U.S. Spectrum Policy and Technology Reform:

Toward smarter, wider-band radios and denser network infrastructure

Douglas C. SickerDBC Endowed Professor of Computer Science

Director of the Interdisciplinary Telecommunications ProgramCollege of Engineering and Applied Science

University of Colorado at Boulder

Executive Director, Broadband Internet Technical Advisory Group (BITAG)

(former CTO of the U.S. FCC and CTO of the U.S. Dept. of Commerce NTIA)

FIA

Athens, Greece

March 2014

• Broad policy reform efforts • Technical evolution• “Laundry List” of U.S. spectrum policy actions• Measurement & data-driven decision making• Challenges and opportunities

But first a quiz!

Overview

Why technical policy matters – incumbent’s fight innovation

What is this?

Hush-a-phone

Carterphone First certified WLAN

UWB TV Whitespace Device

Broad Policy Reform

Spectrum Task ForceThe task force recommended:• Advances in technology changing

spectrum use• Limits of legacy command-and-

control regulation• Evolve towards more flexible and

market-oriented regulatory models.

• Clear definitions of the rights and responsibilities

• Use of white spaces can be increased significantly

• Additional information and measurement is needed in order to more accurately quantify and characterize spectrum usage

• Interference temperaturePublished 2003

Congressional direction in the Recovery Act led to the creation of the National Broadband Plan

Congress said that the plan should:

• “Ensure that all people of the United States have access to broadband capability and establish benchmarks for meeting that goal.”

• “[I]nclude . . . a detailed strategy for achieving affordability . . . and maximum utilization of broadband infrastructure and service”

• “[I]nclude . . . an evaluation of the status of deployment of broadband service”

• “[I]nclude . . . a plan for use of broadband . . . in advancing consumer welfare, civic participation, public safety and homeland security, community development, health care delivery, energy independence and efficiency, education, worker training, private sector investment, entrepreneurial activity, job creation and economic growth, and other national purposes.”

Published March 16, 2010

Because broadband is the great infrastructurechallenge of the early 21st century and US was (is) falling behind the rest of the world

7

Spectrum: a important part of the NBP

Trends in demand and supply suggest a looming spectrum gap

Need to transform spectrum policy to meet demand

NBP framework for recommendations

Ensure greater transparency in allocation and utilization

Make more spectrum available

Facilitate deployment of spectrum for wireless backhaul

Expand incentives and mechanisms available to reallocate or repurpose spectrum

1 2 3

4

Expand opportunities for innovative spectrum access models

Increase comprehensiveness of spectrum policy

5 6

• Spectrum Dashboard

• License View

• Incentive auctions• Spectrum fees

• 500 megahertz• Numerous bands under

consideration

• More flexible rules • New unlicensed allocation

• Opportunistic use• R&D

• Work with NTIA

• Tribes

• International

Focus on licensed spectrum

• Spectrum important for U.S. economic and technological leadership

• Requires 500 MHz of spectrum to be made available for commercial use within 10 years

• Unlocking the value of otherwise underutilized spectrum

• Open new avenues for spectrum users to derive value through the development of advanced, situation aware spectrum sharing technologies

White House Presidential Memo

What are the available spectrum tools?

Reallocate:– Limited resource (scarcity)– Change the use of spectrum (requires time and money)– Economics (incentive auctions, 2nd use, fees)

Improve efficiency:– Technical (e.g., cellular architecture change, receiver specs

and spectral efficiency improvements)Sharing:

– Many flavors - Geographic, Frequency, Time, Code– We have always shared, but now then new technology

brings to sharing

Let’s start with the allocation problem

The Spectrum Allocation Problem

It is highly divided, allocated and assigned

3-6 GHz band

This band appears to be rather crowded, but …

3 4 5 6 GHz

When measured

It is allocated but not always used - at least not everywhere nor all of the time

Usage varies across band, time and location

Pow

er (

dBm

)

Time and Frequency

“Holes” in both the frequency and the time domain

These white space opportunities but if done wrong -> Interference

Technical Evolution

Toward smarter, wider-band radios.Small cell and indoor deployments.

SDR (regulatory distinction): a computer that generates and understands radio signals

Legacy Radios: defined in hardware

Fixed behavior set by operator

Adaptively adjusts to accommodate anticipated events

Cognitive behavior sense their environment and learn how to adapt

Towards a wideband cognitive radio

If X > 1, Then MOVEElse STAY

Cognitive Radios that sense, learn and adapt

Wideband Cognitive Radio – now we need a CR that can operate across a wideband; oh, and do it cheaply, with enough processing power, while moving and

without interfering!

