Choosing a single telecommunications protocol has always been difficult for engineers on Earth, so it’s especially difficult for those who want to communicate with beings from another star system. While it’s nice to imagine that extraterrestrial beings would be able to interface with whatever protocol humans decide to encode a message in, that’s not a realistic way to think. Humanity has developed countless electronic communication technologies since the 19th century. There’s no reason to believe that extraterrestrial beings haven’t done the same thing.
SETI and METI organizations have developed a single protocol for sending messages to potential examples of intelligent life. There’s no way of knowing if another civilization could ever actually interpret these signals but the odds are at least a little better with standardized systems.
Imagine an engineer trying to decode a data transmission that no one had ever encountered before. They’d probably try to compare it to other transmissions sent with the same protocol, and then look for the symbols that appear the most. These symbols are probably encoding the most common glyphs in the written language that the transmission represents.
Now imagine that each transmission that the engineer encounters is in a different code. There’s no way for them to compare different messages, because there aren’t any similarities between the different protocols. By using a single system, Earthlings are giving extraterrestrial cultures a chance to decode messages by comparing them to one another. It wouldn’t have been possible for international communications to be achieved on Earth if everyone decided to use their own technology standards.
In fact, poor choices in the past have hampered many types of technological developments. If standardization had occurred between Earthbound transmission sites years ago, these problems would never have reared their ugly head. For that matter, extraterrestrials might very well have been able to intercept numerous types of incidental transmissions. If signals are as weak as one might expect them to be, every little bit matters when we’re talking about communicating across the universe.
If standardization is important, the types of signals sent are equally important (if not more so). Most scientists agree that radio waves are the best way to communicate with other planets/stars given our current level of knowledge. This is due to the fact that radio waves are able to traverse the vast distances involved in actually reaching other stars/planets outside the Milky Way galaxy. Even the closest stars are about 6 light-years away (each light-year is roughly 6 trillion miles). This means that any signals we send their way have to cut through enormous amounts of gas and other obstructions found in space. Radio waves are able to do this effectively (as opposed to say, lightwaves) while traveling vast distances at the speed of light. I have read the work of some scientists that believe lasers may be a good way to reach extraterrestrials as well. I personally feel this is a great alternative to microwaves alone.
While standardization and appropriate signal types are invaluable, they’re also practical because they help to reduce costs. While practicality isn’t something that most people like to discuss, it’s actually pretty necessary in the world of SETI/METI. Many of these organizations, such as the SETI Institute (SETI Institute listens for signals vs. transmitting signals), survive on public donations. They need to maximize what they get out of the financial resources that they’re given to work with. Developing a single standard algorithm helps to reduce the amount of money spent on research while maximizing the chances of success (choosing the right type of signal to send) are crucial to long-term survival. It also means that different pieces of equipment will always interface properly. This means that expensive converts/integrations won’t ever be necessary as long as everyone adheres to the existing standard.
From an engineering standpoint, these groups might want to look at their antennas and transmission sites next (in terms of standardization). Once protocols are standardized, they can begin to improve in other areas as well. Each little bit matters when trying to talk to someone that may exist on a planet that is trillions of miles away.
Atri, D., DeMarines, J., & Haqq-Misra, J. (2011). A protocol for messaging to extraterrestrial intelligence Space Policy, 27 (3), 165-169 DOI: 10.1016/j.spacepol.2011.01.001
Edmondson, W. (2010). Targets and SETI: Shared motivations, life signatures and asymmetric SETI Acta Astronautica, 67 (11-12), 1410-1418 DOI: 10.1016/j.actaastro.2010.01.017