A structural and functional specification of a SCIM for service interaction management and personalisation in the IMS
- Authors: Tsietsi, Mosiuoa Jeremia
- Date: 2012
- Subjects: Internet Protocol multimedia subsystem , Internet Protocol multimedia subsystem -- Specifications , Long-Term Evolution (Telecommunications) , European Telecommunications Standards Institute , Wireless communication systems , Multimedia communications
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4606 , http://hdl.handle.net/10962/d1004864 , Internet Protocol multimedia subsystem , Internet Protocol multimedia subsystem -- Specifications , Long-Term Evolution (Telecommunications) , European Telecommunications Standards Institute , Wireless communication systems , Multimedia communications
- Description: The Internet Protocol Multimedia Subsystem (IMS) is a component of the 3G mobile network that has been specified by standards development organisations such as the 3GPP (3rd Generation Partnership Project) and ETSI (European Telecommunication Standards Institute). IMS seeks to guarantee that the telecommunication network of the future provides subscribers with seamless access to services across disparate networks. In order to achieve this, it defines a service architecture that hosts application servers that provide subscribers with value added services. Typically, an application server bundles all the functionality it needs to execute the services it delivers, however this view is currently being challenged. It is now thought that services should be synthesised from simple building blocks called service capabilities. This decomposition would facilitate the re-use of service capabilities across multiple services and would support the creation of new services that could not have originally been conceived. The shift from monolithic services to those built from service capabilities poses a challenge to the current service model in IMS. To accommodate this, the 3GPP has defined an entity known as a service capability interaction manager (SCIM) that would be responsible for managing the interactions between service capabilities in order to realise complex services. Some of these interactions could potentially lead to undesirable results, which the SCIM must work to avoid. As an added requirement, it is believed that the network should allow policies to be applied to network services which the SCIM should be responsible for enforcing. At the time of writing, the functional and structural architecture of the SCIM has not yet been standardised. This thesis explores the current serv ice architecture of the IMS in detail. Proposals that address the structure and functions of the SCIM are carefully compared and contrasted. This investigation leads to the presentation of key aspects of the SCIM, and provides solutions that explain how it should interact with service capabilities, manage undesirable interactions and factor user and network operator policies into its execution model. A modified design of the IMS service layer that embeds the SCIM is subsequently presented and described. The design uses existing IMS protocols and requires no change in the behaviour of the standard IMS entities. In order to develop a testbed for experimental verification of the design, the identification of suitable software platforms was required. This thesis presents some of the most popular platforms currently used by developers such as the Open IMS Core and OpenSER, as well as an open source, Java-based, multimedia communication platform called Mobicents. As a precursor to the development of the SCIM, a converged multimedia service is presented that describes how a video streaming application that is leveraged by a web portal was implemented for an IMS testbed using Mobicents components. The Mobicents SIP Servlets container was subsequently used to model an initial prototype of the SCIM, using a mUlti-component telephony service to illustrate the proposed service execution model. The design focuses on SIP-based services only, but should also work for other types of IMS application servers as well.
