Emanuele Di Pascale, Hamed Ahmadi, Linda Doyle, Irene Macaluso
Neutral Host Small Cell Providers (SCP) represent a key element of the 5G\nvision of ultra-dense mobile networks. However, current business models mostly\nfocus on multi-year agreements for large venues, such as stadiums and hotel\nchains. These business agreements are regulated through binding Service Level\nAgreements (SLAs), which tend to be too cumbersome and costly for smaller scale\nSCPs. As a result, the neutral host model does not scale up to its full\npotential. In this paper, we propose a framework to enable the participation of\nsmall- to medium-sized players in the cellular market as providers offering\nnetwork resources to Mobile Network Operators (MNOs). To this purpose, we\nreview the current and emerging spectrum and technology opportunities that SCPs\ncan use for neutral host deployments. We also propose the use of\nblockchain-enabled smart contracts as a simple and cost-efficient alternative\nto traditional SLAs for small-scale SCPs. To demonstrate this, we describe a\nproof of concept implementation of an Ethereum-based smart contract platform\nfor best-effort service between an SCP and an MNO. Our simulations on potential\nsmart contract-based deployments in city centre Dublin show that the received\nsignal strength in the considered area will increase by an average of $10$\npercent.\n
Milan Patnaik, G. Prabhu, Chester Rebeiro, Vashek Matyáš · 5 authors
Spectrum Sharing Data Falsification (SSDF) attacks can cause heavy performance degradation to Cognitive Radio (CR) based Internet of Battlefield Things (IoBT) networks. The challenge in such networks is to handle this security problem real time, in addition to spectrum sharing. This requires a robust CR architecture and protocol that can provide integrity of the spectrum sensing data being shared between Secondary Users (SUs) for collaborative spectrum decisions in protocols like PROLEMus. We propose one such protocol called Proactive Blockchain based Spectrum Sharing (ProBLeSS) protocol which leverages a blockchain to provide security against SSDF attacks in CR-IoBT networks.
Multiple-operators (multi-OPs) spectrum sharing mechanism can effectively improve the spectrum utilization in fifth-generation (5G) wireless communication networks. The secondary users are introduced to opportunistically access the licensed spectrum of idle operators (OPs). However, the identity privacy and data security issues raise great concerns about the secure spectrum sharing among multi-OPs. To address these challenges, a consortium blockchain trust framework is proposed for the spectrum sharing in multi-OPs wireless communication networks in this paper. A real consortium blockchain is constructed among multi-OPs. The Multi-Ops Spectrum Sharing (MOSS) smart contract is designed on the constructed consortium blockchain to implement the spectrum trading among multi-OPs. Without the need of trustless spectrum broker, the MOSS smart contract enforces multi-OPs to share the spectrum truthfully and designs a punishment mechanism to punish malicious OPs. Simulation results tested on the Remix integrated development environment (IDE) indicate the feasibility of the designed MOSS smart contract. The performance analysis of the proposed consortium blockchain trust framework demonstrates that the privacy, openness and fairness of the proposed solution are better than traditional spectrum allocation solutions.
In cognitive wireless networks, multi-node cooperative spectrum sensing can effectively improve the accuracy of spectrum sensing, but there is a non-linear relationship between the number of nodes and sensing accuracy. Nodes with low reliability participate in cooperative sensing, which is not conducive to the improvement of sensing accuracy, and reduces the energy efficiency of spectrum sensing, which poses challenges to the normal operation of cognitive wireless networks. In order to improve energy efficiency and sensing performance, this paper proposes the node evaluation and scheduling (NES) algorithm and the Secure Spectrum Sensing based on Blockchain (SSSB) algorithm, which can evaluate the reliability of sensing nodes in real time, and obtain the trust value of the node. The nodes information is stored in the management center of blockchain. Blockchain encrypts nodes information to ensure that a node corresponds to its own trust value without confusion. Fusion Center of cognitive wireless networks select good performance nodes to participate in cooperative spectrum sensing. Which can reduce energy consumption while improving the sensing performance. The simulation experiment results show that the new algorithm in this paper is far superior to the traditional algorithm. Under the same other conditions, the detection probability is increased by 5%, and the energy consumption is reduced by 10%, and the safety index has also been greatly improved.
