Packet Buffer Research Articles

Adaptive Admission Control for IoT Applications in Home WiFi Networks

Assuring the required quality of service, despite the growing volume and variety of Internet of Things (IoT) traffic, has remained an immense challenge in the popular WiFi networks. The IoT devices using short TCP flows often attain very different levels of service due to the complicated interactions between the transport layer protocol and the shared dynamic wireless medium. We develop in this paper a novel queue management policy by using a transient model to capture the interactions of IoT (short TCP) flows over traditional traffic in WiFi networks. Based on the Markov regenerative processes coupled with fluid model, we discover that the adaptive admission control (AAC) mechanism at the WiFi access point (AP) improves the response time and fairness of IoT traffic over the lossy WiFi links. To this end, under the proposed AAC, packets are admitted into the AP in such a way that the fractions of packets in the AP buffer belonging to the different IoT devices are balanced resulting in a comparable level of service. We furthermore prove the stability of the system dynamics under AAC which provides important practical insights in designing home WiFi IoT system.

Fuzzy-based beaconless probabilistic broadcasting for information dissemination in urban VANET

Multi-hop broadcasting in Vehicular Ad Hoc Network (VANET) is the basic building block for renovating on-road travel experiences because it supports message dissemination among a large number of travelers in real-time. In order to make forwarding decisions, 1-hop neighbor table is suggested to be maintained at each vehicle by exchanging beacon packets on a periodic basis. However, a network crowded with both data packets and beacons gives rise to broadcast storms, resulting in insignificant resource consumption. Therefore, a beaconless approach would be a better solution that can control packet flow throughout the network, owing to minimizing packet collision and drop rate. Some recent literature that does not rely on beacon information broadcasts ample amounts of data packets, promoting wastage of bandwidth. To handle such issues, a Fuzzy-based Beaconless Probabilistic Broadcasting Algorithms (FBBPA) is proposed to notify vehicles about an event in less broadcasting. It is a receiver oriented broadcast suppression technique, where the forwarding probability of the packets in vehicles’ buffer is decided on the basis of their distance, angular orientation, movement direction and buffer load delay. The resultant probability is used to reschedule the packet. Among all the packets in the vehicle's buffer, the one having the highest priority at an instant is broadcasted first. For accident and advertisement packets, the analysis through simulation reveals that the proposed algorithm outperformed the compared protocols in terms of reachability (Information coverage), average delay and saved rebroadcast.

SIR approach in modeling data packets forwarding at a leaky bucket

When network users are intensively interacting during rush hour, avoiding data loss and latency is a concern in guaranteeing segment reliability. Implementing a leaky bucket could be needed to achieve flows effective monitoring by generating network of queues at given output link. Packets associated with different sessions and originated from different hosts may be mixed up and queuing delay may become longer, depending on network segment state, buffering strategy, users’ behavior among other factors. It is interesting to assimilate these stages of packets traveling through network segment to the concept of epidemic control. This paper proposes a SIR (Susceptible–Infected–Recovered) approach in modeling data packets transmission at a leaky bucket at peak hour. We focused our analysis on packets buffering and recovery strategy impact on segment forwarding performance in heavy load situation. Numerical results suggested adapting buffering strategy and packets recovery to enhance transmission and network overall performance.

EnFlow: An Energy-Efficient Fast Flow Forwarding Scheme for Software-Defined Networks

