Dynamic Bandwidth Allocation Scheme Research Articles

Dynamic Bandwidth Allocation with Effective Utilization of Polling Interval over WDM/TDM PON

AbstractWDM/TDM (wavelength-division multiplexing/time-division multiplexing) PON (passive optical network) appears to be an attractive solution for the next generation optical access networks. Dynamic bandwidth allocation (DBA) plays a crucial role in efficiently and fairly allocating the bandwidth among all users in WDM/TDM PON. In this paper, two dynamic bandwidth allocation schemes (DBA1 and DBA2) are proposed to eliminate the idle time of polling cycles (i.e. polling interval), improve bandwidth utilization and make full use of bandwidth resources. The two DBA schemes adjust the time slot of sending request information and make fair scheduling among users to achieve the effective utilization of polling interval in WDM/TDM PON. The simulation and theoretical analyses verify that the proposed schemes outperform the conventional DBA scheme. We also make comparisons between the two schemes in terms of bandwidth utilization and average packet delay to further demonstrate the effectiveness of the scheme of DBA2.

Dynamic Bandwidth Allocation Strategy for Marine VHF Communications

Dynamic Bandwidth Allocation Strategy for Marine VHF Communications

분산 모바일 멀티미디어 통신망에서 파산이론을 적용한 대역폭 할당기법

본 논문에서는 분산 모바일 멀티미디어 통신망에서 유한한 대역폭을 공정하고 효율적으로 사용하기 위해 파산이론을 적용한 파산 대역폭할당 기법을 제안하였다. 제안된 파산 대역폭할당 기법은 협력게임이론에서 파산이론을 활용하여 파산상황에서 각 서비스의 최소 대역폭보장을 통해 각 서비스의 최소 QoS를 제공한다. 성능평가 결과로 제안한 파산 대역폭 할당기법(BBA)은 CEA, CEL, Reverse Talmud에 비해 공정성지수(FI:Fairness Index)를 통해 공정성 있고, Erlang blocking formular 를 통해 서비스 차단율에 대해서도 높은 성능을 보임을 나타냈다. 제안된 파산 대역폭할당 기법은 분산 모바일 멀티미디어 통신망에서, 다양한 상황에서 서비스별 우선순위를 통한 대역폭 할당기법이나 동적인 대역폭 할당기법에 최소 대역폭 할당기준으로도 적용할 수 있다.

A midterm DBA algorithm for quality of service on aggregation layer EPON networks

This work presents a new approach on dynamic bandwidth allocation (DBA) for Ethernet Passive Optical Networks (EPONs). A brief introduction to the DBA area and major term definitions are given. The related research and standardization efforts are presented. Justification that EPONs can be used on the aggregation network is provided, based on their evolution and related research proposals. Focus is given to the Long Reach-Passive Optical Networks (LR-PONs) and their limitations which show the need for a non-polling, midterm DBA scheme for next-generation EPONs. The challenges arising, because of this new approach, are discussed along with possible solutions. Finally, this work proposes the EMDBA algorithm which is able to overcome the discussed issues. The correct operation of this algorithm is confirmed by a set of simulations using OMNet++ framework, and the outcome results show that EMDBA performance is satisfactory in terms of delay and service differentiation.

A Hybrid Scalable Peer-to-Peer IP-Based Multimedia Services Architecture in Ethernet Passive Optical Networks

Peer-to-peer (P2P) applications such as P2P video streaming and internet video calling have gained tremendous popularity and are expected to be vastly increasing in the next few years. However, low-cost large-scale video services have remained an intangible goal. The ethernet passive optical network (EPON) is being regarded as one of the promising for next-generation optical access solutions in the access networks attempt to tackle this problem but facing a major challenge to offer scalable large-scale video services. Therefore, in this paper, we propose an architecture which combines the advantages of EPON and P2P architecture to provide scalable Internet Protocol delivery multimedia services and improve quality-of-services. In the proposed architecture, we design new optical network unit (ONU) mechanisms, which support traffic redirection communication among ONUs in combination with caching. Thus, it can reduce the resource consumption and add extra downstream bandwidth at the optical line terminal since the intra-PON traffic is not necessary to be buffered and scheduled in the downstream direction. Finally, we propose a “Redirect” dynamic bandwidth allocation scheme, which can support intra-PON traffic redirection and intertraffic bandwidth allocation. Simulation results have shown that our proposed architecture can improve the overall QoS in terms of end-to-end delay, jitter, system throughput, fairness, and packet dropping rate.