How are the policy making embracing CR?

Sensing Based Sharing• Sharing based on Dynamic Frequency Selection (DFS) and derivatives• Devices “listen” and perform processing to detect primary

Geolocation (e.g.,TVWS)

• Final rules:– Device identifies its location and

accesses a database that tells the device what spectrum is available

– Database identifies protected services & locations: Full power TV, low power TV, wireless microphones…

– Model is transferrable to other spectrum bands

3 6 8 10Non-

Broadcastspectrum

PhiladelphiaFull PowerTV Stations

WhiteSpace

WhiteSpace

WhiteSpace

Etc.

Low Power TV

Only for illustrative purposes

WirelessMicrophones

Clearing spectrum for licensed use• Incentive auction

Basic idea: - Government “buys” spectrum back from broadcasters- Government “sells” spectrum to mobile broadband

carrier (e.g., Verizon and AT&T)

- Broadcasters are reluctant to “sell” back to government- Problematic repacking (but doable)

• Other bands are under consideration to be cleared for licensed use

An interesting case study:1755 – 1850 MHz Reallocation:

• Analysis– Uses: Airborne Operations (Air Combat

Trainings System, Unmanned Aerial Vehicles, Precision Guided Munitions, ‐Aeronautical Telemetry), tactical radio, covert surveillance, …

– NTIA concluded that the entire 95 MHz can be repurposed but…

• Findings– $18 Billion – 10 years or more– Move DoD into broadcast spectrum

Point-to-Point MW Link Tactical Radio Relay Space Ground Link System Explosive Ordnance Disposal Precision Guided Munitions

Air Combat Training Systems Unmanned Aerial Vehicle Air-to-Ground Telemetry Video Surveillance (nationwide)

FEDERAL OPERATIONS IN THE 1755-1850 MHZ BAND

• Poster-child for sharing! • Use sharing, tolerance, exclusion zones and relocation• CSMAC (a federal advisory committee) process underway

to convene industry and government in this study• Not all 95 MHz desirable by licensed spectrum players

1755 – 1850 MHz

• Airborne Operations (Air Combat Trainings System, Unmanned Aerial Vehicles, Precision Guided Munitions, Aeronautical ‐Telemetry)

• Determine protection requirements for federal operations

• Understanding of periodic nature and the impact to commercial wireless of government airborne operations

• Can the new service tolerate the interference of the incumbent and not interfere? What about exclusion zones?

New models for Interference Tolerance

Question is - can cellular operate around DoD services?

PCAST Spectrum Report

…clearing and reallocation of Federal spectrum is not a sustainable basis for spectrum policy due to the high cost, lengthy time to implement, and disruption to the Federal mission. The essential element of this new Federal spectrum architecture is that the norm for spectrum use should be sharing, not exclusivity. …spectrum should be managed not by fragmenting it into ever more finely divided exclusive frequency assignments, but by specifying large frequency bands that can accommodate a wide variety of compatible uses and new technologies that are more efficient with larger blocks of spectrum.

PCAST high level findings

“the PCAST Spectrum Report”

• Fragmentation of spectrum for exclusive Federal use leads to inefficiency, artificial scarcity, and constraints on current and future users.

• Immediately identify 1,000 MHz of Federal spectrum in which to implement the new architecture

• New approach– Cognitive– Agile Radios– Wideband– Small Cell Technologies– New Architecture– Systems design (receiver specs)– New Metric for Utilization

• Implement a new Federal Spectrum Access System

PCAST – high level recommendations

“Laundry List”

TVWS rollout

FCC authorized approved TV white space database systems (2013)• Provide service to unlicensed radio devices (TVWS devices) that operate

on unused spectrum in the TV bands on a nationwide basis• Follows a related action (December 2012) the Commission’s on-line

unlicensed wireless microphone registration system for large entertainment, sports, and similar venues where a significant number of unlicensed wireless microphones are used

• System allows qualifying major event/production venues to register with the database systems so that their operations of unlicensed wireless microphones and other low power auxiliary station devices will be protected from potential interference caused by TVWS devices

From concept, to testing, to incumbent registration and now WSD trials

TVWS DB testing

The FCC is running TVWS DB trials with specific DB operators (2013-)

During this trial, participants are encouraged to test:• the channel availability calculator• the MVPD receive site (cable headend and satellite receive site) registration utility• the broadcast auxiliary temporary receive site registration utility• the fixed TVWS device registration utility• the wireless microphone registration utility