In recent years, the huge expansion of Datacenters (DC) to execute billions of end-user applications in real-time leads to a large amount of energy consumption across the globe. So, the traditional TCP/IP-based networks which are being used for DC inter-connections are facing challenges of managing stringent Quality-of-Service (QoS) requirements of different applications of the end-users and service providers. Moreover, the existing solutions rely on distributed architecture and do not scale for large scale data centers. The issue of high power consumption at DC arises with the increase in the number of nodes and links in the network. Also, it becomes problematic on the DC whenever the underlying network resources (switches and routers) are not efficiently utilized at the time of peak data traffic resulting in high operational cost of energy utilization. However, Software-Defined Networking (SDN) emerges as one of the leading technologies to address the aforementioned issues using the programmable switches and controllers. Inspired from these facts, in this paper, we have formulated the Energy-Aware Routing (EAR) problem of DCs as a Mixed Integer Non-Linear Programming (MINLP) for which an Energy-Efficient Fast Flow Forwarding (EnFlow) scheme is designed. The EnFlow scheme uses the power-saving mode of the network to solve the EAR problem. It has three modules namely- priority scheduling, routing, and re-routing. The first module works according to the First-in-First-Out Push Out Priority (FIFO-POP) scheduling using the multiple OpenFlow switches. The FIFO-POP is designed to save the energy usage of multiple switches by reducing the average waiting time of incoming packets in the queue buffers. The second module is based upon an efficient flow re-routing for a new node and link adaptation to provide the maximum bandwidth to the wired links. The third module is based upon the meta-heuristic Ant Colony Routing (ACR) to execute the stochastic decision policy on the network controller for computation of the shortest path of the forwarding nodes. The proposed EnFlow scheme is simulated using the data traces of 34 cities of NorthAmerica zone with Omnet++ 5.1 using various performance evaluation metrics. The results obtained demonstrated that the proposed EnFlow scheme is 24.55% and 71.15% more energy-efficient in comparison to the RE-FPR and ILP-EAR schemes. Also, it consumes 9.72% and 40.83% lower energy in comparison to the FFHA and EXR schemes respectively.

Complimentary code keying of spectral amplitude coding signals in optical buffering with increased capacity

Signal buffering services such as contention resolution and congestion avoidance are essential in optical packet switching networks. In this paper, an optical memory scheme based on spectral amplitude coding (SAC) and complementary code keying (CCK) is proposed to increase the buffer capacity. CCK is applied to packet buffering by selecting an available code set and encoding the payload bits with either an SAC signal or its complementarity. The capacity constraint is effectively released, as the usable codes for queuing packets are twice those for the conventional code-domain buffers. To minimize system costs by reducing the codec number, a shared structure based on an arrayed waveguide grating (AWG), which is capable of processing both the typical and complimentary coded signals simultaneously, is also investigated.

Performance analysis of IEEE802.11e EDCA wireless networks under finite load

In the majority of IEEE 802.11 series wireless networks, the quality of service (QoS) requirements are related to the queueing behavior of buffers in mobile stations, e.g., the buffer stability, overflow probability and packet delay, etc. Thus, it is important to accurately evaluate the performance of such networks in non-saturation environments. In this paper, we analyze the IEEE 802.11e enhanced distributed channel access (EDCA) wireless network under finite load. We develop an analysis model by a 3-dimensional Markov chain and derive its steady state distribution using the spectral method. We present a variety of performance measures including the buffer stability, the collision probability, the non-saturation throughput and the probability generating function of head-of-line delay (HoL-delay). For IEEE 802.11e EDCA wireless networks, these results are very useful in optimizing the network architecture and system parameters under the given QoS requirements.

Performance analysis and hardware implementation of a nearly optimal buffer management scheme for high‐performance shared‐memory switches

SummaryBurst traffic is a common traffic pattern in modern IP networks, and it may lead to the unfairness problem and seriously degrade the performance of switches and routers. From the perspective of switching mechanism, the majority of commercial switches adopt the on‐chip shared‐memory switching architecture, and high‐speed packet buffer with efficient queue management is required to deal with the unfairness and congestion problem. In this paper, the performance of a shared‐private buffer management scheme is analyzed in detail. In the proposed scheme, the total memory space is split into shared area and private area. Each output port has a private memory area that cannot be used by other ports. The shared area is completely shared among all output ports. A theoretical queuing model of the proposed scheme is formulated, and closed‐form formulas for multiple performance parameters are derived. Through the numerical studies, we demonstrate that a nearly optimal buffer partition policy can be obtained by setting an equally small amount of private area for each queue. This work is validated by simulations as well as hardware experiments. Software simulations show that the proposed scheme performs better than existing methods, and packet dropping caused by burst traffic can be significantly reduced. Besides, a prototype of the buffer management module is implemented and evaluated in field programmable gate array platform. The evaluation shows that the proposed scheme can ensure the efficiency and fairness while keeping a high throughput in real workload.

