Packet loss

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

Time Valid One-Time Signature for Time-Critical Multicast Data Authentication

Abstract: It is challenging to provide authentication to time-critical multicast data, where low end-to-end delay is of crucial importance. Consequently, it requires not only efficient authentication algorithms to minimize computational cost, but also avoidance of buffering packets so that the data can be immediately processed once being presented. Desirable properties for a multicast authentication scheme also include small communication overhead, tolerance to packet loss, and resistance against malicious attacks. In this paper, we propose a novel signature model - Time Valid One-Time Signature (TV-OTS) - to boost the efficiency of regular one-time signature schemes. Based on the TV-OTS model, we design an efficient multicast authentication scheme "TV-HORS" to meet the above needs. TV-HORS combines one-way hash chains with TV-OTS to avoid frequent public key distribution. It provides fast signing/verification and buffering-free data processing, which make it one of the fastest multicast authentication schemes to date in terms of end-to-end computational latency (on the order of microseconds). In addition, TV-HORS has perfect tolerance to packet loss and strong robustness against malicious attacks. The communication overhead of TV-HORS is much smaller than regular OTS schemes, and even smaller than RSA signature. The only drawback of TV-HORS is a relatively large public key of size 8 KB to 10 KB, depending on parameters.

A Versatile Model for Packet Loss Visibility and its Application to Packet Prioritization

Abstract: In this paper, we propose a generalized linear model for video packet loss visibility that is applicable to different group-of-picture structures. We develop the model using three subjective experiment data sets that span various encoding standards (H.264 and MPEG-2), group-of-picture structures, and decoder error concealment choices. We consider factors not only within a packet, but also in its vicinity, to account for possible temporal and spatial masking effects. We discover that the factors of scene cuts, camera motion, and reference distance are highly significant to the packet loss visibility. We apply our visibility model to packet prioritization for a video stream; when the network gets congested at an intermediate router, the router is able to decide which packets to drop such that visual quality of the video is minimally impacted. To show the effectiveness of our visibility model and its corresponding packet prioritization method, experiments are done to compare our perceptual-quality-based packet prioritization approach with existing Drop-Tail and Hint-Track-inspired cumulative-MSE-based prioritization methods. The result shows that our prioritization method produces videos of higher perceptual quality for different network conditions and group-of-picture structures. Our model was developed using data from high encoding-rate videos, and designed for high-quality video transported over a mostly reliable network; however, the experiments show the model is applicable to different encoding rates.

Optimization of PDP context usage

Abstract: In a mechanism for controlling a communication connection with policy control, after the communication connection with policy control is established in a communication network between a user equipment and service providing network element via a network control element on the basis of an initial packet data protocol context, a modification of the initial packet data protocol context for the communication connection is requested or initiated at the network control element. When the modification is authorized, relevant resources for a modified packet data protocol context usable for signalling traffic and transmission of media stream data are set up.

Seamless SIP-based mobility for multimedia applications

Abstract: Application-level protocol abstraction is required to support seamless mobility in next-generation heterogeneous wireless networks. Session initiation protocol (SIP) provides the required abstraction for mobility support for multimedia applications in such networks. However, the handoff procedure with SIP suffers from undesirable delay and hence packet loss in some cases, which is detrimental to applications like voice over IP (VoIP) or streaming video that demand stringent quality of service (QoS) requirements. In this article we present a SIP-based architecture that supports soft handoff for IP-centric wireless networks. Soft handoff ensures that there is no packet loss and that the end-to-end delay jitter is kept under control

Selective packet capture

Abstract: Methods and systems for providing selective packet capture are described. One example method includes identifying a packet capture rule from a set of packet capture rules, the packet capture rule including a trigger condition and an action to perform when the trigger condition is detected; monitoring a network flow to detect whether the network flow satisfies the packet capture rule's trigger condition, wherein monitoring the network flow includes analyzing one or more packets included in the network flow to determine a set of protocol metadata associated with the network flow; and selectively performing the action associated with the packet capture rule on the network flow based on a result of the monitoring.