Packet Arrival Rate Research Articles

Bandwidth Slicing in Software-Defined 5G: A Stackelberg Game Approach

With the explosive development of mobile Internet and the emergence of multimedia-rich applications such as augmented reality, virtual reality, video streaming, online gaming, and social networks, the traffic demands in the incoming fifth-generation (5G) era could grow significantly. To accommodate this massive amount of data traffic, Internet service providers (ISPs) must deploy new infrastructures to expand the capacity of current networks, which results in high capital and maintenance costs. Furthermore, mobile Internet applications in 5G will have diverse quality-of-service (QoS) requirements in terms of latency, burst size, throughput, and packet arrival rate, and reliable QoS provisioning depends on efficient and on-demand resource allocation [1], [2]. However, it is difficult to realize intelligent resource allocation due to the coupling between service provisioning and the taskoriented hardware.

Efficient priority queueing routing strategy on networks of mobile agents

As a consequence of their practical implications for communications networks, traffic dynamics on complex networks have recently captivated researchers. Previous routing strategies for improving transport efficiency have paid little attention to the orders in which the packets should be forwarded, just simply used first-in–first-out queue discipline. Here, we apply a priority queuing discipline and propose a shortest-distance-first routing strategy on networks of mobile agents. Numerical experiments reveal that the proposed scheme remarkably improves both the network throughput and the packet arrival rate and reduces both the average traveling time and the rate of waiting time to traveling time. Moreover, we find that the network capacity increases with an increase in both the communication radius and the number of agents. Our work may be helpful for the design of routing strategies on networks of mobile agents.

On stability and convergence of optimal estimation for networked control systems with dual packet losses without acknowledgment

This paper studies the optimal state estimation problem for networked control systems with control and observation packet losses but without packet acknowledgment (ACK). The packet ACK is a signal sent by the actuator to inform the estimator whether control packets are lost or not. Systems with packet ACK are usually called transmission control protocol (TCP)-like systems, and those without ACK are named user datagram protocol (UDP)-like systems. For UDP-like systems, the optimal estimator is derived and it is consisted of an exponentially increasing number of terms. By developing an auxiliary estimator, it is shown that there exists a critical observation packet arrival rate determining the stability of the expected EC (EEC), and it is identical to its counterpart for TCP-like systems. It is revealed that whether there is packet ACK or not has no effect on the stability of the EEC. Furthermore, under some conditions the EEC converges exponentially.

Cascade optimization design of inter-satellite link enhanced with adaptability in future GNSS satellite networks

Inter-satellite communication and inter-satellite ranging are the foundation of autonomous navigation for satellite navigation systems. Due to cost limitations, it has been proposed in recent years to equip each satellite with one spot beam antenna, which points to different satellites according to a polling mechanism, resulting in an intermittently connected satellite network. This poses the problem of how to design the inter-satellite link (ISL) contact plan, which determines the evolution of network topology and has important effects on system performance. We propose a new framework for the ISL contact plan design in satellite navigation systems. Considering contact plan design as a multi-parameter and multi-objective optimization problem, the cascade optimization design (COD) is proposed as a method simple to implement and optimize the parameters of the contact plan. COD considers network load and geometry of satellites and has a good adaptability. In the proposed framework, both communication and measurement requirements are taken into account while the contact sequence and the slot length are optimized in two steps. Simulation results show that COD guarantees zero packet drops and achieves the least average delay with a selected network load. When the packet arrival rate is 0.45 packets/s, the packet drop ratio of COD is zero, while that of the traditional simulated annealing design (SAD) is 2.58%. The delay of COD is 22.97 s, which is only two-fifth of the SAD value of 58.77 s. At the same time, using COD the average autonomous navigation weighted dilution of precision decreases from 1.4408 to 0.9671. COD also has strong robustness and performance regardless of the onboard buffer size.

