ITU-T G. 729 is the primarily recommended speech codec by H. 323 standard. This paper describes how to implement G. 729 codec in IP telephony gateway, and goes deep into the programming skills on TMS320C6201 DSP and o...ITU-T G. 729 is the primarily recommended speech codec by H. 323 standard. This paper describes how to implement G. 729 codec in IP telephony gateway, and goes deep into the programming skills on TMS320C6201 DSP and optimizing methods of program code to reduce the speech processing delay time of G. 729 codec. Due to adopting these optimizing methods and programming skills, we have implemented a high-speed speech codec that can process concurrently 20 voice channels with single TMS320C6201 chip in IP telephony gateway. Finally, the paper analyzes the performance results of ITU-T G. 729 codec based on TMS320C6201.展开更多
The demand for the telecommunication services,such as IP telephony,has increased dramatically during the COVID-19 pandemic lockdown.IP tele-phony should be enhanced to provide the expected quality.One of the issues th...The demand for the telecommunication services,such as IP telephony,has increased dramatically during the COVID-19 pandemic lockdown.IP tele-phony should be enhanced to provide the expected quality.One of the issues that should be investigated in IP telephony is bandwidth utilization.IP telephony pro-duces very small speech samples attached to a large packet header.The header of the IP telephony consumes a considerable share of the bandwidth allotted to the IP telephony.This wastes the network's bandwidth and influences the IP telephony quality.This paper proposes a mechanism(called Smallerize)that reduces the bandwidth consumed by both the speech sample and the header.This is achieved by assembling numerous IP telephony packets in one header and use the header'sfields to carry the speech sample.Several metrics have been used to measure the achievement Smallerize mechanism.The number of calls has been increased by 245.1%compared to the typical mechanism.The bandwidth saving has also reached 68%with the G.28 codec.Therefore,Smallerize is a possible mechanism to enhance bandwidth utilization of the IP telephony.展开更多
ZTE Corporation announced on April 16, 2009 that it has partnered with Sichuan Telecom to successfully establish the first IMS-based EV-DO Video Telephony (VT) call in China.
Session Initiation Protocol (SIP) is a key technology in the Internettelephony or Voice-over- IP (VoIP), also it is an important signaling technology in the nextgeneration multimedia communications. Based on the compa...Session Initiation Protocol (SIP) is a key technology in the Internettelephony or Voice-over- IP (VoIP), also it is an important signaling technology in the nextgeneration multimedia communications. Based on the comparison between SIP and H. 323 technology,this paper concludes the advantages of SIP. Then grounded on the major components and theirinteraction, it analyzes the mechanism and features of the Internet telephony based on SIP. Finally,it discusses the disadvantages of SIP and provides the emphasis of future work.展开更多
The sharing of telecommunications infrastructure and power supply equipment is currently an applicable and very common model for grouping signal transmission and reception equipment and their power supply on the same ...The sharing of telecommunications infrastructure and power supply equipment is currently an applicable and very common model for grouping signal transmission and reception equipment and their power supply on the same site to ensure coverage of fixed, mobile, Internet and radio and television broadcasting networks. This study consists of producing an inventory of telecommunications and energy infrastructure sharing, focusing on the one hand on analyzing the impacts of active and passive sharing of telecommunications infrastructure from a technical point of view, particularly in terms of legal framework, deployment, coverage and exposure to electromagnetic radiation, and on the other hand on identifying the effects of infrastructure sharing from a socio-economic point of view in a multi-operator mobile telephony environment, by indicating the economic value of the revenue generated as a result of infrastructure sharing. Finally, the results will contribute to identify strategies for ensuring maximum deployment and coverage of the country, and for developing the information and communication technologies (ICT) sector in order to contribute to the digital transformation by digitising services using mobile telephony and the Internet in Burundi.展开更多
