HWANG Jenq-Neng received his Ph.D. degree from the University of Southern California, USA. In the summer of 1989, Dr. HWANG joined the De- partment of Electrical Engineering of the Universi- ty of Washington in Seattl...HWANG Jenq-Neng received his Ph.D. degree from the University of Southern California, USA. In the summer of 1989, Dr. HWANG joined the De- partment of Electrical Engineering of the Universi- ty of Washington in Seattle, USA, where he has been promoted to Full Professor since 1999. He served as the Associate Chair for Research fi'om 2003 to 2005, and from 2011-2015. He is current- ly the Associate Chair for Global Affairs and Inter- national Development in the EE Depamnent. Hehas written more than 330 journal papers, conference papers and book chapters in the areas of machine learning, muhimedia signal processing, and muhimedia system integration and networking, including an au- thored textbook on "Multimedia Networking: from Theory to Practice," published by Cambridge University Press. Dr. HWANG has close work- ing relationship with the industry on muhimedia signal processing and nmltimedia networking.展开更多
Softswitch technology integrates the su-periorities of both an intelligence net-work and the Internet, which embodiesits maturity and advancement. With ahierarchical network model, it effectivelysolves problems of evo...Softswitch technology integrates the su-periorities of both an intelligence net-work and the Internet, which embodiesits maturity and advancement. With ahierarchical network model, it effectivelysolves problems of evolution and convergenceof current communication networks. It also fol-展开更多
It is noted that the revolutionary development of technologies,fundamental change of traffic composition,trend of network convergence as well as market opening and competition have become the driving forces to develop...It is noted that the revolutionary development of technologies,fundamental change of traffic composition,trend of network convergence as well as market opening and competition have become the driving forces to develop Next Generation Networks (NGN).After introducing the concepts and characteristics of NGN,the paper details its 5 strategic development directions:evolution to softswitch-based next generation switching network, evolution to next generation mobile communication network represented by 3G,evolution to IPv6-based next generation Internet,evolution to diversified broadband access network,and evolution to next generation transport network based on optical networking.Finally,it briefs the strategic thinking on NGN of China Telecom,the largest fixed network carrier in the world.展开更多
The provision mode of the telecommunication service has experienced an evolving process, and showing the developing trend from distributed to centralized, from integrated to separated, and from closed to open. To suit...The provision mode of the telecommunication service has experienced an evolving process, and showing the developing trend from distributed to centralized, from integrated to separated, and from closed to open. To suit this trend, there will be three provision modes as Session Initiation Protocol (SIP) server, Open Service Access (OSA) application server and intelligent network(IN) in Next Generation Network (NGN), provides all kinds of services and applications to the subscribers. With the popularity of broadband access and Internet, the NGN will provide single telecommunication service and act as the important national infrastructure to offer various information services to the subscribers. The service provision mode will be more open, diversified, and individualized.展开更多
The convergence of communication services becomes a focus in the industry along with the requirement for full-service operation and technical development. Service convergence includes two aspects: The convergence of t...The convergence of communication services becomes a focus in the industry along with the requirement for full-service operation and technical development. Service convergence includes two aspects: The convergence of the fixed and mobile networks; and the convergence of traditional communications and Internet services. This requires balancing the conflicts between the openness and operationability of terminal capability and network convergence. Unified authentication and authorization are the basis for service convergence in terms of operationability. Modular network and open terminal are technical solutions for the service convergence.展开更多
By using netflow traffic collecting technology, some traffic data for analysis are collected from a next generation network (NGN) operator. To build a wavelet basis neural network (NN), the Sigmoid function is rep...By using netflow traffic collecting technology, some traffic data for analysis are collected from a next generation network (NGN) operator. To build a wavelet basis neural network (NN), the Sigmoid function is replaced with the wavelet in NN. Then the wavelet multiresolution analysis method is used to decompose the traffic signal, and the decomposed component sequences are employed to train the NN. By using the methods, an NGN traffic prediction model is built to predict one day's traffic. The experimental results show that the traffic prediction method of wavelet NN is more accurate than that without using wavelet in the NGN traffic forecasting.展开更多
Next Generation Network(NGN)is not a single architecture but a set of architectures with a common set of principles and hence varies by service provider history,target applications and assets.The paper introduces NGN ...Next Generation Network(NGN)is not a single architecture but a set of architectures with a common set of principles and hence varies by service provider history,target applications and assets.The paper introduces NGN functional requirements,NGN services and NGN architectural features.It also discusses why NGN is needed,when NGN is targeted,NGN trends and NGN deployment.It concludes that it is no longer a case whether NGN is needed but rather when and at what speed of the evolution.展开更多
