A Framework for the Management of Operator Policies and User Preferences for Service Compositions in the IP Multimedia Subsystem
- Tsietsi, Mosiuoa, Terzoli, Alfredo, Wells, George C
- Authors: Tsietsi, Mosiuoa , Terzoli, Alfredo , Wells, George C
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430680 , vital:72708 , https://ieeexplore.ieee.org/abstract/document/6032212
- Description: The IP Multimedia Subsystem (IMS) is a telecommunication middleware platform with robust service features that enables the delivery of a wide range of services to mobile network subscribers. Network operators are encouraged to develop services from service building blocks in order to avoid redundancies by re-using existing functionality. In this environ-ment, operators must be able to control the service execution chain in order to prevent undesirable interactions from occurring between indi-vidual building blocks. It is also in their interests to provide subscribers with personalisation options so that they can modify service composi-tions and define their own preferences for how they would like their ser-vices to behave during live sessions. This paper describes a solution for these challenges that involves the storage of service information in an XDMS and allows operator staff and subscribers to manage this in-formation using the XCAP protocol. The ETSI-defined XCAP applica-tion usage named simservs was chosen to demonstrate an application usage that can be used to create service compositions in XML format. A prototype is described that uses components of the open source Mo-bicents project to verify the suitability of the design. This work is part of a larger effort aimed at modeling interaction management in the IMS through the use of a service broker that is part of an extended IMS ser-vice layer (EISL). The service broker's functional and structural architec-ture have not yet been standardised.
- Full Text:
- Date Issued: 2011
- Authors: Tsietsi, Mosiuoa , Terzoli, Alfredo , Wells, George C
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430680 , vital:72708 , https://ieeexplore.ieee.org/abstract/document/6032212
- Description: The IP Multimedia Subsystem (IMS) is a telecommunication middleware platform with robust service features that enables the delivery of a wide range of services to mobile network subscribers. Network operators are encouraged to develop services from service building blocks in order to avoid redundancies by re-using existing functionality. In this environ-ment, operators must be able to control the service execution chain in order to prevent undesirable interactions from occurring between indi-vidual building blocks. It is also in their interests to provide subscribers with personalisation options so that they can modify service composi-tions and define their own preferences for how they would like their ser-vices to behave during live sessions. This paper describes a solution for these challenges that involves the storage of service information in an XDMS and allows operator staff and subscribers to manage this in-formation using the XCAP protocol. The ETSI-defined XCAP applica-tion usage named simservs was chosen to demonstrate an application usage that can be used to create service compositions in XML format. A prototype is described that uses components of the open source Mo-bicents project to verify the suitability of the design. This work is part of a larger effort aimed at modeling interaction management in the IMS through the use of a service broker that is part of an extended IMS ser-vice layer (EISL). The service broker's functional and structural architec-ture have not yet been standardised.
- Full Text:
- Date Issued: 2011
Extending Java’s communication mechanisms for multicore processors
- Authors: Wells, George C
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430526 , vital:72697 , https://citeseerx.ist.psu.edu/document?repid=rep1type=pdfdoi=4068ed60c317e81dc70288cf36ff586dc057233f
- Description: With the current trend towards the increased use of multicore proces-sors, there is a growing need for simple, efficient parallel programming mechanisms. While Java has good support for multithreaded and dis-tributed application development, our research into tuple-space systems for multicore processors highlighted a gap in the concurrency facilities available in Java. This arises in the context of independent applications (running in separate virtual machines) that need to synchronise their ac-tivities or communicate with each other. There are several possible solu-tions to this problem, ranging from extensions to the language and/or runtime environment through to the use of distributed programming methods. Using the latter introduces considerable performance over-heads, and so we explored the use of the Java Native Interface in order to take advantage of the interprocess communication (IPC) facilities pro-vided by the underlying operating system. The analysis and comparison of the performance of the standard approaches and our prototype library suggest that there are real benefits to be gained by alternative ap-proaches to the provision of IPC mechanisms for independent Java programs executing on multicore systems. We hope that these findings will spur further investigation of this problem and other possible solu-tions.
