white space networking: the road ahead ranveer chandra microsoft research
TRANSCRIPT
White Space Networking: The Road Ahead
Ranveer ChandraMicrosoft Research
Challenge 1: Limited Capacity due to Growing Demand
Devices Proliferation*
VideoUploads
Mobile Data Traffic**
Streaming VideoIncreasing Wireless Demand
20X - 40XOVER THE NEXT
FIVE YEARS
50 BILLIONCONNECTED DEVICES
BY 2020
35X2009 LEVELS
BY 2014
24 HOURSUPLOADED EVERY
60 SECONDS
*See Ericsson Press Release, quoting its President and Chief Executive Officer Hans Vestberg, April 13, 2010, available at http://
www.ericsson.com/thecompany/press/releases/2010/04/1403231
**. Federal Communications Commission, Staff Technical Paper, Mobile Broadband: The Benefits of Additional Spectrum, OBI Technical Paper No. 6 (Oct. 2010).
Challenge 2: Limited Range for Universal BB Access
2 Billion Internet
Connected Consumers
555 Million Wired Broadband
Subscribers
943 Million Wireless
Broadband Subscribers
5 Billion Cell Phones
*2010 Estimates: ITU World Telecommunications/ ICT Indicators database
Most Spectrum Is Not Used Most of the Time
We Are Experiencing Exponential Mobile Data
Growth
We Need to Promote Technologies That Make
More Efficient Use of Spectrum
Spectrum Policy Needs to Become More Nimble
Industry Forecasts of Mobile Data Traffic
0X
5X
10X
15X
20X
25X
30X
35X
40X
45X
50X
2009 2010 2011 2012 2013 2014
Traf
fic R
elat
ive
to 2
009 Cisco
Coda
Yankee Group
Average
Increasingly sophisticated online databases that automate spectrum allocation and use.
Wideband radios with sensing, channel notching, suppression, bonding, and other capabilities.
Our Ask of Policy Makers
We need policies that allow dynamic access to more spectrum across a range of bands, enabling complementary shorter-range and wide-area networks, and automated and adaptive solutions.
Powerful, yet inexpensive hardware and software technologies now offer new and more attractive solutions to our longstanding spectrum allocation problems (cognitive radios, online databases that automate spectrum allocation and data networks that can dynamically modulate their transmission power)
Adopting these advances will enhance the user experience by enabling literally billions of new devices as they go live over the course of the next decade on the Internet of Things.
We need policy makers to create opportunities for new technologies that are available today AND more nimble policy frameworks
TV band white spaces database access represents a version one opportunity. Greater capabilities and spectrum bands will be enabled.
TVWS is a FIRST STEP
• TV band white spaces are gaps left between broadcast channels
• They occur in different places on different channels
What are TV White Spaces?
Database Access Safeguards Incumbents from Interference – This is No Free-For-All!
White Spaces
Base Station
White SpacesClient Device
TV White Spaces
Link
White Spaces Database 1. Devices only use the TV white spaces
channels specified by the database.2. Devices are required to re-check the
database for the list of available channels.
3. Databases are prohibited from providing devices access to the channels occupied by incumbent operators (e.g., broadcasters).
4. Databases are required to maintain up-to-date lists of protected operators.
5. Databases can block newly occupied channels to prevent further white spaces device access.
• Operation of unlicensed devices on unused channels in the TV bands Protection for licensed
services And some others
• Available channels identified via Geo-location capability Database access
TV White Spaces Access
• Query the availability database• Transmit in “available
frequencies”• Detect if primary user appears • Move to new frequencies• Adapt bandwidth and power levels
Pow
e r
Frequency
PU1
PU2
PU4
PU3
Sample TV Band Channels Available for White Spaces Devices
UHF TV Bands Enable New Wi-Fi Opportunities
10 50 100
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Capacity versus RangeTVWS TVWS-Fixed WLAN-2.4 WLAN-5
Range (meters)
Capacit
y (
Mega b
its p
er
second)
Wi-Fi , 2.4 GHz
Wi-Fi , 5 GHz
TV White Spaces, 600 MHz
Source: BT Innovate & Design
Sub 1 GHz: Key to Ubiquitous Access
This slide shows the results of simulating the coverage that could be achieved, with 20% access point penetration, in a 1 km2 urban area, with 5K population, in Fulham, London. The simulation was repeated for each of the three bands
TV White Spaces Signals Travel Farther
Wi-Fi: 100 Meters
TV White Spaces: 400 Meters (with increased flexibility, could be up to 8 kms or more)
Four times the distance; 16 times the area covered. Same power comparing 2.4 GHz to 600 MHz. The result is more bandwidth, lower network costs, lower power consumption.
TV White Spaces Signals Penetrate More Walls
•In a typical home, a Wi-Fi signal can penetrate up to two walls. At the same power, a TV white spaces signal can penetrate more walls and obstacles, enabling whole home media distribution.•This will simplify and enrich in-home/in-building networking opportunities.
• Utilizing long range characteristics Rural broadband
Wide-coverage hotspots
Bridge among small networks
Sensor network
Wireless surveillance system
Cellular offloading
• Utilizing obstacle penetration/avoidance characteristics M2M –factory floor automation
Indoor video distribution
Device to device network
Potential TV White Spaces Use Cases
Greater Spectrum Sharing Opportunities Should Be Pursued
Who I am.
What I am.
Where I am.
Database-enabled sharing will evolve from simple look up tables to real time arbiters of spectrum access and usage (e.g., accounting for the cost of interference, filtering capabilities, power limits,
geolocation and mobility, prioritization, and duration).
TodayIn the Future, Additional
Variables Will be Considered
My willingness to pay/be paid for interference.
My desired power output.
My out-of-band emission mask.
My knowledge of nearby transmissions (sensing).
My geolocation accuracy.
My spectrum tuning range.
My desired quality of service.
Am I moving.
Where I am going.
When I will get there.
How long I will be there.
© 2011 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions,
it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.
• Devices are permitted to emit radio frequency energy without a specific grant of a license. Devices still undergo certification and are subject to regulatory
oversight. In the case of white spaces, databases operate under authority
granted by the relevant regulatory authority.• Devices cannot cause harmful interference to licensed operations.
And, they must accept interference from operation of an authorized radio station.
• Licensed and unlicensed uses can readily coexist. Complementary business models Each supports the other (think Wi-Fi in a coffee shop)
What Is “Unlicensed” Spectrum Use?
• 20,339 unlicensed devices certified in 2.4 GHz spectrum band Three times more than any other band
• Wi-Fi devices will use more bandwidth than wired devices in 2015• Mobile data offloaded to Wi-Fi from the networks of mobile
operators Expected to reach almost 90% by 2015
• Wi-Fi accounts for over 50% of mobile user connections to the Internet
• The Internet of Things is coming …
The Value of Unlicensed Spectrum