Effect of Social Relations on Cooperative Sensing in ... · Effect of Social Relations on Cooperative Sensing in Cognitive Radio Networks CanGüven,$Suzan$Bayhan*,$Fatih$Alagöz $

Effect of Social Relations on Cooperative Sensing in

Cognitive Radio Networks

Can Güven, Suzan Bayhan*, Fatih Alagöz

Department of Computer Engineering, Boğaziçi University, Turkey * Helsinki Institute for Information Technology HIIT, Aalto University, Finland

Can Güven – BlackSeaCom 2013 Effect of Social Rela;ons on Coopera;ve Sensing in Cogni;ve Radio Networks

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Agenda

¨  Introduc)on ¤  Coopera)ve Sensing ¤  Social Network Analysis

¨  Key Contribu)ons ¨  Social-‐Aware Coopera)ve Spectrum Sensing (SAC)

¤  System Model ¤  SAC ¤  RAND (Social-‐Oblivious Scheme)

¨  Performance Analysis ¨  Conclusion and Future Direc)ons


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Cooperative Sensing

¨  Coopera)ve vs. Local Sensing ¤  Improvements

n Combined decision accuracy n  Spectrum capacity gain

¤ Messaging overhead – Repor)ng delay ¤ Common effec)ng factor: User selec)on

n  Independent, non-‐malicious users n Coopera)on investment must have posi)ve returns

n  Clever selec)on of coopera)ng CRs


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Social Network Analysis

¨  Social Network Analysis (SNA) ¤ Rela)ons, paOerns between en))es ¤ Social Characteris)cs

n Understanding the Implica)ons

¤ Popularity of online social networks

n Need to study social rela)onships and )es n  SNA: Important tool

n  Crea)ng a new design approach n  New protocols, policies or applica)ons


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¨  Friendship and Community in SNA ¤ Posi)ve Social Characteris)cs

¨  Selfishness in SNA ¤ Nega)ve Social Characteris)cs (ra)onality)

¨  Long term characteris)cs, less vola)le.


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¨  Homophily ¤ Similar interests – befriending, behavior, contact

¨  In our work ¤ To assign friendship )es ¤ Use friendship and community rela)ons

n  Select coopera)on set n  Evalua)ng if a node should respond


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Key Contributions

¨  New CRN Model ¤ CRs’ opera)on mimic human socie)es ¤ No assump)on of altruis)c coopera)on ¤ Social Aware Scheme

n Clever choice of coopera)on candidates n  Exploit mutual sympathy n  Select accep)ng and trustworthy CRs (RAND?)

¨  Bringing two emerging research domains together ¤ Social Networks & Cogni)ve Radio Networks


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System Model

¨  CR in the system ¤ C – Community ¤ Lf – Friend list ¤ Ls – Sympathy list ¤ Lc – Coopera)on score list ¤ β – Coopera)on tendency / selfishness

¨ Wireless device with a social context


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System Model

¨  Community Membership ¤  Interests, educa)on etc.

¨  Assigning of communi)es to users ¤  Random

¨  Assignment of friends ¤ Homophily


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System Model

¨  Friend list Lf ¤  Sta)c vs. Dynamic

¨  Dynamic ¤  Sympathy list – changes in community percep)on ¤  Coopera)on score list -‐ Lc

n Memory n Previous and most recent


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System Model

¨  Coopera)on Tendency (Selfishness) – β ¤ Dominant in a CR’s response ¤ Social )e – selfishness (can be altered by social )es)

n  Selfishness high – friends only n Average selfishness – same community may be enough


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Social-‐Aware Cooperative Spectrum Sensing (SAC)

¨  Operates in three steps: ¤ STEP 1: Coopera;on set selec;on

n  Friend score, community score, coopera)on score n Coopera)on receiving CRs respond (social )es and tendency)

¤ STEP 2: Coopera;ve sensing n Majority Logic from accep)ng CRs

¤ STEP 3: Upda;ng scores n Community and coopera)on scores


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Social-‐Unaware Cooperative Spectrum Sensing (RAND)

¨  RAND operates in two steps ¤ Coopera)on set selec)on:

n Randomly select CRs from the grid n Coopera)on receiving CRs respond according to tendency

¤ Coopera)ve Sensing

¤ No contact memory or social-‐)e based knowledge.


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Malicious Users

¨  Realis)c model ¤ Exploit coopera)ve sensing

¨ Malicious user ¤ Also a CR with social informa)on

¨  Opera)on ¤ Accept ¤ No sensing ¤ Return busy channel result


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Performance Analysis

¨  Simula)on Scenarios ¤ Effect of Coopera)on Tendency β ¤ Effect of Maliciousness dm


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¨  β vs. Opportunity discovery ra)o


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¨  dm vs. probability of malicious user coopera)on


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¨  dm vs. opportunity discovery ra)o


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Conclusion

¨  We have presented a coopera)ve sensing scheme ¨  Makes use of social rela)ons (homophily)

¨  Selec)ng cooperators

¨  Eliminates the altruis)c coopera)ve behavior assump)on ¨  Modeling coopera)on tendency according to social )es

¨  Makes use of previous coopera)ons ¨  Sensing performance memory

¨  Trust mechanism between users ¨  Experience, recommenda)on and knowledge


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Conclusion

¨  Strengths ¨  Dis)nguish malicious and selfish users ¨  Prefer eager-‐to-‐cooperate CRs ¨  Local > coopera)ve sensing if coopera)ve sensing isn’t beneficial

¨  Weakness ¨  Prejudice and sympathy for communi)es

¨  SAC outperforms RAND overall. ¨  Benefits of social-‐aware models over social-‐oblivious models.


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Future Directions

¨  Extending the model to various network models ¨  e.g. Erdős–Rényi (ER), Barabási–Albert model

¨  Currently: Individual preven)on mechanisms ¨  Network-‐wide methods of encouraging coopera)on

¨  And discouraging selfishness/malicious ac)vity ¨  Quicker discovery of malicious nodes

¨  Random mobility –> Homophily


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Thank you.

Any ques)ons?

Contact Info: [email protected]

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Effect of Social Relations on Cooperative Sensing in ... · Effect of Social Relations on Cooperative Sensing in Cognitive Radio Networks CanGüven,$Suzan$Bayhan*,$Fatih$Alagöz $