Recycling Cellular Energy for Self-Sustainable IoT Networks: A Spatiotemporal Study

This paper investigates the self-sustainability of an overlay Internet of Things (IoT) network that relies on harvesting energy from a downlink cellular network. Using stochastic geometry and queueing theory, we develop a spatiotemporal model to derive the steady state distribution of the number of packets in the buffers and energy levels in the batteries of IoT devices given that the IoT and cellular communications are allocated disjoint spectrum. Particularly, each IoT device is modelled via a two-dimensional discrete-time Markov Chain (DTMC) that jointly tracks the evolution of the data buffer and energy battery. In this context, stochastic geometry is used to derive the energy generation at the batteries and the packet transmission success probability from buffers taking into account the mutual interference from other active IoT devices. To this end, we show the Pareto-Frontiers of the sustainability region, which define the network parameters that ensure stable network operation and finite packet delay. Furthermore, the spatially averaged network performance, in terms of transmission success probability, average queueing delay, and average queue size are investigated. For self-sustainable networks, the results quantify the required buffer size and packet delay, which are crucial for the design of IoT devices and time critical IoT applications.

Multi-Level Buffering Services Based on Optical Packet Encoding of Composite Maximal-Length Sequences in a GMPLS Network

Generalized multi-protocol label-switching (GMPLS) provides packet-switching with multiple speeds and quality-of-services (QoSs). Packet buffering in GMPLS reduces packet loss by resolving the conflicts between packets requesting for a common channel. Presently, due to the diversity of multimedia applications, enabling multiple services in networks has become necessary. In this paper, a family of codes known as composite maximal-length sequence (CMLS) codes is introduced into an optical buffering scheme based on code-switching. A given number of available CMLS codes is divided into several code subsets. The buffer selects an unused CMLS code from a code subset and assigns it to the incoming packet. When all codes in a specific subset have been distributed to the queued packets, a free CMLS code in another subset is chosen for the new arrival. To achieve multi-level buffering services, the partition scenario with a lower subset number but with a higher number of codes in an individual subset is used as a code-assigning method for buffering high-QoS users. A two-level buffering system is demonstrated by examining the QoS of each class in terms of packet-dropping probability (PDP). The results show that different levels of PDPs can be effectively supported by a common buffer architecture.

Экспериментальное исследование структуры пакетного буфера Ethernet коммутатора

Экспериментальное исследование структуры пакетного буфера Ethernet коммутатора

A Multi-Objective Model Checking for Transmission Policy Optimization in Hybrid Powered Small Cell Networks

In the fifth generation (5G) communication system, maximizing energy utilization is one of the key challenges especially with limited green energy sources. In particular, it is important to determine the optimal transmission policy for the hybrid model with grid and green energy in small cell networks. The optimal transmission policy should minimize both grid power consumption and wastage of green harvested energy at the same time; while satisfying the quality of service (QoS) requirements such as minimum packet drop probability. In contrast to existing policies with a single objective for the hybrid powered small cell networks, the proposed transmission policy adopts a multi-objective model checking for Markov decision process (MOMC-MDP) with a linear temporal logic (LTL) scheme. The MOMC-MDP firstly determines all feasible decisions for packet transmissions in every time slot, and then chooses one of the best feasible decisions to obtain the optimal transmission policy. Three dimension Markov decision process (3D-MDP) that includes packet buffer, battery capacity, and channel state, are used with the age of information (AoI) of the packet arrivals to improve the overall performance of the proposed MOMC-MDP scheme. Numerical results validate that the proposed MOMC-MDP with AoI can provide higher green energy utilization compared to the conventional MDP-based schemes.

On hybrid energy utilization for harvesting base station in 5G networks

AbstractIn this paper, hybrid energy utilization was studied for the base station in a 5G network. To minimize AC power usage from the hybrid energy system and minimize solar energy waste, a Markov decision process (MDP) model was proposed for packet transmission in two practical scenarios. In this model, one buffer is transmitted with a given number of data packets over finite transmission time intervals. In the two scenarios of packet transmission, solar energy harvesting (SEH) is stored in the first scene, while the other scene uses the energy immediately. The MDP model determines the best actions and decisions for both scenarios. When considering a finite battery size and finite packet buffer, the MDP model defines the actions, states, state transition probabilities, and cost value for each action. In the first scenario, the received solar energy harvester will not be used if it is not enough to transmit the packets in the buffer. In the second scenario, the received solar energy harvester will be used immediately. In both scenarios, the cost value is the weighted sum of AC power and SEH wastage. The simulation results showed the optimum buffer sizes could be determined for the balance between AC power consumption and SEH wastage based on the cost value of the proposed model. Finally, the numerical results indicated that the proposed MDP model could reduce AC power usage by up to 50%.