Kalman Filtering Over Fading Channels: Zero–One Laws and Almost Sure Stabilities

In this paper, we investigate probabilistic stability of Kalman filtering over fading channels modeled by *-mixing random processes, where channel fading is allowed to generate non-stationary packet dropouts with temporal and/or spatial correlations. Upper/lower almost sure (a.s.) stabilities and absolutely upper/lower a.s. stabilities are defined for characterizing the sample-path behaviors of the Kalman filtering. We prove that both upper and lower a.s. stabilities follow a zero–one law, i.e., these stabilities must happen with a probability either zero or one, and when the filtering system is one-step observable, the absolutely upper and lower a.s. stabilities can also be interpreted using a zero–one law. We establish general stability conditions for (absolute) upper and lower a.s. stabilities. In particular, with one-step observability, we show the equivalence between absolutely a.s. stabilities and a.s. ones, and necessary and sufficient conditions in terms of packet arrival rate are derived; for the so-called non-degenerate systems, we also manage to give a necessary and sufficient condition for upper a.s. stability.

Impacts of Retransmission Limit on Stability and Throughput Regions of S-ALOHA Systems

Limiting the number of retransmissions in practical random access systems such as S-ALOHA and IEEE 802.11 systems has been used, since it was often considered as a way of preventing the system from being congested, by dropping packets in retransmission or letting users know network congestion after the maximum of retransmissions. Therefore, it can be expected that the smaller the maximum of retransmissions is allowed, the smaller the backlog size gets with a higher packet dropping probability. This paper explores how such a retransmission limit alters the shape of the stability and throughput regions of S-ALOHA systems. To do this, we first consider an S-ALOHA system, where two users with infinite queue length have different packet arrival rate and retransmission probability, which is called asymmetric user. Then, we obtain those results of the systems with $N$ symmetric users.

Network Coordination Function for uplink traffic steering in tightly coupled LTE Wi-Fi networks

Tight coupling of LTE and Wi-Fi networks is accomplished by binding their protocol stacks. LTE Wi-Fi radio level integration with IPSec tunnel (LWIP) corresponds to realizing this binding at IP layer. A collocated deployment of LWIP enables greater flexibility in utilizing the channel efficiently. With the advent of bandwidth-hungry smartphone Apps and IoT applications, the cellular uplink resources become highly demanding. This enforces Wi-Fi to support efficient uplink transmissions since the uplink transmissions through Wi-Fi suffers high contention because of distributed nature of Wi-Fi MAC. In order to improve Wi-Fi channel utilization by leveraging the potential of LWIP in controlling and coordinating the transmissions through LTE and Wi-Fi links, we introduce Network Coordination Function (NCF) in LWIP. The proposed NCF focuses on coordinating the uplink transmissions through Wi-Fi in a network with high load. NCF enhances the channel utilization of Wi-Fi network by regulating the packet arrival rate to the Wi-Fi link and also by revamping medium access techniques at the Wi-Fi interface of users associated with LWIP node. NCF is composed of four different uplink traffic steering algorithms with diverse objectives which improve Wi-Fi channel utilization by (i) minimizing collisions among LWIP users, (ii) increasing transmission opportunities for Wi-Fi users that are connected to legacy Wi-Fi APs operating on the same channel, and (iii) ensuring fairness for both LWIP and Wi-Fi users. Interestingly, NCF has not only improved the throughput of LWIP users but also the throughput of Wi-Fi users. Simulation experiments reveal that NCF has reduced collisions in the Wi-Fi uplink by 13–53% and improved throughput by 10–37% as compared to Wi-Fi offloading and Distributed Coordination Function (DCF).

Delay-Optimal Biased User Association in Heterogeneous Networks

In heterogeneous networks (HetNets), load balancing among different tiers can be effectively achieved by a biased user association scheme with which each user chooses to associate with one base station (BS) based on the biased received power. In contrast to previous studies, where a BS always has packets to transmit, we assume in this paper that incoming packets intended for all the associated users form a queue in the BS. In order to find the delay limit of the network to support real-time service, we focus on the delay optimization problem by properly tuning the biasing factor of each tier. By adopting a thinned Poisson point process model to characterize the locations of BSs in the busy state, an explicit expression of the average traffic intensity of each tier is obtained. On that basis, an optimization problem is formulated to minimize a lower bound of the network mean queuing delay. By showing that the optimization problem is convex, the optimal biasing factor of each tier can be obtained numerically. When the mean packet arrival rate of each user is small, a closed-form solution is derived. The simulation results demonstrate that the network queuing performance can be significantly improved by properly tuning the biasing factor. It is further shown that the network mean queuing delay might be improved at the cost of a deterioration of the network signal-to-interference ratio coverage, which indicates a performance tradeoff between real-time and non-real-time traffic in HetNets.

