NorthwesternUniversity

McCormickSchoolofEngineeringandAppliedScience

MasterofScienceinInformationTechnology

MSIT413:WirelessTechnologies

InternetforAll:StratosphericsolutionsbyGoogle

LoonandFacebookDrone

AbdulsalamA,HangLi,JieZhangMarch16,2014

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TableofContent

Introduction

Figure1:Top20connectedcountries,bypriceandspeed

StratosphericSolutions

Overview

Table1:LoonvsDrone

GoogleProjectLoon

Engineering/HowLoonWorks

StratosphericEnvironment

Figure2:Wavecurrentandballoonsmovement

Figure3:Stratospherebyaltitude

Balloon

Figure4:LoonvsDrone

Power

Figure5:SolarpanelforLoon

Figure6:Batteryinsulation

CircuitryandTransmission

Figure7:PatentcircuitryofLoon

Figure8:Originalon-boardcircuitryforearlypilots

Connectivity

Figure9:MeshnetworkofLoon

Figure10:Dualpolarizeddipoleantennaforthereceiver

TechnicalconsiderationsforProjectLoon

FacebookDrone

Figure11:TitanSolaraDrone

Regulatory/PoliticalIssues

Costandwhatnext?

Criticisms

Conclusion

Appendix

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Introduction

Over the past 25 years of internet and evolution of the world wide web, some population of

the world have enjoyed the benefits and goodies of online lifestyles while other majority

have not experienced an hour of internet. The thought that everyone is on the internet is

very wrong, and this is true, because for every one connected person, there are two

unconnectedpeople.

The way the world works is changing; we used to live in a resource based economy where

things are shared or traded, but the world is now a knowledge economy, which means we

can share knowledge and information almost freely to improve our lives. The imagination of

how a connected world can provide basic information such as primary health care data,

education and research, environmental data, media and entertainment, etc to the rest of the

world is a serious concern, because the internet is the backbone of the knowledge economy.

Indeed, if everyone had access to basic information and tools, then everyone would benefit

fromthecreativity,innovationandideasthateveryoneembodies.1

The reason behind the access challenge is obvious; the high cost of providing internet

connectivity, due to the level of technology and current infrastructure. The paradox is that;

as it is ineffective and costly for ISPs to expand especially into rural, low economic regions,

so also people living below the poverty line of $1 per day can not afford the highly priced

internet service. Even in the developed world, where most have disposable incomes to join

this knowledge economy, the cost and speed of access is still a challenge. Figure 1 belows

shows the top 20 connected nations, and its obvious that no appreciable throughput can be

achievedfor$1permonth.

Figure1:Top20connectedcountries,bypriceandspeed

1Making internet affordable by Mark Zuckerberg - http://www.youtube.com/watch?v=AdXwthh-xLQ

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The challenge poses the idea of finding alternate solutions, that can balance the

ever-growing needs of global development. Interestingly, there has been some research

works, trying to solve the problem. There are also several papers presented in the past 10

years on scalable approaches, that will either improve current technologies or completely

disruptwithsomethingnew.

However, five interesting ideas may likely make a difference if successful . These wireless 2

solutionsareinnovativeandscalable;

● Low-orbitingsatellites

● Metamaterialantennas

● Balloons

● Drones

● TVwhitespace

While low-orbiting satellites are almost the same as satellite communication systems, there

are good business reasons for the approach. Also, metamaterial antennas are not new, but

are redefined for cheap usage in high-powered transceivers or base station . TV whitespace, 3

is quite a challenge, because it tries to solve the problem from the spectrum standpoint,

which becomes policy and change issues. TV white space lobbyists are trying to re-acquire

unusedTVfrequenciesforwirelessinternetserviceandimprovespectrumefficiency.

Two keys solutions are referred to as stratospheric solutions . The concepts tries to 4

address; Ubiquity, True Coverage, Reliability, Affordability and Scalability. Importantly, to

note is that the current iterations of these projects are funded not by Government or

research labs, but by vested interests that have excess funds to support research and

development to fruition. This is also obvious, because these companies have markets to

coverandgainenoughpotentialsforitsbusinesses.

Google Inc. (Google X lab) is in active research on using Balloons to activate wireless

internet connectivity to everyone, with its Project Loon . Currently, in its pilot stage, 30 5

balloons floated in New Zealand in Summer of 2013, show positive results. Google strongly

believes that the stratosphere is common to everyone and with the amount of data available,

thismediumcanbehelpsolvetheinternetdivide.

