Showing papers on "Roaming published in 2021"

Machine Learning Empowered Trajectory and Passive Beamforming Design in UAV-RIS Wireless Networks

Abstract: A novel framework is proposed for integrating reconfigurable intelligent surfaces (RIS) in unmanned aerial vehicle (UAV) enabled wireless networks, where an RIS is deployed for enhancing the service quality of the UAV. Non-orthogonal multiple access (NOMA) technique is invoked to further improve the spectrum efficiency of the network, while mobile users (MUs) are considered as roaming continuously. The energy consumption minimizing problem is formulated by jointly designing the movement of the UAV, phase shifts of the RIS, power allocation policy from the UAV to MUs, as well as determining the dynamic decoding order. A decaying deep Q-network (D-DQN) based algorithm is proposed for tackling this pertinent problem. In the proposed D-DQN based algorithm, the central controller is selected as an agent for periodically observing the state of UAV-enabled wireless network and for carrying out actions to adapt to the dynamic environment. In contrast to the conventional DQN algorithm, the decaying learning rate is leveraged in the proposed D-DQN based algorithm for attaining a tradeoff between accelerating training speed and converging to the local optimal. Numerical results demonstrate that: 1) In contrast to the conventional Q-learning algorithm, which cannot converge when being adopted for solving the formulated problem, the proposed D-DQN based algorithm is capable of converging with minor constraints; 2) The energy dissipation of the UAV can be significantly reduced by integrating RISs in UAV-enabled wireless networks; 3) By designing the dynamic decoding order and power allocation policy, the RIS-NOMA case consumes 11.7% less energy than the RIS-OMA case.

Robust and Universal Seamless Handover Authentication in 5G HetNets

Abstract: The evolving fifth generation (5G) cellular networks will be a collection of heterogeneous and backward-compatible networks. With the increased heterogeneity and densification of 5G heterogeneous networks (HetNets), it is important to ensure security and efficiency of frequent handovers in 5G wireless roaming environments. However, existing handover authentication mechanisms still have challenging issues, such as anonymity, robust traceability and universality. In this paper, we address these issues by introducing RUSH, a Robust and Universal Seamless Handover authentication protocol for 5G HetNets. In RUSH, anonymous mutual authentication with key agreement is enabled for handovers by exploiting the trapdoor collision property of chameleon hash functions and the tamper-resistance of blockchains. RUSH achieves universal handover authentication for all the diverse mobility scenarios, as exemplified by the handover between 5G new radio and non-3GPP access regardless of the trustworthiness of non-3GPP access and the consistency of the core network. RUSH also achieves perfect forward secrecy, master key forward secrecy, known randomness secrecy, key escrow freeness and robust traceability. Our formal security proofs based on the BAN-logic and formal verification based on AVISPA indicate that RUSH resists various attacks. Comprehensive performance evaluation and comparisons show that RUSH outperforms other schemes in both computation and communication efficiencies.

A Novel Blockchain-as-a-Service (BaaS) Platform for Local 5G Operators

Abstract: 5G is a promising technology that has the potential to support verticals and applications such as Industrial Internet of Things IoT (IIoT), smart cities, autonomous vehicles, remote surgeries, virtual and augmented realities, and so on. These verticals have a diverse set of network connectivity requirements, and it is challenging to deliver customized services for each by using a common 5G infrastructure. Thus, the operation of Local 5G operator (L5GO) networks or private 5G networks are a viable option to tackle this challenge. A L5GO network is a localized small cell network which can offer tailored service delivery. The adaptation of network softwarization in 5G allows vertical owners to deploy and operate L5GO networks. However, the deployment of L5GOs raises various issues related to management of subscribers, roaming users, spectrum, security, and also the infrastructure. This paper proposes a blockchain-based platform to address these issues. The paper introduces a set of blockchain-based modularized functions such as service rating systems, bidding techniques, and selection functions, which can be used to deploy different services for L5GOs. Exploitation of blockchain technology ensures availability, non-reliance on trusted third parties, secure transfer payments, and stands to gain many more advantages. The performance and the viability of the proposed platform are analyzed by using simulations and a prototype implementation.