A Randomized Variance-based Sensor Scheduling for Remote State Estimation

In this paper, the problem of sensor transmission power schedule for remote state estimation is studied. A sensor sends its local state estimate to a remote estimator through an unreliable wireless channel where packet dropouts may occur. A transmission module at the sensor side needs to decide the transmission power levels that correspond to different packet arrival rates. By extracting the information of the acknowledgement (ACK) sequence from the remote estimator, we propose a randomized variance-based sensor transmission power schedule. A closed-form expression for its asymptotic estimation performance is obtained based on the Markov chain theory. Numerical examples are presented to illustrate the implementation and performance of the proposed method.

Low-latency Data Gathering with Reliability Guaranteeing in Heterogeneous Wireless Sensor Networks

In order to achieve low-latency and high-reliability data gathering in heterogeneous wireless sensor networks (HWSNs), the problem of multi-channel-based data gathering with minimum latency (MCDGML), which associates with construction of data gathering trees, channel allocation, power assignment of nodes and link scheduling, is formulated as an optimization problem in this paper. Then, the optimization problem is proved to be NP-hard. To make the problem tractable, firstly, a multi-channel-based low-latency (MCLL) algorithm that constructs data gathering trees is proposed by optimizing the topology of nodes. Secondly, a maximum links scheduling (MLS) algorithm is proposed to further reduce the latency of data gathering, which ensures that the signal to interference plus noise ratio (SINR) of all scheduled links is not less than a certain threshold to guarantee the reliability of links. In addition, considering the interruption problem of data gathering caused by dead nodes or failed links, a robust mechanism is proposed by selecting certain assistant nodes based on the defined one-hop weight. A number of simulation results show that our algorithms can achieve a lower data gathering latency than some comparable data gathering algorithms while guaranteeing the reliability of links, and a higher packet arrival rate at the sink node can be achieved when the proposed algorithms are performed with the robust mechanism.

Efficient quality of service‐aware packet chunking scheme for machine‐to‐machine cloud services

SummaryWith the recent advances in machine‐to‐machine communications, huge numbers of devices have become connected and massive amounts of traffic are exchanged. Machine‐to‐machine applications typically generate small packets, which can profoundly affect the network performance. Namely, even if the packet arrival rate at the router is lower than the link bandwidth, bits per second, it can exceed the router forwarding capacity, which indicates the maximum number of forwarded packets per second. This will cause the decrease in the network throughput. Therefore, eliminating the packets per second limitation by chunking small packets will enable machine‐to‐machine cloud services to spread further. This paper proposes new packet‐chunking schemes aimed at meeting both application requirements and improving achievable router throughput. In our schemes, multiple buffers, each of which accommodates packets classified based on their delay requirement, are installed in parallel. Herein, we report on analysis of the theoretically performance of these schemes, which enabled us to derive some important features. We also propose a scheme whereby a single chunking buffer and parallel multiple buffers were arranged in tandem. Through our simulation and numerical results, we determined that these schemes provide excellent performance in reducing the number of outgoing packets from the router while meeting various delay requirements.

