at sites.
• Components not meeting specifications.

The results of these problems include:

• No access by mobiles or portables into the system.
• Operation does not match the FCC authorizations.

The other major issue that we find is that the SOP for the organization does not obey the laws of physics. The radios cannot work from some locations back to the repeater or trunking system. A change of the SOP and hardware might be necessary to correct these problems.

Proper Operation

Even if your system does have good coverage and meets all of your demands and needs, you still may have issues and not even know that they exist until an incident arises and you find out there is a problem, but only after someone is injured or killed.

If you can answer yes to every one of the following items, then you probably do have a good system. If you answer no to any of these, then there probably are other items that also need examination.

• Does the system range cover the entire jurisdiction?
• Can you go into a building that is burning with the AC power off, and that building has a bi-directional amplifier that is battery powered?
• Do you have all of your radio channels properly licensed and all of your interoperability channels also licensed properly?
• Does everybody hear everybody else?

It only takes one incident to wake up your department that there is a problem with the radio system.

FCC Licenses

The FCC — and the NTIA for all federal government stations — does an excellent job to help achieve have good radio coverage, if the applications are in proper order. The designated frequency coordinators are very diligent in trying to keep interference as low as possible, and also keeping co-channel users as far apart as is practical. No agency can use transmitters that are not authorized. Just because your local radio dealer says it has taken care of the licensing does not mean that it was done. The licensee is fully responsible for having the correct authorization for every radio channel that it uses.

Some of the problems that we have found include:

• Base stations on the wrong frequency, running the wrong emission type and modulating more than the authorized bandwidth.
• Mobile and portable unit counts grossly understated, on the wrong frequency, running the wrong emission type, modulating more than the authorized bandwidth and working outside of the authorized operational area.
• Control station counts grossly understated, not licensed, on the wrong frequency, running the wrong emission type, modulating more than the authorized bandwidth and working outside of the authorized operational area.
• Interoperable channels that are not properly authorized between agencies and jurisdictions.

Operational Plans and Radios

Every agency has at least one dispatch location. Sometimes it is inside the headquarters of that agency. Many times, the county sheriff provides that service. What is missing at many agencies is a backup dispatch point that can be activated should there ever be a technical or operational problem at the primary dispatch point. In addition, the backup dispatch point is required to be properly licensed if a base station is at that site.

Many agencies use pagers for alerting field personnel. The pager count and operating parameters are required to be stated on the FCC authorization.

The tactical and ground-control channels also are required to be licensed. Many agencies are purchasing digital radios, and these do require that the FCC license be modified for the change in emission type.

You cannot use your neighbor's channels for interoperability unless you are using them with the written permission from that agency and within the operational area of the other agency's FCC authorization.

All agencies are supposed to be NIMS-compliant, and as such, codes and phrases are supposed to be translated into plain English so that they cannot be misunderstood during large-scale operations.

Interoperability

Many states have set up interoperable channels that any public-safety agency can put into their mobile units and the states have covered these units in their FCC licenses. In every case, the state has not licensed the base stations for these channels. It is the responsibility of each agency or county to license the fixed or portable repeaters and base stations for their agency.

Besides the normal public-safety (police, fire, EMS) agencies with which you interoperate, you also should have interoperability agreements with the schools, utility companies, wreckers, highway departments, water and sewer departments, and amateur radio operators that can help in the event of a major disaster in your area. You need to have all of the pieces in place in a standby mode before an event occurs.

Narrowband is Coming

The FCC has mandated that almost all VHF and UHF radios and radio systems must convert to narrowband (12.5 kHz-wide channels) by Jan. 1, 2013. There are a few exceptions, but for most radio systems, you will be required to change your systems from wideband (25 kHz-wide channels) to the narrowband channels.

Many agencies are opting to go the 6.25 kHz super-narrowband channels, which eventually will be a requirement for everybody operating systems below 512 MHz.

If your radio was manufactured after Jan. 1, 1996, it should have the 12.5 kHz narrowband mode in the radio. If the radio was manufactured before that date, it will need to be replaced.

As a way to help move the narrowbanding process forward, the FCC has begun issuing licenses that are 12.5 kHz away from existing wideband licenses. The only way to avoid interference is to have the wideband channel converted to narrowband immediately.

For the most part, there will not be a change in the range of your system when you convert from wideband to narrowband. If you have certain kinds of radio-frequency interference, however, this might not be the case. You might want to have your radio service company or outside consulting firm check for RFI before you make the move to narrowband.

Finally, all of the FCC authorizations for the wideband VHF and UHF channels that are required to be narrowbanded by the January 2013 deadline will be canceled, so your FCC licenses must have at least one narrowband emission line item for each channel that you want to continue to operate after 2012.

Conclusion

Whether your radio system is a single base station or a multi-site simulcast trunking system, the purpose of the radio system is to provide reliable communications between the field units and the dispatchers. There are several issues that can and do prevent these systems from providing reliable communications between these units.

To ensure that these systems are working properly, they need to be properly engineered, installed and maintained. If you used the project managers from the manufacturing company to also ensure that the system acceptance test was perfect, they many not report to you design flaws, equipment that is malfunctioning, or other issues that do not put the company that gives them their paycheck in a good light. An independent audit or review of your system will give you the straight answer to some of your questions on the true integrity of your system.

Every VHF and UHF license will be scrutinized by the FCC for compliance with the new narrowbanding rules. The overwhelming amount of work that needs to be accomplished in the short time span opens the possibility that some systems will be less than optimally modified and the performance might be compromised.

While the FCC and the Department of Homeland Security have been encouraging and funding systems for interoperability, the FCC authorizations need to match the channels that your agency uses. In addition, reciprocal operating agreements are required to use a different agency's channels by your units.

Finally, narrowband channels work as well as wideband channels, but are susceptible to certain types of RFI; thus you might want to review some of these issues before you have to make the change to narrowband operation.

Many systems have problems, and in most instances, these can be corrected if the problem is attacked in a scientific way with the proper test equipment and procedures. There is no reason to have a first responder injured or killed because the radio system is flawed.

Ira Wiesenfeld, P.E., is a consulting engineer who has been involved in the radio communications business since 1966. He has provided service for the broadcast, public-safety radio, mobile telephone, radio common carrier, paging, manufacturing, military, and education markets, and also provides training.

Roger Blouch, Ph.D., is a communications consultant involved in the communications business since 1967.

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