Non-real Time Flows Research Articles

DEEP PACKET INSPECTION USING HYBRID CLASSIFIER FOR UNKNOWN TRAFFIC FLOWS IN THE INTERNET

In this era of Internet every electronic device being manufactured comes with built-ins to connect itself with the Internet. Such electronic gadgets create a massive amount of traffic flows every second. Managing this immense Internet traffic has become an exhausting job. Classifying these massive flows of data and interpreting them has attained considerable importance in the sight of researchers and Internet Service Providers. Many methods have been presented by various researchers to address this classification issue. This paper presents a Hybrid Classifier algorithm, which is a combination of the well-known machine learning types; the supervised learning and unsupervised learning to solve this classification issue. Accurate and Efficient recognition of flows is the key to manage flows in real-time. This algorithm classifies the traffic flows into real time flows and non-real time flows. It uses the built decision support model for classifying the flows based on the target class. To further validate the classification, it applies the k-means model. A significant improvement in the classification accuracy has been obtained.

Traffic-aware performance optimization in Real-time wireless network on chip

Network on Chip (NoC) is a prevailing communication platform for multi-core embedded systems. Wireless network on chip (WNoC) employs wired and wireless technologies simultaneously to improve the performance and power-efficiency of traditional NoCs. In this paper, we propose a deterministic and scalable arbitration mechanism for the medium access control in the wireless plane and present its analytical worst-case delay model in a certain use-case scenario that considers both Real-time (RT) and Non Real-time (NRT) flows with different packet sizes. Furthermore, we design an optimization model to jointly consider the worst-case and the average-case performance parameters of the system. The Optimization technique determines how NRT flows are allowed to use the wireless plane in a way that all RT flows meet their deadlines, and the average case delay of the WNoC is minimized. Results show that our proposed approach decreases the average latency of network flows up to 17.9%, and 11.5% in 5 × 5, and 6 × 6 mesh sizes, respectively.

Joint Realtime and Nonrealtime Flows Packet Scheduling and Resource Block Allocation in Wireless OFDMA Networks

In this paper, we consider joint realtime (RT) and nonrealtime (NRT) flows packet scheduling and resource block (RB) allocation in orthogonal frequency division multiple access (OFDMA) wireless networks. Radio RBs in the OFDMA plane are to be distributed among RT and NRT flows. In the conventional approach, RT and NRT flows are served sequentially. This sequential approach is inefficient because an RT flow may presumably have enough time until its delay deadline while its channel is in deep fade. In this situation, the transmission of NRT flows with higher level of efficiency can be performed. Intuitively speaking, the conventional sequential approach is too conservative, which can be reengineered. We propose a novel joint RT and NRT flows disutility-based packet scheduling and RB allocation in a common pool of RBs. The proposed joint approach enlarges the effective capacity of the associated wireless system when compared with the separated pool of RBs. The joint approach is particularly relevant for improving voice over LTE (VoLTE). We use mean bit-rate, mean queue-length, and instantaneous queuing delay information, in addition to channel information, to match the demand and supply. Furthermore, we develop a novel model for input–output bit-rate behavior of the mixture of RT and NRT flows. This model sheds light on the identification of different load regions and understanding of the system in an intuitive manner. Our approach and methodology can be extended for broader quality-of-service (QoS) requirements and for the utility of future applications. Simulation results show that the proposed framework is able to unify the serving mechanism of the RT and NRT flows and is able to achieve higher admissible bit-rate when handling mixed RT and NRT flows, compared with various baselines.

Queue-Aware Channel-Adapted Scheduling and Congestion Control for Best-Effort Services in LTE Networks

In this paper, we study the performance of long-term evolution (LTE) for various types of channel-adapted scheduling for nonreal-time flows, while an end-to-end congestion control algorithm controls the rate of elastic traffic at the end users. First, we propose a new type of queue-aware channel-adapted scheduling at a base station, and explain how it allocates resources to competing nonreal-time flows where channel conditions are time-varying. We also introduce a new congestion measure function for a minimum cost flow control (MCFC) algorithm in the LTE and call it an individual flow-based congestion measure. We show that using different combinations of channel-adapted scheduling at the base station and congestion control algorithms can lead to major differences in the obtained throughput and fairness for the best-effort traffic. The results clearly show that the transport protocol and scheduling algorithm can cause significant conflict in some situations. We show the advantages of the proposed queue-aware channel-adapted scheduling in performance improvement and we also show that the combination of an MCFC algorithm (in which the new individual flow-based congestion measure is applied), with queue-aware proportional fair scheduling, leads to a better tradeoff between overall throughput and fairness compared with the other studied combinations.

