Wireless Access – DAS ; WiFi ; 5G ; CBRS ; WiFi 6

October 8, 2021

Ever since the first digital camera in the 1980s, we have been diving head first into the exponentially deep waters of the digital age. As we continue to dive deeper,  every facet of industry reveals new approaches to how information is accessed, stored, and disseminated. So much so, that our very way of life has adapted to this change almost imperceptibly over time. Consider:

Can you imagine NOT using google maps or your favorite Spotify podcast  in your car? We can extend this thought to a discussion of the future for  wireless technologies such as  cell service and WiFi in commercial and government buildings.   In just a span of twenty years there has been a major shift in the technological ecosphere of how Internet Service Providers (ISPs) implement wireless network technologies in a commercial setting. And major changes can be seen in advances with  the Distributed Antenna System (DAS) to verify cell signals in commercial buildings.  Each of these technologies provide access to mobile broadband, allowing for unparalleled human communication via a PC, laptop, mobile phone, tablet, etc. 

Nielsen Law


When Nielsen's Law was first presented, it may have seemed far-fetched to believe it could remain true for any significant length of time.  Now, as it approaches 40 years later, it has proven remarkably accurate.  The thirst for more bandwidth by the collective population has not waned, nor is it expected to do so in the foreseeable future.



The evolution of DAS and WiFi  have answered the demand for more bandwidth.

As we entered the 21st century, DAS was essentially a large antenna on a hill, or  jutting up into the sky from the top of a building.

This antenna often gave one particular ISP sole dominance of data access to that specific building or campus. At that time, DAS was available only for  very large buildings or venues, and it often came with a 7-figure price tag.  It wasn't uncommon for an ISP to pay for the system, effectively giving them a 'wireless data monopoly' for that building or campus.  If another ISP wanted to have coverage, that company would have to negotiate with the ISP who paid for the system. 

Today's DAS offers host-neutral alternatives for far smaller buildings and venues, at a much lower  investment to answer a  specific need.   This was in response to the reality that DAS was once only needed for the largest of buildings and campuses, but now is often a requirement in many buildings because the demand for bandwidth has driven a need to provide it.  

To add perspective… The average smartphone has more computing power than the entirety of NASA when they sent the APOLLO 11 crew to the moon.  And unlike the cell phone from the year 2002 (which made cellular phone calls only),  today’s smartphone does nearly everything a PC or laptop can do.   Of course, those additional applications require bandwidth which meant our data infrastructure had to evolve in order to support the level of mobile communication that we expect today.

Leap forward to today.  If you watch TV, you have likely seen advertisements for the new 5G phone.  And even as 5G settles in as the latest-and-greatest, WiFi 6 (and 6E)  is now being touted by some as the new best available system. From the technical perspective (for those who care about the underlying technology), instead of using the slower 2.4 Ghz range that dominated in the early years.  WiFi 6E operates up to the 6 Ghz range for newer, faster devices.  Plus, in addition to accessing new available bandwidth thanks to CBRS (CBRS Gets FCC Approval, WiFi 6E capabilities will offer a safer and more secure frequency. 

If you can remember where you were on 9/11, you have witnessed the evolution of DAS and WiFi  from a front row seat. You probably recall when we reached the  4G milestone,  and hearing a new term - LTE (Long Term Evolution).  LTE refers to the 4G WiFi solution, and any generation thereafter. The  Evolved Universal Terrestrial Radio Access (E-UTRA) is the interface for LTE technologies which operate along the spectrum from 3.5 Ghz to 3.8 Ghz. 

How will wireless technology evolve from where we are now?

The most apt metaphor for a discussion of this technology is the information highway (wireless access, for our purposes here).  We all have known a local road that became a thoroughfare and grew over time. An extreme example would be a local  connecting road that once had one lane going either way, transforming into a 5 or 6 lane highway over time to handle the increased traffic that was causing congestion..   Wireless access is the road in this metaphor, and wireless devices are the ‘cars’ causing the traffic jams.

Once the demand for wireless access exceeds the “road’s” ability to handle the traffic, the result can be no access,  bad connections, and dropped calls.   Even with advances in technology, the demand for access exceeded the information highway’s ability to handle the traffic.  In addition to the traffic jam, there was also a rise of unlicensed spectrums for private data which lacked adequate security and encryption. In  2015,  the FCC responded by adopting rules for the Citizens Broadband Radio Spectrum (CBRS) to be used for commercial use.   This added bandwidth to handle the increased demand, and provided an opportunity for a more secure connection.