The trial is intended to ensure that elements of the database system are working properly and providing the interference protection required under FCC rules-Participants are encouraged to report any inaccuracies or provide comments on other issues with any aspect of the database system

This process will allow DB operators to apply corrective measures as needed

Testing is progressing along

Experimental Radio Service

Changes to Part 5 Experimental Radio Service (ERS) 2013

Accelerate the rate that ideas transform from prototypes to devices and services1. Create new opportunities for researchers to use a wide variety of frequencies for

experimentation under a broad research license that eliminates the need to obtain prior authorization before conducting individual experiments

2. Empower researchers to conduct tests in specified locations with pre-authorized boundary conditions through the creation of “innovation zones”

3. Promote advancement in the development of medical radio devices by creating a medical experimental authorization that would be available to qualified hospitals, Veterans Administration (VA) facilities, and other medical institutions

4. Broaden opportunities for market trials by revising and consolidating our rules5. Promote greater overall experimentation by consolidating and streamlining our

existing rules and procedures

Make it easier to get and use experimental licenses, while protecting incumbent users

Interference LimitsFCC TAC explores the concept of an Interference limit (2013 - )

Some equate this to receiver standards -In-band and out-of-band interfering signal levels that must be exceeded before a radio system can claim that it is experiencing harmful interference (inspired by Receiver standards and OFCOM’s SUR)-Statistical : a threshold is exceeded if the observed signal strength exceeds the stated value for more than some percentage of locations and times, at some specified confidence level

An interesting concept but difficult to enact

Measuring MobileFCC Mobile BB Speed App – extends “Sam Knows” (2013 - )

Measuring Broadband America 2013 – FCC speed test app for Android2014 – FCC speed test app for iPhone

• Same interface and technologies • Challenging privacy issues (Deep commitment to PII or UII collected)• Contributes information to the public on the nation’s mobile broadband performance

There are some differences between apps: • iOS app cannot run periodically in the background; need to run tests manually

Step toward furthering network measurement

MSS SpectrumSatellite spectrum converted to (co-exist with) mobile services (2???)

Lots happening

Globalstar petitioned the FCC to operate FDD LTE service in parts of its spectrum band spanning 1610-1618.725 and 2483.5-2495 MHz (channel 14 spanning 2473 – 2495 MHz)

3.5 GHz

Spectrum Access System in the 3.5 GHz Band (2013 - )

• Recent proposal to make at least 100 megahertz of spectrum available for shared small cell use in the 3550-3650 MHz band

• The NPRM proposed the creation of a dynamic Spectrum Access System (SAS) to govern interactions between and among devices in the 3.5 GHz band

• Three tiers of access- Incumbent Access; Priority Access; and General Authorized Access

• Workshops explored the technical requirements, architecture, and operational parameters of the SAS

• Recently FCC sought additional comments

SAS extends earlier concepts tied to TVWS; builds on PCAST efforts

5 GHzBattles in 5 GHz – U-NII and ITS bands (2013 - )

Many bands in play: -U-NII-1: 5.15-5.25 GHz, Indoor use only, 50 mW-U-NII-2: 5.25-5.35 GHz, outdoor & indoor, Dynamic Frequency Selection (DFS), 250mW-U-NII-2e: 5.47-5.725 GHz, outdoor & indoor use, DFS, 250 mW-U-NII-3: 5.725 to 5.825 GHz, U-NII / IS, 1W (WISPs)-ITS band: 5.85-5.925 GHz, dedicated short-range communications for vehicles • Many players

- Auto industry wants guarantee that unlicensed users not interfere with auto collision-avoidance system that sit in 5.9 GHz

- Vendors and ISPs say this is 75 MHz of underutilized spectrum; need to remove restrictions on indoor use of band and allow for higher powers

- Battle between cellular and Wi-Fi over LTE-A in unlicensed bands- Globalstar uses the 5.15 GHz spectrum for MSS feeder links

- ISPs want to expand for 802.11ac - Wider use of Wi-Fi in the 5.35-5.47 GHz and 5.85-5.925 GHz bands - More …

Very interesting space to watch!