Multi-path Stable QoS Routing for Real-time Traffic Applications in MANET

mobile ad hoc networks (MANET), the existing routing protocols consider the routing metrics such as bandwidth, delay and link stability in partial manner. Also the real time and non- real time traffic flows are not distinguished based on delay and bandwidth requirements. In order to overcome these issues, in this paper multipath stable QoS routing for real time traffic in MANET is proposed. In this technique, multiple paths are discovered among source and destination. Among the discovered routes, the optimal paths are selected based on bandwidth constraints, delay constraints and path stability. When any flow request is received, it is initially categorized as real time and non-real time flows where real time flows are given higher priority. For real time flows, bandwidth and delay constrained paths are chosen. For non-real time flows, the stable paths are chosen. By simulation results, the proposed approach is validated and the approach minimizes delay and overhead.

STATELESS AGGREGATE FAIR MARKING SCHEDULER FOR DIFFERENTIATED SERVICE NETWORKS

In diffserv networks, as the traffic flows vary constantly, it is very difficult to maintain the per-flow state. The computation of rate information of the traffic flow also becomes complex. In this study, we propose a Stateless Aggregate Fair Marking (SAMQ) with Multiple Queue Priority Scheduler for Differentiated Service (DiffServ) networks. Initially, priority scheduler is applied to the flows entering the ingress edge router. If it is real time flow like Voice over IP (VoIP) or Video, then the packets are given higher priority else lower priority. In core router, for higher priority flows the Multiple Queue Fair Queuing (MQFQ) is applied that allows a flow to utilize multiple queues to transmit the packets. In case of lower priority, Stateless Aggregate Fair Marking technique is utilized. This technique applies Core Stateless Fair Queuing (CSFQ) technique for maintaining the rate information of packet flow and distributes the token to each incoming packet without maintaining the per-flow state. By simulation results, we show that this technique improves the throughput of non-real time flows.

A QoS guaranteeing MAC layer protocol for the "underdog" traffic

With the tremendous boom in the wireless local area network arena, there has been a phenomenal spike in the web traffic which has been triggered by the growing popularity of real-time multimedia applications. Towards this end, the IEEE 802.11e medium access control (MAC) standard specifies a set of quality-of-service (QoS) enhancement features to ensure QoS for these delay sensitive multimedia applications. Most of these features are unfair and inefficient from the perspective of low priority (non-real time) traffic flows as they tend to starve the non-real time flows depriving them of appropriate channel access, hence throughput. To that extent, this article proposes a MAC protocol that ensures fairness in the overall network performance by still providing QoS for real-time traffic without starving the "underdog" or non-real-time flows. The article first presents analytical expressions supported by Matlab simulation results which highlight the performance drawbacks of biased protocols such as 802.11e. It then evaluates the efficiency of the proposed "fair MAC protocol" through extensive simulations conducted on the QualNet simulation platform. The simulation results validate the fairness aspect of the proposed scheme.

Novel Radio Link Buffer Management Schemes for End-User Multi-class Traffic in High Speed Packet Access Networks

The requirement to provide multimedia services with QoS support in mobile networks has led to standardization and deployment of high speed data access technologies such as the High Speed Downlink Packet Access (HSDPA) system. HSDPA improves downlink packet data and multimedia services support in WCDMA-based cellular networks. As is the trend in emerging wireless access technologies, HSDPA supports end-user multi-class sessions comprising parallel flows with diverse Quality of Service (QoS) requirements, such as real-time (RT) voice or video streaming concurrent with non real-time (NRT) data service being transmitted to the same user, with differentiated queuing at the radio link interface. Hence, in this paper we present and evaluate novel radio link buffer management schemes for QoS control of multimedia traffic comprising concurrent RT and NRT flows in the same HSDPA end-user session. The new buffer management schemes—Enhanced Time Space Priority (E-TSP) and Dynamic Time Space Priority (D-TSP)—are designed to improve radio link and network resource utilization as well as optimize end-to-end QoS performance of both RT and NRT flows in the end-user session. Both schemes are based on a Time-Space Priority (TSP) queuing system, which provides joint delay and loss differentiation between the flows by queuing (partially) loss tolerant RT flow packets for higher transmission priority but with restricted access to the buffer space, whilst allowing unlimited access to the buffer space for delay-tolerant NRT flow but with queuing for lower transmission priority. Experiments by means of extensive system-level HSDPA simulations demonstrates that with the proposed TSP-based radio link buffer management schemes, significant end-to-end QoS performance gains accrue to end-user traffic with simultaneous RT and NRT flows, in addition to improved resource utilization in the radio access network.

