6 research outputs found
Differential Privacy-Based Online Allocations towards Integrating Blockchain and Edge Computing
In recent years, the blockchain-based Internet of Things (IoT) has been
researched and applied widely, where each IoT device can act as a node in the
blockchain. However, these lightweight nodes usually do not have enough
computing power to complete the consensus or other computing-required tasks.
Edge computing network gives a platform to provide computing power to IoT
devices. A fundamental problem is how to allocate limited edge servers to IoT
devices in a highly untrustworthy environment. In a fair competition
environment, the allocation mechanism should be online, truthful, and privacy
safe. To address these three challenges, we propose an online multi-item double
auction (MIDA) mechanism, where IoT devices are buyers and edge servers are
sellers. In order to achieve the truthfulness, the participants' private
information is at risk of being exposed by inference attack, which may lead to
malicious manipulation of the market by adversaries. Then, we improve our MIDA
mechanism based on differential privacy to protect sensitive information from
being leaked. It interferes with the auction results slightly but guarantees
privacy protection with high confidence. Besides, we upgrade our
privacy-preserving MIDA mechanism such that adapting to more complex and
realistic scenarios. In the end, the effectiveness and correctness of
algorithms are evaluated and verified by theoretical analysis and numerical
simulations
A Double Auction for Charging Scheduling among Vehicles Using DAG-Blockchains
Electric vehicle (EV) is becoming more and more popular in our daily life,
which replaces the traditional fuel vehicles to reduce carbon emissions and
protect the environment. The EVs need to be charged, but the number of charging
piles in a charging station (CS) is limited and charging is usually more
time-consuming than fueling. According to this scenario, we propose a secure
and efficient charging scheduling system based on DAG-blockchain and double
auction mechanism. In a smart area, it attempts to assign EVs to the available
CSs in the light of their submitted charging requests and status information.
First, we design a lightweight charging scheduling framework that integrates
DAG-blockchain and modern cryptography technology to ensure security and
scalability during performing scheduling and completing tradings. In this
process, a constrained double auction problem is formulated because of the
limited charging resources in a CS, which motivates the EVs and CSs in this
area to participate in the market based on their preferences and statuses. Due
to this constraint, our problem is more complicated and harder to achieve the
truthfulness as well as system efficiency compared to the existing double
auction model. To adapt to it, we propose two algorithms, namely the truthful
mechanism for charging (TMC) and efficient mechanism for charging (EMC), to
determine the assignments between EVs and CSs and pricing strategies. Then,
both theoretical analysis and numerical simulations show the correctness and
effectiveness of our proposed algorithms
Resource Allocation and Pricing in Secondary Dynamic Spectrum Access Networks
The paradigm shift from static spectrum allocation to a dynamic one has opened many challenges that need to be addressed for the true vision of Dynamic Spectrum Access (DSA) to materialize. This dissertation proposes novel solutions that include: spectrum allocation, routing, and scheduling in DSA networks. First, we propose an auction-based spectrum allocation scheme in a multi-channel environment where secondary users (SUs) bid to buy channels from primary users (PUs) based on the signal to interference and noise ratio (SINR). The channels are allocated such that i) the SUs get their preferred channels, ii) channels are re-used, and iii) there is no interference. Then, we propose a double auction-based spectrum allocation technique by considering multiple bids from SUs and heterogeneity of channels. We use virtual grouping of conflict-free buyers to transform multi-unit bids to single-unit bids. For routing, we propose a market-based model where the PUs determine the optimal price based on the demand for bandwidth by the SUs. Routes are determined through a series of price evaluations between message senders and forwarders. Also, we consider auction-based routing for two cases where buyers can bid for only one channel or they could bid for a combination of non-substitutable channels. For a centralized DSA, we propose two scheduling algorithms-- the first one focuses on maximizing the throughput and the second one focuses on fairness. We extend the scheduling algorithms to multi-channel environment. Expected throughput for every channel is computed by modelling channel state transitions using a discrete-time Markov chain. The state transition probabilities are calculated which occur at the frame/slot boundaries. All proposed algorithms are validated using simulation experiments with different network settings and their performance are studied
Designing Truthful Spectrum Double Auctions with Local Markets,β http://iqua.ece.toronto.edu/~weiwang/papers/weiwang-tmc12.pdf
Abstract-Market-driven spectrum auctions offer an efficient way to improve spectrum utilization by transferring unused or underused spectrum from its primary license holder to spectrum-deficient secondary users. Such a spectrum market exhibits strong locality in two aspects: 1) that spectrum is a local resource and can only be traded to users within the license area, and 2) that holders can partition the entire license areas and sell any pieces in the market. We design a spectrum double auction that incorporates such locality in spectrum markets, while keeping the auction economically robust and computationally efficient. Our designs are tailored to cases with and without the knowledge of bid distributions. Complementary simulation studies show that spectrum utilization can be significantly improved when distribution information is available. Therefore, an auctioneer can start from one design without any a priori information, and then switch to the other alternative after accumulating sufficient distribution knowledge. With minor modifications, our designs are also effective for a profit-driven auctioneer aiming to maximize the auction revenue