The advent of the Next Generation Network (NGN), a new service-driven network, urges the telecom service operators to consider transforming from single-service providers to full-service providers. During the transform...The advent of the Next Generation Network (NGN), a new service-driven network, urges the telecom service operators to consider transforming from single-service providers to full-service providers. During the transformation, they should be concerned about the network user number and the network quality as well as the value added network information. The low threshold for service provision brings a new breed of service providers, which impacts upon the current regulation policy. To adapt to the development of the NGN, it is a necessity to improve the regulation policy in terms of service operators management, user management, Quality of Service (QoS) assurance, service monitoring, charging, and settlement. Meanwhile, regulatory authorities should establish a new body as quickly as possible to meet the trend of the NGN convergence. The new regulatory body would be responsible for regulating operators who will be awarded full-service licenses, and managing new service providers effectively to guarantee the user’s interests.展开更多
To guarantee the Quality of Service (QoS) is one of the key objectives of the next generation network.Based on the introduction of the Next Generation Network(NGN) and the definition of QoS,various aspects of QoS are ...To guarantee the Quality of Service (QoS) is one of the key objectives of the next generation network.Based on the introduction of the Next Generation Network(NGN) and the definition of QoS,various aspects of QoS are analyzed in this article,with emphasis on different approaches and business models.It is noted that QoS concerns the parametric network performance parameters and the application “satisfaction” level.展开更多
ZTE Corporation (ZTE),a leading global provider of telecommunications equipment and network solutions,shined at the Mobile World Congress (MWC) 2009 by rolling out its next generation intelligent Converged Transport
With the continuous advancement of Intemet technology, Intemet is penetrating to various sectors of the society and every comer of life, which spawned a variety of needs. Therefore. the development of the Interact sho...With the continuous advancement of Intemet technology, Intemet is penetrating to various sectors of the society and every comer of life, which spawned a variety of needs. Therefore. the development of the Interact should ahvays meet the needs of customers. How the next generation of the lntemet will develop? How the technology will get the breakthrough? How to use MPLS technology to make the transition of the lntemet more practical and more scientific? And so on. These questions need network technical staff give full play of the technical expertise to promote Interact technology' continues moving forward. This paper first introduces MPLS technology, and then analyzes the overall architecture of the next generation Interact and the service quality required by the next generation lntemet, and at last study how to make the MPLS-based transition technology of next-generation more perfect.展开更多
Network slicing is one of the most important concepts in 5G networks. It is enabled by the Network Function Virtualization (NFV) technology to allow a set of Virtual Network Functions (VNFs) to be interconnected to fo...Network slicing is one of the most important concepts in 5G networks. It is enabled by the Network Function Virtualization (NFV) technology to allow a set of Virtual Network Functions (VNFs) to be interconnected to form a Network Service (NS). When network slices are created in 5G, some are shared among different 5G services while the others are dedicated to specific 5G services. The latter are called dedicated slices. Dedicated slices can be constructed with different configurations. In this research, dedicated slices of different configurations in 5G Core were evaluated in order to discover which one would perform better than the others. The performance of three systems would be compared: 1) Free5GC Stage 2 with each dedicated slice consisting of only UPF;2) Free5GC Stage 3 with each dedicated slice consisting of only UPF;3) Free5GC Stage 3 with each dedicated slice consisting of both SMF and UPF in terms of their registration time, response time, throughput, resource cost, and CPU utilization. It is shown that not one of the above systems will always be the best choice;based on the requirements, a specific system may be the best under a specific situation.展开更多
The forwarding address plays an important role in constructing a communication network. In this paper, a new forwarding address suitable for next generation networks named the vector address (VA) is proposed which i...The forwarding address plays an important role in constructing a communication network. In this paper, a new forwarding address suitable for next generation networks named the vector address (VA) is proposed which is different from the forwarding address coding methods of current networks. The characteristics of the VA are analyzed. Complex network theory and a theoretical analysis method are introduced to study the average address length of the VA when used to construct a global network Simulation experiments in a practical network topology model are carried out to validate the results. The results show that not only can the VA construct a simpler, more secure, and more scalable network, but it also can accommodate many more users than an Internet Protocol (IP) network with the same address length.展开更多