A Hybrid OFDM-TDM Architecture with Decentralized Dynamic Bandwidth Allocation for PONs

One of the major challenges of passive optical networks is to achieve a fair arbitration mechanism that will prevent possible collisions from occurring at the upstream channel when multiple users attempt to access the common fiber at the same time. Therefore, in this study we mainly focus on fair bandwidth allocation among users, and present a hybrid Orthogonal Frequency Division Multiplexed/Time Division Multiplexed architecture with a dynamic bandwidth allocation scheme that provides satisfying service qualities to the users depending on their varying bandwidth requirements. Unnecessary delays in centralized schemes occurring during bandwidth assignment stage are eliminated by utilizing a decentralized approach. Instead of sending bandwidth demands to the optical line terminal (OLT) which is the only competent authority, each optical network unit (ONU) runs the same bandwidth demand determination algorithm. ONUs inform each other via signaling channel about the status of their queues. This information is fed to the bandwidth determination algorithm which is run by each ONU in a distributed manner. Furthermore, Light Load Penalty, which is a phenomenon in optical communications, is mitigated by limiting the amount of bandwidth that an ONU can demand.

Efficient inter-thread scheduling scheme for long-reach passive optical networks

These days there is a clear trend toward extending the reach of passive optical networks to cover large geographical areas, which enables reduction of the number of central offices and hence has the potential of cost saving in network operation. On the other hand, this reach extension necessitates the design of efficient dynamic bandwidth allocation schemes in order to tackle performance degradation caused by the increased propagation delay in long reach PONs. Among many existing approaches, the multithread-based DBA scheme where several bandwidth allocation processes are performed in parallel is considered one of the most effective options to improve network performance in LRPONs. We have found that without proper intercommunication between the overlapped threads, multi-thread DBA may lose efficiency and even perform worse than the conventional singlethread algorithm. With this in mind, this article reviews different inter-thread scheduling schemes for LR-PONs, and proposes a novel approach of integrating the key ideas of the existing ones. Extensive simulation results confirm that our proposed scheme can significantly improve DBA performance for LR-PONs under a variety of scenarios with consideration of different values of network load and reach.

Adaptive Limited Dynamic Bandwidth Allocation Scheme to Improve Bandwidth Sharing Efficiency in Hybrid PON Combining FTTH and Wireless Sensor Networks

This paper proposes a dynamic bandwidth allocation algorithm that improves the network performance and bandwidth sharing efficiency in the upstream channels of a hybrid passive optical network (PON) that combines a fiber-to-the-home (FTTH) access network and wireless sensor networks (WSNs). The algorithm is called the adaptive limited dynamic bandwidth allocation (ALDBA) algorithm. Unlike existing algorithms, the ALDBA algorithm is not limited to controlling just FTTH access networks, it also supports WSNs. For the proposed algorithm, we investigate the difference in the lengths of generated data packets between the FTTH terminals and sensor nodes of WSN to effectively evaluate the end-to-end average packet delay, bandwidth utilization, time jitter, and upstream efficiency. Two variants of the proposed algorithm and a limited service (LS) scheme, which is an existing well-known algorithm, are compared under non-uniform traffic conditions without taking into consideration priority scheduling. We demonstrate the proposed scheme through simulation by generating a realistic network traffic model, called self-similar network traffic. We conducted a detailed simulation using several performance parameters to validate the effectiveness of the proposed scheme. The results of the simulation showed that both ALDBA variants outperformed the existing LS scheme in terms of average packet delay, bandwidth utilization, jitter, and upstream efficiency for both low and high traffic loads.