- Full Text:
- Date Issued: 2010
- Authors: Wells, George C
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430526 , vital:72697 , https://citeseerx.ist.psu.edu/document?repid=rep1type=pdfdoi=4068ed60c317e81dc70288cf36ff586dc057233f
- Description: With the current trend towards the increased use of multicore proces-sors, there is a growing need for simple, efficient parallel programming mechanisms. While Java has good support for multithreaded and dis-tributed application development, our research into tuple-space systems for multicore processors highlighted a gap in the concurrency facilities available in Java. This arises in the context of independent applications (running in separate virtual machines) that need to synchronise their ac-tivities or communicate with each other. There are several possible solu-tions to this problem, ranging from extensions to the language and/or runtime environment through to the use of distributed programming methods. Using the latter introduces considerable performance over-heads, and so we explored the use of the Java Native Interface in order to take advantage of the interprocess communication (IPC) facilities pro-vided by the underlying operating system. The analysis and comparison of the performance of the standard approaches and our prototype library suggest that there are real benefits to be gained by alternative ap-proaches to the provision of IPC mechanisms for independent Java programs executing on multicore systems. We hope that these findings will spur further investigation of this problem and other possible solu-tions.
- Full Text:
- Date Issued: 2010
Towards IPTV service discovery and selection in an IMS environment
- Tsietsi, Mosiuoa, Musvibe, Ray, Terzoli, Alfredo, Wells, George C
- Authors: Tsietsi, Mosiuoa , Musvibe, Ray , Terzoli, Alfredo , Wells, George C
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430795 , vital:72716 , 10.1109/ICUMT.2010.5676637
- Description: The IP Multimedia Subsystem (IMS) is a telecommunication middleware architecture that behaves as a docking station for a wide range of mul-timedia services. Several so-called killer applications have been envi-sioned for this platform such as multimedia group communications and location based services (LBS), but one of the most common business cases for IMS remains IPTV (Internet Protocol TV). Several IMS stand-ards development bodies and non-IMS players have contributed knowledge to the topic of IPTV, and the mechanisms needed to support various IPTV services are well understood. In addition, there are exam-ples of researchers who have implemented IPTV services in their net-work testbeds. However, many of them do not make use of the full power of the specifications which describe the mechanisms of service discovery and service selection. These processes define support for customer device configuration, service personalisation and service se-lection in a multi-service provider ecosystem. This position paper pro-poses solutions to some of the open questions in this area and pro-vides an architecture for a testbed that properly supports service dis-covery and selection. An initial implementation addressing the topic of auto-configuration of IMS terminals for service discovery is also pre-sented.
- Full Text:
- Date Issued: 2010
- Authors: Tsietsi, Mosiuoa , Musvibe, Ray , Terzoli, Alfredo , Wells, George C
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430795 , vital:72716 , 10.1109/ICUMT.2010.5676637
- Description: The IP Multimedia Subsystem (IMS) is a telecommunication middleware architecture that behaves as a docking station for a wide range of mul-timedia services. Several so-called killer applications have been envi-sioned for this platform such as multimedia group communications and location based services (LBS), but one of the most common business cases for IMS remains IPTV (Internet Protocol TV). Several IMS stand-ards development bodies and non-IMS players have contributed knowledge to the topic of IPTV, and the mechanisms needed to support various IPTV services are well understood. In addition, there are exam-ples of researchers who have implemented IPTV services in their net-work testbeds. However, many of them do not make use of the full power of the specifications which describe the mechanisms of service discovery and service selection. These processes define support for customer device configuration, service personalisation and service se-lection in a multi-service provider ecosystem. This position paper pro-poses solutions to some of the open questions in this area and pro-vides an architecture for a testbed that properly supports service dis-covery and selection. An initial implementation addressing the topic of auto-configuration of IMS terminals for service discovery is also pre-sented.
- Full Text:
- Date Issued: 2010
Using JAIN SLEE as an interaction and policy manager for enabler-based services in next generation networks
- Tsietsi, Mosiuoa, Terzoli, Alfredo, Wells, George C
- Authors: Tsietsi, Mosiuoa , Terzoli, Alfredo , Wells, George C
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431382 , vital:72770 , https://journals.pan.pl/dlibra/publication/100205/edition/86373/content
- Description: The IP Multimedia Subsystem is a telecommunications framework with a standard architecture for the provision of services. While the services themselves have not been standardised, standards do exist for basic technologies that can be re-used and aggregated in order to construct more complex services. These elements are called service capabilities by the 3GPP and service enablers by the OMA, both of which are repu-table standards bodies in this area. In order to provide re-usability, there is a need to manage access to the service capabilities. Also, in order to build complex services, there is a further need to be able to manage and coordinate the interactions that occur between service capabilities. The 3GPP and the OMA have separately defined network entities that are responsible for handling aspects of these requirements, and are known as a service capability interaction manager (SCIM) and a policy enforcer respectively. However, the internal structure of the SCIM and the policy enforcer have not been standardised by the relevant bodies. In addition, as the SCIM and the policy enforcer have been defined through complementary yet separate processes, there is an opportunity to unify efforts from both bodies. This paper builds on work and stand-ards defined by the bodies, and proposes the design of an interaction manager with features borrowed from both the SCIM and the policy en-forcer. To help validate the design, we have identified a platform known as JAIN SLEE which we believe conforms to the model proposed, and we discuss how JAIN SLEE can be used to implement our ideas.