The exponential growth of mobile applications and services during the last years has challenged the existing network infrastructures.Consequently,the arrival of multiple management solutions to cope with this explosio...The exponential growth of mobile applications and services during the last years has challenged the existing network infrastructures.Consequently,the arrival of multiple management solutions to cope with this explosion along the end-to-end network chain has increased the complexity in the coordinated orchestration of different segments composing the whole infrastructure.The Zero-touch Network and Service Management(ZSM)concept has recently emerged to automatically orchestrate and manage network resources while assuring the Quality of Experience(QoE)demanded by users.Machine Learning(ML)is one of the key enabling technologies that many ZSM frameworks are adopting to bring intelligent decision making to the network management system.This paper presents a comprehensive survey of the state-of-the-art application of ML-based techniques to improve ZSM performance.To this end,the main related standardization activities and the aligned international projects and research efforts are deeply examined.From this dissection,the skyrocketing growth of the ZSM paradigm can be observed.Concretely,different standardization bodies have already designed reference architectures to set the foundations of novel automatic network management functions and resource orchestration.Aligned with these advances,diverse ML techniques are being currently exploited to build further ZSM developments in different aspects,including multi-tenancy management,traffic monitoring,and architecture coordination,among others.However,different challenges,such as the complexity,scalability,and security of ML mechanisms,are also identified,and future research guidelines are provided to accomplish a firm development of the ZSM ecosystem.展开更多
Based on the demand of the admission control of softswitch-based clustered media server, this pa- per proposed a new dynamic quota-based admission control algorithm that has a sub-negotiation process. The strongpoint ...Based on the demand of the admission control of softswitch-based clustered media server, this pa- per proposed a new dynamic quota-based admission control algorithm that has a sub-negotiation process. The strongpoint of quota-based algorithm had been inherited in the algorithm and at the same time some new ideas had also been introduced into it. Simulations of the algorithm had been conducted on the Petri net model and the results show that this algorithm has excellent performance. In order to find the optimal resource quota set- ting in real time, the paper proposed two approximation analysis methods. It can be seen from analysis results that these two methods can be used to get sub-optimal quota values quickly and effectively. These two ap- proximation analysis methods will play important roles in implementation of the algorithm in system.展开更多
The forthcoming Next Generation Network (NGN) is an all IP network. Multimedia communications over IP networks are a type of bundled session communications, which cannot directly traverse Network Address Translations ...The forthcoming Next Generation Network (NGN) is an all IP network. Multimedia communications over IP networks are a type of bundled session communications, which cannot directly traverse Network Address Translations (NATs) and firewalls even in NGN. To solve the problem that the existing traversal methods are not suitable for service providers to set up a real system in NGN, a Distributed Broker-agent Architecture (DBA) is addressed. DBA is secure and realizable for service providers and enterprises because it is easy to set up and does not need to upgrade the existing devices like Firewalls, NATs or endpoint devices of subscribers. DBA is composed of two-layer distributed agents, the server proxies and the client agents, in which all multimedia communications use shared tunnels to carry signaling messages and media data between broker-agents, and the call signaling is encrypted over Security Socket Layer (SSL) to guarantee the security of calling. Moreover, the function model and multiplexed connection messages format of DBA are designed, which lays a basis for the protocol in the future NGN. In addition, a simple implementation based on H.323 verifyies the main function of traversing firewalls and NATs.展开更多
This paper presents the design and implementation of the policy management layer of the softswitch system, which is currently under development in our lab. The distinguish key feature of our policy management subsyste...This paper presents the design and implementation of the policy management layer of the softswitch system, which is currently under development in our lab. The distinguish key feature of our policy management subsystem is that the Parlay policy management architecture and the specific technical requirements of softswitch system management are closely incorporated. In this way, not only network providers but also authorized 3rd party application providers and application developers can develop services and applications to manage the access and use of network resources on a per user or application basis to best support established business objectives. The material presented in this document is heavily based on the work of Parlay policy management and IETF policy framework working group.展开更多
