Multichannel adaptive routing for intensive data packet flows transmission: SpaceWire networks and protocols, long paper

We propose a novel transmission scheme suitable for short packet transmission over wireless channels. The proposed scheme is characterized by two schemes: 1) multicopy transmission per transmission payload and 2) multiple fragmented packet (referred to as minipacket) transmission. The multicopy transmission is to mitigate the transmission inefficiency of short packets and improve the decoding probability at the receiver. On the other hand, the minipacket transmission is to avoid the retransmission of correctly received symbols. By implementing the proposed scheme into the traditional IEEE 802.11b WLAN system, simulation results show the improved system throughput and reduced packet transmission time.

In recent times, the interest for different multimedia applications such as video conferencing, surveillance system, and video on request service over Mobile ad-hoc networks (MANETs) has been developing quickly. However, it is difficult for data transmission by satisfying end to-end delay requirements and security issues are distinct in MANETs because every node can act as the gateway, the topology is constantly changing, energy constrained operation and lack of centralized administration. Secure transmission without node failure in MANETs is an important issue. In order to rectify these traps, this article presents key-policy attribute based encryption (KP-ABE) to provide packet security from malicious clients and adaptive Routing Information Protocol next generation (RIPng) to identify the optimal path among autonomous energy constrained nodes by which routing overhead is reduced and it requires less communication cost during packet transmission. This novel method utilizes reliability matrix and connectivity matrix to identify the routes rather than the commonly utilized hop count thus minimizing time. Hence, a secure path is discovered with minimum time thus rectifying the issues in existing works. In addition to this, priority based scheduling operation is performed to organize packet according to their weights. The performance of the proposed scheme is surveyed with respect to different evaluation metrics in different node density levels and also under different routing attacks. The obtained result clearly describes the introduced scheme that provides adaptable and feasible decision to select the route that meets the security requirement of data packets transmission in MANET’s environment.

Our objective is to analyze and minimize the amount of energy needed to transmit packets in a multihop wireless network, such as a sensor network or an ad hoc network. The total energy consumed to transmit a packet from a source to a destination is a function of the number of hops along the path and the energy needed to successfully transmit a packet in one hop. Given a path, the number of hops needed depends on the transmission range. The energy consumed for a successful transmission in a hop depends on not only the transmission range but also the medium access strategy. In this paper, we generalize the analysis of the energy consumption on packet transmission in multihop wireless networks. The analysis is applicable to a range of multiaccess schemes from TDM to random access schemes. The results show that typically, there is a transmission range that results in the minimum energy. However, a smaller transmission range does not always lead to less energy consumed by packet transmission. The optimum energy consumption is the result of balancing several factors, including: 1) the ratio of an overhead packet length to a data packet length, where overhead packets refer to the control packets used to reserve the media or the data packets involved in collisions; 2) the number of transmissions of the overhead packets; 3) the number of hops along a path; and 4) the transmission range.

Competitive interaction model with Holling type and application to IP network data packets forwarding

Streaming is the continuous transmission of audio or video files from a server to a client. Streaming is real-time, and it's more efficient than downloading media files. Just like other data that is sent over the Internet, audio and video data is broken down into data packets. Each packet contains a small piece of the file, and an audio or video player in the browser on the client device takes the flow of data packets and interprets them as video or audio. The concept of video streaming services means free or subscription-based services offering online streaming of films and television programs. Video streaming platforms allow people to watch videos anywhere and anytime, provided they have an Internet connection, or even without it, if the preload option is available. This article covers the concepts of streaming, streaming media, and video streaming services. The subject matter is implementation of a video streaming web service with monolithic architecture. Selection justification is given for the architecture type. Explanations for the specific implementation details are provided as well. The service is flexible enough to carry out predetermined tasks and provides ample opportunities to adapt to various hardware platforms.

Popularity of Software Defined Network (SDN) technology is spreading rapidly and corporate networks are deploying to take advantages of its features. Control & Data planes are segregated in SDN and simple forwarding devices enabled with OpenFlow protocol is used to forward data planes. The responsibility of control planes are taken by controller into SDN network. The data packets are generated by source host and forwarded to destination host by seeing destination address of such packet without validating source host address. Flow of data packets is controlled by controller setting up required flow entries into flow table of forwarding devices. Initially forwarding devices do not have any security & control and they are not able to forward traffic generated by attached hosts. Data packets of attached hosts are sent to the controller by forwarding devices for generation of control packets and setup necessary flow entries into device flow table. Source IP spoofed attacks may be setup by attacker in this situation and perform different type of attacks. There are some techniques for prevention and mitigation from such attacks. In this study, we offer an analysis of available source address validation techniques for SDN environment. The study discussed various features, limitations and gaps of source address validation solutions and provided various areas in SDN Security for future research.