An Effective Edge-Intelligent Service Placement Technology for 5G-and-beyond Industrial IoT

Abstract: With the rapid development of 5G-and-beyond Industrial Internet of Things (IIoT), mobile Edge Computing (MEC) can improve the Quality of Experience (QoE) of end-users and save the energy consumption of mobile end devices by providing computing resources and storage space. However, when these mobile end devices are roaming around different MEC servers' areas, it may cause discontinuity of services. To solve this problem, we propose an effective Edge-Intelligent Service Placement Algorithm (EISPA), which transfers the service placement problem into finding a globally optimal solution via nature-inspired-based Particle Swarm Optimization (PSO). Moreover, we use a shrinkage factor and combine it with the Simulated Annealing (SA) algorithm to adjust the particles' position in our algorithm to avoid falling into a locally optimal solution. Performance analysis results show that the EISPA can reduce the delay and energy consumption of MEC servers, and its performance is better than the existing algorithm.

Multi-Agent Reinforcement Learning in NOMA-aided UAV Networks for Cellular Offloading

Abstract: A novel framework is proposed for cellular offloading with the aid of multiple unmanned aerial vehicles (UAVs), while non-orthogonal multiple access (NOMA) technique is employed at each UAV to further improve the spectrum efficiency of the wireless network. The optimization problem of joint three-dimensional (3D) trajectory design and power allocation is formulated for maximizing the throughput. Since ground mobile users are considered as roaming continuously, the UAVs need to be re-deployed timely based on the movement of users. In an effort to solve this pertinent dynamic problem, a K-means based clustering algorithm is first adopted for periodically partitioning users. Afterward, a mutual deep Q-network (MDQN) algorithm is proposed to jointly determine the optimal 3D trajectory and power allocation of UAVs. In contrast to the conventional deep Q-network (DQN) algorithm, the MDQN algorithm enables the experience of multi-agent to be input into a shared neural network to shorten the training time with the assistance of state abstraction. Numerical results demonstrate that: 1) the proposed MDQN algorithm is capable of converging under minor constraints and has a faster convergence rate than the conventional DQN algorithm in the multi-agent case; 2) The achievable sum rate of the NOMA enhanced UAV network is 23% superior to the case of orthogonal multiple access (OMA); 3) By designing the optimal 3D trajectory of UAVs with the MDON algorithm, the sum rate of the network enjoys 142% and 56% gains than invoking the circular trajectory and the 2D trajectory, respectively.

P4G2Go: A Privacy-Preserving Scheme for Roaming Energy Consumers of the Smart Grid-to-Go.

Abstract: Due to its flexibility in terms of charging and billing, the smart grid is an enabler of many innovative energy consumption scenarios. One such example is when a landlord rents their property for a specific period to tenants. Then the electricity bill could be redirected from the landlord's utility to the tenant's utility. This novel scenario of the smart grid ecosystem, defined in this paper as Grid-to-Go (G2Go), promotes a green economy and can drive rent reductions. However, it also creates critical privacy issues, since utilities may be able to track the tenant's activities. This paper presents P4G2Go, a novel privacy-preserving scheme that provides strong security and privacy assertions for roaming consumers against honest but curious entities of the smart grid. At the heart of P4G2Go lies the Idemix cryptographic protocol suite, which utilizes anonymous credentials and provides unlinkability of the consumer activities. Our scheme is complemented by the MASKER protocol, used to protect the consumption readings, and the FIDO2 protocol for strong and passwordless authentication. We have implemented the main components of P4G2Go, to quantitatively assess its performance. Finally, we reason about its security and privacy properties, proving that P4G2Go achieves to fulfill the relevant objectives.

