modular wireless networks for infrastructurally -challenged environments
DESCRIPTION
Modular Wireless Networks for Infrastructurally -Challenged Environments. PhD Proposal Talk Mariya Zheleva. PhD Advisor: Committee Members:. Professor Elizabeth Belding, UCSB Professor Heather Zheng , UCSB Professor Ben Zhao, UCSB Ranveer Chandra, Microsoft Research. - PowerPoint PPT PresentationTRANSCRIPT
Modular Wireless Networks for Infrastructurally-Challenged
EnvironmentsPhD Proposal TalkMariya Zheleva
PhD Advisor:
Committee Members:
Professor Elizabeth Belding, UCSB
Professor Heather Zheng, UCSBProfessor Ben Zhao, UCSBRanveer Chandra, Microsoft Research
2Connectivity as an Enabler
Economic growth High-quality workforce Improved job-search Purchasing ability
[internetinnovation.org][Silicon Alley Insider]
Education Online education Remote tutoring
Healthcare Disease spread prediction
3Affordability and Accessibility
Source: ITU
Prepaid handset-based (500MB)
Postpaid handset-based (500MB)
Prepaid computer-based (1GB)
Postpaid computer-based (1GB)
0 10 20 30 40 50 60 701.3
1.2
2.2
1.4
15.7
11.3
24.7
18.8
11.4
7.5
17.7
12.7
38.8
36.2
58.3
54.6
Price of mobile broadband services, 2013(% from monthly income)
Africa World Developing Developed
An African may pay 39 times more than a Westerner for Internet access.
4Affordability and Accessibility
Source: ITU
5Subscription Trends
Mobile subscriptions approach the world population
Plain Cellular
Developing world subscription stats do not capture the number of people with access
People carry multiple SIM cards Pricing Coverage availability
6Subscription Trends
Computer-basedMobile-based
BroadbandBroadband access is still very limited.
7
“Mobile network operators find it commercially infeasible to operate in rural areas.”
World Bank’s 2012 report on maximizing mobile
8Why Commercially-Infeasible?
9What if the call could be local?
10Thesis Statement
In order to optimize user experience, rural networks and applications need to be highly modular and use this modularity to switch between global and local context according to network conditions and demand.
In order to optimize user experience, rural networks and applications need to be highly modular and use this modularity to switch between global and local context according to network conditions and demand.
In order to optimize user experience, rural networks and applications need to be highly modular and use this modularity to switch between global and local context according to network conditions and demand.
11
Identifyingchallenges
Connectivitysolutions
Sociological Approach(interviews)
Cellular network traces analysis
Internet traffic analysis
Enabling network performance analysis
Bringing visibility to rural users [ICTD13]
Community detection in cellular [ICTD13]
Internet usage [IJoC12]
Cellphone usage [MobiSys13]
Cellphones in healthcare [GSWC12]
The bandwidth divide [IJoC12]
The increased bandwidth fallacy
[ACM DEV13] and WiP
AirLab [SIGCOMM CCR11]
Technological Approach
Connectivity
Long distance Last mile
PHY/MAC Layer Application Layer
Applications
VillageLink [COMSNETS14]
HybridCellWiP
Kwiizya [MobiSys13]
ImmuNet [GSWC12]
*WiP – Work in Progress
Completed
In progress
TxMinerWiP
Bringing visibility to rural users [ICTD13]
The increased bandwidth fallacy
[ACM DEV13] and WiP
Kwiizya [MobiSys13]
Identifying Challenges
13Methodology: Sociological Approach
Goal:• Understand cellphone usage• Cellphones in healthcare
Methodology:• In-person interviews• Volunteer at the hospital in Macha
14Methodology: Technological Approach
Goal:• Cellphones (rural vs. urban) :
• Usage• Provisioning• Community detection
• Internet:• Usage• Performance• Avenues for improvement
Methodology:• Cellular: Analysis of large-scale datasets• Internet: Rural network traffic analysis
Antenna-to-antenna statistics
Egocentric graphs over
time
Identifying Challenges: Internet Usage
16Network ArchitecturePre-upgrade
Macha WLAN Internet
Switch
MonitoringServer
Gateway
Post-upgrade
Macha WLAN Internet
Switch
MonitoringServer
Gateway
DL: 256kbps (bursting to 1Mbps)
UL: 64kbps
2Mbps
[Zheleva, Schmitt, Vigil, Belding, ACM DEV 2013]
17
PostPre
Background of Analysis
April 9th, 2011
Long-Term (LT)
March 9th – April 9th, 2011
April 9th – May 9th, 2011 July, 2011
While bandwidth increase may improve network usability, it is not proportional to improved user experience.