With next generation networks driving the confluence of multi-media,broadband,and broadcast services,Cognitive Radio(CR)networks are positioned as a preferred paradigm to address spectrum capacity challenges.CRs addre...With next generation networks driving the confluence of multi-media,broadband,and broadcast services,Cognitive Radio(CR)networks are positioned as a preferred paradigm to address spectrum capacity challenges.CRs address these issues through dynamic spectrum access.However,the main challenges faced by the CR pertain to achieving spectrum efficiency.As a result,spectrum efficiency improvement models based on spectrum sensing and sharing models have attracted a lot of research attention in recent years,including CR learning models,network densification architectures,and massive Multiple Input Multiple Output(MIMO),and beamforming techniques.This paper provides a survey of recent CR spectrum efficiency improvement models and techniques,developed to support ultra-reliable low latency communications that are resilient to surges in traffic and competition for spectrum.These models and techniques,broadly speaking,enable a wide range of functionality ranging from enhanced mobile broadband to large scale Internet of Things(IoT)type communications.In addition and given the strong correlation between the typical size of a spectrum block and the achievable data rate,the models studied in this paper are applicable in ultra-high frequency band.This study therefore provides a good review of CRs and direction for future investigations into newly identified 5G research areas,applicable in industry and in academia.展开更多
文摘HWANG Jenq-Neng received his Ph.D. degree from the University of Southern California, USA. In the summer of 1989, Dr. HWANG joined the De- partment of Electrical Engineering of the Universi- ty of Washington in Seattle, USA, where he has been promoted to Full Professor since 1999. He served as the Associate Chair for Research fi'om 2003 to 2005, and from 2011-2015. He is current- ly the Associate Chair for Global Affairs and Inter- national Development in the EE Depamnent. Hehas written more than 330 journal papers, conference papers and book chapters in the areas of machine learning, muhimedia signal processing, and muhimedia system integration and networking, including an au- thored textbook on "Multimedia Networking: from Theory to Practice," published by Cambridge University Press. Dr. HWANG has close work- ing relationship with the industry on muhimedia signal processing and nmltimedia networking.
文摘Softswitch technology integrates the su-periorities of both an intelligence net-work and the Internet, which embodiesits maturity and advancement. With ahierarchical network model, it effectivelysolves problems of evolution and convergenceof current communication networks. It also fol-
文摘It is noted that the revolutionary development of technologies,fundamental change of traffic composition,trend of network convergence as well as market opening and competition have become the driving forces to develop Next Generation Networks (NGN).After introducing the concepts and characteristics of NGN,the paper details its 5 strategic development directions:evolution to softswitch-based next generation switching network, evolution to next generation mobile communication network represented by 3G,evolution to IPv6-based next generation Internet,evolution to diversified broadband access network,and evolution to next generation transport network based on optical networking.Finally,it briefs the strategic thinking on NGN of China Telecom,the largest fixed network carrier in the world.
文摘The provision mode of the telecommunication service has experienced an evolving process, and showing the developing trend from distributed to centralized, from integrated to separated, and from closed to open. To suit this trend, there will be three provision modes as Session Initiation Protocol (SIP) server, Open Service Access (OSA) application server and intelligent network(IN) in Next Generation Network (NGN), provides all kinds of services and applications to the subscribers. With the popularity of broadband access and Internet, the NGN will provide single telecommunication service and act as the important national infrastructure to offer various information services to the subscribers. The service provision mode will be more open, diversified, and individualized.
文摘The convergence of communication services becomes a focus in the industry along with the requirement for full-service operation and technical development. Service convergence includes two aspects: The convergence of the fixed and mobile networks; and the convergence of traditional communications and Internet services. This requires balancing the conflicts between the openness and operationability of terminal capability and network convergence. Unified authentication and authorization are the basis for service convergence in terms of operationability. Modular network and open terminal are technical solutions for the service convergence.
文摘By using netflow traffic collecting technology, some traffic data for analysis are collected from a next generation network (NGN) operator. To build a wavelet basis neural network (NN), the Sigmoid function is replaced with the wavelet in NN. Then the wavelet multiresolution analysis method is used to decompose the traffic signal, and the decomposed component sequences are employed to train the NN. By using the methods, an NGN traffic prediction model is built to predict one day's traffic. The experimental results show that the traffic prediction method of wavelet NN is more accurate than that without using wavelet in the NGN traffic forecasting.
文摘Next Generation Network(NGN)is not a single architecture but a set of architectures with a common set of principles and hence varies by service provider history,target applications and assets.The paper introduces NGN functional requirements,NGN services and NGN architectural features.It also discusses why NGN is needed,when NGN is targeted,NGN trends and NGN deployment.It concludes that it is no longer a case whether NGN is needed but rather when and at what speed of the evolution.
