Showing papers on "Transmission delay published in 1979"

The Single Server Queue with Periodic Arrival Process and Deterministic Service Times

Abstract: We derive an algorithm for computing the exact delay distribution for the following first-come-first-served single server queue. The arrival process is the superposition of N + 1 independent equivalent deterministic arrival streams, and the service times are deterministic. Numerical results are used to compare this system with an approximating system which has been used in the absence of exact results: the M/D/1 queue (Poisson input, deterministic service time). A comparison with a finite source model is also given. This study was motivated by the following issue germane to packet switching data networks. There are N + 1 packet processes, arriving over identical trunks, which must share the transmission capacity of a single high-speed trunk in a store-and-forward manner. The idealized queueing model above analyzes the worst-delay situation for this problem when the incoming trunks are fully utilized and the packets are maximum sized. The results indicate that an M/D/1 approximation can be quite pessimistic in predicting the performance of such a system.

Optimal Packet Length for Packet Voice Communication

Abstract: It is shown that for typical operating parameters, the optimal packet length for a single link packet voice system is of the order of 300-700 bits. This is contrary to both the optimal length of a data packet (approximately 1000 bits), and documented experimental implementations of such network architecture for voice (approximately 1000 bits).

The Tradeoff Between Delay and TASI Advantage in a Packetized Speech Multiplexer

Abstract: A packetized speech multiplexer differs from a circuitswitched TASI system in that the presence of a packet buffer allows a tradeoff where the TASI advantage can be increased at a cost in packet delay. This tradeoff is investigated via a simulation. Results are presented to show the relations between TASI advantage and delay, for both an average delay criterion and a maximum delay criterion. It is shown that, particularly for the case where small numbers of talkers are multiplexed, the packetized system offers significant improvements in TASI advantage over the conventional circuit-switched multiplexer, at modest costs in packet delay.

Issues in packet voice communication

Abstract: Because of perceived economic and technical benefits, digital voice techniques and corresponding packet network architectures are receiving considerable attention. In this paper we summarise speech traffic models, followed by a discussion of performance criteria. A queuing model for a link carrying packetised voice is introduced and solved. The results and network implications of this link model are addressed; results on optimal packet length, transient behaviour, and buffer length are presented.

A Theoretical Traffic Performance Analysis of an Integrated Voice-Data Virtual Circuit Packet Switch

Abstract: A time division packet switch capable of concurrently handling both voice and data traffic is proposed, and some of its performance limitations are analyzed. The voice packet traffic is handled at a higher priority level than data traffic, in order to meet stringent timing criteria, and can be shown to be handled just as if it were circuit switched. The data traffic utilizes whatever time slots are not occupied with voice traffic. The principal performance limitations described in this exploratory study are the fraction of time the voice traffic is blocked due to all the available time slots already being used for voice traffic, and an upper bound on the mean delay encountered by the data traffic as it waits to find an available time slot. An illustrative numerical result is the following. If we assume that each voice telephone conversation lasts for a mean of five minutes, and that twenty voice calls are generated over a six hour time span, and each data session lasts for a mean of forty minutes, and that five data calls are generated over a six hour time span, then if separate line switched networks are used for voice and for data with long term blocking probability of one percent, a total of 703 64 kbits links would be required to support 461 voice stations and 882 data terminals. On the other hand, using the integrated voice/data switch described here, and if we assume that the total delay due to the switch alone for data packets cannot exceed a long term mean value of one second, then only 298 64 kbit/s links are required to support 461 voice stations and 882 data terminals, reducing the number of required links by a factor of about two. Moreover, the assumptions leading to this comparison suggest that the packet switch could in fact support significantly more than this number of voice stations and data terminals. This is achieved at the expense of additional buffering for the data in the packet switch approach.

Delay related issues in integrated voice and data transmission: A review and some experimental work

Abstract: This paper focuses on network delays as they apply to voice transmission. First the nature of the problem is discussed and this is followed by a review of circuit, packet and hybrid switching. The concept of introducing delay to resolve contention in speech interpolation is also noted, and when applied to both voice and data messages, forms a basis for a relatively new and so-called “transparent” approach to network design. The second part of the paper deals with experimental work. First, external link considerations involving subnet access by frame synchronous vocoders is discussed, and an experimental software interface is described which exploits the 60 to 65% idle time in voice calls. Secondly, based on the simulation of variable network delays, first indications are that with 180 ms “hangover”, the perceptable threshold of variable delay is about 200 ms average. Finally, suggestions for further works on performance analysis and subjective testing are made.

The Influence of Protocols on the Stability Conditions in Packet-Switching Networks

Abstract: A packet-switching network is considered as a tandem system of store-and-forward links. In this paper, it is shown that the maximum input traffic, with finite intermediate buffer size, is very sensitive to the distribution of the transmission time. The performance of two different protocols is compared under various distributions of transmission times.