Multiple-operators (multi-OPs) spectrum sharing mechanism can effectively improve the spectrum utilization in fifth-generation (5G) wireless communication networks. The secondary users are introduced to opportunistically access the licensed spectrum of idle operators (OPs). However, the identity privacy and data security issues raise great concerns about the secure spectrum sharing among multi-OPs. To address these challenges, a permissioned blockchain trust framework is proposed for the spectrum sharing in multi-OPs wireless communication networks in this paper. The Multi-OPs Spectrum Sharing (MOSS) smart contract is designed on the constructed permissioned blockchain to implement the spectrum trading among multi-OPs. Without the need of trustless spectrum broker, the MOSS smart contract enforces multi-OPs to share the spectrum truthfully and designs a punishment mechanism to punish malicious OPs. The MOSS smart contract is tested on the Remix integrated development environment (IDE) and the gas costs of MOSS smart contract is estimated. The performance analysis of the proposed permissioned blockchain trust framework demonstrates that the privacy, openness and fairness of the proposed solution are better than traditional spectrum allocation solutions.
Traditionally, dynamic spectrum access (DSA) based on cooperative spectrum sensing relies on a centralized fusion centre to fuse and store the sensing results, which is vulnerable to single point of failure. In this paper, we propose a sensing-based DSA framework which is enabled by blockchain. The proposed DSA framework includes a protocol that specifies a time-slotted-based five-phase operations. In the proposed framework, each secondary user (SU) acts as both a sensing node for cooperatively sensing the spectrum and a node, i.e., a miner and a verifier, in the blockchain network for mining and updating the sensing and access results in a distributed and secure manner without the need for a fusion centre. In order to incentivize SUs for participating in such energy-consuming operations of the blockchain network, we reward them with tokens for sensing and mining, which can be used to bid for the access to the spectrum opportunities. The sensing and mining policies which they use to determine when to sense and mine affect the number of tokens they can obtain and subsequently how they bid for the spectrum. Hence, the performance of the system depends on their sensing-access-mining policy. Therefore, we consider a heuristic sensing-access-mining policy that determines whether to participate in sensing and mining in a probabilistic manner and that determines how much to bid based on its buffer occupancy and the number of available tokens. Simulation results show that although increasing sensing and mining probabilities can increase average transmission rate, it also leads to higher energy consumption. Moreover, there exists an optimal set of sensing and mining probabilities that maximize the system energy efficiency.
The demand for frequency is continuously increasing owing to the growth of wireless communication devices and the development of network technology. To share frequency effectively in a limited frequency resource environment, studies to develop spectrum-sharing technology should be conducted. In this study, a blockchain-based spectrum- sharing system, in which various types of users can efficiently share spectrum in dense networks, is proposed. Furthermore, a method to apply game theory to obtain cooperation from users who do not participate in the spectrum-sharing system is studied. When the simulation was conducted based on game theory, the proposed blockchain-based spectrum-sharing technique was simulated by using the tit-for-tat (TFT) strategy, in which the system cooperates with the users if the users collaborate and the system does not cooperate with the users if the users do not collaborate. Simulations show that there are more than a certain percentage of users who use the TFT strategy, and if users are encouraged to change their sharing strategy on a regular basis, they can provide more efficient spectrum sharing than traditional centralized methods. It was confirmed that this technique can improve spectrum sharing by 55.1% or more through optimization.
Taras Maksymyuk, Juraj Gazda, Longzhe Han, Minho Jo
The concept of spectrum and infrastructure sharing appeared to solve the problem by allowing operators to cooperate between each other. However, the current architecture of mobile network, which is mostly based on the centralized management entities is not suitable for the spectrum and infrastructure sharing due to the complexity of billing procedure. Moreover, the operator oriented mobile network is slowing the overall technological development, because operators must balance between capital expenditures and profit margins. Such situation negatively affects users, because they are either experience lower quality of service or forced to pay higher price. In this paper, we propose a new intelligent network architecture, which leverage the blockchain technology to handle relationship between operators and users based on smart contracts. The new unlicensed spectrum sharing algorithm between operators using the virtual cryptocurrency has been developed based on game theory. Simulation results show that proposed algorithm achieves Nash equilibrium between operators within few seconds.