Observer‐based controllers with data dropout rate adaptation

SummaryIn this work, we address the observer‐based control problem for networked control systems with an unknown time‐varying packet arrival rate (PAR) and under root mean square‐norm bounded disturbances. We assume packetized transmissions of both measurement and control input through a communication network with successful delivery acknowledgement. Using the measurement reception state and the control transmission acknowledgement, we derive a filter to estimate the PAR. We consider that the PAR changes sporadically from a constant value to another one; that is, it has two different behaviours: transient and steady state. While the observer only updates the state estimation using the current received measurements, the controller computes the control action employing the current state estimation and the previous applied control input. We propose to schedule both the observer and controller with rational functions of the PAR estimation. We show that the separation principle applies, and then, seeking higher performance accuracy, we develop an optimization observer and controller design procedure that considers the two possible behaviours of the PAR. This optimization procedure attempts to maximize the estimation and control performances for each of the possible constant values of the PAR while offering robustness against PAR estimation errors and variations of the PAR. By exploiting sum‐of‐squares decomposition techniques, the design procedure involves an optimization problem over polynomials. A numerical example illustrates the effectiveness of the proposed approach. Copyright © 2017 John Wiley & Sons, Ltd.

Modeling Improved Low Latency Queueing Scheduling Scheme for Mobile Ad Hoc Networks

In a recent study, an Enhanced Low Latency Queue (ELLQ) scheduling algorithm that categorizes and prioritizes the real-time traffic was developed. In this algorithm the high priority queues are introduced for scheduling the video applications separately along with the voice applications, with voice applications having a higher priority over video applications. The low priority queues are serviced using CBWFQ. However, at high arrival rate of voice packets, the video packets may suffer resource starvation. To overcome this drawback, we propose an improved LLQ algorithm which delays voice packets that arrive while the video packets are already in the queue and services video packets found in the queue before servicing voice packets as long as the voice packets are not delayed beyond the maximum tolerable delay limit. The numerical results obtained from the derived models show that average waiting time of both voice and video packets increase with increase in load and arrival rates of packets in the system. We also observe that delaying voice packets leads to reduction in the average waiting time of video packets and an increase in the average waiting time of voice packets, however the reduction in average waiting time of video packets is higher than the increase in the average waiting time of voice packets. The reduction in average waiting time of video packets and increase in average waiting time of voice packets are higher for high loads and high arrival rates. Furthermore, we observe that voice packets can be delayed to serve video packets as long as the load and arrival rates of voice packets does not exceed 81% and 14 packets/second respectively and less dependent on the load and arrival rates of video packets.

Security Enhancement Architectural Model for IMS based Networks

Objectives: The IP Multimedia Subsystem (IMS) is an architectural framework for delivering protocol-based services that enables an easy deployment of new rich multimedia services mixing voice and data. In fact, the IMS is vulnerable to several malicious uses that can be conducted by its users. We propose in this paper, a security enhancement architectural model to monitor the system and build a rapid and normal functioning retrieval after failing. Methods/Statistical Analysis: The weakness of the IMS network topology structure makes it a target for both normal cellular threats and IP-related threats. We propose a model that consists of dividing a complex set of end-of-end (IMS-based) network security related features into separate architectural components, layers and tiers in order to divide the system and to be more precise in the problems’ detection phase. Findings: Using the proposed approach, an effective evaluation study is investigated. The simulated network adopting our model showed an excellent behavior. The quality metric measuring call quality showed some excellent results. In other words, the adoption of the proposed model does not affect the normal frame delays, packet arrival durations and packet loss rates. The results showed how our proposed model is lightweight and effective in handling security issues. Application/Improvements: This paper fulfills a huge need of handling security using an effective lightweight architectural model adopting the proposed approach. Our methodology ensures designing a secure, flexible and easily monitored network with a rapid location of the affected areas and effective security supervision.

Impact of Packet Arrivals on Wi-Fi and Cellular System Sharing Unlicensed Spectrum

We investigate the coexistence performance of Wi-Fi and cellular systems under an unlicensed spectrum sharing environment. For this, we provide a mathematical framework based on queuing theory depicting the time-domain behaviors of a Wi-Fi access point (AP) and a cellular small-cell base station (SCBS) under unlicensed spectrum sharing. Based on the proposed framework, we make an analysis of the delay performance of both systems with respect to the changes in their packet arrival rates. Through the analysis, we identify the maximum allowable packet arrival rates of both systems, under which the required Wi-Fi delay performance is achieved without spectrum etiquette for coexistence at the cellular SCBS, such as carrier-sensing adaptive transmission. This will serve as a guideline for the cellular SCBS on when it needs to employ the spectrum etiquette.