- Full Text:
- Date Issued: 2010
- Authors: Tsietsi, Mosiuoa , Terzoli, Alfredo , Wells, George C
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431382 , vital:72770 , https://journals.pan.pl/dlibra/publication/100205/edition/86373/content
- Description: The IP Multimedia Subsystem is a telecommunications framework with a standard architecture for the provision of services. While the services themselves have not been standardised, standards do exist for basic technologies that can be re-used and aggregated in order to construct more complex services. These elements are called service capabilities by the 3GPP and service enablers by the OMA, both of which are repu-table standards bodies in this area. In order to provide re-usability, there is a need to manage access to the service capabilities. Also, in order to build complex services, there is a further need to be able to manage and coordinate the interactions that occur between service capabilities. The 3GPP and the OMA have separately defined network entities that are responsible for handling aspects of these requirements, and are known as a service capability interaction manager (SCIM) and a policy enforcer respectively. However, the internal structure of the SCIM and the policy enforcer have not been standardised by the relevant bodies. In addition, as the SCIM and the policy enforcer have been defined through complementary yet separate processes, there is an opportunity to unify efforts from both bodies. This paper builds on work and stand-ards defined by the bodies, and proposes the design of an interaction manager with features borrowed from both the SCIM and the policy en-forcer. To help validate the design, we have identified a platform known as JAIN SLEE which we believe conforms to the model proposed, and we discuss how JAIN SLEE can be used to implement our ideas.
- Full Text:
- Date Issued: 2010
An Asterisk-based framework for E-learning using open protocols and open source software
- Tsietsi, Mosiuoa, Shibeshi, Zelalem S, Terzoli, Alfredo, Wells, George C
- Authors: Tsietsi, Mosiuoa , Shibeshi, Zelalem S , Terzoli, Alfredo , Wells, George C
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429091 , vital:72559 , https://ieeexplore.ieee.org/abstract/document/5338904
- Description: This paper describes the conceptual design of an e-learning system that is based on open protocols and open source software. This is an initial step towards providing a framework within which remote lectures at our university can be conducted with other institutions in the Southern African region. The motivation for this effort is born out of a desire to avoid expensive and inflexible commercial tools that have been used in the past, often with undesirable side effects. Our design promises to deliver most of the features that can be expected of a modern e-learning system such as a Web interface, space for lecture material, real-time audio and video support, instant messaging and the ability to convey presence. We identified two modes of operation, one as a Web-based video archive and the other as a live virtual classroom. It is hoped that this dual-mode setup will support different modes of learning for students and suit different bandwidth resources among institutions.
- Full Text:
- Date Issued: 2009
- Authors: Tsietsi, Mosiuoa , Shibeshi, Zelalem S , Terzoli, Alfredo , Wells, George C
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429091 , vital:72559 , https://ieeexplore.ieee.org/abstract/document/5338904
- Description: This paper describes the conceptual design of an e-learning system that is based on open protocols and open source software. This is an initial step towards providing a framework within which remote lectures at our university can be conducted with other institutions in the Southern African region. The motivation for this effort is born out of a desire to avoid expensive and inflexible commercial tools that have been used in the past, often with undesirable side effects. Our design promises to deliver most of the features that can be expected of a modern e-learning system such as a Web interface, space for lecture material, real-time audio and video support, instant messaging and the ability to convey presence. We identified two modes of operation, one as a Web-based video archive and the other as a live virtual classroom. It is hoped that this dual-mode setup will support different modes of learning for students and suit different bandwidth resources among institutions.
- Full Text:
- Date Issued: 2009
A tuple space web service for distributed programming-Simplifying distributed web services applications
- Wells, George C, Mueller, Barbara, Schulé, Lo¨ıc
- Authors: Wells, George C , Mueller, Barbara , Schulé, Lo¨ıc
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430437 , vital:72691 , https://www.scitepress.org/PublishedPapers/2008/15170/15170.pdf
- Description: This paper describes a new tuple space web service for coordination and communication in distributed web applications. This web service is based on the Linda programming model. Linda is a coordination lan-guage for parallel and distributed processing, providing a communica-tion mechanism based on a logically shared memory space. The origi-nal Linda model has been extended through the provision of a pro-grammable mechanism, providing additional flexibility and improved performance. The implementation of the web service is discussed, to-gether with the details of the programmable matching mechanism. Some results from the implementation of a location-based mobile appli-cation, using the tuple space web service are presented, demonstrating the benefits of our system.
