Technical articles A selection of technical papers and articles, relevant to your industry.
Voice Coders  | Voice Over IP
David Lake, CISCO Systems Ltd (November 2004)
View the Power Point slides from David Lake's paper presented at the Hot Topics Forum, November 2004.
Source: Hot Topics Forum, November 2004 | | | Subjective Testing of Voice Coders [Slides]
Ronald van Buuren, TNO Human Factors (October 2002)
Testing of candidate voice coders Speech quality ? Intelligibility ? Language Dependency?
Source: NC3A workshop on Stanag 4591, October 18th 2002, The Hague | | | Interoperability:Where will / may STANAG [Slides]
Michael Street and John Collura (October 2002)
Interoperability: How widespread will STANAG 4591 be ? Military and government systems Potential use in civil communciations systems
Source: NC3A workshop on Stanag 4591, October 18th 2002, The Hague | | | STANAG 4591 The new NATO Narrow Band Voice Coder Results [Slides]
Michael Street, NC3A (October 2002)
Results: Performance of winning voice coder Performance of candidate voice coders Performance comparrisons with other widely used standards eg CELP,CVSD,LPC
Source: NC3A workshop on Stanag 4591, October 18th 2002, The Hague | | | The Selection Process for STANAG 4591 [Slides]
Michael Street, NC3A (October 2002)
The Selection Process for the new NATO voice coder What range of voice coders were tested? How were they tested ? How representative were the tests ?
Source: NC3A workshop on Stanag 4591, October 18th 2002, The Hague | | | STANAG 4591 in Voice over IP - Related Studies in Tactical IPv6 based Communications [Slides]
Peter Sevenich, FGAN/ FKIE (October 2002)
This presentation covers the following: The INSC Project and FKIE involvement Tactical Scenario VoIP, Quality of Voice Transmission Solution based on IPv6 Header Reduction and Resource Management IPSec Network Layer Security and related Problems Summary and Outlook Examples Fieldtests with STANAG 4591
Source: NC3A workshop on Stanag 4591, October 18th 2002, The Hague | | | FEC coding and MELPe [Slides]
John S. Collura, National Security Agency (October 2002)
The objectives of the research presented were as follows: Investigate error bounds for joint Source-Channel coding Vary bit error rates Vary Source + FEC coding rates Provide some info of combined degradations
Source: NC3A workshop on Stanag 4591, October 18th 2002, The Hague | | | A 1200/ 2400 Bps Coding Suite Based On MELP [slides]
Tian Wang, Kazuhito Koishida, Vladimir Cuperman, Allen Gersho and John S. Collura (October 2002)
STANAG 4591: The winner ! Technical overview of the MELPe voice coding suite Operation at multiple bit rates 2400 / 1200 bps Performance with additional Forward Error Correction
Source: NC3A workshop on Stanag 4591, October 18th 2002, The Hague |
Voice Communications | | Voice Over IP
David Lake, CISCO Systems Ltd (November 2004)
View the Power Point slides from David Lake's paper presented at the Hot Topics Forum, November 2004.
Source: Hot Topics Forum, November 2004 | | | Just What Is...ATCA?
Jurgen Eder, SBS Technologies (October 2004)
What does the Advanced Telecom Computing Architecture mean to systems integrators and designers?
Source: Electronics Systems and Software - October 2004 | | | Avoiding the downhill
J P Conti (June 2004)
Until recently, cellular operators around the world had one overriding priority - getting their networks up and running as quickly as possible in order to grab a sizeable share of the growing market. However, increasing competition is forcing operators to pay more attention to improving the quality of their voice services.
Source: Communications Engineer, June 2004 | | | The clearest voice
T Zahariadis and S Spanos, Bell Labs/Ellemedia (March 2004)
Two standards are currently competing for dominance in IP telephony: the H.323 protocol suite by the ITU, and the Session Initiation Protocol (SIP) by the Internet Engineering Task Force. The authors examine the strengths and weaknesses of the two approaches.
Source: Communications Engineer, April 2004 | | | IP phones home
D Ross (March 2004)
Report from the 2004 CeBit show in Hannover, Germany, where visitors and exhibitors were getting excited over the consumer potential of Voice over IP telephony.
Source: IEE Review, April 2004 | | | Avoiding repetition
F Bourget (February 2004)
After decades of playing a vital role in the circuit-switched environment, echo cancellation techniques are proving even more important in IP telephony.
