This paper addresses the problem of bit-rate conversion of a previously compressed video. We provide an MPEG joint transcoder for transcoding several video bitstreams simultaneously. We show that joint transcoding reduces the quality variation between multiple video sequences, as compared to independently transcoding each sequence at a fixed bit rate. Hence, joint transcoding results in a bette...

While Web search engines are built to cope with a large number of queries, query traffic can exceed the maximum query rate supported by the underlying computing infrastructure. We study how response times and results vary when, in presence of high loads, some queries are either interrupted after a fixed time threshold elapses or dropped completely. Moreover, we introduce a novel dropping strate...

Handoffs in a mobile cellular communications environment have become an increasingly important issue accommodating an increasingly large demand for services with simultaneous reduced cell sizes. In this paper, a new Prioritized Hard Handoff (PH2) ordering scheme is proposed which can be used to provide rapid handovers with a smaller percentage of dropped calls than other methods. The performanc...

This paper describes a method for robust streaming of combined MPEG2 audio/video content over in-home wireless networks. We make use of currently used content distribution formats and network protocols. The transmitted bit-rate is constantly adapted to the available network bandwidth, such that audio and video artifacts caused by packet loss are avoided. Bit-rate adaptation is achieved by using...

In a real-time wireless TDMA environment, every packet generated by applications has a deadline associated with it. If the system cannot allocate enough resources to serve QoS defines the call blocking probability and handoff dropping probability, whereas at packet level, or MAC level, QoS defines the packet dropping probability and delay tolerance. the packet before the deadline, the packet wo...

A packet dropping and message tampering attack contains data which routed between source and destination. Packet dropping attack happens accidently or deliberately on network or packet switching network. Message tampering attack causes measure problem in message transmission activity, due to unauthorized party tampered message and can change message contains so it hard to detect that tampered m...