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Recently, the Non-Standalone Architecture option 3 standard is proposed to facilitate the deployment of 5th Generation (5G) New Radio (NR) cellular systems. According to this standard, 5G NR base stations can utilize the 4th Generation (4G) Long-Term Evolution (LTE) core network to provide network services. Additionally, the network can be configured to support LTE-NR dual connectivity enhancement, which means that a User Equipment (UE) can connect to a 4G LTE and a 5G NR base station at the same time. In such a dual connectivity network, the 4G LTE base station dispatches downlink traffic flows between the 4G LTE and 5G NR base stations for UEs. As investigated in previous works, traffic flow controls between 4G LTE and 5G NR base stations will affect network performance. In this work, we propose a downlink flow control algorithm based on the concept of Genetic Algorithm, with the objectives of maximizing throughput and fairness of throughput. We verify our designs through simulation programs and experiments on real platforms. The results indicate that the proposed solution effectively achieves the designed objectives. [ABSTRACT FROM AUTHOR]

Noise and air pollution are among the most important problems and challenges in urban environments. Noise can cause several problems in functioning within urban settlements and may result in a variety of health problems. Continuous monitoring, prevention, and active work on solving these problems are in the focus of research communities, local and national agencies and organizations, and many international organizations. Traffic noise on city roads has been identified as one of the major problems in urban settlements. Fortunately, it can be monitored and controlled in a way that can reduce its level and negative effects. One of the most effective and cheapest ways to monitor and control traffic noise is to use wireless sensor networks, IoT technology, and cloud-based architectures. This article presents an approach in designing urban traffic noise monitoring system based on LoRaWAN and microservices oriented architecture supported with open-source hardware and software solutions. Design of the system includes planning LoRaWAN network and development of the IoT system layered architecture. Methods for traffic routing and rerouting in urban areas, based on experiments that uses Dijkstra and Floyd–Warshall algorithms are presented. The system implementation and evaluation of the proposed routing modifications are presented in the case of the city of Zrenjanin in Serbia. Discussion of extensions and improvements of the presented system, as well as future research directions, are also presented. [ABSTRACT FROM AUTHOR]

Multi-homed devices such as smartphones, tablets and laptops are enabled with multiple heterogeneous interfaces available for transmission. Those interfaces can be utilized for simultaneous transmission of a single TCP flow using Multipath TCP (MPTCP). MPTCP is a protocol that is designed to increase end-to-end throughput and reliability of communications by splitting data through multiple parallel paths. Although delay in MPTCP enhanced significantly in the recent years, high number of data transmissions remains an issue. In this paper, we reduce MPTCP delay by reducing the number of transmissions using Opportunistic Routing (OR) technique. OR is a routing model used to increase the delivery rate and reliability of data transmission in wireless networks by using the broadcasting method. This enables each subflow data to be delivered by multiple relays. We adapted OR on a number of MPTCP protocols namely, traditional MPTCP, Multipath TCP Traffic Splitting Control (MPTCP-TSC) and Redundant MPTCP (ReMP TCP) in an Internet of Things (IoT) environment. The results show that OR-based MPTCP schemes outperform existing schemes. We further compared the OR-based MPTCP protocols in terms of startup delay and energy efficiency. We found that ReMP TCP is better than other schemes in all scenarios. [ABSTRACT FROM AUTHOR]

In recent years, the role of vehicular networks has become increasingly important for the future of Intelligent Transportation Systems, as they are useful for providing safety, assistance to drivers, and traffic control management. Many vehicular network applications such as routing, mobility management, service discovery, and collision avoidance protocols would benefit from possessing vehicles' prior location information to improve their performance. However, the rapid mobility of vehicles and the degree of error in positioning systems create a challenging problem regarding the accuracy and efficiency of any location prediction-based model for vehicular networks. Therefore, a number of location prediction techniques has been proposed in the literature. In this paper, we study and compare the accuracy and effectiveness of the following location-based movement prediction models: Kalman filter, Extended Kalman filter (EKF), Unscented Kalman filter (UKF), and Particle filter for vehicular networks. We compare the performances of these prediction techniques with respect to different mobility models, and provide some insights on their capabilities and limitations. Our results indicate that Particle filter outperforms all other predictors with respect to location error. In addition, EKF and UKF demonstrated an increase in efficiency of more than 50% when additional measurements input were integrated with the predictors. [ABSTRACT FROM AUTHOR]