[Zheleva, Schmitt, Vigil, Belding, ACM DEV 2013]
time
18Implications on Content Access/Generation
TCP Flow analysis: Success and Failure of TCP Uploads and Downloads
[Zheleva, Schmitt, Vigil, Belding, ACM DEV 2013]
x4
19Usage: Top Web Sites
[Zheleva, Schmitt, Vigil, Belding, ACM DEV 2013]
20Usage: Top-4 Services Success and Failure
[Zheleva, Schmitt, Vigil, Belding, ACM DEV 2013]
*200 – OK 400 – Bad Request 408 – Request Timeout
21The Increased Bandwidth Fallacy
• Increased bandwidth can improve usability• Bandwidth increase not proportional to improved user experience• Prioritize bandwidth for critical services• E.g. software updates
[Zheleva, Schmitt, Vigil, Belding, ACM DEV 2013]
Internet Local WLAN
Increased 400 and 408 + Failure to update Mozilla
= Prioritize SW update
22
Identifyingchallenges
Connectivitysolutions
Sociological Approach(interviews)
Cellular network traces analysis
Internet traffic analysis
Enabling network performance analysis
Bringing visibility to rural users [ICTD13]
Community detection in cellular [ICTD13]
Internet usage [IJoC12]
Cellphone usage [MobiSys13]
Cellphones in healthcare [GSWC12]
The bandwidth divide [IJoC12]
The increased bandwidth fallacy
[ACM DEV13] and WiP
AirLab [SIGCOMM CCR11]
Technological Approach
Connectivity
Long distance Last mile
PHY/MAC Layer Application Layer
Applications
VillageLink [COMSNETS14]
HybridCellWiP
Kwiizya [MobiSys13]
ImmuNet [GSWC12]
*WiP – Work in Progress
Completed
In progress
TxMinerWiP
Bringing visibility to rural users [ICTD13]
The increased bandwidth fallacy
[ACM DEV13] and WiP
Kwiizya [MobiSys13]
Identifying Challenges:Bringing Visibility to Rural Cellular Users
24Bringing Visibility to Rural Users
December 1, 2011 April 1, 2012
Aggregate # calls/hourAggregate duration of calls/hour
Antenna IDLatitude
Longitude
Antenna IDLatitude
Longitude
+ AfriPop population density dataset
+ OECD typology
< 150/km2 – Rural150 – 300/km2 – Suburban
> 300/km2 – Urban
[Zheleva, Schmitt, Vigil, Belding, ICTD 2013]
Orange in Cote D’IvoireAntenna-to-Antenna communication
25Bringing Visibility to Rural Users
98% Rural territory2% Urban territory
[Zheleva, Schmitt, Vigil, Belding, ICTD 2013]
26Bringing Visibility to Rural Users
[Zheleva, Schmitt, Vigil, Belding, ICTD 2013]
Urban Rural
23
70
Same antenna calls - w/o TRANSPORTATION
% o
f cal
ls
High locality of rural cellular communications.
51.7% of rural antennas are TRANSPORTATION.
27Bringing Visibility to Rural Users
Mobile cellular services are expensive.Prepaid is prevalent.
Urban Rural23
70
% o
f cal
ls
Rural users are under-provisioned.
High locality of interest.
An African may pay 39 times more than a Westerner for Internet access.
Improve the situation by providing alternatives.
Connectivity Solutions: Local Cellular Network
Services in Remote Areas
29Kwiizya*: Architecture
* Kwiizya means “to chat” in Tonga
[Zheleva, Paul, Johnson, Belding, MobiSys 2013]
30Kwiizya: Architecture
[Zheleva, Paul, Johnson, Belding, MobiSys 2013]
31Kwiizya: Call Switching
[Zheleva, Paul, Johnson, Belding, MobiSys 2013]
32Kwiizya: SMS Switching
[Zheleva, Paul, Johnson, Belding, MobiSys 2013]
33Support of SMS Applications (IM-SMS)
[Zheleva, Paul, Johnson, Belding, MobiSys 2013]
34Macha, Zambia
Source: GoogleMaps
[Zheleva, Paul, Johnson, Belding, MobiSys 2013]
35The Base Station
A RangeNetworks SNAP unit
[Zheleva, Paul, Johnson, Belding, MobiSys 2013]
36Installation Sites
LITAWater Tower
[Zheleva, Paul, Johnson, Belding, MobiSys 2013]
37Power Quality in Macha
[Zheleva, Paul, Johnson, Belding, MobiSys 2013]
38The Power Supply
[Zheleva, Paul, Johnson, Belding, MobiSys 2013]
39The Network in Macha
[Zheleva, Paul, Johnson, Belding, MobiSys 2013]
40Evaluation• 20 SIM cards• Local partners (IT staff)• Restricted registration• Voice and SMS
[Zheleva, Paul, Johnson, Belding, MobiSys 2013]
41Controlled Experiments Setup
[Zheleva, Paul, Johnson, Belding, MobiSys 2013]
42Performance: SMS Delay
[Zheleva, Paul, Johnson, Belding, MobiSys 2013]
SMS delivery in Tanzania takes between 6 and 16 seconds depending on provider.