Performance Analysis of Software-Defined Network Switch Using $M/Geo/1$ Model

The aim of this letter is to propose an analytical model to study the performance of software-defined network (SDN) switches. Here, SDN switch performance is defined as the time that an SDN switch needs to process packet without the interaction of controller. We exploit the capabilities of queueing theory-based $M/Geo/1$ model to analyze the key factors, flow-table size, packet arrival rate, number of rules, and position of rules. The analytical model is validated using extensive simulations. This letter reveals that these factors have significant influence on the performance of an SDN switch.

Two-Way Relay Strategies With a Multiaccess Uplink and Queue Stability Constraints

In this paper, we consider energy usage in a three-node, two-way relay system with stochastic data arrivals and Gaussian channels. Specifically, we allow for a set of transmission modes, assuming a multiaccess uplink transmission with the relay as an optimal multiuser receiver, and find the optimal allocation of time and energy resources to the modes. In the downlink, we introduce three transmission strategies, namely, orthogonal transmission of a digital network-coded message and the remainder of the longer source message over time, superposition coding of the digital network-coded message and the remainder of the longer message, and superposition of the two source messages. We then minimize total energy usage subject to queue stability constraints at all nodes for a given pair of average packet arrival rates. The total energy usage of these three strategies in the downlink is compared, and it is found that it is best to use superposition of the network-coded message and the remaining bits in the downlink. To study stability, we present an analysis of the queues at each node under a random scheduling protocol that closely approximates the theoretical design through a Markov chain model.

A proportional fairness scheduling for wireless sensor networks

A packet scheduling algorithm used for wireless sensor network meeting the proportional fairness principle is proposed. Based on the weighted round robin (WRR) strategy, the proposed scheduling algorithm allocates different service quota to different traffics according to their average packet arrival rates to guarantee the proportion fairness on the average packet delivery delay and the average packet loss ratio. Since the scheduling algorithm does not perform the high-load operations such as adding time stamps, sorting and so on, it can be implemented easily and is suitable for resource-limited WSN. The proposed algorithm is tested in a wireless sensor network. The performance shows that the scheduling algorithm can guarantee the average packet delivery delay proportional fairness when the average packet delivery delay is used as the performance metric and the average packet loss ratio proportional fairness is realized when all the queues are overflowing and the average packet loss ratio is used as the performance metric.

Game-Theoretic Queue-Stabilizing Backoff Algorithm in S-ALOHA and CSMA Systems

This letter investigates a queue-stabilizing backoff algorithm for slotted ALOHA and carrier-sense multiple access systems from game-theoretic perspective. Since queue stability of each user could be achieved when user’s throughput is greater than its mean packet arrival rate, every user tries to achieve its throughput up to a certain target level, by playing a non-cooperative game of determining a (re)transmission probability. We characterize Nash equilibrium points (NEPs) of this game and the convergence of a distributed backoff algorithm for users to employ to reach the NEPs.

On the Stability of Static Poisson Networks Under Random Access

We investigate the stable packet arrival rate region of a discrete-time slotted random access network, where the sources are distributed as a Poisson point process. Each of the sources in the network has a destination at a given distance and a buffer of infinite capacity. The network is assumed to be random but static, i.e., the sources and the destinations are placed randomly and remain static during all the time slots. We employ tools from queueing theory as well as point process theory to study the stability of this system using the concept of dominance. The problem is an instance of the interacting queues problem, further complicated by the Poisson spatial distribution. We obtain sufficient conditions and necessary conditions for stability. Numerical results show that the gap between the sufficient conditions and the necessary conditions is small when the access probability, the density of transmitters, or the SINR threshold is small. The results also reveal that a slight change of the arrival rate may greatly affect the fraction of unstable queues in the network.