Source: Communications Engineer, February 2004 | | | Fractal Dimension Segmentation: Isolated Speech Recognition
S Fekkai, M Al-Akaidi, J Blackledge, P Urwin, De Montfort University (March 2000)
Fractal Dimension Segmentation (FDS) characterizes variations in texture across a signal or image in terms of variations in the fractal dimension. In this paper FDS is applied to a number of different speech signals and the results discussed for isolated words and the components (e.g. fricatives) from which these words are composed.
Source: IEE Colloquium on Speech Coding Algorithms for Radio Channels, London, April 2000 | | | Interoperable Secure Voice Communications in Tactical Systems
J S Collura, D J Rahikka, National Security Agency (March 2000)
This paper discusses one next generation voice coding technology, the enhanced Mixed Excitation Linear Prediction (MELPe) voice coding algorithmic suite, and the additions under development and in consideration.
Source: IEE Colloquium on Speech Coding Algorithms for Radio Channels, London, April 2000 | | | Phase Modelling For Low Bit-Rate Speech Coding
B M G Cheetham, University of Manchester , X Q Sun, Lucent Technologies & P A Barrett, BT Laboratories (March 2000)
This paper is concerned with the phase spectra of voiced speech segments digitised at low bit-rates using sinusoidal interpolative coding techniques. Commonly accepted models for voiced speech production are examined to determine ways of more accurately relating phase spectra to magnitude spectra.
Source: IEE Colloquium on Speech Coding Algorithms for Radio Channels, London, April 2000 |
Wireless Communications  | Telecoms Networks: The Next Generation
Various (July 2005)
View the presentations from the Telecoms Networks: The Next Generation event held on the 4th-5th July 2005.
Source: Telecoms Networks: The Next Generation 2005 | | | WiMAX: Interoperable IP Centric Broadband Wireless
Paul Senior, WiMAX Forum Board of Directors and VP Marketing, Airspan Networks (November 2004)
View the Power Point presentations from Paul Senior's paper presented at the Hot Topics Forum, November 2004.
Source: Hot Topics Forum, November 2004 | | | What exactly is...ZigBee? (new wireless technology)
I Poole (August 2004)
A new wireless technology named ZigBee is being launched onto the market. However, with a large number of wireless standards already available, can ZigBee live up to its expectations?
Source: Communications Engineer, August 2004 | | | Analysis: Wi-Fi mania
Claudia Kienzle (August 2004)
America's love affair with wireless LAN connectivity continues to flourish.
Source: Communications Engineer, August 2004 | | | Convergence time
John Walko (December 2004)
John Walko takes a close look at the fading boundaries between fixed and mobile telephony.
Source: Communications Engineer - Dec/Jan 04/05 | | | Cells set sail (mobile phones at sea)
Mike Fitzgerald, Altobridge (August 2004)
The cellular industry goes after its last unconquered territory - the open waters.
Source: Communications Engineer, August 2004 | | | Wireless volume turned up (wireless applications)
Matthew Peach (August 2004)
From consumer goods to the largest industrial plants, wireless functionality is finding new applications by the month. As the proliferating wireless standards are approved, more developers are tuning in.
Source: Computing and Control Engineering, August 2004 | | | Low-power transceivers get patients mobile
C Falcon, AMI Semiconductor (June 2004)
Low power wireless systems are delivering mobility, improved patient care and relative comfort both inside and outside the medical facility. Medical electronic devices are benefiting from transceivers that use the latest mixed-signal ASIC technology to provide desired rates of data transfer over short ranges.
Source: Communications Engineer, June 2004 | | | Designing buildings for the wireless age
A Newbold, Arup Communications (June 2004)
An emerging technology called FSS (frequency selective surface) enables the deployment of secure wireless systems in indoor environments. FSS takes advantage of innovative techniques in building design and the use of attenuating materials.
Source: Communications Engineer, June 2004 | | | Look, no wires
A Cabrera, Appear Networks (June 2004)
Connex employees in Stockholm have delivered significant customer service improvements through the use of wireless technologies.
Source: Manufacturing Engineer, June 2004 | | | Agree to disagree
J Walko (April 2004)
Standardisation over Ultra Wide Band (UWB) has polarised the industry into two contrasting groups.
Source: IEE Review, May 2004 | | | A clearer channel for SMS
C Murray and L Cleary, RadiSys Corporation (March 2004)
There are two ways to alleviate SMS (text messaging) congestion in SS7 networks. Adding more network infrastructure is costly in terms of both equipment and resources needed to carry out the installation. A more economical and efficient approach is to increase the capacity of each signalling link, using clear channel SS7.