Designing a High Performance SRAM-DRAM Hybrid Memory Architecture for Packet Buffers

Designing a High Performance SRAM-DRAM Hybrid Memory Architecture for Packet Buffers

Design and Performance Analysis of a New Framework of Multipath Load Balancing Routing in Ad-Hoc Network

In the communication networks, one of the major problems in the quality of service is congestion. Indeed, the phenomenon of congestion is due to the fact that many packets emitted follow the same paths. As a result, the increase the bandwidth offered can solve the problem only in the short term. In order to solve this problem, several solutions have been proposed, such as multipath routing algorithms, which distribute traffic between a source and a destination on several different paths, while taking into account the level of saturation of the intermediaries nodes, composing the different paths with a objective to avoid cluttered paths. Its purpose is to shed the excessive burden save a knot on its neighbors to improve performance and to exploit efficiently. In this paper we have analysis the load balancing in Multipath routing to achieve better network performance. We have study and reviewed the different load balancing algorithm in multipath network and based on review we have proposed a new load balancing algorithm in the multipath network. We have modified the packet of RREP and RREQ packet to transmit and receive the route information to compute the load of every path and we added a new field in RREP packet Buffer size to store the current node and their neighbor information to find the alternate route if network load in increase we have compare the performance of proposed protocol with the LB-AOMDV, SMR & AOMDV multipath routing protocols. NS2 is used for simulation

Congestion Control in CoAP Observe Group Communication.

The Constrained Application Protocol (CoAP) is a simple and lightweight machine-to-machine (M2M) protocol for constrained devices for use in lossy networks which offers a small memory capacity and limited processing. Designed and developed by the Internet Engineering Task Force (IETF), it functions as an application layer protocol and benefits from reliable delivery and simple congestion control. It is implemented for request/response message exchanges over the User Datagram Protocol (UDP) to support the Internet of Things (IoT). CoAP also provides a basic congestion control mechanism. In dealing with its own congestion, it relies on a fixed interval retransmission timeout (RTO) and binary exponential backoff (BEB). However, the default CoAP congestion control is considered to be unable to effectively perform group communication and observe resources, and it cannot handle rapid, frequent requests. This results in buffer overflow and packet loss. To overcome these problems, we proposed a new congestion control mechanism for CoAP Observe Group Communication, namely Congestion Control Random Early Detection (CoCo-RED), consisting of (1) determining and calculating an RTO timer, (2) a Revised Random Early Detection (RevRED) algorithm which has recently been developed and primarily based on the buffer management of TCP congestion control, and (3) a Fibonacci Pre-Increment Backoff (FPB) algorithm which waits for backoff time prior to retransmission. All the aforementioned algorithms were therefore implemented instead of the default CoAP mechanism. In this study, evaluations were carried out regarding the efficiency of the developed CoCo-RED using a Cooja simulator. The congestion control mechanism can quickly handle the changing behaviors of network communication, and thus it prevents the buffer overflow that leads to congestions. The results of our experiments indicate that CoCo-RED can control congestion more effectively than the default CoAP in every condition.

Globally Synchronized Time via Datacenter Networks

Synchronized time is critical to distributed systems and network applications in a datacenter network. Unfortunately, many clock synchronization protocols in datacenter networks such as NTP and PTP are fundamentally limited by the characteristics of packet-switched networks. In particular, network jitter, packet buffering and scheduling in switches, and network stack overheads add non-deterministic variances to the round trip time, which must be accurately measured to synchronize clocks precisely. We present the Datacenter Time Protocol (DTP), a clock synchronization protocol that does not use packets at all, but is able to achieve nanosecond precision. In essence, the DTP uses the physical layer of network devices to implement a decentralized clock synchronization protocol. By doing so, the DTP eliminates most non-deterministic elements in clock synchronization protocols and has virtually zero protocol overhead since it does not add load at layer-2 or higher at all. It does require replacing network devices, which can be done incrementally and with very small amount of hardware resource consumption. We demonstrate that the precision provided by DTP in hardware is bounded by 4TD where D is the longest distance between any two nodes in a network in terms of number of hops and T is the period of the fastest clock. The precision can be further improved by combining DTP with frequency synchronization. By contrast, the precision of the state-of-the-art protocol (PTP) is not bounded: The precision is hundreds of nanoseconds in an idle network and can decrease to hundreds of microseconds in a heavily congested network.

