WE'RE FINALLY SEEING the "light at the end of the tunnel" with respect to the conclusion of the long-running auction process of the radio frequency (RF) spectrum by the Federal Communications Commission (FCC), and most importantly for our purposes, how it will impact wireless system users in live audio applications such as worship services.
The bottom line: wireless systems, including the wireless systems you may be using at your church, have lost more spectrum for operation.
What does that mean?
Now is the time to start planning and budgeting to replace or re-program existing equipment to be compliant when the time comes.
Let's go through the specifics:
The good news is that users may have up to three years to continue using existing gear in the affected blocks and bands, depending on when the new services start up in each market.
The bad news is that T-Mobile, the largest buyer of the spectrum in the 600 MHz band, has already begun turning on new services, and will continue to do so throughout the remainder of 2017 and early 2018. Some people are already beginning to feel the impact of this activity.
Also note that for now, wireless systems operating between 614 and 698 MHz are still legal to manufacture, sell and use in North America. However, to reiterate, it's certainly not too early to begin planning and budgeting for replacement or re-tuning (where applicable) of these systems.
Fortunately, all reputable manufacturers have been planning for this event by designing systems with wide tuning ranges, flexible operation and good receiver filtering.
Many transmitters also offer user-selectable RF power that can be quite helpful in tailoring for high-channel-count and short-distance applications. In addition, much work has gone into enhancing the efficient use of available spectrum, so that more wireless channels can work together without interference within a particular 6 MHz television channel or other patch of available spectrum.
Key to this spectral efficiency is digital transmission of the signal between the transmitter and receiver, as digital systems can be designed to offer important tradeoffs such as range, channel density and audio fidelity.
Even further, more manufacturers now offer a range of options in the VHF bands, and there are also systems available in alternate bands, including 1.8 GHz, 2.4 GHz, 5 GHz, 6 GHz, and other bands as well. In general, these alternative bands are best used for specialized purposes because higher frequencies don't have the same propagation characteristics as the VHF and lower UHF bands.
The introduction of digital wireless has also coincided with a push toward digital audio networking and computer control within the audio equipment chain. In addition, some of these systems now offer technologies for increasing reliability and resistance to dropouts, transmitting the same signal on more than one frequency (frequency diversity) and transmitting the same audio data in different time slots (time diversity), with algorithms at the receiver reassembling the digital information into coherent order.
Because the emitted signal from the transmitter is digital and the source audio has been converted to data, the audio can be encrypted before it is sent and therefore protected from being monitored by anything other than its assigned receiver.
Encryption at levels of 128-bit and 256-bit is common, and one newly introduced system has upped the ante to 512-bit encryption.
CLOSING THE DISTANCE
Attention has also been directed toward placing antennas closer to the performing area where the transmitters are in use.
One manufacturer has even developed the ability to remove its modular receivers from the chassis bays and remotely mount them (with antennas attached), running a Cat-5/6 cable between these small receiver modules and the receiver chassis.
This helps support the use of lower powered transmitters.
Some of the available antenna systems are active, boosting the received signal level before it travels to the receiver via coax cable. Directional antennas accomplish double duty, with increased sensitivity aimed toward the desired signals and lower sensitivity at the rear to attenuate interfering RF signals within their null zones.
Several manufacturers also offer very good, and constantly updated, software packages that help to manage and monitor wireless system performance over a network, from pre-show planning through post-performance analysis.
Speaking of manufacturers, don't hesitate to contact them for guidance, and take advantage of WorshipTechDirector and ProSoundWeb for a wealth of information written by leading RF/wireless practitioners.
We're all in this together.