- Full Text:
- Date Issued: 2008
- Authors: Wells, George C , Mueller, Barbara , Schulé, Lo¨ıc
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430437 , vital:72691 , https://www.scitepress.org/PublishedPapers/2008/15170/15170.pdf
- Description: This paper describes a new tuple space web service for coordination and communication in distributed web applications. This web service is based on the Linda programming model. Linda is a coordination lan-guage for parallel and distributed processing, providing a communica-tion mechanism based on a logically shared memory space. The origi-nal Linda model has been extended through the provision of a pro-grammable mechanism, providing additional flexibility and improved performance. The implementation of the web service is discussed, to-gether with the details of the programmable matching mechanism. Some results from the implementation of a location-based mobile appli-cation, using the tuple space web service are presented, demonstrating the benefits of our system.
- Full Text:
- Date Issued: 2008
An open service delivery platform for adding value to softswitch-based telephony environments
- Tsietsi, Mosiuoa, Terzoli, Alfredo, Wells, George C
- Authors: Tsietsi, Mosiuoa , Terzoli, Alfredo , Wells, George C
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428450 , vital:72512 , https://www.researchgate.net/profile/Alfredo-Ter-zoli/publication/251923990_An_open_service_delivery_platform_for_adding_value_to_softswitch-based_telephony_environments/links/0c9605298fdf0ef8d3000000/An-open-service-delivery-platform-for-adding-value-to-softswitch-based-telephony-environments.pdf
- Description: Softswitches have played a crucial role in next generation networks (NGNs) not only as the primary agents responsible for controlling the data and media paths between endpoints, but also as hosts of telepho-ny applications such as billing and legal intercept. Even though very useful and flexible application interfaces have been used to program these softswitches, there is much benefit that can be derived from de-coupling the application layer from the switching core. NGN architec-tures such as the IP Multimedia Subsystem (IMS) have borrowed the concept of an application server from the IT domain in order to deliver enhanced services to the network. This paper describes an initial inves-tigation into the development of a service delivery platform (SDP) based on the JAIN Service Logic and Execution Environment (JSLEE) indus-try standard, to provide advanced services that can be deployed over a telephony environment called iLanga, which is based on the open source software PBX named Asterisk.
- Full Text:
- Date Issued: 2008
- Authors: Tsietsi, Mosiuoa , Terzoli, Alfredo , Wells, George C
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428450 , vital:72512 , https://www.researchgate.net/profile/Alfredo-Ter-zoli/publication/251923990_An_open_service_delivery_platform_for_adding_value_to_softswitch-based_telephony_environments/links/0c9605298fdf0ef8d3000000/An-open-service-delivery-platform-for-adding-value-to-softswitch-based-telephony-environments.pdf
- Description: Softswitches have played a crucial role in next generation networks (NGNs) not only as the primary agents responsible for controlling the data and media paths between endpoints, but also as hosts of telepho-ny applications such as billing and legal intercept. Even though very useful and flexible application interfaces have been used to program these softswitches, there is much benefit that can be derived from de-coupling the application layer from the switching core. NGN architec-tures such as the IP Multimedia Subsystem (IMS) have borrowed the concept of an application server from the IT domain in order to deliver enhanced services to the network. This paper describes an initial inves-tigation into the development of a service delivery platform (SDP) based on the JAIN Service Logic and Execution Environment (JSLEE) indus-try standard, to provide advanced services that can be deployed over a telephony environment called iLanga, which is based on the open source software PBX named Asterisk.
- Full Text:
- Date Issued: 2008
Prototyping a p2p sip user agent with support for multiple overlays
- Tsietsi, Mosiuoa, Terzoli, Alfredo, Wells, George C
- Authors: Tsietsi, Mosiuoa , Terzoli, Alfredo , Wells, George C
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430858 , vital:72722 , 10.1109/PERCOM.2008.102
- Description: This paper describes a systematic approach to provide support at the user agent level for peer-to-peer based multimedia communications us-ing SIP (session initiation protocol). In a society that is becoming in-creasingly mobile, the advantages of engaging in interactive sessions without relying on central servers or infrastructure are clear. Yet, cur-rently many user agents and devices have little support for peer-to-peer communications. In this paper, we motivate for the use of structured peer-to-peer protocols called DHTs, as a foundation for a peer-to-peer layer. We introduce the concept of "DHTplug-ins" which assist in ab-stracting the interface between the higher level application and the pro-prietary APIs exposed by the underlying DHTs, allowing us to manipu-late user agents with peer-to-peer logic. This embeddable-DHT concept allows these user agents to use different DHTs with one common inter-face and participate in multiple overlays. We show how an open source SIP user agent was thus modified and how realtime communications were supported.
