A general bandwidth allocation scheme for multi-priority traffic on DQDB networks

[[abstract]]The Distributed Queue Dual Bus (DQDB) Media Access Control (MAC) protocol, the current IEEE 802.6 standard for Metropolitan Area Networks, functions well only for one priority level even when three priority levels are designed to support multi-priority traffic. In this paper, a general and flexible bandwidth allocation scheme for handling the multi-priority traffic is proposed. In this scheme, the entire bandwidth can be shared by different priority levels according to a pre-specified ratio. For any absent priority level, the corresponding pre-allocated bandwidth will be automatically reallocated to other priority levels. This scheme is also rather suitable for solving the bandwidth domination problem, the priority domination problem, the priority capturing problem, and the bandwidth allocation problem of the DQDB networks which are unable be effectively solved by the standard DQDB protocol with the bandwidth balancing mechanism.[[notice]]補正完

Study of isochronous channel reuse in DQDB metropolitan area networks (Conference)

[[abstract]]The isochronous channel reuse problem (ICRP) on DQDB metropolitan area networks is investigated. Given a set of established isochronous connections and a set of isochronous requests, the goal is to use a minimal number of isochronous channels to service these requests. On the other hand, given a limited isochronous bandwidth, the goal is to establish a maximal number of isochronous connections. In this paper, we show that the ICRP is N p-complete. For the simplified ICRP (SICRP), in which all the established isochronous connections as well as the isochronous requests are of the same bandwidth, we suggest a tight lower bound the propose an efficient isochronous channel reuse algorithm (ICRA). Simulation results show that for the SICRP, the solutions obtained by the ICRA are very close to the lower bound which implies the proposed ICRA is very attractive. For a limited isochronous bandwidth, the number of successful established isochronous connections obtained by the ICRA is much more than that of the original DQDB isochronous channels allocation scheme.[[fileno]]2030210030045[[department]]資訊工程學

A distributed multicast tree construction scheme with wavelength reuse and migration for WDM routing networks

[[abstract]]©1997 IREE-The multicast tree construction problem (MTCP) with wavelength reuse and migration on wide-area optical routing networks is investigated. Multicasting, if improperly implemented, can be bandwidth abusive due to the limited number of available wavelengths and the wavelength continuity constraint. Employing spatial reuse of wavelengths provides a high aggregate system capacity thereby increasing the amount of concurrency in the network. Besides, to accommodate new join calls, the wavelength of certain existing multicast connections could be migrated so that the blocking probability can be further reduced. Given a set of established multicast trees and a set of new join requests, the MTCP is to allocate a wavelength for each constructed multicast tree so that the number of wavelengths used is minimized. It is clear that MTCP is NP-complete and we propose an efficient distributed multicast tree construction heuristic for wide-area optical routing networks[[department]]資訊工程學

Bit stream ternary match scheme

[[abstract]]The method for providing a "Don't Care" bit to improve the speed of information matching in a digital information processing system. After the match information is input, it will be divided into multiple sub-bit-streams and then input to a correspondent selector for obtaining the content of a selected memory bank. The output of each selector is forwarded to the product module to compute an unencoded match result. Finally, the priority encoder receives the unencoded match result and performs priority encoding to generate an encoded match result and a match flag. If the match flag is positive, it indicates that there is a hit in the rule table for the match information. Thus, the match result serves as an index for looking up an information table.[[department]]資工

Solving bandwidth and priority domination problems of DQDB MANs

[[booktype]]紙

Hot-spot spanning tree algorithm for a bridged LAN/MAN

[[abstract]]A bridged local area network (BLAN) is an internetwork where a lot of LANs and MANs are interconnected via bridges. The active spanning tree topology of a BLAN is to ensure that one and only one active routing path exists between each pair of end stations to resolve the frame duplication problem. A LAN is a hot-spot LAN if it has a large amount of communicating traffic load compared to other LANs. In this paper, we propose a distributed spanning tree algorithm for a BLAN with hot-spot traffic. The spanning tree constructed by our algorithm is logically rooted at the hot-spot LAN instead of the bridge with the smallest identifier. Such a spanning tree will be more practical and suitable for delivering the inter-LAN frames, and hence will obtain a better performance on end-to-end transmission delay. The effectiveness of the algorithm is evaluated by simulations. From the simulation results, we found that, compared to the standard spanning tree algorithm, the spanning tree constructed by our algorithm obtains a greater improvement in terms of end-to-end transmission delay as the traffic concentration becomes more pronounced.[[fileno]]2030210010016[[department]]資訊工程學

