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

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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