- Full Text:
- Date Issued: 2008
- Authors: Tsietsi, Mosiuoa , Terzoli, Alfredo , Wells, George C
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430858 , vital:72722 , 10.1109/PERCOM.2008.102
- Description: This paper describes a systematic approach to provide support at the user agent level for peer-to-peer based multimedia communications us-ing SIP (session initiation protocol). In a society that is becoming in-creasingly mobile, the advantages of engaging in interactive sessions without relying on central servers or infrastructure are clear. Yet, cur-rently many user agents and devices have little support for peer-to-peer communications. In this paper, we motivate for the use of structured peer-to-peer protocols called DHTs, as a foundation for a peer-to-peer layer. We introduce the concept of "DHTplug-ins" which assist in ab-stracting the interface between the higher level application and the pro-prietary APIs exposed by the underlying DHTs, allowing us to manipu-late user agents with peer-to-peer logic. This embeddable-DHT concept allows these user agents to use different DHTs with one common inter-face and participate in multiple overlays. We show how an open source SIP user agent was thus modified and how realtime communications were supported.
- Full Text:
- Date Issued: 2008
New and improved : Linda in Java
- Authors: Wells, George C
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6613 , http://hdl.handle.net/10962/d1011511 , http://www.sciencedirect.com/science/article/pii/S0167642305000869
- Description: This paper discusses the current resurgence of interest in the Linda coordination language for parallel and distributed programming. Particularly in the Java field, there have been a number of developments over the past few years. These developments are summarised together with the advantages of using Linda for programming concurrent systems. Some problems with the basic Linda approach are also discussed and a novel solution to these is presented. The power and flexibility of the proposed extensions to the Linda programming model are illustrated by considering a number of example applications, including a detailed case study of visual language parsing.
- Full Text:
- Date Issued: 2006
- Authors: Wells, George C
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6613 , http://hdl.handle.net/10962/d1011511 , http://www.sciencedirect.com/science/article/pii/S0167642305000869
- Description: This paper discusses the current resurgence of interest in the Linda coordination language for parallel and distributed programming. Particularly in the Java field, there have been a number of developments over the past few years. These developments are summarised together with the advantages of using Linda for programming concurrent systems. Some problems with the basic Linda approach are also discussed and a novel solution to these is presented. The power and flexibility of the proposed extensions to the Linda programming model are illustrated by considering a number of example applications, including a detailed case study of visual language parsing.
- Full Text:
- Date Issued: 2006
Linda implementations in Java for concurrent systems
- Wells, George C, Chalmers, A G, Clayton, Peter G
- Authors: Wells, George C , Chalmers, A G , Clayton, Peter G
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430555 , vital:72699 , https://doi.org/10.1002/cpe.794
- Description: This paper surveys a number of the implementations of Linda that are available in Java. It provides some discussion of their strengths and weaknesses, and pre-sents the results from benchmarking experiments using a network of commodity workstations. Some extensions to the original Linda programming model are also presented and discussed, together with examples of their application to parallel processing problems.
- Full Text:
- Date Issued: 2004
- Authors: Wells, George C , Chalmers, A G , Clayton, Peter G
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430555 , vital:72699 , https://doi.org/10.1002/cpe.794
- Description: This paper surveys a number of the implementations of Linda that are available in Java. It provides some discussion of their strengths and weaknesses, and pre-sents the results from benchmarking experiments using a network of commodity workstations. Some extensions to the original Linda programming model are also presented and discussed, together with examples of their application to parallel processing problems.
- Full Text:
- Date Issued: 2004
Dynamic run-time application development using CORBA objects and XML in the field of distributed GIS
- Preston, Michael, Clayton, Peter G, Wells, George C
- Authors: Preston, Michael , Clayton, Peter G , Wells, George C
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430500 , vital:72695 , https://doi.org/10.1080/1365881021000026557
- Description: The research presented describes our approach to enabling content developers and end-users to create and/or customise distributed GIS applications dynamical-ly at run-time through the incorporation of GIS services, implemented as stand-alone components or CORBA Objects, with a specialised XML descriptor. It also looks at some of the design considerations that must be dealt with by both the client-application developer as well as the service developer, including the GIS service description, associated GUI and help system.
