Tag Archives: spectrum

Access’ Next Steps with Citizens Broadband Radio Service

If you’ve ever tried to make a call in a hotel or at a conference, only to realize there is no connectivity, or it is too slow to use, you understand the importance of having high capacity wireless networks. We have been working with operators and hardware manufacturers towards a radically new spectrum sharing technique to make bandwidth readily abundant and accessible in the U.S.

The shared spectrum approach is being applied to the Citizens Broadband Radio Service (CBRS) band (3.55GHz-3.7GHz). CBRS will allow large venues such as enterprises, concert halls, sports arenas, theme parks, shopping malls — and yes even hotels and conference centers — to easily deploy private, wireless LTE networks without spending billions to lease spectrum. This will enable more innovation in wireless applications and products going forward.


There are three requirements for the CBRS band to be ready for prime time: (1) a Spectrum Access System (SAS), as mandated by the FCC to manage spectrum sharing; (2) a robust hardware ecosystem; and (3) the deployment of wireless networks. Today, we’ve hit major milestones in the first two requirements: we’ve completed an end-to-end test of consumer devices connecting to CBRS base stations, and formed a trusted tester program to ensure interoperability between CBRS base stations and the Access SAS.

The availability of CBRS consumer devices isn’t so far off. In fact, we’ve demonstrated two device firsts in the band by showing end-to-end operation of phones using Qualcomm (Snapdragon X20 Gigabit LTE modem) and Spreadtrum SOC chipsets, as well as MiFi devices from Juni/Infomark. This is a major milestone for the CBRS band. While it will take time for CBRS phones to be pervasive in the market, MiFi devices provide an excellent bridge in the near term.

On the network hardware side of things, we are introducing the Trusted Tester Citizens Broadband Radio Service Device (CBSD) Program. Trusted testers can now sign up to run a series of self-service tests to ensure their base station equipment works with the Access SAS. The Access SAS communicates to these radios and provisions spectrum in the band in accordance with FCC regulations, and ultimately makes sure that the spectrum gets used fairly and efficiently. Our first batch of successful pre-testers include Nokia, Juni, ZTE, Sercomm, Ericsson, and Ruckus Wireless, representing a diverse group of manufacturers, with experience spanning from small cells to macro cells, as well as indoor and outdoor use cases. SAS certification is expected to happen this year, so we are building the foundation for  a functioning and collaborative environment now.

We’ll continue to work with industry leaders and new participants to realize the promise of shared spectrum, which we believe is the key to abundant and low cost wireless. The industry is ready for private LTE deployments, and this year has set the foundation for this, and future innovation.

See you at Mobile World Congress!



Posted by Mathew Varghese, Product Lead for Mobility

Encouraging Innovation: Wi-Fi and LTE in Unlicensed Spectrum Bands

by Nihar Jindal, Hardware Engineer, Access & Energy

In the 20 years since the Federal Communications Commission (“FCC”) first made spectrum available on an unlicensed basis, technologies such as Wi-Fi and Bluetooth have flourished. Innovation in unlicensed spectrum has given people more opportunity to access the Internet, when and where they need it.

Carriers are also innovating in licensed spectrum, deploying Long Term Evolution (“LTE”) networks that enable the delivery of data traffic faster and more efficiently than previous generations of technology such as 3G. Indeed, a spectrum policy that balances licensed and unlicensed opportunities has allowed expansive growth of the wireless economy, benefiting consumers, innovators, and investors.

With the rapid growth of data services and high bandwidth applications, mobile operators need more capacity than ever. One way to meet the need is to move traffic from their licensed network to the 2.4 GHz and 5 GHz unlicensed bands, known as “Wi-Fi offloading”. Offloading benefits carriers and consumers: carriers find additional capacity to relieve congestion on their network and consumers have a high-quality experience.

In recent months, several carriers and suppliers have announced plans to deploy LTE, a technology historically deployed only in licensed frequencies, in the 5 GHz unlicensed band as a means for providing additional capacity to customers. One part of the LTE stream operates in a licensed frequency, and the mobile operator has the flexibility to determine whether to send other portions over licensed or unlicensed frequencies. This arrangement provides licensed operators access to additional spectrum without the expense of obtaining a license, while allowing them to maintain the quality of service expected for licensed services. This form of LTE cannot be used without access to licensed spectrum.