Similarly, after the demonstration of a drone-like airship called stratellite, by a Mexican

company, Titan Aerospace; with the capability to carry wireless communication devices,

Facebook Inc. is convinced that investing in such a companies promises further development

of an ubiquity solution. While the drones are almost ready for commercial purposes, there

arecontinuedeffortstointegratethesedroneswithcurrentcommunicationinfrastructure.

The project intends to highlight some of the features and engineering behind the Project

Loon and Facebook Drone (Titan Solara 60) and detail some regulatory, economics and

policyissuesinvolvedtoachieveinternetaccessforall.

2 http://spectrum.ieee.org/telecom/wireless/five-ways-to-bring-broadband-to-the-backwoods3 http://spectrum.ieee.org/telecom/wireless/intellectual-ventures-invents-beamsteering-metamaterials-antenna4 http://spectrum.ieee.org/aerospace/satellites/an-eye-in-the-sky5 www.google.com/loon

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StratosphericSolutions

Overview

GoogleLoon FacebookDrone

TransceiverMedium Balloon Drone

Highaltitude 20miles(32km) 11miles(18km)

Duration 100days 5years

Coverage 1,250km2 17,000km2

MotionSpeed 8-32km/h 104.5km/h

Spectrum 2.4GHzand5.8GHz 5.8GHz

Datarate lessthan0.1Gbps greaterthan1Gbps

ResearchandDevelopment In-house(Xlabs) External(TitanAerospace)

Additionalservices VOIP Surveillance

Table1:LoonvsDrone

GoogleProjectLoon

Loon is currently designed to work at 3G speed over unlicensed 2.4GHz and 5.8GHz

spectrum, floating in the stratosphere high above aircrafts, using helium filled

balloon.

Engineering/HowLoonWorks

StratosphericEnvironment

Because the wind below 10km of altitude is not favorable, and because balloons can

not be positioned even above that tropopause, an algorithm is developed to control

movement or flow of the balloons based on national wind data, just like the sailing of

boat to shoreline, adjusting them along right currents in the direction of waves of the

wind.

Figure2:Wavecurrentandballoonsmovement

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Figure 3 below shows altitude levels above the atmosphere and somewhat indicate

that theoretically, radio waves behave well in free space, with no interference of

signal,andpowerisattenuatedbypathlosscoefficientlowerthan2

Figure3:Stratospherebyaltitude

Balloon

The material for the manufacturing the balloon is polyethene, simply 3 times thicker

than typical bread wrapper ~0.076mm (0.030in). These balloons have super

pressure design that can withstand harsh UV radiation and temperatures as low as

-58F. When inflated, each balloon has a dimension of about 50 feet wide, and 40 feet

tall. Also, the balloons have customized electronic air-pump system that control

mixture of helium and air, as the balloon ascend or descend in altitude. In case of

failure, a parachute is installed for safe landing of the payload. Figure 2 below shows

a section of a fully inflated balloon. The balloon released be circling the globe

continuouslyalongthe40thparallel.

Figure4:LoonvsDrone

Power

To power the circuitry and motion of the balloons, the only intuitive solution is solar

energy. However, the temperature at this altitude is really low (-100F), and the

radiation of sun is only for a fraction of the day. This is a challenge for

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solar-powered batteries that allow each balloon to transmit signals, run the heater so

the electronics don’t freeze, and change altitudes to navigate . Alternate or backup 6

solution are therefore required. Figure 5 below shows a proposed 5x5 feet array of

solarpanels,thatwillpower100Wsystemandchargebatteriesfor4-5hours.

Figure5:SolarpanelforLoon

An earlier iteration of Loon, shows that Lithium ion batteries were initially

implemented for dark hours. See Figure 7. However, the system is built to be

self-sustaining and fully employs renewable scheme. To keep the batteries warm

enough to function efficiently, despite the cold environment, special casings and

insulation are designed and tested for true proof. Figure 6 is a shining insulation that

reflectsheatenergybyradiation7

Figure6:Batteryinsulation

6 https://plus.google.com/+ProjectLoon/photos/photo/58965199041087483227 https://www.youtube.com/watch?v=EPDzpxFkTvM

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CircuitryandTransmission

Each balloon carries a payload of about 10 kg, including but not limited to radio

antenna, several sensors, altitude control system, processor chips and batteries.

Figure 7 is a possible patent diagram of the circuitry . The on-board antenna uses an 8

Ubiquiti Network Rocket M2 as a WIFI transceiver. A customized Linux OS is also

loaded on a processor chip to manage and transmit network and location data. The

OSisloadedwithsoftwarethatcanloggedontoremotelyviatheweb.