- Full Text:
- Date Issued: 2003
Dynamic run-time application development using CORBA objects and XML in the field of distributed GIS
- Authors: Preston, Michael , Clayton, Peter G , Wells, George C
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430500 , vital:72695 , https://doi.org/10.1080/1365881021000026557
- Description: The research presented describes our approach to enabling content developers and end-users to create and/or customise distributed GIS applications dynamical-ly at run-time through the incorporation of GIS services, implemented as stand-alone components or CORBA Objects, with a specialised XML descriptor. It also looks at some of the design considerations that must be dealt with by both the client-application developer as well as the service developer, including the GIS service description, associated GUI and help system.
- Full Text:
- Date Issued: 2003
Implementing Location Services in the Location-Transparent, Distributed Environment of the Internet
- Clayton, Peter G, Preston, Michael, Wells, George C
- Authors: Clayton, Peter G , Preston, Michael , Wells, George C
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430467 , vital:72693 , https://link.springer.com/book/10.1007/b13582?page=1#toc
- Description: This volume contains the papers presented at the 5th International Workshop on Advanced Parallel Processing Technologies, APPT 2003. This series of workshops is designed to strengthen the cooperation between the German and Chinese institutions active in the area of these technologies. It has continued to grow, providing an excellent forum for reporting advances in parallel processing technologies. The 5th workshop itself addressed the entire gamut of related topics, ranging from the architectural aspects of parallel computer hardware and system software to the applied technologies for novel applica-tions. For this workshop, we received over 191 full submissions from researchers all over the world. All the papers were peer-reviewed in depth and qualitatively graded on their relevance, originality, signi?cance, presentation, and the overall appropriateness for their acceptance. Any concerns raised were discussed in the program com-mittee. The organizing committee did an excellent job in selecting 78 papers (Among them, 21 were short ones) for presentation. In short, the papers included here represent the forefront of research from China, Germany, and the other countries.
- Full Text:
- Date Issued: 2003
- Authors: Clayton, Peter G , Preston, Michael , Wells, George C
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430467 , vital:72693 , https://link.springer.com/book/10.1007/b13582?page=1#toc
- Description: This volume contains the papers presented at the 5th International Workshop on Advanced Parallel Processing Technologies, APPT 2003. This series of workshops is designed to strengthen the cooperation between the German and Chinese institutions active in the area of these technologies. It has continued to grow, providing an excellent forum for reporting advances in parallel processing technologies. The 5th workshop itself addressed the entire gamut of related topics, ranging from the architectural aspects of parallel computer hardware and system software to the applied technologies for novel applica-tions. For this workshop, we received over 191 full submissions from researchers all over the world. All the papers were peer-reviewed in depth and qualitatively graded on their relevance, originality, signi?cance, presentation, and the overall appropriateness for their acceptance. Any concerns raised were discussed in the program com-mittee. The organizing committee did an excellent job in selecting 78 papers (Among them, 21 were short ones) for presentation. In short, the papers included here represent the forefront of research from China, Germany, and the other countries.
- Full Text:
- Date Issued: 2003
A bi-directional SOAP/SMS gateway service
- Halse, Guy A, Terzoli, Alfredo, Wells, George C
- Authors: Halse, Guy A , Terzoli, Alfredo , Wells, George C
- Date: 2002
- Subjects: Broadband 2 SATNAC 2002
- Language: English
- Type: Conference paper
- Identifier: vital:6600 , http://hdl.handle.net/10962/d1008293
- Description: Many applications need the ability to do real-time notification when events occur. Often the people who need to be kept aware of events are in a remote location. This paper looks at a bi-directional gateway between networked computers and the GSM short message service. The gateway is implemented as a web service, and uses the Simple Object Access Protocol to facilitate data communication. The service interacts with a database in order to facilitate retrieval of sent or received messages, as well as provide accounting abilities. It is intended as a practical proof-of-concept application demonstrating some ofdemonstrating some of the capabilities of the Simple Object Access Protocol.
- Full Text:
- Date Issued: 2002
- Authors: Halse, Guy A , Terzoli, Alfredo , Wells, George C
- Date: 2002
- Subjects: Broadband 2 SATNAC 2002
- Language: English
- Type: Conference paper
- Identifier: vital:6600 , http://hdl.handle.net/10962/d1008293
- Description: Many applications need the ability to do real-time notification when events occur. Often the people who need to be kept aware of events are in a remote location. This paper looks at a bi-directional gateway between networked computers and the GSM short message service. The gateway is implemented as a web service, and uses the Simple Object Access Protocol to facilitate data communication. The service interacts with a database in order to facilitate retrieval of sent or received messages, as well as provide accounting abilities. It is intended as a practical proof-of-concept application demonstrating some ofdemonstrating some of the capabilities of the Simple Object Access Protocol.
