Maximum Transmission Delay Research Articles

Design of a d-connected digraph with a minimum number of edges and a quasiminimal diameter

Two fundamental considerations in the design of a communications network are reliability and maximum transmission delay, which can be respectively measured by the connectivity and diameter of a graph representing the network. A d -connected digraph (directed graph) is constructed, which has a minimum number of edges and the diameter is at most one larger than the lower bound for any d and any number of nodes n > d 3 . It improves upon previous designs, which achieve maximum connectivity with a diameter twice as large as the lower bound.

Speech transmission capacity of standard ethernet systems

This paper is concerned with the estimation of the speech traffic capacity of a standard ethernet system by simulation techniques. The particular interest in this work is the possible trade-off of speech coding rate against number of simultaneous users during peak traffic conditions. The results of simulation studies are given and it is concluded that the decisive factor in such a trade-off is the maximum transmission delay which may be accepted and also the percentage loss of transmitted information which occurs as a result.

An algorithm for construction of a k‐connected graph with minimum number of edges and quasiminimal diameter

AbstractTwo fundamental considerations in the design of a communication network are reliability and maximum transmission delay. In this paper we give an algorithm for construction of an undirected graph with n vertices in which there are k node‐disjoint paths between any two nodes. The generated graphs will have a minimum number of edges and a diameter which is twice as large as the theoretical minimum. The algorithm is useful for the construction of large networks because it has a time complexity of O(n2).

A Multisubscriber Variable-Rate Sampling HCDM System with Dynamic Buffer Control

In this paper we present a multisubscriber variable-rate sampling hybrid companding delta modulation (HCDM) system for simultaneous transmission of several speech signals. This system employs both the statistical multiplexing and variable-rate sampling schemes. It transmits speech signals synchronously at a fixed rate using a buffer. In this system the sampling rate of each subscriber is varied according to the speech activity and the status of buffer occupancy, and only the speech portion is coded for transmission. To optimize the system performance within the allowed maximum transmission delay (300 ms), an efficient dynamic buffer control algorithm is proposed. When the number of subscribers is six and the transmission rate for each subscriber is 16 kbits/s, the proposed system yields a performance improvement of about 10 dB over the conventional single-subscriber HCDM system. The buffer delay in this case is 150 ms, which gives a perceptually negligible effect.

Optimal Bandwidth Assignment on Up- and Downlinks of Satellite with Buffer Capacity

This paper considers a satellite communication system with the slotted ALOHA access mode where the satellite is assumed to have on-board regeneration ability and the finite buffer capacity for storing noncollided packets from the uplink. The system is analyzed with the downlink bandwidth restricted to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1/L</tex> of the uplink bandwidth, and with the conventional slotted ALOHA system where <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L = 1</tex> and the buffer size at the satellite is equal to zero. Maximum throughput and throughput-delay characteristics of this system are analytically obtained. The satellite is given an optimal buffer size to achieve maximum throughput and minimum packet transmission delay. It is shown that the constraints that lead to the downlink bandwidth being lower than the uplink bandwidth do not necessarily result in throughput penalties in a buffered satellite system. Furthermore, when the total bandwidth which can be divided between up- and downlinks is given, if two or three times that of the downlink is assigned to the uplink and if the satellite has buffer storage space only for a few packets, we show that maximum throughput of the system will be improved about 40 percent with little change in delay characteristics in comparison with that of the conventional slotted ALOHA system where the given total bandwidth is equally divided between up- and downlinks.