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为了进一步改善对QoS的支持,在研究了光突发交换网络的TAW、JET、INI等信令协议的基础上,提出了一种新型光突发自适应控制协议INIA.INIA对网络中的控制信息包BCP中的BHP进行了扩充,增加了标识符Class,通过对Class值的控制,达到灵活控制INI改进节点位置的目的.仿真实验结果表明,INIA对提供满足各级业务要求的时延、丢包率等性能方面做出了改善,动态设定网络中的Class值可以更好地动态管理网络传输业务,更好地利用网络资源. 相似文献
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Junling Yuan Xianwei Zhou Jianping Wang Yongqi He Ke Wang 《Optical Switching and Networking》2012,9(3):214-223
Optical burst switching is a promising all-optical switching technology for the next generation optical networks and signaling is one of the key components of it. According to propagation direction of control packets, the existing signaling schemes for optical burst switched networks can be roughly divided into three categories: one-way, two-way, and hybrid signaling. Since one-way signaling launches bursts without the acknowledgment of successful reservation of resources, it has small end-to-end delay but high data loss rate; two-way signaling uses a control packet to gather the state of links and needs the successful acknowledgment before sending out a burst, so it has large end-to-end delay but low data loss rate. A hybrid signaling gets a tradeoff of performance between one-way and two-way signaling. In this paper, we propose another hybrid signaling named inverse two-way signaling. By introducing the process of link state collection into one-way signaling, the inverse two-way signaling can decrease the data loss rate without increasing the end-to-end delay compared to one-way signaling. In other words, the inverse two-way signaling is an improved version of one-way signaling. 相似文献
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QoS performance of optical burst switching in IP-over-WDM networks 总被引:31,自引:0,他引:31
Myungsik Yoo Chunming Qiao Sudhir Dixit 《Selected Areas in Communications, IEEE Journal on》2000,18(10):2062-2071
We address the issue of how to provide basic quality of service (QoS) in optical burst-switched WDM networks with limited fiber delay lines (FDLs). Unlike existing buffer-based QoS schemes, the novel offset-time-based QoS scheme we study in this paper does not mandate any buffer for traffic isolation, but nevertheless can take advantage of FDLs to improve the QoS. This makes the proposed QoS scheme suitable for the next generation optical Internet. The offset times required for class isolation when making wavelength and FDL reservations are quantified, and the upper and lower bounds on the burst loss probability are analyzed. Simulations are also conducted to evaluate the QoS performance in terms of burst loss probability and queuing delay. We show that with limited FDLs, the offset-time-based QoS scheme can be very efficient in supporting basic QoS. 相似文献
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《Optical Switching and Networking》2008,5(4):177-187
In this paper, we present a new hybrid optical burst switch architecture (HOBS) that takes advantage of the pre-transmission idle time during lightpath establishment. In dynamic circuit switching (wavelength routing) networks, capacity is immediately hard-reserved upon the arrival of a setup message at a node, but it is used at least a round-trip time delay later. This waste of resources is significant in optical multi-gigabit networks and can be used to transmit traffic of a lower class of service in a non-competing way. The proposed hybrid OBS architecture, takes advantage of this idle time to transmit one-way optical bursts of a lower class of service, while high priority data explicitly requests and establishes end-to-end lightpaths. In the proposed scheme, the two control planes (two-way and one-way OBS reservation) are merged, in the sense that each SETUP message, used for the two-way lightpath establishment, is associated with one-way burst transmission and therefore it is modified to carry routing and overhead information for the one-way traffic as well. In this paper, we present the main architectural features of the proposed hybrid scheme and further we assess its performance by conducting simulation experiments on the NSF net backbone topology. The extensive network study revealed that the proposed hybrid architecture can achieve and sustain an adequate burst transmission rate with a finite worst case delay. 相似文献