- Full Text:
- Date Issued: 2002
Extending the matching facilities of Linda
- Wells, George C, Chalmer, A B, Clayton, Peter G
- Authors: Wells, George C , Chalmer, A B , Clayton, Peter G
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430452 , vital:72692 , https://doi.org/10.1007/3-540-46000-4_34
- Description: This paper discusses the associative matching mechanism used in the Linda coordination language for the retrieval of data. There are a number of problems with this mechanism which are discussed in the light of the requirements of applications using Linda. A number of solutions to these problems have been proposed. These are discussed and compared with a new approach to solving these problems. The benefits and the limitations of the new approach are considered, showing how it provides a considerable improvement in this area.
- Full Text:
- Date Issued: 2002
- Authors: Wells, George C , Chalmer, A B , Clayton, Peter G
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430452 , vital:72692 , https://doi.org/10.1007/3-540-46000-4_34
- Description: This paper discusses the associative matching mechanism used in the Linda coordination language for the retrieval of data. There are a number of problems with this mechanism which are discussed in the light of the requirements of applications using Linda. A number of solutions to these problems have been proposed. These are discussed and compared with a new approach to solving these problems. The benefits and the limitations of the new approach are considered, showing how it provides a considerable improvement in this area.
- Full Text:
- Date Issued: 2002
XML to facilitate management of multi-vendor networks
- Halse, Guy A, Wells, George C, Terzoli, Alfredo
- Authors: Halse, Guy A , Wells, George C , Terzoli, Alfredo
- Date: 2001
- Subjects: XML Network Management SNMP
- Language: English
- Type: Conference paper
- Identifier: vital:6602 , http://hdl.handle.net/10962/d1009322
- Description: Many standards aimed at managing networks currently exist, and yet networks remain notoriously difficult to maintain. Template-based management systems go a long way towards solving this problem. By developing an XML based language to describe network elements, as well as the topology of a network, we can create tools that are free from vendor specific idiosyncrasies, and are capable of managing both today’s networks and those of the future.
- Full Text:
- Date Issued: 2001
- Authors: Halse, Guy A , Wells, George C , Terzoli, Alfredo
- Date: 2001
- Subjects: XML Network Management SNMP
- Language: English
- Type: Conference paper
- Identifier: vital:6602 , http://hdl.handle.net/10962/d1009322
- Description: Many standards aimed at managing networks currently exist, and yet networks remain notoriously difficult to maintain. Template-based management systems go a long way towards solving this problem. By developing an XML based language to describe network elements, as well as the topology of a network, we can create tools that are free from vendor specific idiosyncrasies, and are capable of managing both today’s networks and those of the future.
- Full Text:
- Date Issued: 2001
Creating a Web-based Spatiotemporal GIS using Java and VRML
- Clayton, Peter G, Wells, George C, Preston, Michael
- Authors: Clayton, Peter G , Wells, George C , Preston, Michael
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433413 , vital:72968 , https://www.learntechlib.org/p/7417/
- Description: This paper presents our approach towards creating a Web-based Spatiotemporal Geographic Information System, in particular, the creation of the spatial data set and the component interaction. It explores the possibility of rendering Virtual GIS Worlds in near real time across the WWW using a standard Web browser as the user interface. A" proof of concept" Web-based VGIS application was developed to investigate methods for the efficient transfer of high-bandwidth multimedia GIS content over the WWW, as well as providing a suitable development environment for research into Web-based Temporal GIS. This paper describes how VRML and Java were used to provide the visualisation of virtual worlds, interaction with individual objects inside the virtual world, and the query tools for adding, deleting, selecting or manipulating these objects or their associated attribute data.
- Full Text:
- Date Issued: 1999
- Authors: Clayton, Peter G , Wells, George C , Preston, Michael
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433413 , vital:72968 , https://www.learntechlib.org/p/7417/
- Description: This paper presents our approach towards creating a Web-based Spatiotemporal Geographic Information System, in particular, the creation of the spatial data set and the component interaction. It explores the possibility of rendering Virtual GIS Worlds in near real time across the WWW using a standard Web browser as the user interface. A" proof of concept" Web-based VGIS application was developed to investigate methods for the efficient transfer of high-bandwidth multimedia GIS content over the WWW, as well as providing a suitable development environment for research into Web-based Temporal GIS. This paper describes how VRML and Java were used to provide the visualisation of virtual worlds, interaction with individual objects inside the virtual world, and the query tools for adding, deleting, selecting or manipulating these objects or their associated attribute data.
