Flexible Spectrum Solutions

Wireless Wonk

Flexible Spectrum Solutions

By Barlow Keener, Attorney  |  May 12, 2014

Broadband microwave radio technology is evolving to spectrum selection using big data and SDN-like architectures. What is lacking is a name that describes the power and scope of the new spectrum sharing technology.  Just as the term software-defined network moved to the top of the Gartner (News - Alert) Hype Cycle for networks, so too are new radio technology names, created for spectrum sharing of licensed and unlicensed spectrum, making their way up and down Hype Cycle curves.  These names include Dynamic Management Access, Shared Access System, White Spaces, Cognitive Radios, Spectrum Sensing, and LSA/ASA.   

The names used by the wireless industry for this new technology are confusing and changing.  The first name used by the FCC (News - Alert) to describe the new spectrum sharing technology was TV White Spaces. This name was confusing because it focused on the TV spectrum and the licensed vs. unlicensed struggle for 54mHz to 698mHz where the TV channels resided. The FCC commissioners also called it Super Wi-Fi because the TV spectrum propagates through walls and buildings well. White Spaces is another name referring to all unassigned and unused spectrum.    

The FCC created in the sharing orders a method for spectrum sharing that is technically similar to SDN for routers; however, instead of software decoupled from but controlling the routes used by the physical layer network router, in spectrum sharing a software database (iConectiv, Google, Spectrum Bridge, or Microsoft) is decoupled from and controls the spectrum to be used by the physical layer radios, which are flexible and agile, changing spectrum as ordered by the database. The spectrum sharing method is now called SAS (News - Alert), or Spectrum Access System, by the FCC. The big data databases residing in the cloud control which slices of spectrum new agile radios could use in multiple dimensions at time, location, height, and power. 

In 2013, the FCC proposed creating a new spectrum sharing band called the Citizens Broadband Service, from 3.5gHz spectrum now exclusively assigned for military radar and satellites. The FCC proposed that the database could assign tiered priorities of spectrum sharing for the database.

After the initial FCC order, a new spectrum sharing industry ecosystem took off. These groups included Dynamic Spectrum Alliance (Microsoft and Google are members) and White Spaces Alliance (Google, Microsoft, iConectiv, Spectrum Bridge). Technology standards organizations jumped in with the IETF standards group Protocol to Access White Space database, or PAWS. IEEE (News - Alert) published 802.22 (2011) a wireless regional area network aimed at using cognitive radios with a database in the TV spectrum (54-790mHz), and 802.11af for wireless area local networks operation using the TV spectrum which is expected to be approved in 2014. 802.11af allows for up to four bonded channels creating 100mbps throughput and the ability to penetrate through concrete and brick walls.

There is a big struggle in wireless between unlicensed and licensed. The big data-controlled radio system has been primarily supported by the companies wanting more unlicensed spectrum.   There is the familiar warning of a looming spectrum crunch. Mobile carriers assert that more licensed spectrum is needed for high-QoS mobile connections. However, Google, Microsoft, Free Press, New America, Public Knowledge, and the startup community (WhatsApp is a startup!) argue that the mobile providers may be just hoarding licensed spectrum for competitive purposes and not building out the necessary  infrastructure to serve the new data demand. 

The unlicensed camp argues that unlicensed spectrum like 2.4gHz Wi-Fi and Bluetooth has actually saved mobile carriers and is one of the principal reasons that many startups have been so successful and generated so much funding. For example, Nest uses unlicensed home 2.4gHz Wi-Fi to connect its thermostat to the smartphone. Mobile carriers have indeed begun embracing the benefits of Wi-Fi for offloading smartphone data. Consider the recent the Boingo (News - Alert)-Verizon Wi-Fi offload deal and the Sprint-Kineto Wi-Fi voice handoff announcement.  

It is clear that the new big data-controlled flexible spectrum radios will be using an advanced new technology that is in parallel to what SDN is to network routing. The power of the technology is that it will be used for all spectrum – licensed and unlicensed or a mix of both as LSA/ASA proposes. However, it is not clear what name describing the innovative big data, dynamic spectrum management of agile, flexible radios will head up as the winner on the technology Hype Cycle.

Barlow Keener is the principal with Keener Law Group (www.keenerlawgroup.com) out of Boston.

Edited by Maurice Nagle