A Dynamic Bandwidth Allocation Scheme for a Multi-spot-beam Satellite System

A multi-spot-beam satellite is an attractive technique for future satellite communications since it can support high data rates by projecting high power density to each spot beam and can reuse a frequency in different cells to increase the total system capacity. In this letter, we propose a resource management technique adjusting the bandwidth of each beam to minimize the difference between the traffic demand and allocated capacity. This represents a reasonable solution for dynamic bandwidth allocation, considering a trade-off between the maximum total capacity and fairness among the spot beams with different traffic demands.

Three Node Tandem Communication Network Model with Dynamic Bandwidth Allocation and Non Homogeneous Poisson Arrivals

networks create lot of interest due to their ready applicability in performance evaluation of several communication systems. In communication systems it is customary to consider that the arrivals are characterized by Poisson process. This assumption holds good if the arrivals are homogeneous and independent of time. But in many tele and satellite communication systems the arrivals are non homogeneous and the arrival rate is time dependent. Hence, in this paper we develop and analyze a three node communication network model with the assumption that the arrivals are characterized by non homogeneous Poisson process. It is further assumed that transmission time required by each packet at each node is dependent on the content of the buffer connected to it. The transient behavior of the network model is analyzed by deriving the system performance measures like mean number of packets in each buffer, mean delay in transmission, the throughput of the nodes, utilization of transmitters, etc,. The sensitivity analysis of the model reveals that the non homogeneous Poisson arrivals and dynamic bandwidth allocation strategy can reduce burstness in buffer and improve quality of service. A comparative study of communication network with non homogeneous Poisson arrivals and Poisson arrivals is also given.

Performance Evaluation of a Communication Network with Dynamic Bandwidth Allocation and Bulk Arrivals

networks had a separate deployment for each emerging service like Telephone networks, data networks and multimedia networks. In Integrated Services Network the packets are transmitted using efficient statistical multiplexing. In this paper, we develop and analyze a two-node communication network with dynamic bandwidth allocation having bulk arrivals. The performance of the statistical multiplexing is measured by approximating the arrival and the service process with Poisson process and the bulk size is uniform which is chosen such that several of the statistical characteristics of the communication network identically match with the Poisson process. Through mathematical modeling, the performance measures of the communication network like the joint probability generating function of the buffer size distribution, the average content of the buffers, the mean delays in transmission, the throughput of the nodes and utilization are derived explicitly under transient conditions. Through numerical studies, the sensitivity of the input parameters on the performance measures is also carried. It is observed that the dynamic bandwidth allocation strategy and bulk size distribution of the arrivals have significant effect on the performance measures. This network is much useful in satellite communications and Internet service providing, etc,

Mitigating Packet Reordering in FiWi Networks

In an integrated fiber and wireless (FiWi) access network consisting of a wireless subnetwork and an optical subnetwork, multipath routing may be applied in the wireless subnetwork to improve throughput. Due to different delays along multiple paths, packets may arrive at the destination out of order, which may cause Transmission Control Protocl (TCP) performance degradation. In this paper, we propose two mechanisms to improve in-order departure of packets from the optical line terminal (OLT) in a FiWi network and enhance the TCP performance. We first propose an effective scheduling algorithm at the OLT to ensure possible in-order packet arrivals at the destination. We then design a dynamic bandwidth allocation (DBA) scheme in the optical subnetwork (i.e., an Ethernet passive optical network) that gives higher priorities to flows that may trigger fast retransmit and fast recovery in upstream bandwidth allocation. Simulation results show that both the proposed scheduling algorithm and the DBA scheme are effective in improving the TCP performance.

Transient Analysis of a Tandem Communication Network with Dynamic Bandwidth Allocation having Two Stage Direct Bulk Arrivals

ABSTRACT Communication network models play a dominant role in optimal utilization of resources. The need for congestion control and to improve quality of service, it is needed to design new communication networks. With this motivation, a two node communication network with dynamic bandwidth allocation (DBA) having two stage bulk arrivals (BA) is introduced and analyzed. The statistical multiplexing of the communication network is developed by characterizing the arrival of packets with compound Poisson process and the transmission completions with Poisson processes. To avoid burstness in buffers, the dynamic bandwidth allocation is adapted utilizing the idle bandwidth in the transmitter depending on content of the buffer. The network performance is evaluated by deriving the performance measures like mean content of the buffers, mean delays in transmitters, throughput of the nodes, utilization of the nodes etc,. The transient analysis of the model reveals that the time has a significant influence on predicting the performance measures of the communication networks. The sensitivity analysis of the model provides evidence that the dynamic bandwidth allocation strategy along with bulk arrival consideration can provide the performance of the network more close to the reality and avoid burstness in buffers. This communication network is much useful for Satellite and Mobile communication, Computer communication etc. This communication network model also includes several of the earlier communication network models as particular cases for specific values of the model parameters.