- Full Text:
- Date Issued: 1999
An extended version of Linda for Transputer systems
- Wells, George C, Clayton, Peter G, Chalmer, A G
- Authors: Wells, George C , Clayton, Peter G , Chalmer, A G
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430512 , vital:72696 , https://dl.acm.org/doi/abs/10.5555/270088.270117
- Description: This paper discusses the associative matching mechanism used in the Linda coordination language for the retrieval of data. There are a number of problems with this mechanism which are discussed in the light of the requirements of applications using Linda. A number of solutions to these problems have been proposed. These are discussed and compared with a new approach to solving these problems. The benefits and the limitations of the new approach are considered, showing how it provides a considerable improvement in this area.
- Full Text:
- Date Issued: 1996
- Authors: Wells, George C , Clayton, Peter G , Chalmer, A G
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430512 , vital:72696 , https://dl.acm.org/doi/abs/10.5555/270088.270117
- Description: This paper discusses the associative matching mechanism used in the Linda coordination language for the retrieval of data. There are a number of problems with this mechanism which are discussed in the light of the requirements of applications using Linda. A number of solutions to these problems have been proposed. These are discussed and compared with a new approach to solving these problems. The benefits and the limitations of the new approach are considered, showing how it provides a considerable improvement in this area.
- Full Text:
- Date Issued: 1996
A comparison of four microcomputer operating systems
- Authors: Wells, George C
- Date: 1993
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430422 , vital:72690 , https://doi.org/10.1007/BF01088835
- Description: This article describes a comparative study of four operating systems for IBM-PC compatible microcomputers. The assessment concentrated on the suitability of the operating systems for use in real-time applications, and on their use as development environments for real-time systems. The study evaluated the predictability and the performance of the operating systems in several areas critical in real-time systems by using comparative benchmarks. In addition, a small-scale simulation of a process control system was developed for each of the systems. The operating systems that were studied were UNIX, OS/2, QNX and FlexOS. These operating systems represent a broad spectrum of systems from general purpose operating systems to small, specialized real-time operating systems. The details of the evaluation process are given and a summary of the results is presented.
- Full Text:
- Date Issued: 1993
- Authors: Wells, George C
- Date: 1993
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430422 , vital:72690 , https://doi.org/10.1007/BF01088835
- Description: This article describes a comparative study of four operating systems for IBM-PC compatible microcomputers. The assessment concentrated on the suitability of the operating systems for use in real-time applications, and on their use as development environments for real-time systems. The study evaluated the predictability and the performance of the operating systems in several areas critical in real-time systems by using comparative benchmarks. In addition, a small-scale simulation of a process control system was developed for each of the systems. The operating systems that were studied were UNIX, OS/2, QNX and FlexOS. These operating systems represent a broad spectrum of systems from general purpose operating systems to small, specialized real-time operating systems. The details of the evaluation process are given and a summary of the results is presented.
- Full Text:
- Date Issued: 1993
An approach to the evaluation of microcomputer operating systems with respect to real-time issues
- Authors: Wells, George C
- Date: 1991
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430484 , vital:72694 , https://doi.org/10.1016/0165-6074(91)90014-K
- Description: This paper gives an overview of the approach used for the assessment of several operating systems for microcomputers. The operating systems are all commercial products and cover a spectrum ranging from general purpose operating systems to small, real-time operating systems. The criteria used for the evaluation are discussed and the approach used is discussed in detail. The results of the evaluation are not discussed in this paper.
- Full Text:
- Date Issued: 1991
- Authors: Wells, George C
- Date: 1991
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430484 , vital:72694 , https://doi.org/10.1016/0165-6074(91)90014-K
- Description: This paper gives an overview of the approach used for the assessment of several operating systems for microcomputers. The operating systems are all commercial products and cover a spectrum ranging from general purpose operating systems to small, real-time operating systems. The criteria used for the evaluation are discussed and the approach used is discussed in detail. The results of the evaluation are not discussed in this paper.
- Full Text:
- Date Issued: 1991
The application of real-time design techniques to simulation
- Authors: Wells, George C
- Date: 1989
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430541 , vital:72698 , 10.1049/sej.1989.0040
- Description: The paper discusses the application of the Ward and Mellor structured development techniques for real-time systems to the field of simulation. The tools and heuristics used by Ward and Mellor are extended to provide a useful approach to the design of real-time simulations. This is illustrated by the example of a real-time simulation of a manufacturing plant and process control system.
- Full Text:
- Date Issued: 1989
- Authors: Wells, George C
- Date: 1989
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430541 , vital:72698 , 10.1049/sej.1989.0040
- Description: The paper discusses the application of the Ward and Mellor structured development techniques for real-time systems to the field of simulation. The tools and heuristics used by Ward and Mellor are extended to provide a useful approach to the design of real-time simulations. This is illustrated by the example of a real-time simulation of a manufacturing plant and process control system.
- Full Text:
- Date Issued: 1989
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