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To provide the differential quality of service(QoS)for different classes of packets and reduce the packet loss probabil ity(PLP),a novel priority-based composite assembly scheme for optical burst switching(OBS)networks is proposed The low and high packet classes are aggregated into a single burst simultaneously,and the highest-priority packets ar placed in the middle,while the low-priority packets are at the tail and head of the burst.The priority is lowered gradu ally from the middle to the ends.Simulation results demonstrate that the proposed assembly strategy not only guaran tees the integrity of the high-priority bursts,but also significantly reduces the average end-to-end delay of the burst and the PLP of network.So it can adapt to the flexible network with QoS requirement. 相似文献
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光突发交换网络基于优先级与突发包分割的光缓存方法 总被引:2,自引:1,他引:1
为了保证光突发交换(OBS)网络中不同优先级业务的服务质量(Qos)和有效地降低突发包的丢失率,提出了一种基于优先级与突发包分割的光缓存方法.该方法通过在输出数据信道上设置光纤延迟线组来缓存被分割的冲突突发包.当冲突发生时,基于突发包的优先级进行"竞争突发包头部分割或者原突发包尾部分割,,处理;无冲突部分进行交换或者直... 相似文献
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Prioritized burst segmentation and composite burst-assembly techniques for QoS support in optical burst-switched networks 总被引:13,自引:0,他引:13
We address the issue of providing quality-of-service (QoS) in an optical burst-switched network. QoS is provided by introducing prioritized contention resolution policies in the network core and a composite burst-assembly technique at the network edge. In the core, contention is resolved through prioritized burst segmentation and prioritized deflection. The burst segmentation scheme allows high-priority bursts to preempt low-priority bursts and enables full class isolation between bursts of different priorities. At the edge of the network, a composite burst-assembly technique combines packets of different classes into the same burst, placing lower class packets toward the tail of the burst. By implementing burst segmentation in the core, packets that are placed at the tail of the burst are more likely to be dropped than packets that are placed at the head of the burst. The proposed schemes are evaluated through analysis and simulation, and it is shown that significant differentiation with regard to packet loss and delay can be achieved. 相似文献
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As the rapid growth of smart hand-held devices, multihop wireless access networks have a lot of potential applications in a variety of fields in civilian and military environments. Many of these applications, such as realtime audio/video streaming, will require some form of end-to-end QoS assurance. In this paper, we present an adaptive per hop differentiation (APHD) scheme towards achieving end-to-end delay assurance in multihop wireless networks. Our scheme is based on EDCA technique which is proposed in 802.11e draft. In EDCA, data packets of different priorities will use different MAC contention parameter set, which translate into different delays. Our APHD scheme extends the capability of EDCA into multihop environment by taking end-to-end delay requirement into consideration at each intermediate hop. Following a cross-layer design approach, APHD is aimed to be a distributed and localized technique. Individual nodes keep track of the channel state independently without any intercommunication overhead. Data packets carry end-to-end delay requirement along with other important information in the packet header. At an intermediate node, based on data packet’s end-to-end requirement, its accumulative delay so far, and the current node’s channel status, APHD smartly adjusts data packet’s priority level in order to satisfy its end-to-end delay requirement. Simulation results show that APHD scheme can provide excellent end-to-end delay assurance while achieving much higher network utilization, compared to a pure EDCA scheme. 相似文献
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OBS网络中基于优先级的先分割后缓存冲突解决方法 总被引:4,自引:2,他引:2
为了有效地降低突发包的丢失率和保证OBS网络中不同优先级业务的服务质量,提出了一种基于优先级的先分割后缓存冲突解决方法。该方法通过在多波长信道系统的输出数据信道上设置光纤延迟线组来缓存被分割的冲突突发包。当冲突发生时,首先基于突发包的优先级和处理完毕时间进行"竞争突发包头部分割或者原突发包尾部分割"处理;无冲突部分进行交换或者直接在事先预留的输出数据信道上处理,冲突部分的分割突发包进行光缓存。仿真结果表明,多波长信道系统中,高优先级突发包的丢失率低于低优先级突发包的丢失率。同时该方法在一定程度上可以有效地减少端到端的传输时延和整个网络的丢包率,从而提高整个OBS网络的性能。 相似文献
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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. 相似文献
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Neal Charbonneau Deepak Chandran Vinod M. Vokkarane 《Photonic Network Communications》2012,23(1):1-15
Random contentions occur in optical burst-switched (OBS) networks because of one-way signaling and lack of optical buffers.
These contentions can occur at low loads and are not necessarily an indication of congestion. The loss caused by them, however,
causes TCP at the transport layer to reduce its send rate drastically, which is unnecessary and reduces overall performance.