Discrete service disciplines have been shown capable of emulating the ideal Generalized Processor Sharing discipline within one maximum-sized packet's transmission time. As a result, the accuracy of such schemes increases with improvements in link speed due to the corresponding reduction in packet transmission delay. However, the merits of such accuracy diminish with improvements in link speed as its impact on call admission decisions decreases. Meanwhile, overhead, in terms of the number of scheduling decisions to be made per unit time, increases with the number of packets transmitted. In response, this paper will present the DQFS service discipline which enables GPS emulation servers to dynamically tune their service quanta based upon the QoS requirements of their currently supported applications rather than the network's maximal packet size. It will also demonstrate how the overhead of a GPS emulation server can be reduced in high speed networks without jeopardizing QoS guarantees or adversely impacting fairness.

LoRa has established itself as one of the main solutions within evolving Low Power Wide Area Networks, LP-WAN. LoRa is primarily pillared on its patented chirp spread spectrum modulation. In LoRa modulation, linearly increasing cyclic chirp signals span the LoRa bandwidth. The rate of increase of these chirp signals is dependent on the applied spreading factor (SF). Increasing the spreading factor extends the coverage range for LoRa communication at the expense of a reduced data rate. Typically, LoRa signals with different spreading factors are quasi-orthogonal such that LoRa essentially supports multiple simultaneous logical networks with different coverage ranges. Given that LoRa utilizes an ALOHA-based protocol for medium access, the total capacity of LoRa networks is governed by the system loads and time-on-air for packet transmissions of each SF-network. In this paper, non-binary single parity check (SPC) codes with soft-decision decoding are introduced as a tool to enhance the capacity of LoRa networks. The LLRs for the soft decision decoding of LoRa symbols are first derived. It is then shown that SPC codes succeed in achieving measurable coding gains for typical LP-WAN applications at the scale of 1.2 dB. Coinciding with enabling/disabling SPC in each logical SF-network, the system loads as well as the packet transmission times could be optimized with the objective of maximizing the packet delivery ratio. The presented capacity results indicate that in fact SPC optimization can achieve capacity gains at the scale of up to 65% compared to the nominal LoRa networks.

In this paper, we propose a direct-sequence spread spectrum multiple access (DS/SSMA) unslotted ALOHA system with two user classes and analyze the throughput of the proposed system. Mobile stations (MSs) are divided into two classes according to priority or traffic characteristics such as delay-intolerant and delay-tolerant. Different permission probabilities are assigned to each class so that the appropriate quality of service can be provided. We assume that the generation of class 1 and 2 messages are Poisson distributed and the message is divided into several packets before transmission. The system is modeled as a two-dimensional Markov chain under the assumption that the number of packets transmitted immediately by both user classes is geometrically distributed and the packet length is constant. We calculate the packet success probability and the throughput as a function of the signal-to-noise ratio (SNR) during packet transmission, considering the number of overlapped class 1 and 2 messages and the amount of their time overlap. Moreover, we show that the proposed system differentiates user messages according to class and maintains a high throughput even under heavy traffic conditions using access control based on the channel load.

Throughput analysis of direct-sequence spread spectrum multiple access (DS/SSMA) unslotted ALOHA with fixed packet length is presented. As the levels of multi-user interference fluctuate during the packet transmission, we calculate the packet error probability and the throughput by considering not only the number of overlapped packets but also the amount of time overlap. On the assumption that packet generation is Poisson, the system can be thought as the queueing system M/D//spl infin/. With Gaussian approximation of multi-user interference, we obtain the throughput as the function of the number of chips in a bit, the packet length, and the offered load of the system. We also analyze the channel load sensing protocol (CLSP), and obtain the optimum threshold of CLSP.