Adaptive channel and superframe allocation (ACSA) for 60 GHz wireless networks

Millimeter-wave (MMW) systems are high frequency wireless systems with a center frequency of around 60 GHz. In this article we propose an adaptive channel–superframe allocation (ACSA) scheme for such a system and evaluate its throughput and delay performance. The ACSA algorithm is designed to serve real-time (RT) and non-real-time (NRT) flows separately in different channels instead of serving them in different times. We also propose to change the sliced superframe of IEEE 802.15.3 to an adaptive unsliced superframe in order to decrease the TCP round-trip time. We compared IEEE 802.15.3 MAC with ACSA MAC, which shows that the throughput and delay could be improved in ACSA MAC. We observed significant improvement in the throughput of NRT flows via the better distribution of bandwidth in ACSA MAC. The channel access delay is also improved by providing an unsliced superframe. In brief, the simulation results also support the analysis of the proposed adaptive channel–superframe allocation algorithm, which could generally improve the quality of service (QoS) in MMW systems.

Delay and data rate decoupled fair queueing for multimedia services in wireless networks

This paper proposes a delay and data rate decoupled fair queueing scheme for wire-less multimedia, where two separate scheduling algorithms are applied respectively for real time and non-real time flows. For real time flows, we propose an explicit-delay-guarantee algorithm to guarantee the delay deadline, while a conventional fair queuing algorithm is adopted for non-real time flows to guarantee fairness and throughput requirements. In erroneous wireless channel, resource swapping is further adopted to guarantee the required quality of service. In addition, a real time flow can easily react to varying channel error condition by controlling the trans-mission order using allocation window and accelerating factor without degrading the performance of other real time flows. Through simulations, it is shown that the proposed scheme provides not only improved performance in terms of delay but also simplified control operation in dynamic channel error condition.

Credit-based processor sharing for decoupled delay and bandwidth allocation

We propose a credit-based processor sharing (CPS) approach for decoupled allocation of delay and bandwidth. For bandwidth guarantees, a CPS system serves traffic flows in proportion to their service weights. For delay guarantees, on the other hand, a CPS system allows real-time flows to temporarily borrow bandwidth from nonreal-time flows using service credits. This borrowing mechanism boosts the delay performance of real-time flows without increasing their long-term bandwidth requirements. By systematically regulating service credits of real-time flows, nonreal-time flows are protected for their aggregate long-term bandwidth share.

Traffic scheduling in a photonic packet switching system with QoS guarantee

The main challenge in the design of future broadband networks is to efficiently support high-bandwidth multimedia services. Recent advances in the optical networking reveal that all optical networks offering multigigabit rate per wavelength may soon become economical as the underlying backbone in wide area networks, in which photonic switch plays a central role. Two issues are the essential in the design of photonic packet switching, the support of end-to-end virtual connections and the support of diverse quality-of-service (QoS) services. Existing work in wide-area optical networks has largely focused on the former, relatively less attention has been given to support heterogeneous traffic types and to satisfy the potentially different QoS requirements of different types of traffic. In this paper, we introduce a novel hierarchical scheduling framework to use in a class of photonic packet switching systems based on WDM, in which we separate the flow scheduling from the transmission scheduling. We show such separation is essential for achieving scalability such that large input-output ports can be accommodated, and also for offering flexibility in that optimal scheduling algorithms can be derived in different level that can be best tuned to the specific system requirements. The salient feature of the proposed scheduling mechanism is that it takes into account potentially different QoS requirements from different traffic flows. A number of interesting findings are observed from the results obtained by both analysis and simulation: (1) QoS requirements can be satisfied for both real-time and nonreal-time flows; (2) the impact Of the real-time traffic head-of-line (HoL) blocking on the system throughput can be effectively alleviated with the prevailing number of traffic flows. In addition, we investigate a variety of performance measures under different system configurations.