Clock signal distributing circuit adjusting device and method

Abstract: A clock signal distributing circuit is provided in its transmission line with delay time varying means and arranged so that a signal at the output terminal of the transmission line is opposite in phase to a signal at its input terminal. In the adjustment of the delay time, the input and output terminals are short-circuited by a line having a predetermined delay time to form a loop, causing oscillation. The sum of the rise and fall delay times of this loop-like transmission line is the oscillation cycle. Since the rise delay time and the fall delay time are substantially equal to each other over the entire loop, the delay time of the loop-like transmission line is obtained as 1/2 of the reciprocal of the oscillation frequency (the oscillation cycle), and from the delay time thus obtained is subtracted the delay time of the short-circuiting line to obtain the delay time between the input and output terminals of the clock signal distributing circuit. The abovesaid frequency is measured by means of a frequency counter. The delay time is adjusted, for example, by changing the length of a discrete wire.

Sensitivity of integrated voice and data networks to traffic and design variables

Abstract: This paper presents quantitative results of cost/performance studies of circuit-switching, packet-switching, and hybrid (circuit/packet) switching technologies. The results expose the cost difference for alternative realizations and usage of a given network technology.

Comparison of some end-to-end flow control policies in a packet-switching network

Abstract: Various techniques may be considered when it comes to setting up a communications system between computers. The "packet-switching" technique described by Davies 1 seems to be one of the best of existing approaches. In the following we consider only such a technique—users of a computer network communicate with each other by the intermediate of a store-and-forward packet-switching network.

Trilateral duplex path conferencing system with broadcast capability

Abstract: A system is disclosed which permits information received from any data terminal or telephone subscriber line at any interface to a digital network to be transmitted to any number of other terminals at any or all of the interfaces to the digital network. The system herein described also permits any terminal at any interface of the digital network to be conferenced, with up to N other terminals at any or all of the interfaces to the digital network where N can be made to depend solely upon the topology and single path transmission delay of the digital network itself. A facility is provided which is independently provisioned at every interface to the digital network and which is independently and concurrently available to any number of combinations of terminals and simplex paths at those interfaces. A broadcast capability is also provided whereby telecommunication information can be simultaneously transmitted from a source terminal to a plurality of destination terminals.

Group Delay Estimation with Wideband Signals

Abstract: A new formula for the group delay of a network is derived. The formula is not restricted to narrow-band signals and is valid up to quite large bandwidths. A simple and very sensitive technique for group delay measurement, based on this new relation, is described.

Monitoring Mobile Packet Radio Devices

Abstract: A store-and-forward broadcast radio network with mobile switching nodes is considered. The problems of monitoring connectivity changes in the network and updating information in switching nodes to enable routing of messages are addressed. Analytical models are developed for determining the fraction of time that switching nodes have correct information as a function of trajectory and speed for mobility, monitoring rate, traffic load, and network topology. The problems are parametrically investigated and results of monitoring rate to obtain performance requirements are obtained. These studies show that the monitoring rate is very sensitive to velocity; specifically, as the velocity doubles, so does the monitoring rate. These results are a first step in obtaining meaningful operating parameters to be used in experimental networks.

Digital voice communication over digital radio links

Abstract: Because of perceived benefits digital voice techniques and corresponding network architectures are receiving considerable attention. Parallel to these developments, packet radio technology is emerging as an efficient and secure way to transmit computer data. Major synergistic benefits can be obtained by superimposing the two systems. In this paper we develop a model for end-to-end packet delay through the network, and we obtain general network implications for packet voice communication over a packet radio system.

Compensation unit for transmission delay time

Abstract: PURPOSE:To reduce the useless time and to increase the transmission efficiency, in the N:M time sharing multiplex transmission system by star coupler constitution, by respectively providing the delay circuit with each remote station. CONSTITUTION:The remote station AM1 having the longest transmitting distance from the traffic controller TC transmits the data to the objective remote station via the star coupler SC2 for data at the center by superimposing on the transmission data of the station, when it receives the time slot TS1. In this case, the signal delay time of AM1 to the TC, synchronous and control star coupler SC1 is td1=tdmax. On the other hand, the remote stations AM2-AMn receive the time slots TS2- TSn corresponding to them in the delay times td2, tdn and give the delay compensation time Delay2-Delayn while the data transmission after the reception, so that different fields can not be duplicated on SC2. This compensation time is 2(tdmax-td2) at AM2.

Talking set system of voice packet

Abstract: PURPOSE:To stabilize a talking quality, by adding time data to voice pakets to compensate fluctuation of the transmission delay time. CONSTITUTION:The voice signal from telephone set 1 is converted to a PCM signal in transmission part 2 and is made into a packet, and time data from time data circuit 3 is added to this packet, and the packet is transmitted to transmission line 5 as a voice packet. Meanwhile, the receiving voice packet is controlled according to the difference between time data and receiving time data in receiving part 4 so that the transmission delay quantity of the voice packet may be fixed, and the packet is decoded and supplied to telephone set 1.

Analoggdigital converter for converting brightness into digital signals

Abstract: PURPOSE:To simplify the overall construction of an analog-digital converter by composing the converter of a photodiode, an oscillator having its power consumption and tage transmission delay time determined, and a counter.