The IEEE 802.15.4 is a well-known standard that is widely utilized for Wireless Sensor Networks due to its low rate and energy efficiency. A novel amendment IEEE 802.15.4k is released for the support of the requirements of critical infrastructure monitoring applications. It is intended to deal with priority packet using the Priority Channel Access (PCA). In this paper, we introduce a new IEEE 802.15.4k protocol through embedding Markov chain models, namely a two dimensional Markov chain model for the IEEE 802.15.4k slotted CSMA/CA with PCA backoff access channel mechanism for priority packet transmission and a three dimensional Markov chain model for the IEEE 802.15.4k CSMA/CA access channel mechanism for non priority packet transmission. Our new model takes into account retry limits, acknowledgment mechanisms, transmission errors and saturated traffic. Furthermore, to test and validate the developed protocol a detailed mathematical expressions of the reliability, power consumption, average delay for successful packet transmission and throughput are given in order to compare the performance of both mechanisms. Moreover parameters that significantly influence on the performance of the network such as network size, Bit Error Rate, packet length and probability that the available packet is priority are analyzed to determine their impact. The obtained numerical results show that a higher reliability, lower throughput, negligible power consumption and lower delay are observed in our new protocol due to the priority channel access instead of the ordinary channel access. Additionally, we conduct a comparative study between our new IEEE 802.15.4k CSMA/CA mechanism and the IEEE 802.15.4 CSMA/CA mechanism. To the best of our knowledge, this is the first work modeling the 802.15.4k mechanisms and evaluating theirs performance under fading channel.

In this paper, we investigate the proportional fair scheduling (PFS) problem for multiuser OFDM systems, considering the impact of packet length. Packet length influences scheduling schemes in a way that each scheduled packet should be ensured to be completely transmitted within scheduled frames. We formulate the PFS problem into an optimization problem. Based on the observations on the structure of optimal solutions, we propose a heuristic scheduling algorithm. The scheme firstly allocates subcarriers among users without considering the packet length constraint. Then subcarrier readjustment is done in a way that surplus subcarriers from length-satisfied users are released and allocated among length-unsatisfied users. The objective is to provide proportional fairness among users while guaranteeing complete transmission of each scheduled packet. Simulation results show that the proposed scheme has quite close performance to the optimal scheme in terms of multi-carrier proportional fairness measure (MCPFM) and average throughput.

One of the laborious communication tasks in a mobile ad hoc network is packet transmission. Due to the MANET node's power backup, many routing paths may experience unsuccessful packet delivery. The routing algorithm chooses the path that packets take as they travel from the source node to the destination nodes, but it makes no guarantees regarding packet delivery. In order to determine the most effective path between nodes, this paper proposed a new routing algorithm with the use of the T-test process. This suggested technique determines the best path between nodes for communication in a recursive manner, ensuring that each node participating in the route discovery has enough energy for transmission. The criteria for evaluating the nodes that are chosen and rejected throughout the route discovery process are defined and supported by the T-Test procedure. This technique, together with T-Test, supports effective packet transmission in MANET packet flow. It is also built with the help of network simulation and compared to the current routing protocol, demonstrating that it performs better overall.

In this paper, for improving the performance of Transmission Control Protocol (TCP) over Wireless Mesh Network (WMN), we introduce a new TCP loss recovery algorithm called T-NCE (A Timestamp based detection of Non-Congestion Events) which is able to detect the Non-Congestion events such as transmission errors and packet reordering and differentiate the loss of packets due to transmission errors from reordering of packets. The existing loss differentiation algorithms have no mechanism to detect the loss of multiple packets from one window due to transmission errors. T-NCE can detect multiple packet loss and improves the performance of TCP by reducing retransmission timeouts and unnecessary retransmissions. T-NCE is implemented in qualnet 4.5 and the simulation results confirm that, T-NCE achieves significant throughput improvement compare to other loss differentiation algorithms.

Adaptive routing that dynamically selects a less congested output port from a set of minimal or non-minimal paths aids in preventing the network from saturating at an early stage of increasing packet injection ratio. However, routing packet to an alternate route rather forwarding them to the priority fixed shortest route may lead to a situation of delivering packets in out-of-order sequence at the sink node. Here, sorting and reordering all disordered packets at the sink node end becomes impossible due to unbounded buffer size at higher packet injection ratio. This work presents a method of guaranteeing packets' in-order delivery after employing an window based end-to-end flow control policy when the priority fixed minimal route is not available due to congestion of adjacent link or router node. Proposed mechanism shows guarantee on packet's delivery ordering sequence without heavily degrading its network performances. Experiments over several synthetic and parallel benchmark traffics reveal that the proposed mechanism may still achieve higher throughput after increasing their packet length which is very close to the throughput, achieved by the adaptive routing that follows reordering mechanism at the destination node end.