Source: Communications Engineer, April 2004 | | | Broadband from heaven
S Karapantazis and F-N Pavlidou, Aristotle Uinversity of Thessaloniki (March 2004)
This article considers whether high altitude platforms (HAPs) can help ease the growing demand for efficient high-speed wireless communications.
Source: Communications Engineer, April 2004 | | | In-building wireless system design
S R Saunders, Cellular Design Services Ltd. (March 2004)
In-building systems are an essential component of most wireless systems. They provide improved coverage in the locations where over 70% of mobile calls originate and terminate, focused capacity for large-public hot-spots such as airports, flexible tariffs and wireless services for corporate offices, and excellent control of interference and wideband channel dispersion for high data rate systems. Many of today’s technologies require the deployment of such systems, including 2G and 3G cellular, TETRA and Wireless LAN. However, despite the increasing maturity and volume of in-building systems, no standard design approach has yet emerged. The absence of objective methods for evaluating and optimising the performance of the system tends to lead to over-design, increasing the expense of systems and reducing the overall take-up of in-building systems, to the detriment of the market.
Source: Communications Engineer, April 2004 - online | | | Useful (under the right circumstances)
W Webb, Ofcom (February 2004)
Already used in digital sound and TV broadcasting, OFDM (orthogonal frequency-division multiplexing) is being deployed in fixed wireless systems and is tipped as the likely technology behind 4G mobile telephony. The article provides a comparison between OFDM and other access technologies in order to demonstrate its strengths and weaknesses.
Source: Communications Engineer, February 2004 | | | The nodes revolution
C Moss, BAE Systems (February 2004)
Ad-hoc (or mesh) networks are wireless networks where intelligent devices or nodes connect to one another in an autonomous, distributed manner. Static or mobile nodes co-operate in relaying data between other nodes. This technology is a means of extending the range of mobile data services beyond that of other networks.
Source: Communications Engineer, February 2004 | | | Centrino puts chip industry in a hot spot
L Collins (March 2003)
Intel's Centrino campaign could corner the Wi-Fi market that other chip makers are hoping will pull the industry out of the current downturn. Centrino combines a mobile processor, chipset and Wi-Fi interface validated to work together. Manufacturers will only be able to use the Centrino brand if they buy all three.
Source: IEE Review April 2003 | | | Changing the Wireless World One Year On
Professor Michael Walker, Vodafone Group R&D Director, Royal Holloway, University of London (March 2003)
Vodafone's latest developments from their top person in R&D. This follows on from an excellent IEE Berkshire Branch lecture last year.
Source: IEE Berkshire Branch Lecture, Newbury RFC Conference Centre, 06 March 2003 | | | Bluetooth - an evolving challenge
I Anderton, The Chilli (February 2003)
Analyses the development and potential of Bluetooth technology. Based on a research report available from The Chilli, a platform for entrepreneurs in the high-tech, media and biotech industries in Europe.
Source: Communications Engineer, February 2003 | | | Vehicles without wires
G Leen, University of Limerick (September 2001)
It is estimated that more than 80% of all innovations within vehicles are derived from electronic systems. The cost of electronics in executive vehicles can amount to over 23% of the vehicle production cost. One wireless technology that may help to re-write the affordability equation for advanced electronic systems is known as Bluetooth. This article discusses the potential of Bluetooth within the automotive industry.
Source: Computing & Control Engineering Journal, October 2001 | | | Home networking: a TV perspective
P Marshall, The Digital Television Group (October 2001)
The limits to the ‘dot.com revolution’ have been discovered the hard way and it has been recognised that TV and audio products are likely to be significant drivers in the development of digital networks in the home. The paper provides a brief overview of developments in the consumer electronics field from the TV manufacturer’s perspective, their relationship to the home network and some of the problems faced.
Source: Electronics & Communication Engineering Journal, October 2001 | | | Wireless in the home
W Tuttlebee, Mobile VCE (October 2001)
2001 may be a year that the electronics and communications industry could be forgiven for wishing to forget. With some companies enduring major cutbacks and sharp falls in stock prices it hasn’t exactly been the best of years! One of the early factors to alarm the markets came at the end of last year, autumn 2000, when Nokia announced a reduction in its forecast for sales of mobile handsets. Since then, with other handset manufacturers failing to achieve anticipated sales, the analysts have concluded that this market is in saturation and that it is time to invest elsewhere—although with the downturn in the world economy they don’t appear to have a clear view of where this should be.
