abacus

© 2013 UZH, CSG@IFI 1

Challenging the Monopoly of Mobile Termination Charges with an Auction-based Charging and User-centric System (AbaCUS)

Christos Tsiaras, Burkhard Stiller

Department of Informatics IFI, Communication Systems Group CSG, University of Zürich UZH

[tsiaras|stiller]@ifi.uzh.ch

NetSys 2013 Stuttgart March 13, 2013

Background High level architecture The AbaCUS protocol

The AbaCUS main components Summary

Future work

© 2013 UZH, CSG@IFI 2

Background

q  Voice service consumer –  Caller –  Callee

q  Voice service price schema –  The caller's provider fee –  Mobile Termination Rate (MTR)

q  MTR is a monopoly –  Only home MNO can terminate calls –  Voice service consumers does not

consider the termination rate before establish a contract

–  MTR raise does not affect MNOs –  MTRs are being regulated

Home MNO Competitive MNO

FNO MNO VoIP

Caller

Callee MSISDN

Contract

Call termination service

Call initiation service

X

I need a new contract! Termination rates?

What is this?

MNO

termination rate

Regulator

The termination rates has been raised? Why do I care?

MTR

© 2013 UZH, CSG@IFI 3

AbaCUS high level architecture q  The caller can reach the callee

through his home MNO q  The callee could be reached by

any MNO –  A virtual MSISDN would be needed

q  An Auction Authority (Au2) will define which MNO will terminate the call –  The call termination service request

parameters are defined by the Quality of Service Class (QoS-C)

–  The price for the call termination service is defined by the Termination Rate Class (TeR-C)

–  The winning MNO decision is made through an auction

Callee (MSISDN)

Home MNO Competitive MNO

Dial the MSISDN Dial a

virtual MSISDN

QoS-C demand

TeR-C demand

FNO MNO VoIP

Caller

Au2

© 2013 UZH, CSG@IFI 4

The AbaCUS protocol

4: Notify

5: Free to register

6: Register

8: Place a call

Update TeR-C / location & QoS-C

ACK

AbaCUS auction traffic AbaCUS protocol traffic Mobile telephony traffic

ACK

Update TeR-C / location & QoS-C

3: Service request

MNO1 MNO2 Au2

Periodic Updates

Callee Caller

7: Ready to call

1: Callee Data (CD)

2: Response

© 2013 UZH, CSG@IFI 5

Quality of Service Classes (QoS-Cs) q  Defines a service request q  QoS

–  Call set-up priority –  Sound quality

QoS-C Call set-up priority Maximum sound quality expected Critical 1st Maximum Excellent 4th Maximum Important 2nd High High 3rd High Normal 5th Good Medium 6th Good Low 7th Good Best-effort 8th Low with possible disconnections Fault-tolerant 9th Low with possible disconnections Poor 10th Low with disconnections expected

© 2013 UZH, CSG@IFI 6

Termination Rate Classes (TeR-Cs)

q  Defines the price for the requested service –  Call set-up price –  Call rate –  Virtual dial-in numbers

TeR-C Call set-up price Rate Premium Standard Premium VIP Standard High Gold Standard Normal Silver - High Bronze - Normal Economy - Low Low Standard Low rate after the 3rd minute Budget Low Low rate after the 3rd minute

Special Standard - Free Low -

0900 xyz vwz

0800 xyz vwz

11 xyz Virtual dial-in Numbers (MSISDNs)

© 2013 UZH, CSG@IFI 7

The AbaCUS auction (1)

TeR-C5

TeR-C3

TeR-C5

TeR-C4

TeR-C5 TeR-C5

Vickrey’s auction

AbaCUS auction

1st bid 2nd bid Winning bid

Bidders: consumers Auctioneer: seller

Bidders: MNOs Auctioneer: “caller” (Au2)

Winning bid: higher Price: next lower bid

Winning bid: lower Price: next higher bid

TeR-C3

TeR-C4

TeR-C5

Winning bid: lower Price: lower bid if next higher bid > lower bid + 1

if next higher bid = lower bid + 1

© 2013 UZH, CSG@IFI 8

The AbaCUS auction (2)

All AbaCUS auction results Auction # Winner Draw case

1 MNO1 ✗

2 MNO1 ✗

3 MNO1 ✔

4 MNO1 ✔

5 MNO2 ✔

Draw winners history Draw # Winner

1 MNO1

2 MNO1

3 MNO2

Last two non draw winners history

w1 MNO1

w2 MNO1

© 2013 UZH, CSG@IFI 9

AbaCUS Auction Evaluation

q  Honest bids incentive –  A winning bid can still be rejected if it is higher than the user’s threshold –  A winning bid increases the MNO's chances to win a future auction in

case of a draw •  Only the non-draw and the non-rejected winning bids are taken in to consideration

–  The winning bidder has a chance to receive a higher TeR-C than the originally requested one

–  The second higher bid will be chosen IFF it is higher at most by one respective TeR-C

•  “Winner-blocking” is not allowed. A bidder is not motivated to place high bids in order to force the caller to reject the second higher bid, which will be proposed to the caller

q  Prisoner's “honest dilemma” –  The bidder is honest (H) –  The bidder is lying (L) MNO1-MNO2 L-L L-H

MNO1-MNO2 H-L H-H

© 2013 UZH, CSG@IFI 10

Auction Authority (Au2)

Au2 q  The area is divided in to grids q  The Au2 receives from the

MNOs their bid per QoS-C and grid periodically

q  The winning bid per QoS-C, grid, and period is calculated

q  When a caller sends a request to the Au2 the precalculated winning bid is proposed to the caller

q  The Au2 will reject the MNO's offer if it is higher than the caller's tolerance

MNO1: Normal → Free MNO2: High → Bronze

High request Gold tolerance

High request Free tolerance

High → Gold

Normal → Low

© 2013 UZH, CSG@IFI 11

Stakeholders

MVNO MNO

Network operators

MNO’s & MVNO’s subscribers

Caller Callee Regulator

Social networks Au2

Au2 provider

Legal relation Economic relation

© 2013 UZH, CSG@IFI 12

Summary

q MNOs subscribers – The caller sets his preference – The caller can influence the final price of the call

q MNOs – Potential infrastructure maximization – QoS-guarantee services offer is possible

q Regulators – Low MTRs regulation demand – Dynamic, live, and on-demand MTRs competition

© 2013 UZH, CSG@IFI 13

Future work

q  System evaluation in a simulated environment q  Protection mechanism in case that a user pay for a

QoS-C but never received it –  QoS monitoring/measuring mechanism

•  Rely on caller's/callee's honesty?

q  System prototyping q  Accounting mechanism for call related data q  Efficiency of such a system in other markets

–  Fixed telephony –  VoIP

© 2013 UZH, CSG@IFI 14

Q & A

Thank you!