Wireless Virtualization (WiVi) is emerging as a new paradigm to provide high speed communications and meet Quality-of-Service (QoS) requirements of users while reducing the deployment cost of wireless infrastructure for future wireless networks. In WiVi, Wireless Infrastructure Providers (WIPs) sublease their RF channels through slicing to Mobile Virtual Network Operators (MVNOs) based on their Service Level Agreements (SLAs) and the MVNOs independently provide wireless services to their end users. This paper investigates the wireless network virtualization by leveraging both Blockchain technology and machine learning to optimally allocate wireless resources. To eliminate double spending (aka over-committing) of WIPs' wireless resources such as RF channels, Blockchain - a distributed ledger - technology is used where a reputation is used to penalize WIPs with past double spending habit. The proposed reputation based approach helps to minimize extra delay caused by double spending attempts and Blockchain operations. To optimally predict the QoS requirements of MVNOs for their users, linear regression - a machine learning approach - is used that helps to minimize the latency introduced due to (multiple wrong) negotiations for SLAs. The performance evaluation of the proposed approach is carried out by using numerical results obtained from simulations. Results have shown that the joint Blockchain and machine learning based approach outperforms the other approaches.
The concept of blockchain radio access network (B-RAN) was proposed to integrate cross-network resources including spectra and infrastructures to meet the explosive growth of diverse connectivity needs. In this work, we consider the prototype design of B-RAN and address the issues arising in its implementation. To reduce the access delay, we develop a fast smart contract deployment (FSCD) for B-RAN. Also, we propose the concept of digitized spectrum assets (DSA) in B-RAN for efficient spectrum sharing and management. We further summarize and demonstrate the B-RAN prototype enhanced by the newly introduced FSCD and DSA, along with the overall workflow. We apply comprehensive simulations based on an inhouse experimental platform to illustrate the effectiveness of the proposed B-RAN prototype.
Martin B. H. Weiss, Kevin Werbach, Douglas Sicker, Carlos Caicedo
Spectrum sharing mechanisms have evolved to meet different needs related to increasing spectrum use efficiency. At first, decentralized and opportunistic cognitive radios (and cognitive radio networks) were the primary focus of research for these mechanisms. This gradually transitioned toward the development of cooperative sharing methods based on databases, typified by TV white spaces databases. Spectrum sharing is now the basis for the dynamic and fine-grained spectrum rights regime for the citizen's band radio service (CBRS) as well as for license shared access (LSA). The emergence of the cryptocurrency Bitcoin has stimulated interest in applying its underlying technology, blockchain, to other applications as well, such as securities trading and supply chain management. This paper explores the application of blockchain to radio spectrum management. While blockchains could underlie radio spectrum management more broadly, we will focus on dynamic spectrum sharing applications. Like the cooperative approaches currently in use, blockchain is a database technology. However, a blockchain is a decentralized database in which the owner of the data maintains control. We consider the benefits and limitations of blockchain solutions in general, and then examine their potential application to four major categories of spectrum sharing.
Although a massive amount of bandwidth is available at mm-waves, physics dictates the use of legacy frequencies in the sub 6-GHz range. This necessitates dynamic spectrum access in the face of exponentially growing spectral demands. However, disorganized spectrum sharing causes interference, leads to a chaotic situation, and loss of capacity. Moreover, it is difficult to ensure that the primary users are compensated for sharing their licensed bands. We propose a Blockchain-based platform to address these limitations. A digital token, called spectral token, is introduced to validate and track the use of a licensed frequency band while enforcing sequential access to spectrum by secondary users to avoid interference. The proposed platform enables both advertising and sensing based spectrum sharing under different leasing policies. Such sharing and leasing policies are coded into smart contracts, which digitally enforce the contractual clauses of the leasing agreement. When a deal is made, the smart contract automatically transfers the spectral token between primary and secondary users within the agreed time frame while paying the primary user in cryptocurrency. We developed a proof of concept solution using the Ethereum Blockchain to demonstrate the utility of the proposed platform and its throughput and latency characteristics.