针对基于SIP协议的SPIT攻击(Spam over Internet Telephony,SPIT),提出一种基于统计的SPIT检测方法。该方法提取用户多个行为属性和采用D-S理论将多个属性进行融合,实现对多种攻击方式的检测。同时,对域进行分类有区别地考虑域发动攻击...针对基于SIP协议的SPIT攻击(Spam over Internet Telephony,SPIT),提出一种基于统计的SPIT检测方法。该方法提取用户多个行为属性和采用D-S理论将多个属性进行融合,实现对多种攻击方式的检测。同时,对域进行分类有区别地考虑域发动攻击的可能性和用户的合法性,提高了检测的准确性。实验及分析表明上述方法具有较好的准确性,能够针对SPIT进行有效的检测。展开更多
This article aims to scale the Brazilian mobile phone market as the number of active lines, carriers participation in the market and teledensity, as well as presenting the main non-quality indicators and rankings of c...This article aims to scale the Brazilian mobile phone market as the number of active lines, carriers participation in the market and teledensity, as well as presenting the main non-quality indicators and rankings of carriers in relation to complaints registered by users. The methodology used was ＂survey＂ with documentary research, enabled through access to the database of the Brazilian National Telecommunications Agency^-ANATEL, and Sindec Report developed by the Brazilian National Secretary of the Consumer--SENACON. The results obtained showed a Brazil of had a teledensity of 132.78 lines every 100 inhabitants, with 261 million mobile lines active, these 19 million enabled in 2012. The leadership of the company ＂Vivo＂ with 29.08% of marketshare and shows the lowest rate of complaints among the big four carriers （Vivo, TIM, Claro, and Oi M6vel） according to the data of Anatel. SENACON data already confirm the big four carriers among the 10 conglomerates more defendants in claims in Brazil. As the indicators of non-quality, the Act of Misappropriation was pointed to by users as the biggest problem in contracted services.展开更多
In the past three years, the author has participated in several projects involved in Intelligent Network (IN). In 1997, we started our research on the project 'The Integration of IN and B ISDN' supported by N...In the past three years, the author has participated in several projects involved in Intelligent Network (IN). In 1997, we started our research on the project 'The Integration of IN and B ISDN' supported by National Science Foundation. Since 1999, the author has engaged in the project 'the Next Generation IN Based Service Platform Interworking with IP Networks' supported by the National 863 Project. While working on the project, the author made a deep research on the architecture and the key technology of the next generation IN defined by ITU T IN CS3 and CS4. In the following parts. 1. I conclude the research work and the innovation in my dissertation. The early research on the interworking of IN and Internet, despite the shortage of materials, the interworking architecture by means of IAF is analyzed. Some key techniques like triggering intelligent service and reporting dynamic IP address are solved. Some new SIBs and INAPs are added, and the dial up software of users is enhanced, too. The incoming call notification service is designed. What we have done paves the way for the future research. 2. The gateway based architecture for the interworking of IN and Internet is described. Considering the research results from ITU, PINT work group and TIPHON work group, we emphasize that the interworking scenario through MG,SCG and C/BG is promising. Based on the CIN software developed by ourselves, we provide the scenario to enhance the function entities and signaling protocol. We address the function of entities and the interaction of signaling with an example like ICW service. 3. With the introduction of mobile agent technology, the author proposes the distributed IN which can be integrated with IP networks. According to the drawbacks of the centralized IN, we address the architecture and conceptual model of distributed IN to support advanced service in IP Telephony. We try to illustrate the role and relationship between function entities. We also present a smooth evolution scenario from today's networks. 4. A novel service control software based on mobile agent technology is proposed. With the adiquately understanding of CIN 02 SCP, we present the OO based framework of MA SCP. And we explore how our new SCP works. We prove that our solution can work efficiently by a service called VPN in IP Telephony. 5. The concept, architecture and related research of active networks are introduced. We take the ticket order service as an example, give the simulation results and prove that active networks can improve the performance of distributed applications. We also compare active networks with mobile agent based IN. We highlight that the two techniques can complement each other and borrow lessons from the other one. 6. The architecture of Broadband IN is discussed. From the angles of architecture, access mode and software structure, a novel B IP that can support multimedia services such as VoD and B VPN is given. Moreover, B IP is introduced into VoD service. To improve the performance of VoD, we present a novel replacement algorithm with the multi layer decision with multi factors.展开更多
