一种使用偏转路由的多信道ATM交换网络

支持多信道传输的多信道交换技术是网络资源有效利用的方法之一。本文提出了一种偏转路由的多信道ＡＴＭ交换网络，可以解决输出信道群中的信道竞争问题。说明了它的结构和原理，并阐述了多信道带宽分配问题，最后给出了在一种突发业务流量模型下的性能分析。     

一种多信道ATM交换机的实现

本文研究了一种多信道ATM交换网络,使用一种多路径交换结构网络作为多信道交换的路由网络代替Banyan网络。给出了信道分配网络的设计原理。阐明了多信道ATM交换的带宽分配方案,重点说明了传输阶段的带宽分配方法。     

一种多信道ATM交换机的实现

本文研究了一种多信道ＡＴＭ交换网络,使用一种多路径交换结构网络作为多信道交换的路由网络代替Ｂａｎｙａｎ网络,给出了信道分配网络的设计原理,阐明是了多信道ＡＴＭ交换的带宽分配方案,重点说明了传输阶段的带宽分配方法。     

多信道ATM交换和多信道传输技术

ATM技术以其统计复用的最大特点正在被广泛采用。支持多信道传输的多信道交换技术是网络资源有效利用的方法之一。本文论述多信道ATM交换和多信道传输技术的原理,说明了多信道带宽分配方案和多信道交换技术要解决的关键问题,以及多信道交换网络设计中存在的一些问题。     

一种用于多信道ATM交换的路由网络

主要提出了一种多信道交换的路由网络,叙述了多信道交换路由网络的工作原理,阐明了信元序列问题的处理方法。     

Ad Hoc网络支持QoS保障的多信道MAC协议

提出一种基于多信道的QoS保障方案,结合业务区分和资源预留两种QoS保障策略,保证优先级高的业务及时接入信道;并且建立节点发送链表,给数据通信预留一段时间,实现数据信道上连续的帧交换,有效地使用了数据信道资源。     

无线通信的交换网络设计

本文着重介绍了利用ＭＣＳ－５１系列单片微机技术，实现对模拟开关阵列集成电路的控制构成交换矩阵网络，完成多条有线电话与多个无线信道之间的自动接续，完成多个无线信道与多个无线信道之间的自动接续。     

Ad Hoc网络支持QoS保障的多信道MAC协议

提出一种基于多信道的Qo S保障方案,结合业务区分和资源预留两种Qo S保障策略,保证优先级高的业务及时接入信道;并且建立节点发送链表,给数据通信预留一段时间,实现数据信道上连续的帧交换,有效地使用了数据信道资源。     

一种宽带多输入多输出双向信道的频域辨识方法

提出一种基于空间交换最大期望(SAGE)算法的信道频域辨识方法。该方法能够有效地估计收发联合宽带多输入多输出(MIMO)双向信道的三维离开角、到达角、极化等特征参数。仿真的结果表明:该方法能准确地估计MIMO双向信道的参数,适合MIMO信道建模的需求。     

一种低复杂度的基于多径时延跟踪的OFDM信道估计算法

本文针对宽带正交频分复用（OFDM）系统，提出了一种低复杂度的基于对多径时延跟踪的信道估计算法，并分析了信道估计的均方误差性能和计算复杂度。分析和仿真结果表明，这种算法通过对多径的跟踪降低了需要估计问题的维数，从而提高了信道估计器的性能，并且降低了运算的复杂度。     

A nonblocking architecture for broadband multichannel switching

The paper investigates multichannel switching as a promising alternative to traditional single-channel switching where virtual paths established in a switch are between a single input channel and a single output channel. A particular non-blocking condition is derived for flip networks, which is exploited to realize a multichannel switching architecture that supports an arbitrary number of channel groups. The architecture is internally nonblocking and bufferless. Using one flip network recursively a number of times based on the number of channel groups, the resulting architecture becomes efficient in the sense that the cross point complexity is O(N log₂ N) for N inputs. Other distinguishing features are the abilities to provide multicasting, superrate switching (i.e., rates that exceed the capacity of a single channel are accommodated), multirate switching (i.e., bit pipes of different rates are supported simultaneously), multiple performance requirements (i.e., services with different performance requirements are treated accordingly), and fair access to all inputs (i.e., no input is systematically discriminated against). In multichannel switching, cells belonging to a single session can traverse multiple channels. Providing the cell sequencing integrity becomes a challenging issue. The architecture proposed in the paper accomplishes the task without employing any cell resequencing mechanism     

A Multirate Switching Network for Broadband Channels

A broadband ISDN switching network model is presented, switching the channel types H2, H3, and H4 envisaged by the CCITT. The synchronous time division multiplex technique is applied. The switching network operates at the basic bit rate of the H2-channel; H3and H4-connections are established via multichannel connections of up to four basic channels. H2-connections which are part of one H3- or H4-connection always have to use common interconnection links. This is a favorable solution to keep digit sequence integrity for multichannel connections, but influences blocking characteristics of the switching network. The implementation of an optimal path selection method plays a fundamental role. In such a multichannel switching network, blocking probabilities for H2-, H3-, and H4-connections must be distinguished. They do not only depend on the total offered load, but also on the proportions of H2-, H3-, and H4-connections (traffic mix). The simulation results presented in this paper prove that multirate switching via multichannel connections is feasible for the broadband channel types H2, H3, and H4, and that the proposed switching network has a sufficiently high traffic capacity whatever the traffic mix may be.     