On the Design of Lightweight and Secure Mutual Authentication System for Global Roaming in Resource-Limited Mobility Networks

Abstract: A secure authentication protocol plays a crucial role in securing communications over wireless and mobile networks. Due to resource-limitations and the nature of the wireless channel, the global mobile networks are highly susceptible to various attacks. Recently, an efficient authentication system for global roaming has been proposed in the literature. In this article, we first show that the analyzed authentication system is vulnerable man-in-the-middle attack, replay attack and Denial-of-Service (DoS) attack, and it does not ensure untraceability and local password-verification process to identify wrong passwords. To fix these security flaws, we propose a more efficient and robust authentication system for roaming in mobility networks. We use the formal verification tools like ProVerif, Automated Validation of Internet Security Protocols and Applications (AVISPA) and Burrows-Abadi-Needham (BAN) logic to check the regularity of the authentication protocol. Moreover, we prove the secrecy of a session key through the formal security using the random oracle model, known as Real-Or-Random (ROR) model. Finally, a detailed performance evaluation proves that the security protocol not only provides a security strength, but also preserves the low computational overhead. Thus, the proposed authentication protocol is secure and computationally efficient as compared to other relevant schemes.

Roaming service for electric vehicle charging using blockchain-based digital identity

Abstract: We present a suitable approach to address the electric vehicle charging roaming problem (e-roaming). Blockchain technologies are applied to support the identity management process of users charging their vehicles and to record energy transactions securely. At the same time, off-chain cloud-based storage is used to record the transaction details. A user wallet settled on a mobile application stores user verified credentials; a backend application in the vehicle charging station validates the user credentials to authorize the energy transaction. The current model can be applied to similar contexts where the user may be required to keep several credentials from different providers to authenticate digital transactions.

Blockchain-based Roaming and Offload Service Platform for Local 5G Operators

Abstract: Local 5G Operator (L5GO) concept is one of the most prominent versatile applications of the 5G in the near future. The popularity of L5GOs will trigger a greater number of roaming and offloading events between mobile operators. However, existing static and the operator-assisted roaming and offloading procedures are inefficient for L5GO ecosystem due to poor service quality, data privacy issues, data transferring delays, excessive costs for intermediary parties and existence of roaming fraud. To address these challenges, we propose a blockchain / Distributed Ledger Technology (DLT) based service platform for L5GOs to facilitate efficient roaming and offload services. As the key contribution, blockchain-based smart contract scheme is proposed to establish dynamic and automated agreements between operators. By using smart contracts, we introduce several novel features such as universal wallet for subscribers, service quality based L5GO rating system, user-initiated roaming process and the roaming fraud prevention system to improve the operational quality of a L5GO. A prototype of the proposed platform is emulated with the Ethereum blockchain platform and Rinkeby Testnet to evaluate the performance and justify the feasibility of the proposal. Upon an extensive evaluation on the prototype, it was observed that the proposed platform offered benefits such as cost effective, more secure and reliable experience.

Smart Contracts in the 5G Roaming Architecture: The Fusion of Blockchain with 5G Networks

Abstract: The rollout of fifth generation (5G) cellular network technology has generated a new surge of interest in the potential of blockchain to automate various use cases involving cellular networks. 5G is indeed expected to offer new market opportunities for small and large enterprises alike. In this article, we introduce a new roaming network architecture for 5G based on a permissioned blockchain platform with smart contracts. The proposed solution improves the visibility for mobile network operators of their subscribers' activities in the visited network, as well as enabling quick payment reconciliation and reducing fraudulent transactions. The article further reports on the methodology and architecture of the proposed blockchain-based roaming solution using the Hyperledger platform.

Lightweight user authentication scheme for roaming service in GLOMONET with privacy preserving.

Abstract: With the development of information technology and the Internet, users can conveniently use roaming services without time and space restrictions. This roaming service is initiated by establishing a session key between a home node, which exists in a home network, and a mobile node, which exists in a foreign network. However, in the process of verifying a legitimate user and establishing a session key, various security threats and privacy exposure issues can arise. This study demonstrates that the authentication scheme for the roaming service proposed in the existing Global Mobility Network (GLOMONET) environment has several vulnerabilities and, hence, is impractical. In addition, the scheme does not satisfy the privacy of the session key or user’s identity or password. Accordingly, we propose a new lightweight authentication scheme to compensate for these vulnerabilities and secure a high level of privacy, such as non-traceability. In addition, formal and informal analyses are conducted to examine the safety of the proposed scheme. Based on the results of our analyses, we prove that the proposed scheme is highly secure and applicable to the actual GLOMONET environment.