Figure7:PatentcircuitryofLoon

Thirditerationoforiginalcircuitryforearlypilots isshownbelowinfigure7;9

Figure8:Originalon-boardcircuitryforearlypilots

8 http://www.patentbolt.com/2013/11/googles-high-altitude-balloon-network-called-project-loon-is-revealed-in-new-patent.html9 https://plus.google.com/+ProjectLoon/photos/photo/5964725567087891410

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Connectivity

There are several ground stations with transceivers similar to that on the balloon, but

they are high-powered Ubiquiti AirMax/Rocket M5 (operating at 5.8Ghz). The 10

network is designed as a mesh layout to ensure reliability. A ground station already

connected via either fiber or other backbone infrastructure to the internet, beams

signal to any nearby balloon. The first balloon that receives the signal, then 11

forwards or hops the signal up to 5 other balloons on its same path in sequence, a

distanceofabout100km(62miles).Figure9showsthemeshstructureofLoon

Figure9:MeshnetworkofLoon

Each balloon then hops the WIFI signal to ground users with coverage of about 1,256

km2 (780 sq miles), in context the twice the size of New York City. Users can receives

signal via smartphones or customized dual-polarization dipole antenna through an

accesspoint.Figure10showscurrentiterationofthegroundreceiverantenna.

Figure10:Dualpolarizeddipoleantennaforthereceiver

10 http://community.ubnt.com/t5/The-Lounge/Internet-for-all/m-p/491445#M2427011 http://www.google.com/loon/how/

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TechnicalconsiderationsforProjectLoon

Radio: Loon’s current radio design negatively interfere on the ground in more

developed areas, due to fading, scattering and Rayleigh effects. This would definitely

affect other local WIFI signals. There would be so much signals and noise in the

airwaves, that may require changes in regulation and implementation of other

technologies.

Connectivity: The WIFI card (Rocket M5) is assumed to be MIMO 802.11a/g/n

standard and uses TDMA, that can deliver 150 Mbps throughput at +50 km, but still 12

the latency is pretty high (about 700+ms), this may be due to the moving balloons.

This may not be a viable option for VOIP service, which could motivate adoption of the

service. Generally, some salient issues still exist, such as interference management

between balloons; handoff between balloons; fading from the ground stations;

latencymanagementanderrorcontrol.

FacebookDrone

Confirmed reports, have it that Facebook is likely going to acquire a Mexico-based

company ; Titan Aerospace for $60m. Titan’s solar-powered drones, which can 13

reportedly stay airborne for five years, can help Facebook achieve its goal of

providing Internet access around the world. In theory, a solar-powered drone

capable of withstanding long flights at high altitude. Titan had demonstrated it debut

Solara 50 and 60, in 2013, showing possibility to provide communication services,

from just above the Tropopause (close to the atmosphere), 60,000 feet altitude that

the FAA doesn't control. Facebook is said to be especially interested in the Solara 60,

a featherweight aircraft built of composite materials that the New Mexico-based

company claims can maintain an altitude of 65,000 feet for years without refueling,

thankstothousandsofsolarcellsblanketingtheaircraft.

Figure11:TitanSolaraDrone

12 http://dl.ubnt.com/datasheets/rocketmgps/RocketM_Ti_DS.pdf13 http://www.theverge.com/2014/3/7/5473692/facebook-drone-titan-aerospace-project-loon

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Solara60

Solara are mounted with both LOS and BLOS (Beyond Line of Sight) small, low cost

radio repeaters and/or transmitters. The repeater receives the signals from

transmitters on the selected radio frequency (RF) channel and then re-transmits them

on another frequency to a receiver. The Solara 60 can complete most of the same 14

functions as an orbital satellite, but is cheaper and more versatile. It can also stay at

an altitude of 20 km for up to five years, without ever having to come back down and

refuel. The platform works exactly like regular satellite communication systems but

are better. Solara can last up to 5 years, has 120 ft wingspan and 50 ft long, has

speeds greater than 1 Gbps, has larger coverage than 1018 sq miles and efficient

powermanagement .15

The Solara offers about an 18-mile radius of coverage—easily covering all of New

York City's five boroughs, as shown in the map below. A "constellation" of Solara craft

could create a persistent communication network for disaster relief efforts or could

providelong-termservices.