Capacity of Multichannel Wireless Networks Under the Protocol Model

This paper studies the capacity of a n node static wireless network with c channels and m radio interfaces per node under the protocol model of interference. In their seminal work, Gupta and Kumar have determined the capacity of a single channel network (c=1, m=1). Their results are also applicable to multichannel networks provided each node has one interface per channel (m=c) . However, in practice, it is often infeasible to equip each node with one interface per channel. Motivated by this observation, we establish the capacity of general multichannel networks (m les c). Equipping each node with fewer interfaces than channels in general reduces network capacity. However, we show that one important exception is a random network with up to O(logn) channels, where there is no capacity degradation even if each node has only one interface. Our initial analysis assumes that the interfaces are capable of switching channels instantaneously, but we later extend our analysis to account for interface switching delays seen in practice. Furthermore, some multichannel protocols proposed so far rarely require interfaces to switch, and therefore, we briefly study the capacity with fixed interfaces as well.     

MOSAIC: a multiwavelength optical subcarrier multiplexed controllednetwork

The experimental demonstration of MOSAIC, a reconfigurable WDM add/drop network with subcarrier multiplexed control, is presented. The MOSAIC network implements the optical layer protocol to support bit-rate transparent multichannel lightpaths. Two types of add/drop multiplexers are implemented and combined in a three-node experiment. Multihop lightpaths are established giving an end-to-end bit error rate of better than 10^-9 at 1.2 Gbps. The reconfigurable add/drop multiplexer is based on a novel dilated 2×2 acoustooptic filter switch crossconnect and an analog optoelectronic crossconnect that drives a ten-wavelength laser array transmitter up to 2.5 Gbps per wavelength. The fixed wavelength add/drop multiplexer utilizes a fast digitally tunable laser transmitter. Both add/drop multiplexers support bit-rate transparent 2R optoelectronic regeneration as well as wavelength translation. Subcarrier multiplexing on each wavelength is used to support channel state monitoring and channel equalization as well as transmission of digital network control information. Systems experiments demonstrate cascaded 2R optoelectronic regeneration with wavelength translation and cascaded multichannel optical switching with up to seven hops. It is shown that combining cascaded 2R optoelectronic regeneration with cascaded multichannel optical switching can be used to balance jitter accumulation and amplified spontaneous emission generated amplitude noise to yield high signal-to-noise ratio for lightpaths     

Channel switching between receivers of FDM coherent optical star network

The authors present channel switching results obtained between receivers of an FDM optical coherent fibre star network. The system consists of six optical channels FSK-modulated at 200 Mbit/s and spaced by 2.2 GHz. The channels are multiplexed by a 16*16 optical star coupler. Two of the multichannel signals exiting this device are demultiplexed by their respective random access digitally tuned heterodyne receivers. Simultaneous switching between pairs of channels is obtained by command of a personal computer controlling both receivers.<>     

Load-balancing routing in multichannel hybrid wireless networks with single network interface

A hybrid wireless network is an extension of an infrastructure network, where a mobile host may connect to an access point (AP) using multihop wireless routes, via other mobile hosts. The APs are configured to operate on one of multiple available channels. Mobile hosts and wireless routers can select its operating channel dynamically through channel switching. In this environment, a routing protocol that finds routes to balance load among channels while maintaining connectivity was proposed. The protocol works with nodes equipped with a single network interface, which distinguishes the work with other multichannel routing protocols that require multiple interfaces per node. The protocol discovers multiple routes to multiple APs, possibly operating on different channels. Based on a traffic load information, each node selects the "best" route to an AP and synchronizes its channel with the AP. With this behavior, the channel load is balanced, removing hot spots and improving channel utilization. The protocol assures every node has at least one route to an AP, where all intermediate nodes are operating on the same channel. The simulation results show that the proposed protocol successfully adapts to changing traffic conditions and improves performance over a single-channel protocol and a multichannel protocol with no load balancing.     

Generation of wavelength-switched optical pulse from a fiber ringlaser with an F-P semiconductor modulator and a HiBi fiber loop mirror

A simple configuration to perform wavelength switching in an actively mode-locked fiber ring laser is demonstrated. A Fabry-Perot laser diode was used as a modulator and a HiBi fiber loop mirror was used as a periodic multichannel wavelength filter in the cavity. By setting the channel spacing of nm can be achieved by tuning the fiber loop mirror filter. In the wavelength-switched process, the modulation frequency was not required to be changed     

Frequency control techniques in coherent multichannel LAN's

This paper describes frequency control techniques for cold start and channel recognition functions in coherent multichannel local area networks. A Z-cut quartz etalon can be used to stabilize the optical transmitter frequencies. The capture range and the influence of humidity on a Fabry-Perot etalon are discussed. The frequency deviation of the optical transmitter was estimated to be less than ±1 GHz in the long term. A double AFC loop has been proposed for local LD frequency control. It showed a wide capture range of ±100 GHz. Coherent FDM receiver switching to the desired channel was demonstrated over a range from 0 to 40°C in an experiment     

Frequency-Selective Limiters Using Nonlinear Bandstop Filters

This paper presents a novel design for frequency-selective limiters based on reflection-mode nonlinear bandstop filters. This technique enables the use of low-Q lossy resonators for high-Q bandstop filter applications. Frequency-selective limiters described here achieve fast switching, high levels of power limiting, and flexible channel bandwidth. The prototype for a third-order device indicates 2-dB insertion loss for low RF powers. At high RF powers, it demonstrates 18-dB limiting level, 3-dBm limiting threshold, and 300-MHz limiting bandwidth. The switching speed is less than 10 ns, thus the spike leakage is minimized. The single-channel limiters are cascaded to provide limiting in wideband channels. The multichannel device is able to compress the dynamic range of the signals over 30 dB.