New security and control protocol for VoIP based on steganography and digital watermarking

In this paper new security and control protocol for Voice over Internet Protocol (VoIP) service is presented. It is the alternative for the IETF's (Internet Engineering Task Force) RTCP (Real-Time Control Protocol) for real-time application's traffic. Additionally this solution offers authentication and integrity, it is capable of exchanging and verifying QoS and security parameters. It is based on digital watermarking and steganography that is why it does not consume additional bandwidth and the data transmitted is inseparably bound to the voice content.Comment: 8 pages, 4 figures, 1 tabl

Evaluation of cross-layer reliability mechanisms for satellite digital multimedia broadcast

This paper presents a study of some reliability mechanisms which may be put at work in the context of Satellite Digital Multimedia Broadcasting (SDMB) to mobile devices such as handheld phones. These mechanisms include error correcting codes, interleaving at the physical layer, erasure codes at intermediate layers and error concealment on the video decoder. The evaluation is made on a realistic satellite channel and takes into account practical constraints such as the maximum zapping time and the user mobility at several speeds. The evaluation is done by simulating different scenarii with complete protocol stacks. The simulations indicate that, under the assumptions taken here, the scenario using highly compressed video protected by erasure codes at intermediate layers seems to be the best solution on this kind of channel

An asynchronous time division multiplexing scheme for voice over IP.

by Yip Chung Sun Danny.Thesis (M.Phil.)--Chinese University of Hong Kong, 2000.Includes bibliographical references (leaves 52-54).Abstracts in English and Chinese.Chapter Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Motivation --- p.1Chapter 1.2 --- Organization of Thesis --- p.5Chapter Chapter 2 --- Background --- p.6Chapter 2.1 --- Speech Codec --- p.6Chapter 2.2 --- RTP/UDP/IP Header Compression --- p.7Chapter 2.2.1 --- Real-Time Transport Protocol --- p.7Chapter 2.2.2 --- RTP/UDP/IP Header Compression --- p.8Chapter Chapter 3 --- Scenario and Assumptions --- p.10Chapter Chapter 4 --- Asynchronous Time Division Multiplexing Scheme --- p.14Chapter 4.1 --- Basic Idea --- p.14Chapter 4.1.1 --- Bandwidth Efficiency Improvement --- p.16Chapter 4.1.2 --- Delay Reduction --- p.18Chapter 4.2 --- Header Compression --- p.19Chapter 4.2.1 --- Header Compression Process --- p.21Chapter 4.2.2 --- Context Mapping Table --- p.23Chapter 4.3 --- Protocol --- p.28Chapter 4.3.1 --- UNCOMPRESSED_RTP Mini-Header --- p.30Chapter 4.3.2 --- SYNCHRONIZATION Mini-header --- p.31Chapter 4.3.3 --- COMPRESSED´ؤRTP Mini-header --- p.32Chapter 4.4 --- Connection Establishment --- p.33Chapter 4.4.1 --- Addressing Phase --- p.34Chapter 4.4.2 --- Connection Phase --- p.36Chapter 4.5 --- Software Implementation --- p.38Chapter Chapter 5 --- Simulation Results --- p.39Chapter 5.1 --- Simulation Model --- p.39Chapter 5.2 --- Voice Source Model --- p.41Chapter 5.3 --- Simulation Results --- p.43Chapter 5.3.1 --- Network Utilization and Delay Performance --- p.43Chapter 5.3.2 --- Number of Supported Connections --- p.45Chapter Chapter 6 --- Conclusion and Future Work --- p.49Bibliography --- p.5

A Survey of Bandwidth Optimization Techniques and Patterns in VoIP Services and Applications

This article surveys the various techniques adopted for optimising bandwidth for VoIP services over the period 1999-2014. The improvement of bandwidth can be realized through; silence suppression measure of repressing the silent portions (packets) in a voice conversation using Voice Activity Detection algorithm; by so doing, the transmission rate during the inactive periods of speech is reduced, and thus, the mean transmission rate can be reduced. A second measure is packet header reduction which defines a process of multiplexing and de-multiplexing packet headers to curb excesses. Voice/ Packet Header compression is considered the most productive of all the techniques, offering a scheme where VoIP packets are compressed from the 40 bytes of size to a smaller byte size of 2 bytes. When combined with aggregation, compression potentially yields a compressed size of up to 1 byte. In either case, bandwidth save is reached using compression and decompression codecs of varying data and bit rates. It is envisaged that an improvement in the performance of codecs would yield a better result in terms of enhancing results favourably in Voice over broadband networksComment: 8 pages, 7 figures. ISSN (Print): 1694-0814 | ISSN (Online): 1694-078

The Research of Increase of Channel Efficiency for IP Traffic Transmission over Digital Power Line Carrier Channels

This article is devoted to the research of channel efficiency for IP-traffic transmission over Digital Power Line Carrier channels. The application of serial WAN connections and header compression as methods to increase channel efficiency is considered. According to the results of the research an effective solution for network traffic transmission in DPLC networks was proposed

Rationale, Scenarios, and Profiles for the Application of the Internet Protocol Suite (IPS) in Space Operations

This greenbook captures some of the current, planned and possible future uses of the Internet Protocol (IP) as part of Space Operations. It attempts to describe how the Internet Protocol is used in specific scenarios. Of primary focus is low-earth-orbit space operations, which is referred to here as the design reference mission (DRM). This is because most of the program experience drawn upon derives from this type of mission. Application profiles are provided. This includes parameter settings programs have proposed for sending IP datagrams over CCSDS links, the minimal subsets and features of the IP protocol suite and applications expected for interoperability between projects, and the configuration, operations and maintenance of these IP functions. Of special interest is capturing the lessons learned from the Constellation Program in this area, since that program included a fairly ambitious use of the Internet Protocol

Robust Header Compression (ROHC) in Next-Generation Network Processors

Robust Header Compression (ROHC) provides for more efficient use of radio links for wireless communication in a packet switched network. Due to its potential advantages in the wireless access area andthe proliferation of network processors in access infrastructure, there exists a need to understand the resource requirements and architectural implications of implementing ROHC in this environment. We presentan analysis of the primary functional blocks of ROHC and extract the architectural implications on next-generation network processor design for wireless access. The discussion focuses on memory space andbandwidth dimensioning as well as processing resource budgets. We conclude with an examination of resource consumption and potential performance gains achievable by offloading computationally intensiveROHC functions to application specific hardware assists. We explore the design tradeoffs for hardware as-sists in the form of reconfigurable hardware, Application-Specific Instruction-set Processors (ASIPs), andApplication-Specific Integrated Circuits (ASICs)