Multipath routing is a burning issue in mobile ad hoc network due to its various advantages over single path routing. Some of these advantages are load balancing, bandwidth aggregation, and fault tolerance. Multipath routing means multiple paths exist between source and destination pair. Many works discussed in section 2 addressed queuing delays, but none of them suggested queuing delay for multiple path deliveries of data in mobile ad hoc network context. In this paper, we have designed a mathematical model to compute delay and throughput for multipath. Our model follow the network of M/M/1 queues, and we have applied Burke's theorem to calculate the queuing delay of the packet in mobile network scenario. This model can be used to estimate delay and throughput of an individual path. Further, through the analysis the best path for data delivery out of available multiple paths as well as the multipath path can be used simultaneously for data delivery to the destination. Simulation result shows that splitted traffic multiple paths outperform splitted traffic. Therefore, our model is useful for design and analysis of ad hoc network. The simulation work has been carried out in Qualnet simulator. [ABSTRACT FROM AUTHOR]

As new network applications have arisen rapidly in recent years, it is becoming more difficult to predict the exact traffic pattern of a network. In consequence, a routing scheme based on a single traffic demand matrix often leads to a poor performance. Oblivious routing (Racke in Proceedings of the 43rd annual IEEE symposium on foundations of computer science 43-52, 2002) is a technique for tackling the traffic demand uncertainty problem. A routing scheme derived from this principle intends to achieve a predicable performance for a set of traffic matrixes. Oblivious routing can certainly be an effective tool to handle traffic demand uncertainty in a wireless mesh network (WMN). However, a WMN has an additional tool that a wireline network does not have: dynamic bandwidth allocation. A router in a WMN can dynamically assign bandwidth to its attached links. This capability has never been exploited previously in works on oblivious routing for a spatial time division multiple access (STDMA) based WMN. Another useful insight is that although it is impossible to know the exact traffic matrix, it is relatively easy to estimate the amount of the traffic routed through a link when the routing scheme is given. Based on these two insights, we propose a new oblivious routing framework for STDMA WMNs. Both analytical models and simulation results are presented in this paper to prove that the performance-in terms of throughput, queue lengths, and fairness-of the proposed scheme can achieve significant gains over conventional oblivious routing schemes for STDMA based WMNs. [ABSTRACT FROM AUTHOR]

Taking advantage of peer-to-peer transmission underlying cellular networks, device-to-device (D2D) communications offer various benefits such as coverage extension, traffic offloading, and improved energy efficiency. In this paper, we focus on a promising scenario where a D2D local area network is formed to relay packets for an out-of-coverage source device. A one-sided auction model is formulated from a unique perspective in which the source device decides the allocation of its packets among the helpers and charges reserve payments to the helpers according to their bids. The winning helpers only collect rewards from the source's deposit at the base station when the assigned packets are successfully relayed. In this model, we further take into account the budget constraints of the helpers to capture the helpers' resource limits and the risks that the helpers are willing to take. Based on this model, we propose three auction mechanisms targeting economic properties such as individual rationality, efficiency, and truthfulness. An enhanced Martello & Toth algorithm is first developed for the VCG-based auction to determine packet allocation that optimizes the source's quality of service. The probabilistic entrance auction mechanism uses sequential second price auction to achieve a low computational cost. The randomized mechanism involves a randomization over the above two mechanisms to satisfy certain requirement for social welfare while minimizing the computational time. We also conduct extensive simulations to examine the performance of the proposed mechanisms. [ABSTRACT FROM AUTHOR]

The traditional vehicle mobility is restricted to the driver habits and the line-of-sight. The new-emerging connected vehicles enable information exchange with each other at vicinity, which will undoubtedly bring a greatly positive effect on the vehicle mobility pattern. In this paper, we propose to modeling and analyzing the vehicle mobility patterns respectively driven by traditional drivers and connected drivers. We perform the extensive simulations to explore the statistical differences between two mobility patterns and the underlying reasons through comparing to the real vehicle trace datasets. The results show that they behave quite diversely at the concerned aspects, e.g. degree distribution, clustering coefficient, topological shortest path, topological coefficient, and vehicle density, and also we find that the connected vehicles are well distributed and contribute a relieved traffic congestion situation. [ABSTRACT FROM AUTHOR]

Differing from the traditional traffic, connected vehicles enable information sharing between vehicles at vicinity to facilitate cooperative path planning, which may positively affect the congestion propagation process. In this paper, we propose to modeling and simulating traffic congestion propagation in such new situation where the path planning is driven by a temporal or spatial preference with aims at investigating the effects of various factors on traffic congestion, e.g. traffic light, mobility pattern, traffic density and communication radius. Simulations show that the traffic congestion is indeed affected by the concerned factors; however, the traffic congestion fails to be mitigated persistently as the communication radius increases beyond a certain threshold. The result is helpful for understanding the traffic congestion propagation in connected vehicles. [ABSTRACT FROM AUTHOR]

