Packet loss

About: Packet loss is a research topic. Over the lifetime, 21235 publications have been published within this topic receiving 302453 citations.

Robust Internet video transmission based on scalable coding and unequal error protection

Abstract: In this article we describe and investigate an Internet video streaming system based on a scalable video coder combined with unequal error protection that maintains an acceptable picture quality over a wide range of connection qualities. The proposed approach does not require any specific support from the network layer and is especially suited for Internet multicast applications where different users are perceiving different transmission conditions and no feedback channel can be employed. We derive a theoretical framework for the overall system by which the Internet packet loss behavior can be directly related to the picture quality perceived at the receiver. We demonstrate how this framework can be used to select appropriate parameter values for the overall system design. Experimental results show how the presented system achieves a gracefully degrading picture quality for packet losses up to 30%.

A feedback-based scheme for improving TCP performance in ad hoc wireless networks

Abstract: Ad hoc networks are completely wireless networks of mobile hosts, in which the topology rapidly changes due to the movement of mobile hosts. This frequent topology change may lead to sudden packet losses and delays. Transport protocols like TCP, which have been designed for reliable fixed networks, misinterpret this packet loss as congestion and invoke congestion control, leading to unnecessary retransmissions and loss of throughput. To overcome this problem, a feedback scheme is proposed so that the source can distinguish between a route failure and network congestion. When a route is disrupted, the source is sent a route failure notification packet, allowing it to invalidate its timers and stop sending packets. When the route is reestablished, the source is informed through a route reestablishment notification packet, upon which it resumes packet transmissions. Simulation experiments show that in the event of route failures, as the route reestablishment time increases, the use of feedback provides significant improvements in performance.

Communications channel selection

Abstract: A communications system (10) is provided for sending and receiving information relative to a mobile unit in which a number of network channels are available through which the information can be transferred. The system includes a link selector (64) for selecting an acceptable network channel using application requirements for the particular channel, together with channel operating parameter values. When such a channel does not become available, the link selector (64) is also involved with recovery procedures. These network channel operating parameters include bandwidth, information transfer costs and information transfer packet loss, latency and jitter. Weighting vectors are also utilized with such channel operating parameters in determining suitability values associated with the available network channels. The link selector (64) communicates with a link scheduler (70) that has responsability for determining when information should be transferred including when there should be a change in the timing of the information transfer.

A node scheduling scheme for energy conservation in large wireless sensor networks

Abstract: In wireless sensor networks that consist of a large number of low-power, short-lived, unreliable sensors, one of the main design challenges is to obtain long system lifetime without sacrificing system original performances (sensing coverage and sensing reliability). In this paper, we propose a node-scheduling scheme, which can reduce system overall energy consumption, therefore increasing system lifetime, by identifying redundant nodes in respect of sensing coverage and then assigning them an off-duty operation mode that has lower energy consumption than the normal on-duty one. Our scheme aims to completely preserve original sensing coverage theoretically. Practically, sensing coverage degradation caused by location error, packet loss and node failure is very limited, not more than 1% as shown by our experimental results. In addition, the experimental results illustrate that certain redundancy is still guaranteed after node-scheduling, which we believe can provide enough sensing reliability in many applications. We implement the proposed scheme in NS-2 as an extension of the LEACH protocol and compare its energy consumption with the original LEACH. Simulation results exhibit noticeably longer system lifetime after introducing our scheme than before. Copyright © 2003 John Wiley & Sons, Ltd.

A One-way Packet Loss Metric for IPPM

Abstract: This memo defines a metric for one-way packet loss across Internet paths. [STANDARDS-TRACK]