Deep Q-learning for 5G network slicing with diverse resource stipulations and dynamic data traffic

Abstract: 5G wireless networks use the network slicing technique that provides a suitable network to a service requirement raised by a network user. Further, the network performs effective slice management to improve the throughput and massive connectivity along with the required latency towards an appropriate resource allocation to these slices for service requirements. This paper presents an online Deep Q-learning based network slicing technique that considers a sigmoid transformed Quality of Experience, price satisfaction, and spectral efficiency as the reward function for bandwidth allocation and slice selection to serve the network users. The Next Generation Mobile Network (NGMN) vertical use cases have been considered for the simulations which also deals with the problem of international roaming and diverse intra-use case requirement variations by using only three standard network service slices termed as enhanced Mobile Broadband (eMBB), Ultra Reliable Low Latency Communication (uRLLC), and massive Machine Type Communication (mMTC). Our Deep Q-Learning model also converges significantly faster than the conventional Deep Q-Learning based approaches used in this field. The environment has been prepared based on ITU specifications for eMBB, uRLLC, mMTC. Our proposed method demonstrates a superior Quality-of-experience for the different users and the higher network bandwidth efficiency compared to the conventional slicing technique.

Service delivery to handed over user equipment (UE) using a software-defined networking (SDN) controller

Abstract: In one embodiment, a method implemented in a virtual network function (VNF) manager (230) for delivering of services to a roaming UE (200) is disclosed. The method includes identifying (1710) a trigger condition for handing-over delivery of at least a subset of services from a radio interface of a source radio base station (210) to a radio interface of a target radio base station (220). The method also includes transferring the subset of the services to the target radio base station (220) through a route based on information from a software-defined networking (SDN) controller (1250) of a SDN system that includes the source radio base station (210) and the target radio base station (220). The method further includes causing at least one VNF (250, 255) to be deployed on the target radio base station (220), the at least one VNF (250, 255) on the target radio base station (220) being adapted to offer the subset of the services to the roaming UE (200).

BlockRoam: Blockchain-based Roaming Management System for Future Mobile Networks

Abstract: Mobile service providers (MSPs) are particularly vulnerable to roaming frauds, especially ones that exploit the long delay in the data exchange process of the contemporary roaming management systems, causing multi-billion dollars loss each year. In this paper, we introduce BlockRoam, a novel blockchain-based roaming management system that provides an efficient data exchange platform among MSPs and mobile subscribers. Utilizing the Proof-of-Stake (PoS) consensus mechanism and smart contracts, BlockRoam can significantly shorten the information exchanging delay, thereby addressing the roaming fraud problems. Through intensive analysis, we show that the security and performance of such PoS-based blockchain network can be further enhanced by incentivizing more users (e.g., subscribers) to participate in the network. Moreover, users in such networks often join stake pools (e.g., formed by MSPs) to increase their profits. Therefore, we develop an economic model based on Stackelberg game to jointly maximize the profits of the network users and the stake pool, thereby encouraging user participation. We also propose an effective method to guarantee the uniqueness of this game's equilibrium. The performance evaluations show that the proposed economic model helps the MSPs to earn additional profits, attracts more investment to the blockchain network, and enhances the network's security and performance.