However, LTE over unlicensed — at least as currently conceived — presents new challenges for coexistence with other unlicensed technologies. A new white paper by Google engineers, which we filed with the FCC this week, summarizes our initial investigation into the issue of coexistence between license-anchored LTE and Wi-Fi in the 5 GHz band. The paper shows that in many circumstances, LTE over unlicensed coexists poorly with Wi-Fi.

Although all players in the wireless ecosystem should have the ability to utilize unlicensed spectrum within the FCC’s rules, LTE over unlicensed has the potential to crowd out unlicensed services. Holders of licensed spectrum shouldn’t be able to convert the unlicensed 5 GHz band into a de-facto licensed spectrum band, and certainly they should not have the ability to drive out other unlicensed users.

The ability for diverse technologies to operate together in the unlicensed bands has typically been resolved through cooperation and without regulatory intervention. Providers of unlicensed services share an incentive to make sure that players are able to deliver services in the band without fundamentally degrading other unlicensed activity. The incentives to coexist may be different when providers can fall back to licensed spectrum in the event of conflicts in unlicensed spectrum. But there is still time for the industry-led cooperation that enables technologies like Wi-Fi and Bluetooth to coexist successfully.

A potential solution that would avoid coexistence problems in the 5 GHz band is for carriers instead to utilize newly available spectrum in the 3.5 GHz band for additional capacity. The FCC recently identified the now-underutilized 3.5 GHz band spectrum as ideal for this kind of use.

The entire wireless ecosystem should be concerned about allowing one innovation to block others — past and future. The best way to stimulate innovation without regulatory intervention is for the industry to maximize use of all available spectrum and develop workable coexistence and coordination mechanisms that encourage widespread access to unlicensed spectrum. 

Spectrum Sharing: The Next Generation

As a child, my sisters and I loved when our father let us use his CB radio. We memorized the code of conduct: Rule #1 - be respectful, listen before speaking and don’t hog the channel. And we had humorous “handles” long before Twitter. CB radios gave me and my family a way to communicate over short distances, and we didn’t need a license for use of the radio waves.

Flash forward to today. We’ve come a long way from CB radios, and we all have more and more devices in our homes and offices connected to Wi-Fi. Unfortunately, the airwaves allocated for this purpose have become congested.  

The good news is that the Federal Communications Commission (or “Friendly Candy Company” in CB lingo) today took a step toward addressing this problem, by creating a new “Citizens Broadband Radio Service,” that makes some spectrum available for shared wireless broadband use in the 3.5 GHz spectrum band.  

The FCC established three tiers of access in the 3.5 GHz band. The first tier is for incumbent access, including both federal and non-federal incumbents (like U.S. Navy radar operations and Fixed Satellite Service earth stations, respectively); the second is for “priority access licensees,” who will gain access by bidding for rights to use small chunks of spectrum for short periods of time; and the third tier is for unlicensed spectrum users in the new Citizens Broadband Radio Service.

Users of the spectrum might deploy “small cell” networks that can carry heavy loads of data in high-traffic areas -- such as crowded stadiums -- or offer fixed wireless broadband services in rural areas. Unlike the large scale infrastructure necessary to operate cellular networks that you see mounted on towers or tall buildings, these small cells are easy to deploy.

A key component to sharing in this band is the Spectrum Access System, which utilizes database technology to protect important federal government uses of spectrum. These systems will ensure that neither priority access or general consumer users interfere with the existing government and private users who will continue to need 3.5 GHz spectrum in a limited number of areas. They also will allow new users to share effectively with each other. Google has been a leader in using databases to free-up available spectrum, and we are one of the companies working to develop a sharing system for the 3.5 GHz band.
The additional spectrum that is now available in the 3.5 GHz band will help relieve Wi-Fi congestion – improving the experience of consumers accessing the Internet over wireless broadband. The Commission recognized today that we don’t have to allocate spectrum for only a single purpose the way the government did in the 1950s. This action will have an impact far beyond what we can imagine today. Creating this “innovation band” by opening the spectrum on a shared basis will advance the goal of wireless broadband abundance.  

Catch ya on the flip-flop. We’re down’n gone.

Posted by Staci Pies, Senior Policy Counsel, Google