On the wavelength assignment problem of multi-channel photonic dual bus networks

[[abstract]]In a multi-channel photonic dual bus network, each unidirectional bus contains a control channel and several data channels (wavelengths), and each station has n tunable transmitters and m tunable receivers. Given a set of serving traffic and a set of new traffic requests, the wavelength assignment problem ((n,m)-WAP) is to assign the transmission wavelengths and receiving wavelengths of each station so that all the traffic requests can be served simultaneously and the number of assigned wavelengths is minimized. In this paper, we prove that the (n,m)-WAP is NP-complete by showing that the simplified version of the (n,m)-WAP (SWAP, or (1,1)-WAP), in which each station has only one tunable transmitter and one tunable receiver, is NP-complete. An efficient distributed wavelength assignment algorithm (DWAA) is proposed for the (1,m)-WAP. The throughput and delay characteristics of the DWAA is evaluated by simulation. Simulation results show that for a limited number of available wavelengths, the solutions obtained by the DWAA is attractive in terms of throughput, access delay, as well as fairness, under general traffic demands.[[conferencetype]]國際[[conferencedate]]19941128~19941202[[booktype]]紙本[[iscallforpapers]]Y[[conferencelocation]]San Francisco, C

A waste-free congestion control scheme for dual bus high-speed networks

[[abstract]]In a high-speed backbone network, each node may act as a router/gateway which connects several LANs as well as hosts. Usually, the routers/gateways might incur congestion due to the transmission rates between the high-speed backbone and the low-speed LANs being mismatched. Because the existance of high-speed LANs becomes possible, the congestion may occur on the routers owing to the limitation of transmission rate to access the backbone network and available buffer spaces on it. To release the congestion, it is desirable to have some congestion control algorithms for the routers. In this paper, we propose a simple and efficient congestion control MAC protocol for dual bus high-speed networks. Based on this protocol, all the buffers in the network can be fully shared so that the transmission rate of each node is proportional to its load. In other words, a heavy loaded node obtains a faster transmission rate to send the packets in its buffer so that the congestion can be prevented. At the same time, each of the uncongested nodes will slow down its transmission and store the new incoming messages into its buffer. This implies that the buffers on the network can be shared dynamically. Simulation results show that compared to the DQDB MAC protocol, the proposed protocol significantly reduces the message queueing delay and message loss rate, and provides an attractive high throughput in the backbone network.[[notice]]補正完

Efficient traffic scheduling and policy for interconnected ATM/Wireless Networks

[[abstract]]Wireless LANs, each consists of a base station and several remote stations, interconnected by ATM backbone network will be one of the most attractive infrastructures for modern multimedia applications. This paper proposes an efficient traffic scheduling architecture and policy for wireless LANs interconnected by an ATM backbone network. Both time-sensitive and time-insensitive transmission services are furnished and guaranteed. An efficient traffic scheduling policy is designed so that multiple real-time connections can be furnished concurrently with guaranteed quality of service (QoS). For each wireless LAN, network bandwidth not consumed by the time-sensitive traffic is fairly used to serve time-insensitive traffic. Simulation results indicate that the proposed protocol successfully guarantees the QoS requirements of established connections and the bandwidth for time-insensitive traffic can be shared equally among the remote stations.[[conferencetype]]國際[[conferencedate]]19981108~19981112[[booktype]]紙本[[iscallforpapers]]Y[[conferencelocation]]Sydney, Australi