The MobyDick Project: A Mobile Heterogeneous All-IP Architecture

Proceedings of Advanced Technologies, Applications and Market Strategies for 3G (ATAMS 2001). Cracow, Poland: 17-20 June, 2001.This paper presents the current stage of an IP-based architecture for heterogeneous environments, covering UMTS-like W-CDMA wireless access technology, wireless and wired LANs, that is being developed under the aegis of the IST Moby Dick project. This architecture treats all transmission capabilities as basic physical and data-link layers, and attempts to replace all higher-level tasks by IP-based strategies. The proposed architecture incorporates aspects of mobile-IPv6, fast handover, AAA-control, and Quality of Service. The architecture allows for an optimised control on the radio link layer resources. The Moby dick architecture is currently under refinement for implementation on field trials. The services planned for trials are data transfer and voice-over-IP.Publicad

Burst Ratio in Concatenated Markov-based Channels

This paper deals with the burst ratio parameter, which describes the burstiness of a packet loss observed in digital networks. It is one of the input parameters of E-model – the most widely used method of assessing conversational quality of telephony. The burst ratio is defined for one channel scenario so it can be calculated when the whole transmission path has been characterized by a single set of parameters. The main objective of the paper is to extend the burst ratio definition when the transmission path is defined as a tandem concatenation of transmission channels being described by their individual burst ratios. It is assumed that packet loss of a single channel is described by a 2-state Markov chain. The final result of the research is an equation describing the burst ratio parameter when the transmission path consists of multiple concatenated channels. The derived formula has been validated by extensive simulations

Transient and stationary characteristics of a packet buffer modelled as an MAP/SM/1/b

A packet buffer limited to a fixed number of packets (regardless of their lengths) is considered. The buffer is described as a finite FIFO queuing system fed by a Markovian Arrival Process (MAP) with service times forming a Semi-Markov (SM) process (MAP/SM/1/b in Kendall’s notation). Such assumptions allow us to obtain new analytical results for the queuing characteristics of the buffer. In the paper, the following are considered: the time to fill the buffer, the local loss intensity, the loss ratio, and the total number of losses in a given time interval. Predictions of the proposed model are much closer to the trace-driven simulation results compared with the prediction of the MAP/G/1/b model

The Design of an Objective Metric and Construction of a Prototype System for Monitoring Perceived Quality (QoE) of Video Sequences

The paper presents different no reference (NR) objective metrics addressing the most important artefacts for raw (source) video sequences (noise, blur, exposure) and those introduced by compression (blocking, flickering) which can be used for assessing quality of experience. The validity of all metrics was verified under subjective tests

Study of No-Reference Video Quality Metrics for HEVC Compression

The paper proposes a No-Reference (NR) quality assessment measurement originally developed for H.264, used for High Efficiency Video Coding (HEVC). In particular, authors present an investigation of NR metrics to objectively estimate the perceptual quality of a set of processed video sequences. The authors take into account typical distortions introduced by the block-based coding approaches like HEVC codec. The underlying processing used for the quality assessment considers the blockiness caused by the boundaries of each coded block and the blurring as a lack of spatial details. The correlation between the NR quality metrics and the well-known and most widely used objective metric, the Video Quality Model (VQM), is performed to validate the quality prediction accuracy based on the provided scores. The Pearson correlation coefficients obtained stand for promising results for different types of videos

: Experimental Research of Data Transmission over Building Electrical Power Wiring Using PLC Homeplug Modems

Istnieje wiele kryteriów podziału sieci teleinformatycznych: ze względu na architekturę, zasięg działania, wykorzystywane medium transmisyjne. Dodatkowym kryterium klasyfikacji mogą być również czynniki ekonomiczne, takie jak koszt budowy infrastruktury sieciowej (np. koszty okablowania strukturalnego dla sieci typu Ethernet 100BaseT, kabla CATV, itp.) czy koszt podłączenia kolejnego odbiorcy. Najbardziej atrakcyjne ze względów ekonomicznych są te sieci, które nie wymagają inwestycji w postaci nowego okablowania (m.in. sieci bezprzewodowe WLAN), ewentualnie sieci, które są w stanie przyjąć nowe formaty transmisji (siec telefoniczna - ADSL, sieć CATV - DOCSIS). W niniejszym artykule omówiony zostanie stosunkowo mało rozpowszechniony w Polsce sposób transmisji danych, wykorzystujący jako medium istniejące sieci elektroenergetyczne niskiego napięcia (~230V). Sieci te ze względu na powszechność instalacji elektroenergetycznej mogą w przyszłości stanowić konkurencję dla najbardziej rozpowszechnionych metod dostępu do Internetu bazujących na pętli abonenckiej oraz lokalnych sieci kablowych i bezprzewodowych WLAN. Ponadto ze względu na niezawodność transmisji mogą być stosowane jako rozwiązanie alternatywne do budowy przemysłowych sieci transmisji danych.Telecommunications networks can be divided into different categories using many different criteria, such as the network architecture, coverage area, media types, etc. Economical aspects such as network installation cost or cost of connecting of a new customer could be considered as an additional network classification level (for example: Ethernet 100BaseT or CATV network structure cabling cost). The most attractive, from a business point of view is structural wiring or existing networks which can convey enhanced transmission formats (PSTN with ADSL, CATV with DOCSIS). In this paper a barely popular in Poland data transmission technique is presented. The described PLC technique takes an advantage of existing low-voltage (~230V) power lines as a data bearer. Ubiquitous power-line networks can be consider in the near future as a very competitive to a typical Internet access network based on customer's local loop or local area, fixed and wireless networks