Alan Norman, Principal of Google’s Access Strategy group, presented the company’s plans for wireless broadband using white spaces at a Nov 2nd Wireless Symposium sponsored by Joint Venture Silicon Valley. Mr. Norman joined Google’s Access Strategy team in 2010 and has since worked on a variety of projects and initiatives.
Google’s goal is to support robust, affordable and open Internet access – via both wireless and wireline technologies. The company has been running the free WiFi network in Mt View, CA for several years, is building out fiber to residential customers in Kansas City for 1 G bit/sec access, and (as described below) is involved in a White Spaces wireless broadband trial in Capetown, South Africa.
There are 4 ways to improve wireless network capacity, according to Mr. Norman:
- Use a better wireless broadband technology, e.g. 3G–>4G, higher speed WiFi (i.e. IEEE 802.11n or 802.11ac).
- Acquire more spectrum (but that can be very costly).
- Use smaller cells (macro–>nano or pico cells) with backhaul transport for each. Smaller cells facilitate spectrum re-use within a given geographical area.
- Offload cellular traffic to WiFi hot spots (which use different spectrum than 3G/4G cellular networks).
Google’s view of how to achieve robust, affordable and open wireless access:
- Support use of a balanced allocation of licensed and unlicensed spectrum
- Advocate unlicensed spectrum sharing using a dynamic spectrum management scheme
- Wherever possible, support a shared wireless infrastructure (especially real estate, conduit and fiber back-haul)
Unlicensed spectrum is important because it enables:
- Greater economies of scale in the number of wireless network endpoints and types of devices
- Consumer identification, which results in increased investment in infrastructure
- Lower barriers for new network operators (and new services)
- Active competition and innovation across the value chain
Mr. Norman talked about use of TV white spaces as an example of dynamic spectrum access and spectrum sharing. He said the U.S. has a lot of TV White Spaces (6 MHz unused TV Channels) that could be used for unlicensed wireless broadband access. Google wants to demonstrate that over the- air TV and wireless broadband using White Spaces can co-exist with licensed spectrum. This, in turn, would create economic opportunities and more available wireless broadband access in the U.S.
The Capetown TV White Spaces Trial:
A White Spaces wireless broadband trial in Capetown, South Africa was cited as an example of unlicensed spectrum sharing. Alan said that 10 white space channels will be available for wireless broadband access with each one delivering 2M bit/sec Internet access to schools over 10Km distances from the carrier PoP (Point of Presence).
We later did some research on this trial and found the following information:
A group of partners, including Google, TENET, CSIR Meraka Institute, eSchools Network and WAPA, has formed to run South Africa’s first TV White Spaces trial (TVWS trial). This wireless broadband network will make use of spectrum which has been allocated to broadcasting services in South Africa, but which is not currently used (hence the term TV white spaces).
The objective of the TVWS Trial network is to provide a fast and reliable connection to the schools identified. The trial is being overseen by ICASA- the communications regulator of South Africa.
With ICASA’s support, this group will plan, execute and report on the results of a TVWS trial to 10 schools in Cape Town in order to:
- Demonstrate that TVWS can be used to deliver affordable broadband and provide important Internet services without interfering with TV reception
- Dramatically increase awareness of the potential for TVWS technology in South Africa and on the continent more generally.
- The Trial Network – The trial will be conducted across a TVWS Trial Network which will include a Base Station (high site or BS) and approximately ten schools (Trial Sites) located within a 10km perimeter around the high site.
This TVWS trial network is expected to launch in December, 2012, according to Arno Hart, TENET‘s project manager for the trial.
For more information, see:
Google’s goal in this and other experimental projects is to demonstrate that TV broadcasts and wireless broadband can co-exist with licensed spectrum. They also want to show that wireless broadband using white space frequencies will not interfere with TV reception.
Proposal to Share Mounting Spaces, Power and Fiber Back-Haul Facilities:
Mr. Norman said that the cost of telecom equipment is tracking Moore’s law for semiconductors. However, the cost of construction, civil works, conduit for fiber cables, etc continues to increase. This has an adverse impact on fiber optic based wireless back-haul
One solution would be to share the conduit or fiber (presumably different carriers would get different fiber cables within the same conduit or use different wavelengths over the same fiber cable via DWDM). Alan said that power for base stations/wireless access points mounted on poles or street lights could also be shared.
The bottom line here is that sharing back-haul facilities among multiple wireless broadband access providers, including light pole sharing for mounting different wireless network nodes there, would lower barriers to entry and free up capital for network growth.
Call for White Space Wireless Broadband in the U.S.:
Mr. Norman summed up by calling for White Space based wireless broadband in the U.S. He said that there are plenty of unused TV channels in the 400M to 698MHz band. He hinted that with less than five percent (5%) of the population watching over-the-air TV over only a few channels, that as much as 250 MHz of spectrum might be freed up for wireless broadband.
After his talk, I asked Alan what technology Google proposes to use for White Space based wireless broadband, considering that the standard IEEE commissioned for that is a commercial failure (802.22) with little or no global deployments. He cited IEEE 802.11af for WiFi sharing and said there was work going on in 3GPP for spectrum sharing using LTE (that’s news to me!).
AW Comment: Wireless broadband via TV white spaces would be particularly useful for deployment of rural broadband, because it would give rural residents broadband wireless access in areas that U.S. carriers feel aren’t densely populated enough to justify a 3G or LTE build-out.
According to the UK Telegram,
“Google and Microsoft are expected to launch a major charm offensive to win control of the valuable airwaves. They could also use the white spaces to provide widespread broadband access, potentially giving them an important calling card with which to win over customers. Google could use the white spaces as a way of offering free wi-fi services to customers with phones powered by its Android operating system, as well as to other members of the public.”
Investment focused Forbes magazine recently weighed in on the rumored Google-Microsoft White Space broadband push in the U.K.
“Could it be in fact that Google and Microsoft also see a way to augment their ability to control infrastructure? And will CISCO be forced to make move into a more consumer-oriented mode? In effect, White Spaces look like a new broadband mobile system.”
Muni WiFi access in Kansas City’s Google Fiber Neighborhood:
During the Q and A, Mr Norman said that there was a muni-WiFi component to Google’s Kansas City FTTH trial. We did some research on this capability and came up with the following:
The Kansas City Star reports that, in promotional fliers for the Google Fiber service, the company said it would also install “Google-powered WiFi hotspots in your favorite public spaces around Kansas City.” A spokesperson for the company said that the WiFi hotspots were part of the agreement with both cities for the initial Google Fiber launch.
Google will install, at their expense, WiFi antennas at over 400 locations in Kansas City. While the WiFi can be set up to be free for the public to use, Google’s spokesperson said, “It’s really up to the discretion of the public building managers.”
For more information see:
A more complete summary of the Nov 2nd Wireless Symposium, including keynote presentations from Leon Beauchman, Director of the Wireless Communications Initiative at Joint Venture Silicon Valley, and Congresswoman Anna Eschoo is at:
[Editor's note: The heat map, in figure 1, showing channel availability was added to this article on 11/15. Thank you Mr. Norman for sharing this important visual aid.]