CBRS - What is it?

Traditionally reserved for military operations, the FCC decided to auction to commercial entities the portion of the spectrum from approximately 3.55 GHz to the 3.7 GHz range for public use. U.S. HB4998 outlaws the use of unlicensed spectrum due to national security, as there is ample proof that encrypted and license use helps reduce foreign cyberattacks.  A recent example was the  foreign hack in an oil pipeline that created a virtual shortage on gas, nearly ablating the supply for the entire U.S. east-coast.   By allowing commercial access by license to more spectrum (bandwidth),  CBRS  offers faster speeds and greater security as a licensed spectrum (another lane or 2 to the information highway, so to speak). 

CBRS or Band 48 operates on a three tiered system:

> Tier 1 - Incumbent - Incumbent refers to military use which will continue, and the military will have 1st priority to all non-Priority spectrum.

> Tier 2 - Priority - Priority is reserved for ISPs and telecommunication companies that bought access to ranges of the spectrum during auction.  For the geeks among us, that is a 150 Mhz range between the 3.55 Ghz to 3.7 Ghz that the FCC set aside for public use.

>Tier 3 - General Access - General Access is the lowest on the priority but offers free connection to unassigned areas of the spectrum that is not assigned to a higher tier. 

As greater coverage becomes an increasingly larger issue, perspective now commercial thinking shifts to Private LTE networks, like CBRS, to address future needs. 

So what does this mean? 

It means that CBRS can address the growing need for connectivity while providing a secure, licensed spectrum that greatly reduces the threat of cyberattacks to businesses. The use of a private, licensed spectrum allows for users to be authenticated by network administrators at a lower cost for required infrastructure.  


To continue our the information highway analogy...
CBRS allows organizations to create their own “express lanes” by creating private LTE networks, which can also extend into 5G.

Technically speaking, a Spectrum Access System (SAS) connects to the FCC database systems which allows  the spectrum to be allocated accordingly between the three-tiered system pictured at right by using an Event-Driven Process Chain (EPC) which authenticates the devices used. 

CBRS as it relates to DAS

A Distributed Antenna System (DAS) has traditionally been used to provide mobile (cellular) phone access.  Before 2010, most small businesses could access the available cellular signal provided by larger ISPs. This available signal is known as “native signal.”   The native signal is no longer adequate for many smaller venues.  Smaller DAS solutions evolved to answer the need for these venues (as mentioned above.

Unlike DAS, CBRS relies on accessing a swath of the reserved spectrum by the FCC that allows only for authenticated use via SAS.  CBRS provides new available bandwidth in  3 tiers of access.  Tier 1 (Incumbent users) access has the greatest  priority,  Tier 2 is licenced to companies and provides priority access.   Tier 2 access avoids interference with Incumbent users by using an SAS monitor to distribute access accordingly between the two tiers.  The unlicenced General Access Tier 3 has the lowest priority access, with no guarantee of connectivity.

Coverage (reliable access) has been a primary concern for WiFi and DAS since we learned the phrase “can you hear me now?”.  Security has entered the equation as the world continues to adopt and embrace new wireless solutions recognizing there are hackers who would like to steal data.    

5G technology expanded mobile networks and incorporated LTE technology, so it also overlaps into the realm CBRS. This means tha ISPs and telecommunication companies can use CBRS  and expand their infrastructure coverage for 5G. Enter WiFi 6E.

WiFi 6E creates (CBRS) new lanes of traffic on our information highway, and can also expand to include 5G.  That is why some are saying that  WiFi 6E is the most recent latest and greatest wireless technology, emerging as this article was written.  And for that reason, we believe it deserves its own article which it will get in our next newsletter.  (If you would like an early version of the article ahead of the publish date, please let us know below).

With technology, the limits are (so far anyway) temporary.   For those of us who work on developments that may take 6 months to a year to design and a year or two to construct (or longer), it is important to have the best available technology designed into our projects.   The question isn’t if there will be a new technology that impacts my development?  The question is, what will be the next technology to impact my development.  At NTI, it is our job to help answer that question.  Hopefully, this article helped do just that.

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