Regulatory/PoliticalIssuesThe biggest obstacles for these projects are not definitely technology or funding, but

regulation and politics. Mesh networks are nothing new, and dirigibles have been around

since the time of Graf Zeppelin . The minefield here is entirely political. Both Google and 16

Facebook, need to maneuver some critical issues. First, is the use of airspace; secondly is use

oftheISMunlicensedspectrum;thirdlyisfearofinsecurityandSpying.

14 http://wordlesstech.com/2013/08/22/solara-an-affordable-alternative-to-satellites/15 http://www.wired.com/business/2014/03/facebooks-drones-launch-race-airborne-internet/16 http://gigaom.com/2013/06/21/project-loon-googles-biggest-obstacle-isnt-technology-its-politics/

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Airspace

This is the portion of the atmosphere controlled by a country above its territory,

including its territorial water, more generally, any specific three-dimensional portion

of the atmosphere. There are many rules regarding airspace and who controls it, and

also disagreements as to how far (up) such control extends. Although, space is still an

open frontier, loosely regulated by international treaties, most governments consider

the stratosphere above them their sovereign airspace, which is why they shoot down

spyplanesthatventureintoit.

Spectrum

The signals currently propagate in the unlicensed ISM spectrum (2.4 and 5.8GHz) the

pilot period. The Internet signals travel in the unlicensed spectrum, which means

Google and Facebook drone do not have to go through the onerous regulatory

processes required for Internet providers using wireless communications networks

orsatellitesduringexperiment.

However, the scenario is not as simple as WiFi. When Google or Facebook become a

global ISP; actually providing or selling internet service, like any communications

service provider are regulated and governments will likely want some say in how that

access is offered, what they can charge, and ultimately whom they are allowed to

connect. Also It can’t just use any old spectrum either. It will have to convince

hundreds of different regulators to agree on a unified band or ride over an existing

one. But the scope and range of Google Loon or Facebook Drone network will likely

requirededicatedairwaves.

Security

This is the part that governments are concerned most about. It revolves around

countries and citizens’ safety to a large extend. With recent NSA and data theft/leak

incidences, both Google and Facebook may need to work harder to assure the

countries it is working with that the network is secure and agree to terms and

conditions of these countries. This is paramount, because some country leaders,

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prefertobeoutofinternet,thantobeattackedbytheUSanditsallies.

Costandwhatnext?The cost for deploying a single balloon is not too high, but Google is planning to fly

about 70,000 balloons to be economically logical on a global scale. The estimated cost

for the pilot in New Zealand for only 30 balloons is about $1.8 million. However, the

cost alone for a single UAV manufactured by Titan is about $2million. This cost does

notincludetheinternetservice.

Item Cost ($)

Polyethyleneplasticenvelopes 4,000

Heliumgas 2,000

Solarpanel 500

Navigationcontrolsystem 1,000

Equipmentbox 12,000

19,500

Totalofcostofballoons(30) $585,000

Stationconstructionand

equipmentinstallation$1,200,000

EstimatedTotal(fornew

zealandpilot)$1,785,000

The difference in economics is the area covered by Google (about 780 sq mile), while

Facebook Drone may even spend more for the projected 1080sq mile. There is also

additional cost for private WIFI licenses which will be dictated by different

governments.

Research continues and patents are been filed everyday to quickly commercialize the

project. Some of the next phases for Google, is work on efficient deployment

mechanisms. Figure 12 shows a system filed for patient. A truck that deliver balloons

andautomaticallylaunchthesystemwithouthumantouch.

Figure12a:Solarpoweredtruck Figure12b:Balloonself-deployment

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Criticisms● Temple University communications professor Patrick Murphy warned of

mixed consequences, pointing to China and Brazil as places where Internet

service promoted democratic principles but also contributed to a surge in

consumerismthathasresultedinenvironmentalandhealthproblems.

● There are some opposing voices such as Bill Gates, who has questioned

whether Google's Project Loon, an effort to bring giant internet-giving

balloons to less-developed countries, is really that good of an idea. During an

interview with Bloomberg Businessweek, Gates was asked whether he thought

bringing internet to parts of the world would help solve problems. "When

you're dying of malaria, I suppose you'll look up and see that balloon, and I'm

notsurehowit'llhelpyou."

ConclusionIndeed in the nearest future, everyone may eventually have affordable high-speed internet.

Both Google Inc and Facebook Inc have devoted themselves to providing worldwide internet

access, and the technologies seem promising. Though, the world may hold different opinions

about such research and solutions, it keep technology enthusiasts excited that after all there

is hope to make the world a global knowledge economy. And the competition between the

twocompanywouldmakestratosphericsolutionapossibility.

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AppendixRocket M2 and M5 datasheet

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