文摘The advent of the Next Generation Network (NGN), a new service-driven network, urges the telecom service operators to consider transforming from single-service providers to full-service providers. During the transformation, they should be concerned about the network user number and the network quality as well as the value added network information. The low threshold for service provision brings a new breed of service providers, which impacts upon the current regulation policy. To adapt to the development of the NGN, it is a necessity to improve the regulation policy in terms of service operators management, user management, Quality of Service (QoS) assurance, service monitoring, charging, and settlement. Meanwhile, regulatory authorities should establish a new body as quickly as possible to meet the trend of the NGN convergence. The new regulatory body would be responsible for regulating operators who will be awarded full-service licenses, and managing new service providers effectively to guarantee the user’s interests.
文摘To guarantee the Quality of Service (QoS) is one of the key objectives of the next generation network.Based on the introduction of the Next Generation Network(NGN) and the definition of QoS,various aspects of QoS are analyzed in this article,with emphasis on different approaches and business models.It is noted that QoS concerns the parametric network performance parameters and the application “satisfaction” level.
文摘ZTE Corporation (ZTE),a leading global provider of telecommunications equipment and network solutions,shined at the Mobile World Congress (MWC) 2009 by rolling out its next generation intelligent Converged Transport
文摘With the continuous advancement of Intemet technology, Intemet is penetrating to various sectors of the society and every comer of life, which spawned a variety of needs. Therefore. the development of the Interact should ahvays meet the needs of customers. How the next generation of the lntemet will develop? How the technology will get the breakthrough? How to use MPLS technology to make the transition of the lntemet more practical and more scientific? And so on. These questions need network technical staff give full play of the technical expertise to promote Interact technology' continues moving forward. This paper first introduces MPLS technology, and then analyzes the overall architecture of the next generation Interact and the service quality required by the next generation lntemet, and at last study how to make the MPLS-based transition technology of next-generation more perfect.
文摘Network slicing is one of the most important concepts in 5G networks. It is enabled by the Network Function Virtualization (NFV) technology to allow a set of Virtual Network Functions (VNFs) to be interconnected to form a Network Service (NS). When network slices are created in 5G, some are shared among different 5G services while the others are dedicated to specific 5G services. The latter are called dedicated slices. Dedicated slices can be constructed with different configurations. In this research, dedicated slices of different configurations in 5G Core were evaluated in order to discover which one would perform better than the others. The performance of three systems would be compared: 1) Free5GC Stage 2 with each dedicated slice consisting of only UPF;2) Free5GC Stage 3 with each dedicated slice consisting of only UPF;3) Free5GC Stage 3 with each dedicated slice consisting of both SMF and UPF in terms of their registration time, response time, throughput, resource cost, and CPU utilization. It is shown that not one of the above systems will always be the best choice;based on the requirements, a specific system may be the best under a specific situation.
基金Project supported by the National Basic Research Program (973) of China (No. 2007CB30710 I), the Fundamental Research Funds for the Central Universities (No. 2009JBM021), and the Open Research Fund from the MOE Key Laboratory for Computer Network and Information Integration (Southeast University), China (No. K93-9-2010-08)
文摘The forwarding address plays an important role in constructing a communication network. In this paper, a new forwarding address suitable for next generation networks named the vector address (VA) is proposed which is different from the forwarding address coding methods of current networks. The characteristics of the VA are analyzed. Complex network theory and a theoretical analysis method are introduced to study the average address length of the VA when used to construct a global network Simulation experiments in a practical network topology model are carried out to validate the results. The results show that not only can the VA construct a simpler, more secure, and more scalable network, but it also can accommodate many more users than an Internet Protocol (IP) network with the same address length.
基金This work has been supported by Fundación Séneca-Agencia de Ciencia y Tecnología de la Región de Murcia-under the FPI Grant 21429/FPI/20,and co-funded by Odin Solutions S.L.,Región de Murcia(Spain)the Spanish Ministry of Science,Innovation and Universities,under the projects ONOFRE 3(Grant No.PID2020-112675RB-C44)+1 种基金5GHuerta(Grant No.EQC2019-006364-P)both with ERDF fundsthe European Commission,under the INSPIRE-5Gplus(Grant No.871808)project.