A Secure and Privacy-Preserving Mutual Authentication System for Global Roaming in Mobile Networks

Abstract: Mutual authentication scheme plays a significant role in the global mobility network to afford roaming service. However, designing secure and privacy-preserving authentication protocols for roaming service is always challenging. Due to the nature of wireless communication medium, these networks are vulnerable to security threats. In recent times, some authentication systems have been proposed for the mobile user roaming in the mobility environments. Nevertheless, most of the security protocols are prone to security attacks. In this paper, a secure mutual authentication protocol is designed using lightweight cryptographic primitives. The protocol design includes initialization phase, registration phase, mutual authentication phase, and the password change phase to ensure the user anonymity, privacy, and security in global mobility networks. In addition, we used a popular formal verification tool called AVISPA (Automated Validation of Internet Security Protocols and Applications) to check the correctness of the proposed protocol. Notably, the formal security analysis has been carried out through BAN logic, which proves the security strength of the proposed framework. Finally, a performance analysis shows that the proposed authentication system preserves low computational and communication overheads.

AMAPG: Advanced Mobile Authentication Protocol for GLOMONET

Abstract: Roaming is when the mobile user goes out of his/her home agent network coverage and loses its signal. Loss of coverage and signals may be limited to a remote area or may occur when mobile user leaves the country and moves to a country where his/her mobile carrier network is not available. In this case, the mobile device is in roaming mode. In this mode, mobile user through connection to a Foreign Agent can still use its home agent services if his/her authentication be successful. In such situations, the authentication mechanism plays a key and important role, where the mobile user often needs to integrate and secure roaming service over multiple foreign agents. Designing a secure mechanism in Global Mobility Network (GLOMONET) is a difficult and complex task due to the computational and processing limitations of most mobile devices, as well as the wireless nature of communication environment. Unfortunately, most of the authentication schemes that have been proposed so far to meet this goal have failed to achieve their goal. In this line, Shashidhara et al. recently reported security vulnerabilities of Xu et al. ’s mobile authentication scheme, and also presented an amended version of it. This paper shows that this proposed scheme has security flaws against impersonation, traceability, forward secrecy contradiction, and stolen smart card attacks, which implies that this protocol may not be a proper choice to be used on GLOMONET. On the other hand, we propose AMAPG, as a cost-efficient remedy version of the protocol which provides desired security against various attacks and also prove its security using BAN logic. We also evaluate AMAPG’s security using Scyther as a widely used formal tool to evaluate the security correctness of the cryptographic protocols.

Measuring Roaming in Europe: Infrastructure and Implications on Users QoE

Abstract: "Roam like Home" is the initiative of the European Commission to end the levy of extra charges when roaming within the European region. As a result, people can use data services more freely across Europe. However, the implications of roaming solutions on network performance have not been carefully examined yet. This paper provides an in-depth characterization of the implications of international data roaming within Europe. We build a unique roaming measurement platform using 16 different mobile networks deployed in 6 countries across Europe. Using this platform, we measure different aspects of international roaming in 4G networks in Europe, including mobile network configuration, performance characteristics, and quality of experience. We find that operators adopt a common approach to implement roaming called Home-routed roaming. This results in additional latency penalties of 60 ms or more, depending on geographical distance. This leads to worse browsing performance, with an increase in the metrics related to Quality of Experience (QoE) of users (Page Load time and Speed Index) in the order of 15-20%. We further analyze the impact of latency on QoE metrics in isolation and find that the penalty imposed by Home Routing leads to degradation on QoE metrics up to 150% in case of intercontinental roaming. We make our dataset public to allow reproducing the results.

A secure three-factor anonymous roaming authentication protocol using ECC for space information networks

Abstract: Nowadays, space information networks (SIN) has been widely used in navigation, observation and military activities due to its advantages of wide coverage, convenient communication and the ability to provide users with multiple services. However, because of the openness of the spatial channel, there are security threats such as information eavesdropping, interception and forgery. So far, many scholars have proposed a series of authentication protocols to support both parties’ authentication and key negotiation in SIN to ensure the security of access and communication. However, most of these protocols lack a login authentication mechanism, which will be vulnerable to smart card theft attacks. In addition, these protocols only support authentication services in the home domain. When users move to a foreign region to use these protocols for access verification, there will be security vulnerabilities, such as authentication failure and the leakage of session keys. To better solve this problem, we design a new ECC-based anonymous authentication protocol with three-factor login verification in this paper. Our protocol not only supports users to authenticate in the home domain, but also supports users to access SIN when roaming to foreign regions. Furthermore, through formal and informal security analysis methods, we prove that our protocol can securely authenticate each other, negotiate the session key and resist various attacks. In addition, combined with performance analysis, our protocol is more suitable for SIN than other related protocols.

