Low Cost and Secure Smart Meter Communications using

the TV White Spaces

Omid Fatemieh (UIUC)Ranveer Chandra (Microsoft Research)

Carl A. Gunter (UIUC)

• AMI: integral part of smart grid• Reconfigurable nature and communication capabilities

of advanced (smart) meters allow for deploying a rich set of applications– Automated meter reading– Outage management– Demand response– Electricity theft detection– Support for distributed power generation

Advanced Meter Infrastructure (AMI)

2

• ISM bands– Crowded in urban areas– Short distances not

suitable for rural areas

• Cellular links– Expensive and low bandwidth– Crowded in urban areas and limited in rural areas

• Proprietary mesh network technology reduces inter-operability and impedes meter diversity

• Idea: Use white spaces for AMI communications• Propose a secure architecture that yields benefits in cost,

bandwidth, and deployment

Existing AMI Communications

3

• White spaces are unused portions of TV spectrum (54-698 MHz)– Excellent long-range communication and penetration properties

• FCC’s recent rulings (Nov ‘08, Sep ‘10) allows for unlicensed communication in white spaces– Spectrum sensing helps with identifying and assessing quality of unused

channels

• Standards and research prototypes– IEEE 802.22 Wireless Broadband Regional Area Network

• Point to multipoint architecture • Typical range: 17 - 33 km (but up to 100 km)

– WhiteFi [BahlCMMW09 - Sigcomm ‘09]• Wi-Fi like connectivity over white spaces for up to 2km• Adaptively operates in most efficient chunk of available spectrum

• Both require centrally aggregating spectrum sensing data

White Spaces

4

• Utility operates WhiteFi networks• Utility buys service from independent 802.22 service provider

• Large number and geographical spread of meters -> great for spectrum sensing -> utility can offer data to 802.22 provider

Proposed Architecture

5

• High data rates (at low cost)• Single hop from meters to WhiteFi base station

– No need for complex meshes– Saves energy used in mesh maintenance and routing

• Large base of sensors for the 802.22 provider– Lowers cost for 802.22 service provider– Lowers 802.22 service cost for utility

• Lowers cost for providing broadband service to rural areas• Facilitates additional meters deployments in rural areas

(particularly along power lines)

Benefits

6

• Cost of equipping meters with CRs and antennas– Will be lowered with large-scale production– May be lowered for utility by contract with 802.22 provider

• Limited availability of white-spaces– Unlikely in rural and suburban areas– Can use ISM or narrow licensed bands as backup

• Primary emulation / unauthorized spectrum usage attacks– Transmitter localization [ChenPR – JSAC ‘08], Anomaly detection [LiuCTG09 -

Infocom ‘09], Signal authentication [LiuND10 - Oakland ‘10]

• Malicious false spectrum sensing report attacks– Vandalism: falsely declare a frequency as free– Exploitation: falsely declare a frequency as occupied

Challenges and Security Considerations

7

• Particularly important for AMI– Errors will disrupt AMI communication

• 802.22 provider cannot only rely on meters– Meters owned by a different entity (utility)– Meters may not be well-distributed, or get compromised– Must use additional sources for spectrum sensing:

mobile units, consumer premise equipment, or deployed sensors• Sensors have unknown integrity and or get compromised• Detecting false reports

– Based on propagation models [FatemiehCG – DySPAN ‘10] – Based on propagation data [FatemiehFCG – NDSS ‘11]

Detecting False Reports

8

Data-based (Classification-based) Detection

9

• Model-based schemes: not clear which signal propagation models, parameters, or outlier thresholds should be used

• Idea: Let data speak for itself• Provide natural and un-natural

signal propagation patterns to train a machine learning SVM classifier

• Subsequently use classifier to detect unnatural propagation patterns -> attacker-dominated cells

FatemiehFCG – NDSS 2011

Evaluation

10

Flat East-Central Illinois Hilly Southwest Pennsylvania (Stress Test)

• Transmitter data from FCC• Terrain data from NASA• House density data from US Census Bureau

FatemiehFCG – NDSS 2011

• 20km by 20km area • Data from 37 transmitters in 150km radius • Train using data from 29• Test on the data from 8 • Represent un-accounted fading and other signal variations: add

Gaussian variations with mean 0 and std. dev up to 6 (dB-Spread) only to test data

Pennsylvania Stress Test Results

11FatemiehFCG – NDSS 2011

• AMI communications a key part of smart grid• Proposed communication architecture that offers improvements in

bandwidth, deployment, and cost• Discussed security and reliability challenges• Identified exploitation/vandalism as important attacks and

proposed techniques to detect them• References

1. O. Fatemieh, R. Chandra, C. A. Gunter, Low Cost and Secure Smart Meter Communications using the TV White Spaces, ISRCS ’10.

2. O. Fatemieh, R. Chandra, C. A. Gunter, Secure Collaborative Sensing for Crowdsoucing Spectrum Data in White Space Networks, DySPAN ’10.

3. O. Fatemieh, A. Farhadi, R. Chandra, C. A. Gunter, Using Classification to Protect the Integrity of Spectrum Measurements in White Space Networks, NDSS ’11.

Summary

12

Backup

13

• IEEE 802.22 standard draft– Wireless broadband regional area networks over TV white spaces– Point to multipoint architecture (base station to up to 255 clients), with the

possibility of having repeaters in between– Each access point covers 17 - 33 km (typical) but up to 100 km– Antennas 10m above the ground, similar to TV antennas– Support for co-existence between cells

• WhiteFi [BahlCMMW09 - Sicgomm ‘09]– Wi-Fi like connectivity over white spaces for up to 2km– Adaptively operates in most efficient contiguous chunk of available spectrum– Client to access point communication: using modified stock Wi-Fi cards– Requires a separate antenna and board for spectrum sensing

• For spectrum allocation, both techniques support spectrum sensing and using transmitter databases

Standards and Research Prototypes for White-Space Communications

14