文摘The exponential growth of mobile applications and services during the last years has challenged the existing network infrastructures.Consequently,the arrival of multiple management solutions to cope with this explosion along the end-to-end network chain has increased the complexity in the coordinated orchestration of different segments composing the whole infrastructure.The Zero-touch Network and Service Management(ZSM)concept has recently emerged to automatically orchestrate and manage network resources while assuring the Quality of Experience(QoE)demanded by users.Machine Learning(ML)is one of the key enabling technologies that many ZSM frameworks are adopting to bring intelligent decision making to the network management system.This paper presents a comprehensive survey of the state-of-the-art application of ML-based techniques to improve ZSM performance.To this end,the main related standardization activities and the aligned international projects and research efforts are deeply examined.From this dissection,the skyrocketing growth of the ZSM paradigm can be observed.Concretely,different standardization bodies have already designed reference architectures to set the foundations of novel automatic network management functions and resource orchestration.Aligned with these advances,diverse ML techniques are being currently exploited to build further ZSM developments in different aspects,including multi-tenancy management,traffic monitoring,and architecture coordination,among others.However,different challenges,such as the complexity,scalability,and security of ML mechanisms,are also identified,and future research guidelines are provided to accomplish a firm development of the ZSM ecosystem.
基金(1) Specialized Research Fund for the Doctoral Program of Higher Education (No.20030013006) (2) National Specialized R&D Pro-ject for the Product of Mobile Communications (Devel-opment and Application of Next Generation Mobile In-telligent Network System) (3) Development Fund for Electronic and Information Industry (Value-added Ser-vice Platform and Application System for Mobile Communications).
文摘Based on the demand of the admission control of softswitch-based clustered media server, this pa- per proposed a new dynamic quota-based admission control algorithm that has a sub-negotiation process. The strongpoint of quota-based algorithm had been inherited in the algorithm and at the same time some new ideas had also been introduced into it. Simulations of the algorithm had been conducted on the Petri net model and the results show that this algorithm has excellent performance. In order to find the optimal resource quota set- ting in real time, the paper proposed two approximation analysis methods. It can be seen from analysis results that these two methods can be used to get sub-optimal quota values quickly and effectively. These two ap- proximation analysis methods will play important roles in implementation of the algorithm in system.
基金TraversingNAT/firewallTeachingandResearchAwardProgramforOutstandingYoungTeachersinHighEducationInstitutionsofMOE ,China (No .2 0 0 0 6 5 )
文摘The forthcoming Next Generation Network (NGN) is an all IP network. Multimedia communications over IP networks are a type of bundled session communications, which cannot directly traverse Network Address Translations (NATs) and firewalls even in NGN. To solve the problem that the existing traversal methods are not suitable for service providers to set up a real system in NGN, a Distributed Broker-agent Architecture (DBA) is addressed. DBA is secure and realizable for service providers and enterprises because it is easy to set up and does not need to upgrade the existing devices like Firewalls, NATs or endpoint devices of subscribers. DBA is composed of two-layer distributed agents, the server proxies and the client agents, in which all multimedia communications use shared tunnels to carry signaling messages and media data between broker-agents, and the call signaling is encrypted over Security Socket Layer (SSL) to guarantee the security of calling. Moreover, the function model and multiplexed connection messages format of DBA are designed, which lays a basis for the protocol in the future NGN. In addition, a simple implementation based on H.323 verifyies the main function of traversing firewalls and NATs.
文摘This paper presents the design and implementation of the policy management layer of the softswitch system, which is currently under development in our lab. The distinguish key feature of our policy management subsystem is that the Parlay policy management architecture and the specific technical requirements of softswitch system management are closely incorporated. In this way, not only network providers but also authorized 3rd party application providers and application developers can develop services and applications to manage the access and use of network resources on a per user or application basis to best support established business objectives. The material presented in this document is heavily based on the work of Parlay policy management and IETF policy framework working group.
文摘With next generation networks driving the confluence of multi-media,broadband,and broadcast services,Cognitive Radio(CR)networks are positioned as a preferred paradigm to address spectrum capacity challenges.CRs address these issues through dynamic spectrum access.However,the main challenges faced by the CR pertain to achieving spectrum efficiency.As a result,spectrum efficiency improvement models based on spectrum sensing and sharing models have attracted a lot of research attention in recent years,including CR learning models,network densification architectures,and massive Multiple Input Multiple Output(MIMO),and beamforming techniques.This paper provides a survey of recent CR spectrum efficiency improvement models and techniques,developed to support ultra-reliable low latency communications that are resilient to surges in traffic and competition for spectrum.These models and techniques,broadly speaking,enable a wide range of functionality ranging from enhanced mobile broadband to large scale Internet of Things(IoT)type communications.In addition and given the strong correlation between the typical size of a spectrum block and the achievable data rate,the models studied in this paper are applicable in ultra-high frequency band.This study therefore provides a good review of CRs and direction for future investigations into newly identified 5G research areas,applicable in industry and in academia.