I had a call today with a sales guy working in the Private Cellular world. He brought up a simple question that I constantly have to help explain. That conversations sparked an idea that is needed in this industry. We need to teach about the alphabet soup that is Private Cellular. Specifically we throw around the terms CBRS, LTE, 5G, PrivateLTE, Private5G, OnGo, EBS, Band 48, etc. that often leads to confusion for anyone new to cellular technologies.
As most of you know, my background comes from the Wifi side of the fence. I’ve been building Enterprise Wifi Networks since 2007. As with many industries, Wifi has a bunch of acronyms that people in the know throw out and can lose the understanding of outsiders in a few seconds.
For those of us in the Private Cellular industry, this happens all day long, whether we are talking to our friends in the Wifi space or business leaders. I think this is a small part of the issues currently holding Private Cellular back. We are taking concepts from an established industry and trying to apply them to other industries but continue to use our existing terms to explain what is happening.
Many Private Cellular vendors are translating Cellular concepts into terms that the Wifi world understands. They use terms like AP instead of gNodeB as an example. This helps to an extent until someone runs into these concepts from the already established vernacular that the cellular world uses.
There is a lot of overlap between Cellular, Wifi, IOT Wireless, and Ham Radio. Terms like Spectrum or Channel are universal, but other terms have wildly different names. Reasons for those name changes can be technical because while they may be close to the same, there may be slightly different nuances. Different terms, on the other hand, may be just from a historical reason to have different names.
After my call this afternoon, I figured it would be a good idea to start helping explain some of these terms that we hear every day if we are in the industry but can confuse our friends from other industries. Let’s start with two terms that get misunderstood most often, CBRS vs Private LTE or 5G.
CBRS vs LTE vs 5G vs Private Cellular vs PCN.. Mouth Full
The first terms that we absolutely need to help our friends from other industries understand is the source of lots of confusion in Private Cellular. Prior to the release of CBRS spectrum by the FCC, Private Cellular was usually a niche solution that costs thousands to millions of dollars to implement in only very large projects. CBRS opened the floodgates to anyone in the United State to build their own Private Cellular network. The Crypto people built very large networks quickly with the now mainly failing Helium and Pollen Mobile projects based on CBRS spectrum.
But what is CBRS? What is Private Cellular? What about Private LTE or 5G? Beyond the words that make up the acronyms?
A Private Cellular Network or PCN is a cellular network operated often by Enterprises or Individuals compared to a Carrier or Public Cellular Network operated by a Telco or Carrier. PCN can use 4G LTE, 5G NR, or even older technologies like 3G. You can use Licensed, like EBS, Shared, like CBRS, or even Unlicensed, like 5GHz, spectrum for PCNs if you can find radios and clients to support the technology. Oftentimes, these networks use a Private Cellular Identifier PLMN such as 315010 for CBRS or 999099 for other PCNs around the world. CBRS stands for Citizen Broadband Radio Service and is only available in the United States. Other options are available in other countries but are not as easy to build as a CBRS PCN. Rich alphabet soup that I will dig deeper into many of those acronyms another time.
A year ago, I was trying to help a good friend understand the Alphabet Soup mess, and we came up with some good metaphors that could help a lot of C-Level people better understand the terms with the technology.
To start building that understanding, we need to make a distinction between Spectrum and Technologies. This blog post will focus on these two pieces and leave the other deeper confusing terms for later posts or podcasts.
Spectrum is a physics term that explains the various different electromagnetic wave frequencies from Radio Waves to Microwaves to Visible Light to Gamma Rays. Waves are defined by their wavelength or number of times they repeat or cycle per second.
Technologies are the Protocols or Rules that we use to put data onto those Radio Waves. Putting data on spectrum is not useful unless we are able to interpret those Radio Waves on the other side. We encode data onto waves then decode them on the other side. These protocols state that a series of 01010100 means “T” when converted to text or vice versa.
Words such as “This is my message” are encoded into:
01010100 01101000 01101001 01110011 00100000 01101001 01110011 00100000 01101101 01111001 00100000 01101101 01100101 01110011 01110011 01100001 01100111 01100101
Those ones and zeros, at a very basic level concept, are then sent as either an UP (crest) or DOWN (trough) on a wave and sent out over the airwaves from the radio’s antenna.
On the other side we receive a wave from the airwaves with a radio’s antenna and interpret the stream as an UP as a 1 or a DOWN as a 0 and covert those waves back to:
01010100 01101000 01101001 01110011 00100000 01101001 01110011 00100000 01101101 01111001 00100000 01101101 01100101 01110011 01110011 01100001 01100111 01100101
Then we can convert that back to “This is my message” by following the Rules or Protocols that were already established before the message was sent.
CBRS Rainbows
The picture above shows a really good metaphor to help explain these differences.
Part of the electromagnetic spectrum is visible light that forms rainbows that we can physically see with our eyes. Other electromagnetic waves, like CBRS, are invisible to the human eye but we can use the concept of rainbows to explain these differences. Rainbows always break out into a uniform sequence of colors: red, orange, yellow, green, blue, and purple with all their respective shades.