Two Variants of Secure Routing Algorithms in Mobile Ad Hoc Network

Background and Objective: Two different variants of secure routing algorithms are proposed in the present work. In both the variants a stable route is established between source and destination. Methods: The selected route is associated with the nodes having sufficient energy to establish the route and to transmit the data packets, minimum velocity to reduce the frequency of link failure, maximum distance from the source node to reduce the number of hops in the selected route, minimum number of neighbors to reduce the routing overhead. Each variant has two phases. In the first phase it is assumed that the selected route has no attackers. The first phase is made more realistic in the second phase by considering the presence of attacker in the selected route. In the first variant a node associated with the selected route overhears the transmission of the next forwarder node to detect an attacker node in the routing path. But a node may fail to overhear its next hop in presence of hidden node, due to limited overhear range etc. Such problem is eliminated in the second variant. In the second variant each node associated with the selected route searches its data packet buffer for the reception of the next data packet from its predecessor node associated with the same route and suspects the predecessor node as an attacker in case the next data packet is not found in the buffer. The performance of both the variants is compared on the basis of packet delivery ratio, throughput and average end-to-end delay. Results: The throughput and packet delivery ratio are higher in the second variant than the first variant whereas the average end-to-end delay is less in the second variant than the first variant. Conclusion: Moreover both the variants outperform the existing schemes in terms of packet delivery ratio, throughput and average end-to-end delay.

Application of computer simulation models in the study of the impact of data buffering on the quality of control in network systems

The work focuses on the computer simulation modeling of the control system with the network channel of information transmission. We have studied the impact of data buffering on the quality of control for the systems with a limited volume buffer for data packets. It has been expected that the data packet transmission over the network channel for the quantization period is carried out with a given probability. If the data packet from the digital sensor is not transmitted in one quantization tact to the controller, it is placed in the sensor buffer. During data is transmitted over the channel, all packets from the sensor buffer are transmitted to the controller buffer. The controller processes incoming data from the buffer sequentially-one packet per quantization tact. To simulate such situations, it was proposed to use the appropriate developed random processes. The novelty of the developed simulation model lies in the fact that in the basis for the development of this model is accepted the modeling of the time gap of the information flow of data. Simulation of the network control system operation was carried out in the environment Simulink of Matlab system.

ProFlow: Proportional Per-Bidirectional-Flow Consistent Updates

Network elements, such as switches, network functions, or middleboxes must preserve states that they maintain on a per-flow basis, during switch updates in a software defined network. If all the packets of a flow, in both the forward and reverse directions, either use the new or the old set of rules but not a combination of both during an update, per-bidirectional-flow consistency (PBFC) is preserved. We propose a PBFC-preserving update as a general solution to solve consistency problems occurring in stateful network elements, during updates for service chaining, network virtualization, and server load balancing. In our update algorithm, ProFlow, the number of switches modified is proportional (equal) to the number of affected switches, improving efficiency. It requires no path computation, packet buffering or network function modifications and works regardless of the relative execution speeds of switches or links, or the number or type of stateful elements, at line rate. It supports wildcarded rules, unlimited concurrent disjoint updates, and practical timing asynchrony. Our prototype in P4 demonstrates that during a ProFlow update, new flows maintain their throughput while old flows undergo a marginal reduction, where the first affected switch in the flow-path has both new and old rules.

Jitter Buffer Control Algorithm and Simulation Based on Network Traffic Prediction

The jitter buffer size is one of the important factors that affect the voice quality of Voice over Internet Protocol (VoIP). In order to reduce buffer delay and packet loss and improve the speech quality of VoIP, an adaptive jitter buffer control algorithm based on network traffic prediction is proposed. Among them, the particle swarm optimization algorithm is used to optimize the weight and threshold of Elman neural network so that it avoids falling into local minimum and improves the accuracy of network traffic prediction. According to the change law of network traffic, the jitter buffer control algorithm under the autoregressive model is proposed. Through the improved stochastic midpoint placement algorithm, a network business traffic prediction model with sudden and self-similarity is established. Then the buffer size is set according to the predicted value of network traffic, and it is continuously improved in use to improve the accuracy of the buffer setting. The simulation results show that the MOS value of the algorithm is high, which improves the voice quality of the network telephone.