White Spaces seems to be the antithesis of the TV Incentive Auction. But it is not. Mobile carriers participating in the auction and the new White Spaces industry vendors can plan a new mobile ecosystem where unlicensed will support licensed use, the way Wi-Fi now supports licensed use.
Coordinating, cooperating, and planning by mobile policy makers and mobile network engineers are the key to a successful new mobile ecosystem. However, traditionally, mobile carrier engineers have not seen the value of unlicensed Wi-Fi and of unlicensed wireless networks built by 80 million U.S. homeowners. The mobile engineers have focused on and depended on cell towers with air-conditioned huts at the tower base and backup generators supporting the huts. All this cost in the mobile network demands and requires licensed spectrum. But Wi-Fi use in the home, relied on by the majority of 120 million smartphone users, defies the mobile engineers’ reality based on costly towers and licensed spectrum. A compromise between licensed and unlicensed is needed, and indeed required, for our mobile future.
White Space is unlicensed like Wi-Fi. Wi-Fi uses unlicensed spectrum from 2.400 to 2.4835gHz (83.5mHz) and from 5.725 to 5.875gHz (150mHz). White Spaces uses free TV channels from 54mHz and 698mHz (TV channels 2-51).
The FCC created White Spaces over a period of six years culminating in a FCC September 2010 order. Chairman Genachowski, in one of the highlights of his chairmanship, coined the White Spaces, “Super Wi-Fi,” because the low 600mHz spectrum allows excellent radio propagation through walls and trees and into our basements and backyards, something Wi-Fi using 2.4gHz has trouble doing.
Unlike White Spaces, the FCC’s TV Incentive Auction will create “exclusive licensed” spectrum taking spectrum that is now allocated for unlicensed White Spaces and licensed TV channels. The FCC TV Incentive Auction (the formal FCC matter is called “Expanding the Economic and Innovation Opportunities of Spectrum (News - Alert) Through Incentive Auctions”) was mandated by Congress in the Spectrum Act of 2012 to a) raise money for a nationwide public safety mobile network and to b) sell spectrum to the mobile carriers. The auction will eventually (it is scheduled for 2014, but TV stations are complaining this is too fast) buy spectrum from TV stations that will exit the TV business and then simultaneously, within minutes or hours, sell the freed TV station spectrum to the highest mobile company bidder. The TV spectrum includes a total 294mHz of potential spectrum for sale across all geographies, with the likely auctionable spectrum coming from TV channels 14 to 51 (470-698mHz).
Unlicensed spectrum has been the savior of mobile carriers rolling out the most amazing devices we have ever held. These devices are more reliant for data use on unlicensed Wi-Fi than on the carriers’ licensed spectrum and multi-billion dollar cellular macro networks sitting on towers across the landscape. Even those folks not in the telecom industry know the term cell tower, which says it all regarding the huge size of the investment. And these folks know the problem with the towers.
The average user knows that where there are no cell towers there is not service, or poor service. Voice calls made outside in urban and rural areas drop regularly and are inconsistent in quality. “Can you hear me?” is said daily across the country. It is the new voice norm. Users have grown to expect the poor voice QoS when outside. Poor service is poor QoS for a mobile engineer. Some have argued that poor QoS is caused not by a lack of licensed spectrum but by a lack of towers or micro and pico cells, known as small cells. However, these same customers know that if they can get to a Wi-Fi router using unlicensed spectrum their new amazing phone will work and QoS goes to 100 percent.
Today, users don’t blame the carriers as they did a couple of years ago. They just hunt for a Wi-Fi network, find one and smile once their Galaxy SIII connects to Gmail, Google Plus, Twitter and Facebook (News - Alert). Users ignore the QoS problem caused by a limited macro tower mobile network. And users know that there are mobile data caps and are careful to ensure that their photos are synched on Wi-Fi only and that their Dropbox (News - Alert) is Wi-Fi only and that Amazon Audible downloads on Wi-Fi only all in an effort to prevent hitting the mobile data caps. When inside at home or at Starbucks or an office meeting, the users depend on Wi-Fi as unlimited, dependable, and unlicensed.
Unlicensed White Spaces will deliver the wireless network redundancy, like Wi-Fi does today, for the mobile carriers that win the TV spectrum auctions. It is anticipated that mobile carriers winning TV spectrum will build a wireless ecosystem that incorporates the use of unlicensed spectrum. That unlicensed spectrum can include White Spaces.
There are two principal uses for unlicensed White Spaces that winning mobile carriers can use: a) backhaul using point-to-point radios for urban and rural small cells and b) short-haul LAN Wi-Fi-type use with 802.11af. 802.11af is getting traction with IEEE for TV White Spaces. 802.11af devices are hoped to be in production before the TV Incentive Auction takes place in 2014. White Spaces point-to-point radios can easily penetrate tree foliage allowing mobile carriers to deliver broadband to small cells and hetnets at a much lower cost in certain rural and urban areas than building fiber (new fiber construction costs around $50,000 per mile if placed on poles and $120,000 per mile if in conduit).
Short-haul LAN White Spaces based on 802.11af will be able to be used in homes and businesses, allowing mobile carriers to offload even larger data requirements to the customer’s local FTTH Internet using White Spaces equipment owned by the home owner. Home and small business owners in the U.S. purchase an estimated $10 billion-plus per year in wireless network equipment in the form of Wi-Fi access points – 90 million homes and businesses x $120 per Wi-Fi access point. It is projected that 800 million homes worldwide will have Wi-Fi by 2016, which equates to home owners purchasing an estimated $90 billion in wireless network equipment, possibly exceeding the total amount of equipment capital expenditures by all the mobile carriers worldwide.
The FCC is going to decide in the TV Incentive Auction proceeding how much unlicensed nationwide spectrum to allocate to White Spaces in the urban areas. In rural areas, where there are few TV stations and where demand for licensed spectrum will be limited, White Spaces will continue to have many available channels. (A TV channel is 6mHz. The TV Auction proceeding is considering changing these channels to 5mHz to match the 3GPP LTE (News - Alert) band plan requirements.). LTE, as defined by 3GPP, requires a large guard band for frequency division duplex of 10-16mHz and a large duplex gap of an additional 20mHz between the LTE uplink and downlink, much larger than 6mHz guard bands required by White Spaces devices today separating TVWS from TV stations.
In the comments filed with the FCC, Google (News - Alert) and Microsoft proposed that the FCC not auction off, but keep for public unlicensed use, the large 20mHz duplex gap and the guard bands required by LTE for a nationwide, unlicensed White Spaces band. The large guard band and duplex gap would allow White Spaces devices to deliver up to 50mbps speeds, or around 10mHz per 6mHz channel.
Unlicensed White Spaces – post TV Incentive Auction – will complement and support the mobile carriers, not compete with them. More significantly, the plan of using a dedicated nationwide, unlicensed White Spaces spectrum band would support the growing data demands required for a healthy economy. Mobile carriers purchasing the surrounding TV spectrum for exclusive licensed use would have the confidence that their customers’ aggregated multi-billion dollar home wireless networks using 802.11af unlicensed White Spaces spectrum devices were efficiently and effectively offloading the heavy data demand that would otherwise be solely dependent on the new LTE networks.
Such free offloading to White Spaces, at no cost to the mobile 600mHz network owners, would support their future customers’ high-demand QoS requirements that the mobile network engineers know has to be met once construction of the new LTE networks is completed.
Edited by Stefania Viscusi