The brief description and comparison are given to the following two signaling protocol standards that are currently used in Internet: ITU T Recommendation H .323 and IETF Session Initiation Protocol ( SIP...The brief description and comparison are given to the following two signaling protocol standards that are currently used in Internet: ITU T Recommendation H .323 and IETF Session Initiation Protocol ( SIP ). After the introduction to the latest Distributed Gateway ( DG ) architecture and its internal protocol Media Gateway Control Protocol ( MGCP ), we describe a framework for DG interworking with H.323/SIP . Other topics, such as address translation, relocation of signaling transport protocol architecture and adding components to DG for interworking with H.323/SIP , are also addressed.展开更多
基金Supported by the National Natural Science Foundation of China under grant!69773046
文摘ITU-T G. 729 is the primarily recommended speech codec by H. 323 standard. This paper describes how to implement G. 729 codec in IP telephony gateway, and goes deep into the programming skills on TMS320C6201 DSP and optimizing methods of program code to reduce the speech processing delay time of G. 729 codec. Due to adopting these optimizing methods and programming skills, we have implemented a high-speed speech codec that can process concurrently 20 voice channels with single TMS320C6201 chip in IP telephony gateway. Finally, the paper analyzes the performance results of ITU-T G. 729 codec based on TMS320C6201.
文摘The demand for the telecommunication services,such as IP telephony,has increased dramatically during the COVID-19 pandemic lockdown.IP tele-phony should be enhanced to provide the expected quality.One of the issues that should be investigated in IP telephony is bandwidth utilization.IP telephony pro-duces very small speech samples attached to a large packet header.The header of the IP telephony consumes a considerable share of the bandwidth allotted to the IP telephony.This wastes the network's bandwidth and influences the IP telephony quality.This paper proposes a mechanism(called Smallerize)that reduces the bandwidth consumed by both the speech sample and the header.This is achieved by assembling numerous IP telephony packets in one header and use the header'sfields to carry the speech sample.Several metrics have been used to measure the achievement Smallerize mechanism.The number of calls has been increased by 245.1%compared to the typical mechanism.The bandwidth saving has also reached 68%with the G.28 codec.Therefore,Smallerize is a possible mechanism to enhance bandwidth utilization of the IP telephony.
文摘ZTE Corporation announced on April 16, 2009 that it has partnered with Sichuan Telecom to successfully establish the first IMS-based EV-DO Video Telephony (VT) call in China.
文摘Session Initiation Protocol (SIP) is a key technology in the Internettelephony or Voice-over- IP (VoIP), also it is an important signaling technology in the nextgeneration multimedia communications. Based on the comparison between SIP and H. 323 technology,this paper concludes the advantages of SIP. Then grounded on the major components and theirinteraction, it analyzes the mechanism and features of the Internet telephony based on SIP. Finally,it discusses the disadvantages of SIP and provides the emphasis of future work.
文摘The sharing of telecommunications infrastructure and power supply equipment is currently an applicable and very common model for grouping signal transmission and reception equipment and their power supply on the same site to ensure coverage of fixed, mobile, Internet and radio and television broadcasting networks. This study consists of producing an inventory of telecommunications and energy infrastructure sharing, focusing on the one hand on analyzing the impacts of active and passive sharing of telecommunications infrastructure from a technical point of view, particularly in terms of legal framework, deployment, coverage and exposure to electromagnetic radiation, and on the other hand on identifying the effects of infrastructure sharing from a socio-economic point of view in a multi-operator mobile telephony environment, by indicating the economic value of the revenue generated as a result of infrastructure sharing. Finally, the results will contribute to identify strategies for ensuring maximum deployment and coverage of the country, and for developing the information and communication technologies (ICT) sector in order to contribute to the digital transformation by digitising services using mobile telephony and the Internet in Burundi.
