Showing papers on "Packet loss published in 1984"

The Spatial Capacity of a Slotted ALOHA Multihop Packet Radio Network with Capture

Abstract: In this paper we determine throughput equations for a packet radio network where terminals are randomly distributed on the plane, are able to capture transmitted signals, and use slotted ALOHA to access the channel. We find that the throughput of the network is a strictly increasing function of the receiver's ability to capture signals, and depends on the transmission range of the terminals and their probability of transmitting packets. Under ideal circumstances, we show the expected fraction of terminals in the network that are engaged in successful traffic in any slot does not exceed 21 percent.

Adaptive preferential flow control for packet switching system

Abstract: Flow control of data packets through a packet switching network (20) to reduce congestion is controlled by an adaptive preferential permit packet (APP) processing from an originating data terminal (10) through each packet switch node of the network to a destination data terminal (11). APP requires less buffer storage capacity at each switch node, and enables data packets to enter the network only when there is a permit packet indication that the data packets are likely to reach, and be accepted by, their destination. The permit packet is sent node to node (16-19, 25, 28) prior to a transmission of a bulk of data packets. Each node is equipped to queue buffer (12-15, 21-24) a permit packet on a preferential basis ahead of data packets. The node discards the permit packet if the number of packets awaiting transmission from that node exceeds a prescribed threshold. This is throttling process, since the originating port times out and resends a permit packing if a permit-return packet is not received within a predetermined time. Permit-return packet processing, adaptive time-out controls, and preferential treatment of permit packets are disclosed.

Performance Evaluation of a Packetized Voice System--Simulation Study

Abstract: Introduction of the packet switching technique into digitized voice communication may afford great advantages in efficient use of the channel, compared to both circuit-switched and DSI systems. Detailed characteristics, however, have not been obtained because of difficulty in the exact analysis. Hence, simalation models are developed in this paper for the packetized voice transmission system, and various characteristics such as tranmission delays and loss probability of voice packets are obtained. We further evaluate three types of voice packet reassembly strategy at the receiving terminal, and obtain the optimal packet length, which keeps both overall packet transmission delay and packet loss probabilty less than a certain permissible value. Comparison among three strategies is also stated.

Packet exchange data transmission system

Abstract: At least two packet exchangers are interconnected through an external transmission line to transmit a data packet. Each packet exchanger comprises a main controller for processing the data packet sent from a packet terminal, in a data link level and a packet level, and a connecting unit for sending the data packet sent from the main controller to the external transmission line and sending the data packet sent from the external transmission line to the main controller.

Performance evaluation of a protocol for packet radio network in mobile computer communications

Abstract: The need to provide computer network access to mobile terminals and computer communications in the mobile environment has stimulated and motivated the current developments in this area. Packet radio technology has developed over the past decade in response to the need for real-time, interactive communications among mobile users and shared computer resources. In computer communication systems we have a great need for sharing expensive resources among a collection of high peak-to-average (i.e., bursty) users. Packet radio networks provide an effective way to interconnect fixed and mobile resources. The results of an attempt to study the performance of the mobile packet radio network for computer communications over degraded channels are presented. We develop a model under fading conditions and derive a protocol for evaluating the performance of the mobile packet radio network (MPRNET) in terms of the packet error rate, packet delay, throughput and average number of retransmitted packets per cycle. The analytical results are presented and numerical examples are given to illustrate the behavior of these performance criteria as a function of packet transmission rate, packets transmitted per cycle, packet size, and vehicle speed with the help of appropriate plots.

Congestion control system in packet switching network

Abstract: PURPOSE:To enable shortening of packet transfer time and dispersion of load in a packet switching network by determining passage of sending out packet depending on alternative control information added to the packet and information of the state of congestion of adjoining packet exchange which is on the passage to destination when a relaying packet exchange received the packet. CONSTITUTION:In a transfer packet, alternative control information (cr) is added besides destination information (dn) and originating station information (on) to terminal transmitting packet (pkt). The alternative control information (cr) is set to logical value ''0'' to general packet that makes a detour to a packet exchange which is in the state of congestion, and set to logical value ''1'' to specific packet that does not make a detour. The relaying packet exchange A discirciminates alternative control information (cr) of arriving packet, and when it is set to logical value ''1'', sends out the packet to a relaying path L2 even when it is receiving congestion notice packet from a packet exchange B. Consequently, the packet is transferred to destination packet exchange C by the shortest route similar to the case where the packet exchange B is not in the state of congestion.

A Three-Node Packet Radio Network

Abstract: A two-hop packet radio network consisting of three nodes is considered. The three nodes have infinite buffers and share a common radio channel for transmitting their packets. Two of the nodes forward their packets to a third node that acts as a source of data as well as a relay that forwards all the packets entering the network to a main station. We assume that two of the nodes are granted full rights in accessing the channel while the third node uses a random access scheme. For this network we derive the condition for steady state and the generating function of the joint queue length distribution at the nodes in steady state. We also give several numerical examples and compare the performance of the network with and without a relay node.