- Full Text:
- Date Issued: 2012
- Authors: Tsietsi, Mosiuoa Jeremia
- Date: 2012
- Subjects: Internet Protocol multimedia subsystem , Internet Protocol multimedia subsystem -- Specifications , Long-Term Evolution (Telecommunications) , European Telecommunications Standards Institute , Wireless communication systems , Multimedia communications
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4606 , http://hdl.handle.net/10962/d1004864 , Internet Protocol multimedia subsystem , Internet Protocol multimedia subsystem -- Specifications , Long-Term Evolution (Telecommunications) , European Telecommunications Standards Institute , Wireless communication systems , Multimedia communications
- Description: The Internet Protocol Multimedia Subsystem (IMS) is a component of the 3G mobile network that has been specified by standards development organisations such as the 3GPP (3rd Generation Partnership Project) and ETSI (European Telecommunication Standards Institute). IMS seeks to guarantee that the telecommunication network of the future provides subscribers with seamless access to services across disparate networks. In order to achieve this, it defines a service architecture that hosts application servers that provide subscribers with value added services. Typically, an application server bundles all the functionality it needs to execute the services it delivers, however this view is currently being challenged. It is now thought that services should be synthesised from simple building blocks called service capabilities. This decomposition would facilitate the re-use of service capabilities across multiple services and would support the creation of new services that could not have originally been conceived. The shift from monolithic services to those built from service capabilities poses a challenge to the current service model in IMS. To accommodate this, the 3GPP has defined an entity known as a service capability interaction manager (SCIM) that would be responsible for managing the interactions between service capabilities in order to realise complex services. Some of these interactions could potentially lead to undesirable results, which the SCIM must work to avoid. As an added requirement, it is believed that the network should allow policies to be applied to network services which the SCIM should be responsible for enforcing. At the time of writing, the functional and structural architecture of the SCIM has not yet been standardised. This thesis explores the current serv ice architecture of the IMS in detail. Proposals that address the structure and functions of the SCIM are carefully compared and contrasted. This investigation leads to the presentation of key aspects of the SCIM, and provides solutions that explain how it should interact with service capabilities, manage undesirable interactions and factor user and network operator policies into its execution model. A modified design of the IMS service layer that embeds the SCIM is subsequently presented and described. The design uses existing IMS protocols and requires no change in the behaviour of the standard IMS entities. In order to develop a testbed for experimental verification of the design, the identification of suitable software platforms was required. This thesis presents some of the most popular platforms currently used by developers such as the Open IMS Core and OpenSER, as well as an open source, Java-based, multimedia communication platform called Mobicents. As a precursor to the development of the SCIM, a converged multimedia service is presented that describes how a video streaming application that is leveraged by a web portal was implemented for an IMS testbed using Mobicents components. The Mobicents SIP Servlets container was subsequently used to model an initial prototype of the SCIM, using a mUlti-component telephony service to illustrate the proposed service execution model. The design focuses on SIP-based services only, but should also work for other types of IMS application servers as well.
- Full Text:
- Date Issued: 2012
Dynamic adaptive cost model for wireless Internet connectivity in African rural communities
- Authors: Sibanda, Khulumani
- Date: 2010
- Subjects: Internet , Community development -- South Africa -- Eastern Cape , Cost effectiveness , Wireless communication systems , Rural development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Computer Science)
- Identifier: vital:11389 , http://hdl.handle.net/10353/380 , Internet , Community development -- South Africa -- Eastern Cape , Cost effectiveness , Wireless communication systems , Rural development -- South Africa -- Eastern Cape
- Description: In today’s dynamic technological landscape, wireless communication networks have become an important part of economic development. The emergence of wireless technologies raises hopes to extend communication to remote areas that have not seen any tangible deployment to date. As developing nations pin their hopes to wireless technologies, cost models for wireless communication networks are becoming vital to support the emerging technologies. However, varying cost changes raise critical challenges to the estimation of both capital expenditure and operational expenditure. The network deployment process has numerous events that may cause adjustments to initially estimated project costs. These adjustments are necessary for a cost management plan and this plan includes monitoring cost performance and ensuring that only appropriate changes are made to the network project. The incidents that may cause cost changes can not be entirely predicted as their distribution tend to change dynamically from time to time. Estimating network deployment costs in such a dynamic environment necessitates cost models that can adapt to random occurrence of cost changes. Widely used cost models are usually performed by experienced personnel whose engineering experience is derived from deploying similar networks. In this approach experienced personnel add a certain percentage to the cost estimate to cater for contingency costs. Certainly such an approach depends on individual opinion, making it subjective and void of mathematical estimating relationships which are of paramount importance in ensuring that estimated deployment costs are sufficient to deal with cost uncertainties. We observe that existing approaches can only explore a limited solution space and hence can lead to cost overruns if implemented in dynamically cost changing environments. This thesis presents a wireless communication network deployment cost model that incorporates uncertainties into the final cost estimate. The model is adaptive to unpredictable cost changes since it allows adjustments of confidence levels when calculating contingency costs. This allows dynamically updating the cost changes without the cost model being reconstructed from scratch. We make use of the Poisson process in modeling the occurrence of incidents that are responsible for causing cost changes during network deployment. We also show that the occurrence of the incidents causing cost change are random and tend to follow the Poisson distribution. Using different levels of confidence we model various cost contingencies and make sensitivity analyses to identify the probability of cost overrun when given different contingencies. The dynamic adaptive cost model can be used either at the strategic level to understand the cost of a particular technique or at the operational level, as a way to show how Poisson process in network deployment can compare with engineering experience and other estimating techniques. We believe that the model is useful for remote areas where deployment costs are volatile and the distribution of incidents causing cost change to original cost estimates are diverse and dynamically changing. Further we expect that our research improves the knowledge base of information about the costs for rural communities to connect to the Internet, consequently providing useful input to future policy debates. This work is further poised to be a utility function to help those planning internet infrastructure deployments in least developed regions.