Bandwidth Distribution Solutions for Performance Enhancement in Long-Reach Passive Optical Networks

Long-reach Passive Optical Networks (LR-PONs) aim to combine the capacity of metro and access networks by extending the reach and split ratio of the conventional PONs. LR-PONs appear as efficient solutions having feeder distances around 100km and high split ratios up to 1000-way. On the other hand, transmission of the signals in long distances up to 100km leads to increased propagation delay whereas high split ratio may lead to long cycle times resulting in large queue occupancies and long packet delays. Before LR-PON becomes widely adopted, the trade-off between the advantages and performance degradation problem which is resulting from long reach and high split ratio properties of LR-PONs needs to be solved. Recent studies have focused on enhancing the performance of dynamic bandwidth allocation in LR-PONs. This article presents a comprehensive survey on the dynamic bandwidth allocation schemes for LR-PONs. In the article, a comparative classification of the proposed schemes based on their quality-of-service awareness, base-types, feeder distances and tested performance metrics is provided. At the end of the article, a brief discussion on the open issues and research challenges for the solution of performance degradation in LR-PONs is presented.

Integrated Dynamic Bandwidth Allocation in Converged Passive Optical Networks and IEEE 802.16 Networks

IEEE 802.16 and Passive Optical Network (PON) are two promising broadband access technologies for high-capacity wireless access networks and wired access networks, respectively. The convergence of 802.16 and PON networks can take the mobility feature of wireless communications and the bandwidth advantage of optical networks jointly. Dynamic bandwidth allocation (DBA) plays an important role in each of these two networks for QoS assurance. In converged 802.16 and PON networks, the integration of the DBA schemes in both networks plays an even more critical role, since bandwidth request/grant mechanisms used in 802.16 and PON are different and the performance of the integrated DBA directly determines the overall system performance. In this paper, we investigate integrated dynamic bandwidth allocation schemes and their signaling overhead. First, this paper starts with discussing the converged network architecture and especially the issues on integrating optical network unit (ONU) and 802.16 base station (BS). Second, it proposes a slotted DBA (S-DBA) scheme and its performance analytic model. The S-DBA scheme takes into account the specific features of the converged network, aiming to reduce signaling overhead caused by cascaded bandwidth requests and grants. The simulation results show that the proposed S-DBA scheme can effectively reduce signaling overhead and increase channel utilization.

Inter-Layer Fairness Problem in TCP Bandwidth Sharing in 10G-EPON

In order to provide high speed broadband access to users in next generation networks, Gigabit Ethernet-Passive Optical Network (GE-PON) has emerged as one of the most promising technologies. The evolution of the GE-PON technology permits the users to connect to the Internet via gigabit access networks, which contribute to the increase of the network traffic in not only downstream but also along the upstream direction. However, the increase of the upstream traffic may lead to network congestion and complicate the bandwidth allocation issue, thereby affecting the Quality-of-Service (QoS) requirements of the users. In this paper, we point out the performance degradation issue of Transmission Control Protocol (TCP) communications due to the unanticipated effect of Dynamic Bandwidth Allocation (DBA) mechanism employed in GE-PONs. When network congestion occurs, DBA fails to achieve efficient and fair sharing of the bottleneck bandwidth amongst a number of competing TCP connections. In order to overcome this shortcoming of the conventional DBA scheme, we envision an appropriate solution by controlling the TCP flows' rates based upon packet marking. The envisioned solution, dubbed as PPM-TRC, aims at controlling the TCP throughput for achieving both high efficiency and fair utilization of the passive optical line. The effectiveness of the PPM-TRC approach, verified through extensive computer simulations, demonstrates its applicability in dealing with a large number of competing traffic flows.