文摘针对基于SIP协议的SPIT攻击(Spam over Internet Telephony,SPIT),提出一种基于统计的SPIT检测方法。该方法提取用户多个行为属性和采用D-S理论将多个属性进行融合,实现对多种攻击方式的检测。同时,对域进行分类有区别地考虑域发动攻击的可能性和用户的合法性,提高了检测的准确性。实验及分析表明上述方法具有较好的准确性,能够针对SPIT进行有效的检测。
文摘This article aims to scale the Brazilian mobile phone market as the number of active lines, carriers participation in the market and teledensity, as well as presenting the main non-quality indicators and rankings of carriers in relation to complaints registered by users. The methodology used was ＂survey＂ with documentary research, enabled through access to the database of the Brazilian National Telecommunications Agency^-ANATEL, and Sindec Report developed by the Brazilian National Secretary of the Consumer--SENACON. The results obtained showed a Brazil of had a teledensity of 132.78 lines every 100 inhabitants, with 261 million mobile lines active, these 19 million enabled in 2012. The leadership of the company ＂Vivo＂ with 29.08% of marketshare and shows the lowest rate of complaints among the big four carriers （Vivo, TIM, Claro, and Oi M6vel） according to the data of Anatel. SENACON data already confirm the big four carriers among the 10 conglomerates more defendants in claims in Brazil. As the indicators of non-quality, the Act of Misappropriation was pointed to by users as the biggest problem in contracted services.
文摘In the past three years, the author has participated in several projects involved in Intelligent Network (IN). In 1997, we started our research on the project 'The Integration of IN and B ISDN' supported by National Science Foundation. Since 1999, the author has engaged in the project 'the Next Generation IN Based Service Platform Interworking with IP Networks' supported by the National 863 Project. While working on the project, the author made a deep research on the architecture and the key technology of the next generation IN defined by ITU T IN CS3 and CS4. In the following parts. 1. I conclude the research work and the innovation in my dissertation. The early research on the interworking of IN and Internet, despite the shortage of materials, the interworking architecture by means of IAF is analyzed. Some key techniques like triggering intelligent service and reporting dynamic IP address are solved. Some new SIBs and INAPs are added, and the dial up software of users is enhanced, too. The incoming call notification service is designed. What we have done paves the way for the future research. 2. The gateway based architecture for the interworking of IN and Internet is described. Considering the research results from ITU, PINT work group and TIPHON work group, we emphasize that the interworking scenario through MG,SCG and C/BG is promising. Based on the CIN software developed by ourselves, we provide the scenario to enhance the function entities and signaling protocol. We address the function of entities and the interaction of signaling with an example like ICW service. 3. With the introduction of mobile agent technology, the author proposes the distributed IN which can be integrated with IP networks. According to the drawbacks of the centralized IN, we address the architecture and conceptual model of distributed IN to support advanced service in IP Telephony. We try to illustrate the role and relationship between function entities. We also present a smooth evolution scenario from today's networks. 4. A novel service control software based on mobile agent technology is proposed. With the adiquately understanding of CIN 02 SCP, we present the OO based framework of MA SCP. And we explore how our new SCP works. We prove that our solution can work efficiently by a service called VPN in IP Telephony. 5. The concept, architecture and related research of active networks are introduced. We take the ticket order service as an example, give the simulation results and prove that active networks can improve the performance of distributed applications. We also compare active networks with mobile agent based IN. We highlight that the two techniques can complement each other and borrow lessons from the other one. 6. The architecture of Broadband IN is discussed. From the angles of architecture, access mode and software structure, a novel B IP that can support multimedia services such as VoD and B VPN is given. Moreover, B IP is introduced into VoD service. To improve the performance of VoD, we present a novel replacement algorithm with the multi layer decision with multi factors.
文摘The brief description and comparison are given to the following two signaling protocol standards that are currently used in Internet: ITU T Recommendation H .323 and IETF Session Initiation Protocol ( SIP ). After the introduction to the latest Distributed Gateway ( DG ) architecture and its internal protocol Media Gateway Control Protocol ( MGCP ), we describe a framework for DG interworking with H.323/SIP . Other topics, such as address translation, relocation of signaling transport protocol architecture and adding components to DG for interworking with H.323/SIP , are also addressed.