- Full Text:
- Date Issued: 2010
- Authors: Sibanda, Khulumani
- Date: 2010
- Subjects: Internet , Community development -- South Africa -- Eastern Cape , Cost effectiveness , Wireless communication systems , Rural development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Computer Science)
- Identifier: vital:11389 , http://hdl.handle.net/10353/380 , Internet , Community development -- South Africa -- Eastern Cape , Cost effectiveness , Wireless communication systems , Rural development -- South Africa -- Eastern Cape
- Description: In today’s dynamic technological landscape, wireless communication networks have become an important part of economic development. The emergence of wireless technologies raises hopes to extend communication to remote areas that have not seen any tangible deployment to date. As developing nations pin their hopes to wireless technologies, cost models for wireless communication networks are becoming vital to support the emerging technologies. However, varying cost changes raise critical challenges to the estimation of both capital expenditure and operational expenditure. The network deployment process has numerous events that may cause adjustments to initially estimated project costs. These adjustments are necessary for a cost management plan and this plan includes monitoring cost performance and ensuring that only appropriate changes are made to the network project. The incidents that may cause cost changes can not be entirely predicted as their distribution tend to change dynamically from time to time. Estimating network deployment costs in such a dynamic environment necessitates cost models that can adapt to random occurrence of cost changes. Widely used cost models are usually performed by experienced personnel whose engineering experience is derived from deploying similar networks. In this approach experienced personnel add a certain percentage to the cost estimate to cater for contingency costs. Certainly such an approach depends on individual opinion, making it subjective and void of mathematical estimating relationships which are of paramount importance in ensuring that estimated deployment costs are sufficient to deal with cost uncertainties. We observe that existing approaches can only explore a limited solution space and hence can lead to cost overruns if implemented in dynamically cost changing environments. This thesis presents a wireless communication network deployment cost model that incorporates uncertainties into the final cost estimate. The model is adaptive to unpredictable cost changes since it allows adjustments of confidence levels when calculating contingency costs. This allows dynamically updating the cost changes without the cost model being reconstructed from scratch. We make use of the Poisson process in modeling the occurrence of incidents that are responsible for causing cost changes during network deployment. We also show that the occurrence of the incidents causing cost change are random and tend to follow the Poisson distribution. Using different levels of confidence we model various cost contingencies and make sensitivity analyses to identify the probability of cost overrun when given different contingencies. The dynamic adaptive cost model can be used either at the strategic level to understand the cost of a particular technique or at the operational level, as a way to show how Poisson process in network deployment can compare with engineering experience and other estimating techniques. We believe that the model is useful for remote areas where deployment costs are volatile and the distribution of incidents causing cost change to original cost estimates are diverse and dynamically changing. Further we expect that our research improves the knowledge base of information about the costs for rural communities to connect to the Internet, consequently providing useful input to future policy debates. This work is further poised to be a utility function to help those planning internet infrastructure deployments in least developed regions.
- Full Text:
- Date Issued: 2010
- «
- ‹
- 1
- ›
- »