SLA-Aware Dynamic Bandwidth Allocation for QoS in EPONs

The Ethernet passive optical network (EPON) is one of the most promising broadband access networks. We propose a new dynamic scheduling algorithm, referred to as cyclic-polling-based dynamic bandwidth allocation with service level agreements (CPBA-SLA), for service differentiation that meets the service level agreements between the OLT and ONUs. The proposed dynamic bandwidth allocation (DBA) scheme provides a constant and predictable average packet delay and an improved delay jitter of the expedited forwarding traffic without the influence of load variations. A performance evaluation shows the effectiveness of the proposed DBA scheme.

A new predictive dynamic priority scheduling in Ethernet passive optical networks (EPONs)

Efficient uplink scheduling in Ethernet passive optical networks (EPONs) is very important for maximizing the network capacity while maintaining the required quality of service (QoS). Several variants of dynamic bandwidth resource allocation have been proposed in recent research literature. However, the available techniques do not fully exploit the elastic properties of the user traffic. In this paper, we explore optimal predictive resource allocation strategies by exploiting the elasticity of QoS-constrained traffic and using the knowledge of traffic patterns of different service classes. We propose a predictive dynamic uplink bandwidth allocation scheme that offers lower access delay and packet loss rate, yet achieves a higher overall network throughput. We formulate a model for determining the traffic burstiness-dependent optimum prediction order that would enhance the quality of prediction with a minimum possible prediction-related processing overhead. We then demonstrate that, in a multi-class access scheduling, with respect to the conventional dynamic allocation strategies, our priority scheduling with judicious prediction of individual traffic classes can enhance the system performance significantly. Our analytic observations are supported by extensive simulation results.

Design and Analysis of a WDM EPON for Supporting Private Networking and Differentiated Services

Although EPONs have been proposed as a means of overcoming the bandwidth bottleneck problem in local access networks, they may not be able to meet the ever-growing bandwidth demand from users in the near future. Accordingly, this study presents what we believe to be a novel wavelength-division-multiplexing (WDM) Ethernet passive optical network (EPON) system based on an arrayed-waveguide-grating (AWG) module to meet the rapidly increasing bandwidth demand anticipated in the future. The use of the AWG enables the proposed WDM EPON architecture to achieve wavelength spatial reuse and to provide an intercommunication capability between optical network units (ONUs). As a result, the architecture not only allows upstream access to the central office, but also facilitates a truly shared LAN capability among the end users. Furthermore, the proposed WDM EPON scheme takes account of the requirement for backward compatibility with the IEEE 802.3ah multipoint control protocol and incorporates a dynamic bandwidth allocation scheme and a quality-of-service provisioning mechanism to arbitrate the access of the individual ONUs over the WDM layer. An analytical framework is developed for evaluating the mean packet delay and mean queue length of the proposed WDM EPON system. The analytical results derived using this framework are found to be in good agreement with those obtained from computer simulations.

PRNN/ERLS-based predictive QoS-promoted DBA scheme for upstream transmission in EPON

This article proposes a PRNN/ERLS-based predictive QoS-promoted dynamic bandwidth allocation (PQ-DBA) scheme for upstream transmission in Ethernet passive optical network (EPON) systems. The proposed PQ-DBA scheme originally divides incoming packets of voice, video, data service traffic into six priorities, where packets having less room before QoS requirements violation or being in starvation situation will be dynamically promoted to high priority cycle-by-cycle. It predicts packets arriving at prediction interval for ONUs using pipeline recurrent neural network (PRNN)/extended recursive least squares (ERLS) so that the bandwidth allocation can be more up-to-date and then accurate. Simulation results show that the proposed PQ-DBA scheme achieves higher system utilization and lower average voice, video, data packet delay time than the DBAM scheme [Luo and Ansari, OSA J Opt Netw 4(9):561–572] by 4, and 21, 90, 43%, respectively, and the PQ-DBA scheme but without prediction by 2, and 26, 29, 34%, respectively.