43Performance: Call Quality
[Zheleva, Paul, Johnson, Belding, MobiSys 2013]
GSM FR (6.10)Min delay 20ms
GSM FR (6.10)Max MOS 3.46
44Performance: IM to SMS
[Zheleva, Paul, Johnson, Belding, MobiSys 2013]
45Performance: IM to SMS
[Zheleva, Paul, Johnson, Belding, MobiSys 2013]
46
Identifyingchallenges
Connectivitysolutions
Sociological Approach(interviews)
Cellular network traces analysis
Internet traffic analysis
Enabling network performance analysis
Bringing visibility to rural users [ICTD13]
Community detection in cellular [ICTD13]
Internet usage [IJoC12]
Cellphone usage [MobiSys13]
Cellphones in healthcare [GSWC12]
The bandwidth divide [IJoC12]
The increased bandwidth fallacy
[ACM DEV13] and WiP
AirLab [SIGCOMM CCR11]
Technological Approach
Connectivity
Long distance Last mile
PHY/MAC Layer Application Layer
Applications
VillageLink [COMSNETS14]
HybridCellWiP
Kwiizya [MobiSys13]
ImmuNet [GSWC12]
*WiP – Work in Progress
Completed
In progress
TxMinerWiP
Bringing visibility to rural users [ICTD13]
The increased bandwidth fallacy
[ACM DEV13] and WiP
Kwiizya [MobiSys13]
TxMinerWiP
HybridCellWiP
Proposed Work: HybridCell: Coexistence
of Cellular Networks
48HybridCell: Architecture
L-Cell
C-Cell
Village
*C-Cell – Commercial cell*L-Cell – Local cell
RTL-SDRsniffer
Observe
Control
49
RF Frontend
HybridCell vs. Commercial Network
In-Village Out-Village
Users
Loca
l (Kw
iizya
)Co
mm
erci
al
BTS
BTS
RNC
MSC
SGSN
HLRVLR
GGSN
PSTN
Internet
Core Network
MSC+VLR+HLR + GSN
Internet Gateway
Wireless
Expensive: Highly centralized Hardware Software Backbone
Low-cost: Local SDR hardware Open-source software Generic IP backbone
50HybridCell Use-CasesLocal Services for End Users Local Services for Organizations
Low-Cost Packet-Switched Data Disaster Communications
[Source: BBC]
51HybridCell: Research Challenges
• Understanding the state of rural commercial cellular access:• Measuring signal quality – capture SNR using an RTL-SDR setup• Measuring packet-switched data quality
• HybridCell use with existing SIM.• User-triggered• System-triggered
• Monitoring C-Cell’s activity:• RTL-SDR setup• Use TxMiner
• Mobile data offload through local cells.
Proposed Work: TxMiner: DSA beyond TV
White Spaces
53TxMiner: DSA Beyond TV White Spaces
512MHz 700MHz
-130
dBm
-60d
Bm
Power Spectral Density: TVWS
-130
dBm
-30d
Bm
30MHz 6000MHz
-110dBm
Power Spectral Density: Beyond TVWS
54TxMiner Goal
Power Spectral Density Graph
PSD,
dBm
/Hz
Frequency, MHz
Transmissions:• Bandwidth• TDMA/FDMA• Mobility• Direction
55
• Enhance existing DSA systems
• Support spectrum regulations in developing nations and worldwide
TxMiner Applications
• TX periodicity• TX bandwidth• Mobile TX over time• Primary or Secondary
TxMiner-enhancedDSA Database
Secondary User Network
1) Spectrum availability?
2) Spectrum availability +
Transmitter Characteristics
3) Bandwidth X satisfies user
demand
Geo-location database
56In Conclusion
• Identified challenges associated with access• Cellular networks• Internet
• Designed solutions for local cellular access• With support for SMS applications
• Propose extensions• Cellular networks coexistence• DSA beyond TV White Spaces
Thesis Statement: In order to optimize user experience, rural networks and applications need to be highly modular and use this modularity to switch
between global and local context according to network conditions and demand.
57PhD Timeline NOV DEC JAN FEB MAR APR MAY JUN
Africa conferences and fieldwork
Preparing job applications
TxMiner evaluation and paper submission
HybridCell research
HybridCell paper
Increased bandwidth fallacy, journal PhD dissertation and
defence
Preparing job talk/interviewing
58
Thank you!Mariya Zheleva
This work was done in collaboration with: Elizabeth Belding; Veljko Pejovic; David
Johnson; Arghyadip Paul; Morgan Vigil; Paul Schmitt; Partners from LinkNet, Macha; Kate
Milosavljevic