Source: Electronics & Communication Engineering Journal October 2001 | | | Bluetooth wireless technology in the home
R Shepherd, Cambridge Consultants Ltd. (October 2001)
The Bluetooth wireless technology is a cable replacement technology that exploits the wireless interconnectivity that is possible with radio. Bluetooth chips are already available and early applications include cordless connections from mobile phones to laptop computers and wireless headsets. Even if only 10% of mobile phones and computers were to incorporate Bluetooth chips, then the technology would achieve the critical mass necessary for chip prices to fall below $5 and for the standard to become firmly established in the market-place. It is expected that Bluetooth products will be present in the home, where applications will include: conversion of the humble cellphone to a short-range cordless handset; providing a link from a PC to the Internet; home automation and cable replacement; toys and white goods. This paper introduces the Bluetooth wireless technology and its applications and provides a concise description of its air interface and protocol stack.
Source: Electronics & Communication Engineering Journal October 2001 | | | Reducing the cost of Bluetooth systems
M Phillips, CSR Ltd. (October 2001)
The Bluetooth industry has set itself an ambitious goal of just $5 for the implementation of a complete receiver/transmitter, including its DSP-based subsystem and associated ROM and RAM. Although this is unlikely to be realised until Bluetooth wireless technology has achieved considerable market penetration and gained economy of scale through very high volume production, some manufacturers appear to be closer to this goal than others. CSR, for example, had shipped over 1 million of its BlueCore single-chip Bluetooth radios by June this year, and 48% of all Bluetooth equipped end-user products on the market now contain this chip. This article takes a look at some of the design techniques that CSR has employed to reduce cost as much as possible, and outlines some of the issues that are likely to affect how quickly the market ramps up.
Source: Electronics & Communication Engineering Journal, October 2001 | | | Overview of EGPRS: the packet data component of EDGE
D Molkdar, W Featherstone and S Lambotharan, Motorola Research Group (January 2002)
The explosive growth of the Internet and the subsequent demand for wireless data communications have led to data services being a major component in the standardisation process of many cellular mobile radio systems across the world. In GSM, the standardisation of the first phase of a new data service, initiated by ETSI and collectively known as Enhanced Data rates for GSM Evolution (EDGE), was finalised in 1999. The Enhanced Circuit Switched Data (ECSD) and Enhanced General Packet Radio Service (EGPRS) components of EDGE will enhance the existing GSM circuit-switched and packet-switched data services, respectively. This paper provides an overview of EGPRS and its performance.
Source: Electronics and Communication Engineering Journal February 2002 | | | High-altitude platforms for wireless communications
T C Tozer and D Grace, University of York (May 2001)
The demand for high-capacity wireless services is bringing increasing challenges, especially for delivery of the ‘last mile’. An emerging solution is offered by high-altitude platforms (HAPs) operating in the stratosphere at altitudes of up to 22 km to provide communication facilities. This paper outlines the application and features of HAPs, and some specific development programmes. Particular consideration is given to the use of HAPs for delivery of future broadband wireless communications.
Source: Electronics & Communication Engineering Journal June 2001 | CDMA | | What exactly is...HSPDA?
I Poole (June 2004)
High-speed downlink packet access (HSDPA) is expected to allow 3G to become more competitive with other high-speed data systems now available. This article provides an overview of the technology.
Source: Communications Engineer, June 2004 | | | Old standard, new use
J Andrews and A Hasan, University of Texas at Austin (February 2004)
Most research on wireless ad hoc networks has so far concentrated on the network layers of the system, which co-ordinate routing and maintain link reliability. This article focuses on physical layer and multiple access techniques for such networks, in particular CDMA (code division multiple access).
Source: Communications Engineer, February 2004 | | | The evolution of TD-SCDMA - China takes its pick
C Edwards (February 2003)
China has reserved 155 MHz of spectrum for time-division sychronised CDMA, a version of 3G developed by Siemens and a spinout from a Chinese research institution. Although this is an unfinished protocol, the power and influence of the Chinese market may help to ensure its success.
Source: Communications Engineer, February 2003 | TETRA | | Encrypted Video Over TETRA
M I Samarakoon and B Honary, Lancaster University and M Rayne, Simoco (February 2000)
The TETRA system uses the frame stealing synchronisation process on end-to-end encrypted data. However, this degrades the quality of video and is insecure. This paper proposes an alternative technique for video called frame insertion, which is more suitable for video. ‘Fly wheeling’ is used to recover from problems caused by dropped data packets. A method of reducing the synchronisation delay is also discussed.