In this paper, we propose forward segment redundancy (FSR), a proactive technique to prevent data loss during random contentions in the optical core. With FSR, redundant TCP
segments are appended to each burst at the edge and redundant burst segmentation is implemented in the core, so that when
a contention occurs, primarily redundant data are dropped. We develop an analytical throughput model for TCP over OBS with
FSR and perform extensive simulations. FSR is found to improve TCP’s performance by an order of magnitude at high loads and
by over two times at lower loads. 相似文献
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Biao Chen Jianping Wang 《Selected Areas in Communications, IEEE Journal on》2003,21(7):1071-1080
One promising switching technology for wavelength-division multiplexing optical networks is optical burst switching (OBS). However, there are major deficiencies of OBS. (1) The delay offset between a control message and its corresponding data burst is based on the diameter of a network. This affects network efficiency, quality-of-service, and network scalability.( 2) OBS adopts one-way resource reservation scheme, which causes frequent burst collision and, thus, burst loss. We address the above two important issues in OBS. In particular, we study how to improve the performance of delay and loss in OBS. To reduce the end-to-end delay, we propose a hybrid switching scheme. The hybrid switching is a combination of lightpath switching and OBS switching. A virtual topology design algorithm based on simulated annealing to minimize the longest shortest path through the virtual topology is presented. To minimize burst collision and loss, we propose a new routing algorithm, namely, p-routing, for OBS network. The p-routing is based on the wavelength available probability. A path that has higher available probability is less likely to drop bursts due to collision. The probability-based p-routing can reduce the volatility, randomness, and uncertainty of one-way resource reservation. Our studies show that hybrid switching and p-routing are complementary and both can dramatically improve the performance of OBS networks. 相似文献
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Maurizio Casoni 《Optical Switching and Networking》2007,4(1):33-43
This paper presents an analytical model of TCP throughput in optical burst-switched (OBS) networks. Several parameters characterize this system and influence the network design process, such as the assembly time, the access bandwidth, the burst loss rate, and they are taken into account in the formulation of TCP send rates. Moreover burst loss is considered a consequence of contention in core nodes and it is formulated in relation to a quite general core node architecture. The novelty of the work is represented by the possibility of analytically representing the whole end-to-end connection so that a fast and effective tool to evaluate the relationships between network and access design is provided. An application example is given to prove the practical significance of the approach. Simulation results are provided to validate the model and the related assumptions. 相似文献
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Quality of Service (QoS) support in Mobile Ad Hoc Networks (MANETs) for group communication necessitates design of reliable networks with multicast support mechanisms. Reliable network connectivity among MANET nodes require high quality links that have much less packet drops and reliable nodes considering node mobility and failures. Reliability of a network can be enhanced by designing an end-to-end network pipe that satisfies the required QoS in terms of in-flight packets from source to a destination as well as by using a path comprising of reliable nodes. In-flight packets may be computed by using bandwidth delay product (BDP) of a network pipe. To meet the QoS requirements of an application, BDP should be maintained stable irrespective of vibrant network conditions. In this paper, we propose a BDP based multicast routing scheme in MANET using reliable ring mesh backbone. The scheme operates in the following sequence. (1) Reliable node pairs are computed based on mobility, remaining battery power and differential signal strength. The node pairs also compute BDP between them. BDP of a reliability pair is assessed using available bandwidth and delay experienced by a packet between them. (2) Backbone ring mesh is constructed using reliable pair nodes and convex hull algorithm. Reliable ring mesh is constructed at an arbitrary distance from the centroid of the MANET area. (3) Multicast paths are found by discovering a path from source to each destination of the group with concatenated set of reliability pairs that satisfy the BDP requirement. (4) The ring mesh maintains high BDP on ring links and can recover in case of node mobility and failures. Results show that there is an improvement in terms of end-to-end delay, packet delivery ratio, control overhead, memory overhead and application rejection ratio as compared to the Enhanced On Demand Multicast Routing Protocol. 相似文献
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Optical burst switching (OBS) presents itself as a promising technology for bridging the gap between optical wavelength switching
and optical packet switching. Increasingly, researchers attempt to incorporate more realistic constraints into the design
of OBS networks. Optical signal transmission quality is subject to various types of physical impairment introduced by optical
fibers, switching equipment, or other network components. The signal degradation due to physical impairments may be significant
enough such that the bit-error rate of received signals is unacceptably high at the destination, rendering the signal not
usable. In this paper, based on earlier work, we study the burst scheduling problem in OBS networks, taking into account physical
impairment effects. We propose three effective burst scheduling algorithms: (1) a JET based Physical Impairment Constrained
Algorithm (JETPIC), (2) an Integrated Physical Impairment Constrained Algorithm (IPIC), and (3) an Enhanced Integrated Physical
Impairment Constrained Algorithm (EIPIC). At an OBS node, the proposed algorithms schedule bursts for transmission by searching
for available resources as well as verifying signal quality. Our simulation results show that the proposed algorithms are
effective in terms of reducing the burst blocking probability. In general, algorithm JETPIC outperforms algorithms IPIC and
EIPIC in burst blocking probability and average end-to-end delay performance.
相似文献
Bin WangEmail: |
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Yang Chen Chunming Qiao Xiang Yu 《IEEE network》2004,18(3):16-23