Nguyen Cong Luong, Tran The Anh, Huỳnh Thị Thanh Bình, Dusit Niyato · 6 authors
To ensure that the data aggregation, data storage, and data processing are all performed in a decentralized but trusted manner, we propose to use the blockchain with the mining pool to support IoT services based on cognitive radio networks. As such, the secondary user can send its sensing data, i.e., transactions, to the mining pools. After being verified by miners, the transactions are added to the blocks. However, under the dynamics of the primary channel and the uncertainty of the mempool state of the mining pool, it is challenging for the secondary user to determine an optimal transaction transmission policy. In this paper, we propose to use the deep reinforcement learning algorithm to derive an optimal transaction transmission policy for the secondary user. Specifically, we adopt a Double Deep-Q Network (DDQN) that allows the secondary user to learn the optimal policy. The simulation results clearly show that the proposed deep reinforcement learning algorithm outperforms the conventional Q-learning scheme in terms of reward and learning speed.
Mobile network operators can expand their capacity by aggregating their licensed spectrum with the spectrum discovered opportunistically, i.e., spatiotemporally unused spectrum by other primary users. For an accurate identification of the spectral opportunities, the mobile network has to deploy multiple sensors or it can offload this task to nearby nodes with sensing capabilities, so called helpers. Unfortunately, incentives are limited for helpers to perform energy-wasteful spectrum sensing. Instead, we envision spectrum sensing as a service (Spass) in which a smart contract running on a blockchain (BC) describes the required sensing service parameters and the contracted helpers receive payments only if they perform sensing accurately as agreed in the contract. In this paper, we first introduce Spass and derive a closed formula defining the profitability of a Spass-based business as a function of the spectral efficiency, cost of helpers, and cost of the service. Moreover, we propose two-threshold based voting (TTBV) algorithm to ensure that the fraudulent helpers are excluded from Spass. Via numerical analysis, we show that TTBV causes almost zero false alarms and can exclude malicious users from the contract after only a few iterations. Finally, we develop a running prototype of Spass on Ethereum BC and share the related source code on a publicly-available repository.
This paper proposes Consensus-Before-Talk (CBT), a spectrum etiquette architecture leveraged by distributed ledger technology (DLT). In CBT, secondary users' spectrum access requests reach a consensus in a distributed way, thereby enabling collision-free distributed dynamic spectrum access. To achieve this consensus, the secondary users need to pay for the extra request exchanging delays. Incorporating the consensus delay, the end-to-end latency under CBT is investigated. Both the latency analysis and numerical evaluation validate that the proposed CBT achieves the lower end-to-end latency particularly under severe secondary user traffic, compared to the Listen-Before-Talk (LBT) benchmark scheme.
Wireless network virtualization is regarded as an emerging paradigm to enhance RF spectrum utilization to support exponentially increasing demand caused by emerging Internet-of-Things (IoT) applications. To create virtual wireless networks (VWNs), there are no automated secure approaches for allocating RF spectrum to meet the dynamically changing quality-of-service (QoS) requirements of the users. In wireless networks, RF spectrum is shared among many users and the given RF spectrum could be easily overcrowded because of the over commitment of limited resources by the service providers. There is a direct incentive in terms of revenue to service providers to have more number of users. In this paper, we propose to leverage a distributed Blockchain - also known as a public ledger - based scheme to create VWNs where primary wireless resource-owners (PWROs) sublease their wireless resources (e.g., slice of RF spectrum, infrastructure) to mobile virtual network operators (MVNOs) using machine-to-machine communication based on the service level agreements (SLAs) between PWROs and MVNOs. The proposed distributed Blockchain-based scheme provides security to participating PWROs and MVNOs as well as prevents PWROs from over committing their resources (that stops double spending) and helps MVNOs to meet the QoS requirements of their users. The US Federal Communications Commission (FCC) or similar regulatory bodies in other countries participate in this framework by providing the guidelines and regulations about maximum power levels, licensing and geographic coverages, etc. This essentially helps users to meet their desired QoS requirements while complying the government regulations. Performance is evaluated using numerical results.