Source: IEE Colloquium on Tetra Market and Technology Developments London, February 2000. | | | Multi-carrier techniques for broadband multimedia PMR systems
A G Burr, University of York (February 2000)
This paper considers the provision of broadband multimedia services using Private Mobile Radio (PMR) systems, and reviews the system requirements. A PMR scheme based on Frequency Division Multiple Access (FDMA) is proposed, and a multi-carrier PMR concept introduced. This concept can yield significant diversity advantages.
Source: IEE Colloquium on Tetra Market and Technology Developments London, February 2000. | | | Global Deployment of TETRA and Market Developments
I Marwood, Simoco (January 2000)
A review of the status of TETRA within the global marketplace and developments within the industry.
Source: IEE Colloquium on Tetra Market and Technology Developments London, February 2000 | | | Increasing Talk-Time with Efficient Linear Pas (Slides)
S Mann, M Beach, P Warr and J McGeehan, University of Bristol (January 2000)
The effect of power amplifier efficiency on talk-time is demonstrated for a handportable - the PA efficiency effects on talk-time are largest at higher output powers. To increase talk-time, hybrid solutions to PA linearisation are required.
Source: IEE Colloquium on Tetra Market and Technology Developments London, February 2000 | | | Increasing Talk-Time with Efficient Linear PAs
S Mann, M Beach, P Warr and J McGeehan, University of Bristol (January 2000)
The effect of power amplifier efficiency on talk-time is demonstrated for a handportable - the PA efficiency effects on talk-time are largest at higher output powers. To increase talk-time, hybrid solutions to PA linearisation are required.
Source: IEE Colloquium on Tetra Market and Technology Developments London, February 2000 | | | TETRA Conformance Testing Techniques (slides)
C Rodmell , IFR Ltd (January 2000)
A review of testing procedures for both radio and protocol aspects of TETRA mobile and base station radio equipment.
Source: IEE Colloquium on Tetra Market and Technology Developments London, February 2000. | | | Simulation Tool for the Assessment of Adaptive Techniques to Improve The TETRA Air Interface
J Irvine and J Dunlop, University of Strathclyde (January 2000)
This paper presents an evaluation system for the dynamic control of TETRA radio systems. Detailed link-level simulation results are controlled by event driven system level simulations. The system is particularly useful for studying the behaviour of adaptive algorithms when the system is in a transition between different states, and for predicting the Quality of Service.
Source: IEE Colloquium on Tetra Market and Technology Developments London, February 2000 | | | Dynamic Bearer Selections Schemes in an Adaptive TETRA Resource Manager and Their Influence on QoS
G Le Bodic, J Irvine, D Girma and J Dunlop, University of Strathclyde (January 2000)
This paper investigates the use of link adaptation techniques for the TETRA air interface. A quality of service (QoS) contract is used to specify the expected network performance and a degree of degradation tolerance. Simulation results show the effect of various parameters. A service adaptation scheme for multimedia applications is also presented.
Source: IEE Colloquium on Tetra Market and Technology Developments London, February 2000 | | | Video over TETRA
L Thornton, M Chakraborty and J Soraghan, University of Strathclyde and National Engineering Laboratory (February 2000)
In wireless multimedia communications there is a need to design error resilience schemes that keep redundancy to a minimum while offering a high level of visual quality in the decoded video. This paper investigates specific error protection techniques including shortened Reed-Solomon codes and synchronisation words.
Source: IEE Colloquium on Tetra Market and Technology Developments London, February 2000 |
Wireless Systems | | P-QoS requirements for mobile multimedia
D Hands, BTexact Technologies (April 2002)
Two experiments, one using circuit switched network conditions, the other using packet switched network conditions, were performed to examine user perceived quality of service (P-QoS) for a simulated mobile multimedia service. In both experiments, subjects were presented with audio-video (head and shoulders) test material coded at different bit-rates. For each bit-rate, six different network QoS conditions were generated. The results of the test found that for this type of test material, 64 kbit/s was roughly equivalent to 128 kbit/s and 32 kbit/s can offer sufficient QoS, but only for robust networks. The implications for emerging mobile multimedia services are discussed.
Source: IEE Seminar on Visual media standards for today and tomorrow, 25 April 2002 | | | Home networking: a TV perspective
P Marshall, The Digital Television Group (October 2001)
The limits to the ‘dot.com revolution’ have been discovered the hard way and it has been recognised that TV and audio products are likely to be significant drivers in the development of digital networks in the home. The paper provides a brief overview of developments in the consumer electronics field from the TV manufacturer’s perspective, their relationship to the home network and some of the problems faced.