Inter-Service Interference Checking

Evaluating new methods

FCC looking to create a new predictive model (2013 - )

Methods to define thresholds of coverage and interference with engineering specifications to create a predictive model (tends toward overly conservative methods)

60 GHzFCC modified Part 15 of its rules for intentional radiators operating on an unlicensed basis in the 57-64 GHz frequency range (2013)1) Allow higher emission limits for 60 GHz devices that operate outdoors with

very high gain antennas to encourage broader deployment of point-to-point broadband systems

2) Specify the emission limit for all 60 GHz devices as an EIRP power level to promote repeatability of measurement data and provide uniformity and consistency in the rules

3) Eliminate the requirement for certain 60 GHz devices to transmit identification information (transmitter ID)

• Rules allow longer communication distances for unlicensed 60 GHz point-to-point systems that operate outdoors; thereby extend the ability of such systems to provide broadband service

• Other interesting work happening in the THz range

Backhaul and direct BB access

RF Exposure

FCC Report and Order (Order), Further Notice of Proposed Rulemaking (Notice) and Notice of Inquiry (Inquiry) on RF exposure (2013)

Order – minor regulations implementing NEPA (Environmental Protection) and NHPA (Historic)

Notice – propose to update and revise procedures and treat all services equally

Inquiry – determine whether RF exposure limits and policies need to be reassessed

• Proceeding does not reach the issue of whether exposure limits are appropriate

Delay decision making because of lack of record

MISC – Architecture, Enforcement, WRC 15

Enforcement will be a challenge

VARIOUS OTHER ITEMS (2013 - 2014)

Architecture:FCC encouraging new architectures for most efficient use of the radio spectrum – Cloud, SDN, C-RAN and Small-cellEnforcement:Numerous challenges as we move toward new spectrum models and tools. Less resources, harder problems.Also great opportunity – e.g., in automation through dense deployment of cheap spectrum analyzers with feedback to DBWRC 15:Let’s skip this one!

Measurement & Decision Making

National Broadband MapLicense ViewSpectrum DashboardSamKnows

National Broadband Maphttp://www.broadbandmap.gov/

License Viewhttp://reboot.fcc.gov/license-view/

Spectrum Dashboardhttp://reboot.fcc.gov/reform/systems/spectrum-dashboard

Challenges and opportunities…

Where are we making progress?• Policymakers are embracing trends toward

– Small cell– SDR/CR– Wideband/multiband– Sharing – Database and sensing– Additional unlicensed– Thinking about systems approach (e.g., Harms Claim Threshold)– Data focused

• Technology is progressing but more work needed– Need for additional R&D– Better HW & SW; better models, methods and measurements– Where’s the market?– What enforcement model (security models)?– What are the incentives?– What else do the Regulators need to do?

• Better HW & SW (reconfig HW, DSP, sensing, multi-band…)– Affordable, dynamic receivers that can move around in a wide band with high

channel selectivity

• Sensing versus GeoDB – in a world of high protection ratios– “Dumb” detectors can't match performance of a matched filter

– Broadcasters want protection below kTB, not practical, hence GeoDB  • Incumbents demand high detection probability (Pd), which drives false alarm

probability (Pfa) high - more sophisticated time-frequency signal processing (cyclostationary) improves the situation...but at what cost?

• Proper operation – ensuring the GeoDB system– Progress is being made, but focus required on coordination, validation, security…

• Processes for detecting, identifying, locating, mitigating and reporting interference sources; building confidence that the applicable rules and regulations regarding such sharing will be enforced

• Which Bands? Are we focusing on the wrong spectrum?– Most attention on .6-6 GHz, but 6-90 GHz ( and beyond) might be a better focus

Some basic challenges remain

Thank you

(sicker@colorado.edu)

• Spectrum Sharing Partnership Steering Committee – an Advisory Committee of Industry Representatives – to Advise on Federal Spectrum

Sharing System Implementation

• Scalable Real World ‐ Test Services – (a Test City and Mobile Test Service) to test Federal Bands and Public Safety

• Release R&D Wireless Innovation Fund (WIN) ‐ Appropriated in 2012 Payroll Tax Agreement

• Formalize the White House‐based Spectrum Management Team (SMT)

• Support International Harmonization of new Shared Federal Bands• Implement a Mechanism that gives Federal Agencies Incentives to

Share Spectrum (e.g., Spectrum Currency)• Redefine Spectrum Relocation Fund to Revolving “Spectrum

Efficiency Fund”• Experiment with new shorter term licensing models

PCAST – detailed recommendations

• Developing meaningful coexistence models• Better measurement, modeling and

thresholding – a system• Application aware closed coupling models• Realtime measurement

My personal interests - Coexistence Modeling

Modeling Propagation

Questions:• Which is right?• What about actual measurements?• What about realtime measurements?

Images courtesy of Dale Hatfield

Measured versus Modeled

Question: How do we measure?

Thresholds Matter

Slides courtesy of Matthew Oetting (and EDX)

2 dB!