FCC Removes Amateur Radio Symbol Rate Limit Signaling New Era

Potential Impact of Symbol Rate Limit Removal

For decades sending “data” with a ham radio meant tapping out a message in Morse code. In recent years, however, modern data modes have become an exciting part of the radio operator’s toolkit. Data modes allow hams to send digital information over the airwaves, enabling everything from text chat to image transfers and it’s going to get a lot more interesting real soon. The speed of that data, however, was limited by something known as the symbol rate. In this article, I’ll take a look at what symbol rate is and what it’s removal means for amateur radio.

On April 20, 2023, the FCC removed the symbol rate limit on amateur radio transmissions, thus sparking discussions about how faster data rates could reshape the field. If you’re a new ham or just new to the concept of data over radio, let’s explore the popular amateur radio data modes and discuss how the removal of the symbol rate limit could pave the way for new services and applications for all hams.

Popular Data Modes in Amateur Radio

Data modes allow amateur radio operators to send digital information, often enabling clearer and more efficient communication than voice alone. Some of the most popular data modes include:

• FT8 is one of the most widely used digital modes for low-power communication. Known for its weak-signal capabilities, FT8 can send brief exchanges (callsign, location, signal report) even in low bandwidth and challenging conditions. However, it is relatively slow, with a bandwidth of just 50 Hz, and typically suited for very basic exchanges.
• PSK31 (Phase Shift Keying 31 Baud) is a narrow band digital mode optimized for keyboard-to-keyboard communication. It’s popular for real-time “chat” communication on HF bands, where bandwidth is limited. Despite being slow by modern data standards, PSK31 remains popular for reliable text communication over long distances.
• APRS (Automatic Packet Reporting System) APRS is a packet-based mode that allows for location tracking, messaging, and telemetry. It is widely used for tracking assets, vehicles, and weather conditions in real time, making it especially useful for emergency response and community events.
• JS8Call Built on FT8’s protocols, JS8Call allows for more conversational exchanges than FT8. It’s great for low-power, weak-signal environments and is increasingly popular with operators interested in mesh networking and extended range digital communications.
• Winlink Winlink is a global messaging system that allows hams to send email over the airwaves. Often used in emergencies, it enables email communication without the need for internet infrastructure. Gateways allow Winlink messages to be exchanged with internet email addresses.

Each of these modes has been limited by symbol rate restrictions, particularly for those relying on high-speed data exchanges or packet-based systems. Now, with the removal of these limits, we should see at least some incremental improvements in these older protocols and schemes over the next few years.

Understanding Symbol Rate and the Impact of its Removal

The symbol rate refers to the rate at which changes in the signal (or “symbols”) are transmitted per second. In the past, the FCC set a limit on the symbol rate, effectively capping the speed at which data could be sent over amateur radio frequencies. This rate limit restricted modes that required higher speeds or broader bandwidths, especially when high-speed internet and modern data communication technologies emerged.

The removal of the ham radio symbol rate limit could enable data to be sent more efficiently and at faster speeds, perhaps even comparable to early cellular data. This doesn’t mean unlimited bandwidth for amateur operators—there are still restrictions on bandwidth to prevent interference—but it does mean that hams now have more freedom to experiment with faster and more capable digital modes.

A faster symbol rate does not necessarily solve all of ham radio’s problems either. As symbol rate increases so does impact from noise. The really fast commercial schemes like the various flavors of QAM would be mostly worthless on HF due to their intolerance to flutter and the polarity distortion that takes places as signals bounce around in the atmosphere, but I do expect we will see new protocols and modulation schemes released over time that will function on and significantly improve the experience of working digital modes on HF bands.

New Opportunities in Amateur Radio Data Modes

With faster data rates now possible, amateur radio operators have a wider range of potential applications to explore. Perhaps the three most exciting:

Let’s take a closer look at these and some of the other exciting possibilities as well:

• Higher Quality Digital Voice and Video Transmissions. Hams are now open to experiment with higher-fidelity voice and even low-resolution video transmissions. While the bandwidth restrictions still limit streaming capabilities, sending short video clips for emergency reporting or data bursts in visual communication could be within reach.
• Real-Time Mesh Networking and Digital Chat Networks. Creating ad hoc networks that function independently of the internet are of great interest to a lot of people. Faster symbol rates could allow for more robust networks that can handle real-time messaging, emergency alerts, and even location tracking in a more detailed and rapid manner. With APRS and packet radio, enhanced speeds may help build a more comprehensive “internet-like” experience for real-time messaging and data exchange.
• Enhanced Emergency Communications. In disaster situations, the ability to send and receive emails, images, and live group text chat is invaluable. With faster symbol rates, ham operators can relay essential information like map coordinates and rescue coordination documents more effectively. Winlink and similar systems become even more valuable when they can operate over faster, more reliable connections.
• Scientific Experimentation and Remote Sensing. Faster data rates could allow for more advanced telemetry applications, such as remote sensing in environmental and atmospheric studies. For example, ham operators could deploy flood level sensors or other observational devices that can send data back to a central station for logging and reporting.
• Advanced Weather Data and Satellite Communications. The amateur satellite network has limited data throughput, restricting what can be sent back and forth. With higher symbol rates, operators could potentially receive more complex data and support more users from these satellites, making the cost-benefit analysis a much easier sell when looking for funding of a new ham satellite.

The Future For Ham Data Throughput Is Looking Up!

The removal of the symbol rate limit represents a significant milestone for amateur radio. With faster data rates, the ham community has the potential to push the boundaries of what’s possible in areas ranging from emergency communication to real-time digital networking. Though amateur radio will continue to operate under unique limitations, the increased freedom to experiment with high-speed data modes invites a new era of innovation. Whether you’re a seasoned operator or a newcomer, this is an exciting time to explore the world of ham radio data modes and discover new ways to connect and communicate.

Radio Manufacturers Need to Get On Board

The American Radio Relay League (ARRL) has actively supported this regulatory change, emphasizing its potential to enhance digital communications and foster innovation within the amateur radio community. As of Nov. 11, 2024, however, there have been no public statements from the major radio manufacturers regarding the FCC’s removal of the symbol rate limit for amateur radio.

We need a commitment from “The Big Three” radio makers that they will work with the ham radio community to develop new modulation schemes and protocols that maximize our investments in their products without locking us to a single brand. Most of us own rigs from at least two of the major brands anyway so the idea that they’re going to “lock us in” is old school thinking and if they really believe it, they’re in much worse shape culturally than I thought. We don’t want proprietary digital nonsense.

When I entered this hobby, I thought there would be a lot more brand loyalty and bickering about which brand is better, but what I see is a community with a more agnostic buying habit. The same folks who had to have the latest Yaesu mobile rig two years ago are now lining up for the new tri-band HT from Kenwood. Most of the hams I know are a pretty pragmatic bunch and do their shopping based on feature set, value, or some combination of both regardless of the name on the placard.

If these radio manufacturers cannot get on board with common, open protocols and standard encoding schemes, the community will do it without them. We are already seeing community-developed and supported firmware for a few models and I expect that to grow with time. As interesting as that is, what we really need is a commitment to support established, open source protocols and codecs.