In this article, we propose a blockchain verification protocol as a method for enabling and securing spectrum sharing in moving cognitive radio (CR) networks. The spectrum-sharing mechanism is used as a medium-access protocol for accessing wireless bandwidth among competing CRs. We introduce a virtual currency, called Specoins, for payment to access the spectrum. An auction mechanism based on a first-come-first-served queue is used, with the price for the spectrum advertised by each primary user in a decentralized fashion. The blockchain protocol facilitates the transactions between primary and secondary users and is used to validate and save each user's virtual wallet. Also important for mobile networks, the blockchain serves as a distributed database that is visible by all participating parties, and any node can volunteer to update the blockchain. The volunteer nodes are called miners, and they are awarded with Specoins. We propose diverse methods to exchange the Specoins to make leasing possible even by CRs that are not miners. We show the improvement of the proposed algorithm compared with the conventional Aloha medium-access protocol in terms of spectrum usage. This difference is investigated using small-scale fading variation in the wireless channel to compare the performance of our secure method with the conventional medium access used in vehicular communications. The secure blockchain verification protocol is not only secure but also outperforms the conventional system in moderate cases of small-scale fading. In the case of severe small-scale fading, the blockchain protocol will outperform the conventional system if multipath diversity is not used.
Cognitive radio plays an important role in improving spectrum utilization in wireless services. In the cognitive radio paradigm, secondary users (SUs) are allowed to utilize licensed spectrum opportunistically without interfering with primary users (PUs). To motivate PU to share licensed spectrum with SU, it is reasonable for SU to pay PU a fee whenever the former is utilizing the latter's licensed spectrum. SU's detailed usage information, such as when and how long the licensed spectrum is utilized, is needed for PU to calculate payment. Providing usage information to PU, however, may compromise SU's privacy. To solve this dilemma, we are the first to propose a novel privacy-preserving mechanism for cognitive radio transactions through commitment scheme and zero-knowledge proof. This mechanism, on one hand, only allows PU to know the total payment to SU for a billing period, plus a little portion of SU's usage information. On the other hand, it guarantees PU that the payment is correctly calculated. We have implemented our mechanism and evaluated its performance.
Majed Haddad, Eitan Altman, Sana Ben Jemaa, Salah Eddine Elayoubi · 5 authors
Distributing Radio Resource Management (RRM) in heterogeneous wireless networks is an important research and development axis that aims at reducing network complexity, signaling, and processing load in heterogeneous environments. Performing decision-making involves incorporating cognitive capabilities into the mobiles such as sensing the environment and learning capabilities. This falls within the larger framework of cognitive radio (Mitola, 2000) and self-organizing networks (3GPP, 2008). In this context, RRM decision making can be delegated to mobiles by incorporating cognitive capabilities into mobile handsets, resulting in the reduction of signaling and processing burden. This may however result in inefficiencies such as those known as the “Tragedy of commons” (Hardin, 1968) that are inherent to equilibria in non-cooperative games. Due to the concern for efficiency, centralized network architectures and protocols keep being considered and being compared to decentralized ones. From the point of view of the network architecture, this implies the co-existence of network-centric and terminal-centric RRM schemes. Instead of taking part within the debate among the supporters of each solution, the authors propose a hybrid scheme where the wireless users are assisted in their decisions by the network that broadcasts aggregated load information (Elayoubi, 2010). At some system’s states, the network manager may impose his decisions on the network users. In other states, the mobiles may take autonomous actions in reaction to information sent by the network. Specifically, the authors derive analytically the utilities related to the Quality of Service (QoS) perceived by mobile users and develop a Bayesian framework to obtain the equilibria. They then analyze the performance of the proposed scheme in terms of achievable throughput (for both mobile terminals and the network) and evaluate the price of anarchy which measures how good the system performance is when users play selfishly instead of playing to achieve the social optimum (Johari, 2004). Numerical results illustrate the advantages of using the hybrid game framework in a network composed of HSDPA and 3G LTE system that serve streaming and elastic flows. Finally, this chapter addresses current questions regarding the integration of the proposed hybrid Stackelberg scheme in practical wireless systems, leading to a better understanding of actual cognitive radio gains.