The search for what to do with white space spectrum is on.
Cambridge Consultants, a radio consulting company in UK, identified three promising applications: in-home video distribution, municipal wireless, and rural broadband. Scores of companies have tried to address these three markets but with limited commercial success. There are solutions for in-home video distribution using Wireless HD, WHDI, 802.11n and UWB – and many of them commercially available. Several companies build outdoor WiFi gear for municipal deployments. Broadband can be provided in rural areas with a wide range of mature wireless technologies (EVDO, UMTS, LTE, WiMAX etc.) running in both licensed and unlicensed bands. Licensed spectrum is dirt cheap in rural areas. All this raises the question – is there enough demand for these applications and is new technology needed to address them?
According to Ruckus, a company that builds WiFi gear with beam forming antennas, “white space will be ideal for creating “urban overlays” to higher-speed microcell Wi-Fi and macrocell LTE networks… perfect for offloading low bit rate “chatter” traffic, such as application notifications (email, presence lists, etc. generated by handheld wireless devices) from high speed cellular or Wi-Fi networks”. Though an interesting application, it is doubtful that carriers will add a new radio into their handsets to offload low bit rate chatter. The incremental cost of adding WiFi to a handset had to fall below $10 before carriers starting making it a standard feature in their smartphone lineups.
Brough Turner, founder of a a 802.11n based ISP called netBlazr and former CTO/founder of NMS communications, points out that white space spectrum being “beachfront” spectrum is based on 20th century technology, not physics. Brough, in other blog posts and presentations at industry forums, has argued that large amounts of spectrum at higher frequencies is significantly more valuable for offering broadband and connectivity than few 6 MHz channels in lower frequency bands.
Of course, those who have commercially viable ideas on what to do in this spectrum are not advertising them on the Internet. I was recently reading the history of ISM bands on the website of Michael Marcus and at George Mason’s Internet Economy Project. It is notable that both WiFi and Bluetooth, poster child applications for ISM bands took off more than 15 years after this spectrum was opened up for unlicensed use. Spread spectrum, the technology that folks at FCC believed would be deployed in ISM bands was replaced by OFDM. None of the companies that were pioneers in the ISM band are in business today. Plus, not all unlicensed spectrum creates billion dollar markets. Unlicensed PCS (UPCS), a 20 MHz band what was offered for unlicensed use in 1995, has no application to date. Still, in these relatively early days, it is better for all us to stay optimistic about the possibilities and keep our thinking hats on!