Edge-enabled Mobile Crowdsensing to Support Effective Rewarding for Data Collection in Pandemic Events

Abstract: Smart cities use Information and Communication Technologies (ICT) to enrich existing public services and to improve citizens’ quality of life. In this scenario, Mobile CrowdSensing (MCS) has become, in the last few years, one of the most prominent paradigms for urban sensing. MCS allow people roaming around with their smart devices to collectively sense, gather, and share data, thus leveraging the possibility to capture the pulse of the city. That can be very helpful in emergency scenarios, such as the COVID-19 pandemic, that require to track the movement of a high number of people to avoid risky situations, such as the formation of crowds. In fact, using mobility traces gathered via MCS, it is possible to detect crowded places and suggest people safer routes/places. In this work, we propose an edge-anabled mobile crowdsensing platform, called ParticipAct, that exploits edge nodes to compute possible dangerous crowd situations and a federated blockchain network to store reward states. Edge nodes are aware of all critical situation in their range and can warn the smartphone client with a smart push notification service that avoids firing too many messages by adapting the warning frequency according to the transport and the specific subarea in which clients are located.

Adaptive Multi-Channel Clustering in IEEE 802.11s Wireless Mesh Networks.

Abstract: WLAN mesh networks are one of the key technologies for upcoming smart city applications and are characterized by a flexible and low-cost deployment. The standard amendment IEEE 802.11s introduces low-level mesh interoperability at the WLAN MAC layer. However, scalability limitations imposed by management traffic overhead, routing delays, medium contention, and interference are common issues in wireless mesh networks and also apply to IEEE 802.11s networks. Possible solutions proposed in the literature recommend a divide-and-conquer scheme that partitions the network into clusters and forms smaller collision and broadcast domains by assigning orthogonal channels. We present CHaChA (Clustering Heuristic and Channel Assignment), a distributed cross-layer approach for cluster formation and channel assignment that directly integrates the default IEEE 802.11s mesh protocol information and operating modes, retaining unrestricted compliance to the WLAN standard. Our concept proposes further mechanisms for dynamic cluster adaptation, including subsequent cluster joining, isolation and fault detection, and node roaming for cluster balancing. The practical performance of CHaChA is demonstrated in a real-world 802.11s testbed. We first investigate clustering reproducibility, duration, and communication overhead in static network scenarios of different sizes. We then validate our concepts for dynamic cluster adaptation, considering topology changes that are likely to occur during long-term network operation and maintenance.

5G Non-Public-Networks (NPN) Roaming Architecture

Abstract: With the increasing deployment of 5G Non-public Networks, the telco environment is becoming massively multi-administrated with a wide range of full networks deployed close and covering only the use case area. To benefit the most of this, a roaming solution must be set in place enabling devices to safely communicate using visited infrastructures either with local service or with the ones from the home networks. As a first step in this direction, this article proposes a new architecture for Non-public Networks roaming, stemming from the 3GPP 5G macro-operator roaming and adapted to the specifics of the communication for geographically-distant, small networks interconnected by third party unreliable backhauls. Furthermore, the architecture is exemplified, and its potential is evaluated as further extensions to the Fraunhofer FOKUS Open5GCore, showing that it outperforms today’s roaming solution in terms of flexibility and privacy of deployment, backhaul usage and reduced network administration.

Steering of roaming in wireless communication networks

Abstract: A method for steering of roaming (SOR) in wireless communication networks includes sending by a mobile equipment (ME) a registration message to a visited public land mobile network (VPLMN). The ME receives a first message from a home public land mobile network (HPLMN) through the VPLMN. The ME determines that the first message has failed a security check. In response to determining that the first message has failed the security check, the ME sends a second message to the VPLMN, the second message including an indication that the first message has failed the security check.