Exact solution for the initialization time of packet radio networks with two station buffers

Abstract: The Packet Radio Network (PRNET), a store-and-forward packet-switching system sharing a single radio channel via multi-access techniques and spread spectrum, is an effective communication medium for data and voice transmission in situations requiring fast deployment, non-fixed hardware locations, encryption and anti-jamming in hostile military environments 1 – 5 , 14 , 15

Surge reception type fault locator requiring no delay correction

Abstract: PURPOSE:To obtain a surge reception type fault loctor which requires no delay correction by providing a pair of signal transmission lines featuring the same signal transmission delay time between the master and slave stations installed across the monitored line. CONSTITUTION:Master station M and slave station S which are conncted to each other via transmission line TL2 and TL3 featuring the same transmission delay time are installed across monitored line TL1. In case some fault takes place at point F of line TL1, the surge voltage propagates across line TL1 to drive signal generation circuit SG1 and SG2 of station M and S respectively as well as to make counter CT1 and CT2 start clock counting. The signals of SG1 and SG2 are transmitted to their remote stations each via line TL3 and TL2 respectively to stop operations of counter CT2 and CT2 of the remote stations. The contents of CT2 is sent to the master station side via another transmission line TL4, and arithmetic circuit LOG1 calculates fault point F based on the contents of CT1 and CT2.

Link Systems with Delay

Abstract: This paper discusses two classical methods of calculating grade of service parameters for link systems, i.e., the methods of Jacobaeus and Lotze. The possibility of extending these theories to cover delay systems and in particular to calculate the waiting time distribution is looked into. Numerical results from the theories are compared with simulations results. Throughout this paper, pure Poisson arrivals and negative exponentially distributed service times are considered.

Throughput Considerations in a Multi-Processor Packet-Switching Node

Abstract: The prime objective of the present paper is to analyze the throughput characteristics of a multi-processor configuration for packet switching-suggested in the context of an integrated network for circuit and packet switching-and to identify the major parameters on which it depends. The results provide a fundamental insight into how the most relevant system and traffic parameters determine throughput as a function of the number of packet-handling modules. In particular, it is shown that the proposed partitioning of the packet-handling function does indeed permit high throughput before saturation is encountered.

Multiplex data transmission system of ring shape cyclic type

Abstract: PURPOSE:To avoid ring shape cyclic multiplex data transmission network from being system down with any station bypassed, by performing correstion with the amount corresponding to the transmission delay time between the local station and the subsequent station for all stations.

Interface circuit system for digital multiple lines suited to timeedividion exchange

Abstract: PURPOSE:To reduce the transmission delay and thus to increase the performance by reading out the data synchronized with the frame phase within the exchange with the timing determined corresponding to the plural digital multiple transmission lines through the frame aligner circuit. CONSTITUTION:Reception pulse generator circuits 1-1-1-n receive the multiple signals from plural digital transmission lines to convert them into the reception pulses for the exchange. And frame aligner circuits 2'-1-2'-n receive the output pulses from circuits 1-1-1-n and convert the pulse phases into the frame phases within the exchange respectively. Then the data synchronized with the frame phase within the exchange is read out with the timing of generator circuit 6 which is determined in accordance with the plural digital transmission lines sent from the frame phase synchronous memory provided within circuits 2'-1-2'-n each, and then the data read out is introduced to circuit network highway HW of the exchange in the form of the sum of the data output. As a result, the transmission delay is reduced thus to increase the performance.

Control of Satellite-Packet Switched Telecommunications Networks

Abstract: This paper discusses the results of an investigation of control techniques for packet switching networks utilizing satellite transmission under stressed conditions. Emphasis is placed on controlling TDM satellite networks to enhance traffic carrying capacity and maintain performance under stressed conditions.

Analysis of Packet Switching Communication Networks with Finite Buffers

Abstract: The method of the imbedded Markov chain is used to analyze queuing network models for packet switching communication networks with finite storage capacity, pie limitations of the method are discussed and as an example joint and marginal equilibrium distributions for the tandem queue are derived. These distributions are used to find the delay time and the blocking probability of the system, to discuss their dependence on the system parameters, and to suggest design principles optimizing the performance of the system. Übersicht: Mit Hilfe der Methode der eingebetteten Markoy-Kette werden Modelle, aufgebaut als Netzwerk von Warteschlangen, für packet-switching-Nachrichtennetze mit endlicher Speicherfähigkeit untersucht. Die Grenzen der Methode werden abgeschätzt, und als Anwendungsbeispiel werden die stationäre Verteilung sowie die Randverteilungen für die Kettenschaltung von zwei Walteschlangen hergeleitet. Ausgehend von diesen Verteilungen werden Wartezeit und Verlustwahrscheinlichkeit für das System berechnet, ihre Abhängigkeit von den Systemparametern diskutiert und Verfahren für eine optimale Dimensionierung solcher Systeme vorgeschlagen. Für die Dokumenta t ion: Warteschlange / Netzwerk von Warteschlangen / packet-switching / Computer Netzwerk / Computer Modell / Markov-Kette