The broadcasting communication mode is widely used in Vehicular Ad hoc Networks. It is used for sending emergency messages, road-traffic information or to help routing protocols to determine routes. This communication mode is known to be hard to achieve efficiently since it depends on the network density. Indeed, broadcasting methods may cause network congestion if they are not well designed. This paper introduces a novel Autonomic Dissemination Method (ADM) which delivers messages in accordance with given message classes and network density levels. The proposed approach is based on two steps: an offline optimization process and an online adaptation to the network characteristics. ADM allows each node to dynamically adapt its broadcasting strategy not only with respect to the network density, but also according to the class of the message to send: emergency (high-priority), road-traffic (medium-priority) or either comfort message (low-priority). The ultimate goal of ADM is to make effective use of radio resources when there are many messages to send simultaneously. This approach increases the efficiency of the broadcast process in terms of message delivery ratio, latency and interferences reduction. The autonomic computing paradigm improves the robustness of protocols. [ABSTRACT FROM AUTHOR]

In vehicular ad hoc networks, road traffic information can be used to support efficient routing. However, dissemination of up-to-date global road traffic information usually consumes considerable network resources and may also lead to the scalability issue. On the other hand, the highly dynamic nature of road traffic information makes it difficult to collect and disseminate such information in a timely fashion. Outdated information can lead to inefficient routing decisions and thus degraded routing performance. This paper proposes a distributed routing protocol using partial accurate routing information (RPPI). In RPPI, each node uses accurate local traffic information in its local zone and statistical traffic information in remote areas for route selection, which can significantly reduce the communication overhead. Simulation results show that RPPI can achieve better routing performance in terms of end-to-end packet delivery ratio and end-to-end packet delivery delay as compared with existing work. [ABSTRACT FROM AUTHOR]

In high mobility areas such as shopping malls and transportation stations, mobile users tend to move in and out in a bursty fashion, and hence location update (LU) and paging signaling cause substantial traffic burden to the cellular networks, leading to signaling congestion. This poses a great challenge to the system design for wireless cellular systems. Traditional cellular systems cannot cope with this situation very well. However, with the ad hoc operational mode recently introduced into the cellular systems, the added multi-hop relaying via mobile devices provides a new way to mitigate location management traffic. In this paper, based on this new architecture, we propose a novel scheme, called aggregative location management, which aggregates multiple location updates into group location updates. For the scenarios of high capacity transit (HCT) systems, we use this grouping scheme to alleviate the signaling traffic when mobile users in an HCT move into new location areas. For other scenarios with mass arrivals of LU requests, we develop a generic aggregative location management scheme in which LU requests can be first aggregated by designated mobile devices and then are periodically sent to the location registers. Performance evaluation is carried out and shows their significant effectiveness. [ABSTRACT FROM AUTHOR]

We consider a scenario where devices with multiple networking capabilities access networks with heterogeneous characteristics. In such a setting, we address the problem of efficient utilization of multiple access networks by devices via optimal assignment of traffic flows with given utilities to different networks. We develop and analyze a device middleware functionality that monitors network characteristics and employs a Markov Decision Process (MDP) based control scheme that in conjunction with stochastic characterization of the available bit rate and delay of the networks generates an optimal policy for allocation of flows to different networks. The optimal policy maximizes, under available bit rate and delay constraints on the access networks, a discounted reward which is a function of the flow utilities. The flow assignment policy is periodically updated and is consulted by the flows to dynamically perform network selection during their lifetimes. We perform measurement tests to collect traces of available bit rate and delay characteristics on Ethernet and WLAN networks on a work day in a corporate work environment. We implement our flow assignment framework in ns-2 and simulate the system performance for a set of elastic video-like flows using the collected traces. We demonstrate that the MDP based flow assignment policy leads to significant enhancement in the QoS provisioning (higher rate allocation, lower packet delays and packet loss rates) for the flows and better access network utilization, as compared to policies that allocate flows to different networks using greedy approaches or heuristics like average available bit rate on the networks. [ABSTRACT FROM AUTHOR]

Multi-service traffic engineering has a strong impact in Mobile Broadband Systems (MBS) revenues, allowing one to obtain merit functions for optimisation purposes, a key aspect in cellular planning. A net cost model is presented for the design trade-offs between re-use pattern, K, coverage distance, R, and spectral efficiency, Sef(R). It allows for the determination of the revenue per basic channel, R384, that achieves a given value for the annual profit per kilometre. Fast terminal mobility has an important impact in handover failure probability, hence, in system capacity. While in the business city centre and other urban scenarios mobility has no significant effect, it strongly affects the supported traffic in main roads. Comparing the urban with the roads scenarios, a reduction up to 54% may come as a consequence, from (Sef)TOT=32.2 to 15.2%, for R=100 m and K=2; R384 has to be 0.005 and 0.045 math>/min, respectively, i.e., the prices in the roads scenario have to be around one order of magnitude higher than in the urban one. As time goes by, and the use of MBS evolves, the operator will be able to choose different cell coverage distances, in order to support a different number of users, whilst maximising profit. In a medium term scenario, while the number of foreseen users is less than 70% of the number of users in the mature phase, cells with R=200 m will be used. [ABSTRACT FROM AUTHOR]