Source: Electronics & Communication Engineering Journal, October 2001 | | | Wireless in the home
W Tuttlebee, Mobile VCE (October 2001)
2001 may be a year that the electronics and communications industry could be forgiven for wishing to forget. With some companies enduring major cutbacks and sharp falls in stock prices it hasn’t exactly been the best of years! One of the early factors to alarm the markets came at the end of last year, autumn 2000, when Nokia announced a reduction in its forecast for sales of mobile handsets. Since then, with other handset manufacturers failing to achieve anticipated sales, the analysts have concluded that this market is in saturation and that it is time to invest elsewhere—although with the downturn in the world economy they don’t appear to have a clear view of where this should be.
Source: Electronics & Communication Engineering Journal October 2001 | | | Bluetooth wireless technology in the home
R Shepherd, Cambridge Consultants Ltd. (October 2001)
The Bluetooth wireless technology is a cable replacement technology that exploits the wireless interconnectivity that is possible with radio. Bluetooth chips are already available and early applications include cordless connections from mobile phones to laptop computers and wireless headsets. Even if only 10% of mobile phones and computers were to incorporate Bluetooth chips, then the technology would achieve the critical mass necessary for chip prices to fall below $5 and for the standard to become firmly established in the market-place. It is expected that Bluetooth products will be present in the home, where applications will include: conversion of the humble cellphone to a short-range cordless handset; providing a link from a PC to the Internet; home automation and cable replacement; toys and white goods. This paper introduces the Bluetooth wireless technology and its applications and provides a concise description of its air interface and protocol stack.
Source: Electronics & Communication Engineering Journal October 2001 | | | Reducing the cost of Bluetooth systems
M Phillips, CSR Ltd. (October 2001)
The Bluetooth industry has set itself an ambitious goal of just $5 for the implementation of a complete receiver/transmitter, including its DSP-based subsystem and associated ROM and RAM. Although this is unlikely to be realised until Bluetooth wireless technology has achieved considerable market penetration and gained economy of scale through very high volume production, some manufacturers appear to be closer to this goal than others. CSR, for example, had shipped over 1 million of its BlueCore single-chip Bluetooth radios by June this year, and 48% of all Bluetooth equipped end-user products on the market now contain this chip. This article takes a look at some of the design techniques that CSR has employed to reduce cost as much as possible, and outlines some of the issues that are likely to affect how quickly the market ramps up.
Source: Electronics & Communication Engineering Journal, October 2001 | | | In-home wireless networking: an entertainment perspective
D Evans, Phillips Research Laboratories (October 2001)
The availability of digital entertainment devices is increasing rapidly and the need to interconnect them is ever more important. This paper gives a description of the technical standards that are key to the definition and design of high-speed integrated digital networks and the approach that is being taken to extend the network into the wireless domain. These standards address both the method of interconnection and the means to ensure that there is full interoperability between digital entertainment appliances in a user-friendly manner.
Source: Electronics & Communication Engineering Journal October 2001 | TETRA | | Encrypted Video Over TETRA
M I Samarakoon and B Honary, Lancaster University and M Rayne, Simoco (February 2000)
The TETRA system uses the frame stealing synchronisation process on end-to-end encrypted data. However, this degrades the quality of video and is insecure. This paper proposes an alternative technique for video called frame insertion, which is more suitable for video. ‘Fly wheeling’ is used to recover from problems caused by dropped data packets. A method of reducing the synchronisation delay is also discussed.
Source: IEE Colloquium on Tetra Market and Technology Developments London, February 2000. | | | Multi-carrier techniques for broadband multimedia PMR systems
A G Burr, University of York (February 2000)
This paper considers the provision of broadband multimedia services using Private Mobile Radio (PMR) systems, and reviews the system requirements. A PMR scheme based on Frequency Division Multiple Access (FDMA) is proposed, and a multi-carrier PMR concept introduced. This concept can yield significant diversity advantages.
Source: IEE Colloquium on Tetra Market and Technology Developments London, February 2000. | | | Video over TETRA
L Thornton, M Chakraborty and J Soraghan, University of Strathclyde and National Engineering Laboratory (February 2000)
In wireless multimedia communications there is a need to design error resilience schemes that keep redundancy to a minimum while offering a high level of visual quality in the decoded video. This paper investigates specific error protection techniques including shortened Reed-Solomon codes and synchronisation words.
Source: IEE Colloquium on Tetra Market and Technology Developments London, February 2000 |
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