For our Wifi friends they understand this concept. Wifi typically operates in the 2.4GHz, 5GHz, and 6GHz ranges of the Electromagnetic Spectrum in the Microwave range. Let’s, for the sake of this metaphor, refer to a Red color being 2.4GHz, a Green is 5GHz, and a blue is 6GHz. Those waves are different frequencies so they don’t interfere with each other just like they don’t interfere in a rainbow even though they are next to each other. Channels within Wifi or Cellular spectrum, say 2.4GHz, are just different shades of a color like Red.
2.4GHz = RED
Channel 1
Channel 6
Channel 11
2.4GHz = RED
3.55GHz = YELLOW (CBRS)
5GHz = GREEN
6GHz = BLUE
The metaphor helps when explaining that CBRS is the name for a “band” of spectrum ie the “Color“. CBRS is 4G LTE Band 48 or 5G NR Band n48 in the United States ONLY. The band of spectrum has different names in other parts of the world. Specifically CBRS is 3.55GHz to 3.7GHz. In this metaphor, let’s say CBRS is a yellow color as it sits between 2.4GHz and 5GHz. CBRS is the NAME of an area of spectrum or specific wavelength.
Other Bands of LTE or 5G such as Band 41 ie “EBS” are different colors. EBS is 2.5GHz so it would be a shade of Red-Orange since it is closer to the 2.4GHz band used by Wifi.
1G, 2G, 3G, 4G LTE, 5G NR, 6G Technologies
The other main ingredient of our alphabet soup is technology. Private LTE or Private 5G or just 4G LTE or 5G NR are technologies. Looking at it from a Wifi perspective, the technology is just the simple term “Wi-Fi”. Wifi is the rules and protocols.
Within Wifi, we have different flavors of Wifi 6, Wifi 6e, or Wifi 7, etc. Wifi technologies used to be called with a different name such as 802.11b, 802.11n or 802.11ac. To avoid confusion, they just changed the name such as Wifi 5 replacing 802.11ac. Wifi 6e extends the Wifi 6 Rules into the 6GHz band. Like Wifi 6e, CBRS extends 4G LTE or 5G NR into the CBRS band. One metaphor that is useful for explaining this is to use spoken languages.
Language is a set of “Rules” to define that certain sounds or drawings on a paper have a specific meaning.
“CAT” when spoken in english, or translated into Spanish as “GATO”, is established and known to mean a feline type of animal. You can speak the word “CAT” out loud, ie encode the pulses in your brain onto the airwaves, then someone else can hear or decode the audio waves from the air back to pulses in their brain and understand that you said “CAT” and are referring to a feline type animal.
When it comes to technology, for our metaphor let’s say that 1G is Latin, then 2G is French, then 3G is Portuguese, then 4G LTE would be Spanish, and 5G NR is English. I’m not saying one language is better than the other, but for this metaphor, there are words that cross languages and are derived from a similar ancestor, such as the word “NO”.
“NO” is the same in Spanish, English, and similar in other languages, which is translated from the root in Latin as “NON”. In wireless technologies, examples such as “NO” would be spectrum or RSSI. Differences would be like the word “CAT” above, as translated into Spanish as “GATO” and the latin root “FELIS” where we get the word feline as reference previously. CBRS vs Wifi differences would be PLMN vs SSID; as they similarly identify networks are but have different purposes.
1G = LATIN
2G = FRENCH
3G = PORTUGUESE
4G LTE = SPANISH
5G NR = ENGLISH
These example languages are all Latin based or Latin influenced. But transitioning from one language to another, you have to TRANSLATE them or follow rules to transition between technologies.
Someone that speaks Portuguese may be able to understand a good amount of Spanish and may be able to communicate, but to truly understand each other you need to know the Rules or Protocols for the other language.
The Rules or Protocols used by Wifi 6, Wifi 6e, 3G, 4G LTE, 5G, etc have a lot of similarities because they build upon their parent 802.11 prime or 1G. These rules or protocols define things such as SSID, PLMN, RSRP, SIM Cards, Encryption, and a plethora of other things that go into making up a technology, more alphabet soup for a future blog post or podcast.
These are NOT to be confused with certain names used to refer to parts of Spectrum. 5G (a technology) is sometimes used erroneously to reference 5GHz (a spectrum). Same with 6GHz and 6G. 2G does not reference 2.4GHz. The “G” in Cellular technologies stands for “Generation” while in the Spectrum world the “G” (or properly abbreviated GHz) stands for Gigahertz or Billions of Hertz or cycles per second.
Protocols + Spectrum Better Together
Using Spectrum without a Protocol is useless for communication. We can even use visible light to communicate over distances. The World Navys used Signal Lamps to communicate ship to ship during World War 1. Today, Stop Lights at intersections use different colored lights to signal to traffic to Go, Yield, or Stop. These technologies would be gibberish unless we know the protocols to explain what those flashes of light mean.
Having Protocols that are used to translate words into Ones and Zeros then into Waves and passed across the electromagnetic spectrum that can be decoded back into Ones and Zeros then into words we understand on the other side compliment each other. These are the basis of wireless communications today. We need both. BUT we need to understand what is a protocol or technology verses what is a spectrum or wave.
CBRS is the name of a section of Radio Waves or Spectrum. 4G LTE or 5G NR are the names of similar but different technologies or rules that help us encode and decode data on top of the Radio Waves. The two come together to make a delicious alphabet soup.