Enhanced WSN Routing Protocol for Internet of Things to Process Multimedia Big Data

Abstract: Due to the massive use of wireless Internet of Things (IoT), the advent of multimedia-big-data in recent decades poses numerous obstacles for successful contact with the virtual era. Mobile Adhoc Network-based IoT (MANET IoT) framework is increasingly common in this regard owing to its increased communication protocols and economic efficiency. MANET comprises arbitrary, battery-driven, roaming nodes that do not have architecture that can handle the traffic and control the IoT network. In MANET-IoT, energy usage and traffic management for the handling of MBD information are significant issues. For rapid and precise response, it is essential to route or forward information like the locations of happenings and defected in a disaster. However, it is difficult to transfer this information to the Wireless Sensor Network in disaster areas because the current networks are a disaster that has been removed. In these situations, the transmission of opportunistic knowledge may play a vital role. Current opportunistic protocols need large messages for the restoration of the cluster that leads to more energy consumption and packet loss. To overcome these issues, this work proposes the reliable, energy-efficient opportunistic protocol known as Opportunistic Density Clustering Routing Protocol. This method sends information opportunistically in emergencies and disasters through a density-clustering protocol. Results from simulations demonstrate that the designed protocol exceeds several well-known current routing mechanisms for network energy usage and dissemination of information.

Attention to Wi-Fi Diversity: Resource Management in WLANs With Heterogeneous APs

Abstract: Many home networks integrate a small number (typically 2-4) of Wi-Fi Access Points (APs), with heterogeneous characteristics: different 802.11 variants, capabilities and security schemes. This paper proposes the consideration of these specific characteristics in order to improve the management of network resources. Three use cases are presented in order to showcase the potential benefits. By the use of a user-space AP, which works in coordination with a controller, the network is able to assign each connected station to the AP that best fits with its characteristics. The system also manages security, avoiding the need of adding specific elements for authentication, encryption or decryption. Extensions are proposed to an existing protocol that defines the communication between the AP and the controller, in order to communicate and store the specific characteristics of each AP and end device. This includes new association and handoff schemes that do not introduce any additional delay. The system has been implemented in a real environment, and a battery of tests has been run using three hardware platforms of different characteristics. The results show that handoffs between bands are possible, and estimate the processing delays, the Round-Trip Time and the handoff delay, which is small enough in order not to produce any significant disruption to the user (10-50 ms). Finally, the scenarios of interest have been replicated in a simulation environment, showing that significant benefits can be achieved if the specific characteristics of each AP and station are considered.

Robust and anonymous handover authentication scheme without key escrow problem in vehicular sensor networks

Abstract: Vehicular ad hoc Networks (VANETs) encompass the Internet of Vehicles, Vehicular Sensor Networks (VSNs), and electronic vehicles and tend to be an essential part of the world. In this network, communications are done through an open channel and are inevitably susceptible to a range of security issues. Their high mobility also adds to this concern. Roaming services are essential for global VANETs and mobility-based networks, which require a robust authentication mechanism to be maintained. Therefore, an effective and secure authentication and session key agreement mechanism in VANET is a challenge yet to be tackled. Recently, different three-party schemes were proposed to use in the handover authentication process, though they have their deficits. The present study showed that the three related schemes (Zhou et al., Patonico et al., and Eftekhari et al.) have security flaws such as insecurity against impersonation attack, key compromise impersonation attack, and man-in-the-middle attack. Also, a secure and robust handover authentication scheme is proposed for roaming service in VSNs, which stamps out the existing schemes' security problems. It considers the intra-network and inter-network roaming authentication models. Our proposed scheme, free from key escrow problems, is highly anonymous and provides forward/backward secrecy. Widely accepted random oracle model, AVISPA tool, and BAN logic used for security analysis. Our scheme outperforms the others in security metrics and improves communication overhead by up to 75%. Also, the simulation results show that our scheme is energy-efficient and imposes a lower end-to-end delay to the network.