Radio Access Technology

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Erik Dahlman - One of the best experts on this subject based on the ideXlab platform.

  • SPAWC - 5G Evolution and Beyond
    2019 IEEE 20th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC), 2019
    Co-Authors: Erik Dahlman, Janne Peisa, Stefan Parkvall, Hugo Tullberg
    Abstract:

    This paper provides an overview of the evolution of the 5G NR Radio-Access Technology, starting with 3GPP release 16 but also including potential further evolution steps. It also provides a discussion about the use of AI and machine learning as important components of the future evolution of wireless communication

  • What Is 5G
    5G NR: the Next Generation Wireless Access Technology, 2018
    Co-Authors: Erik Dahlman, Stefan Parkvall, Johan Sköld
    Abstract:

    Abstract The chapter gives background to 5G mobile communication, describing the earlier generations and the justification for a new generation. It describes the high-level 5G use cases, eMBB, mMTC, and URLLC. It also describes the 3GPP process for developing the new 5G/NR Radio-Access Technology.

  • VTC Spring - NR - The New 5G Radio-Access Technology
    2018 IEEE 87th Vehicular Technology Conference (VTC Spring), 2018
    Co-Authors: Erik Dahlman, Stefan Parkvall
    Abstract:

    This paper provides a detailed overview of the key Technology features of the new 5G/NR Radio-Access Technology, the first release of which has recently been published by 3GPP release 15, of the NR specifications finalized by the end of 2017. This first release is limited to non-standalone NR operation, implying that NR devices rely on LTE for initial Access and mobility. The final release-15 specifications, to be available in June 2018, will also support stand-alone NR operation. The difference between stand-alone and non-standalone operation is primarily affecting higher layers and the interface to the core network; the basic Radio Technology is the same in both cases. This paper will give a detailed overview of the NR RadioAccess Technology with focus on the key features that distinguish it from 4G LTE.

  • NR: The New 5G Radio Access Technology
    IEEE Communications Standards Magazine, 2017
    Co-Authors: Stefan Parkvall, Anders Furuskar, Erik Dahlman, Mattias Frenne
    Abstract:

    This article provides an overview of the Technology components and capabilities of the New Radio (NR) Radio interface standard currently under development by 3GPP. NR will enable new use cases, requiring further enhanced data rates, latency, coverage, capacity, and reliability. This needs to be accomplished with improved network energy performance and the ability to exploit spectrum in very high frequency bands. Key Technology components to reach these targets include flexible numerology, latency-optimized frame structure, massive MIMO, interworking between high and low frequency bands, and ultra-lean transmissions. Preliminary evaluations indicate that, with these Technology components, NR can reach the 5G targets.

  • New 5G Radio-Access Technology
    4g LTE Evolution and the Road to 5G, 2016
    Co-Authors: Erik Dahlman, Stefan Parkvall, Johan Sköld
    Abstract:

    This chapter goes more into the details of the new 5G Radio-Access Technology to be developed by 3GPP. It begins with a discussion of some key design principles that needs to be followed in order to ensure a high performance, flexible, and future proof air interface. It then goes more into the details on the key 5G Technology components including but not limited to duplex arrangement, 5G waveform, massive MIMO, multi-site connectivity, flexible system plane, and Access/backhaul integration.

Suhaidi Hassan - One of the best experts on this subject based on the ideXlab platform.

  • A Context-aware Radio Access Technology selection mechanism in 5G mobile network for smart city applications
    Journal of Network and Computer Applications, 2019
    Co-Authors: Adib Habbal, Swetha Indudhar Goudar, Suhaidi Hassan
    Abstract:

    Abstract The Fifth Generation (5G) mobile network will revolutionize the way of communication by supporting new innovative applications that require low latency and high data rates in smart city environments. In order to meet these applications' requirements, Ultra-Dense Network (UDN) is considered as one of the promising technological enablers in 5G. 5G UDN deployments are envisaged to be heterogeneous and dense, mainly through the provisioning of small cells such as picocells and femtocells, from different Radio Access Technologies (RATs). Nevertheless, various studies have reported that the densification is not always beneficial to the network performance. As the network density increases, this will pose further requirements and complexity of determining which RAT a user should connect with at a given time. Hence, an efficient RAT selection mechanism to choose the best Radio Access Technology among multiple available ones is a must. This paper proposes a new Context-aware Radio Access Technology (CRAT) selection mechanism that examines the context of the user and the networks in choosing the appropriate RAT to serve. A simplified conceptual model of the Context-aware RAT selection is introduced. Then, a mathematical model of CRAT considering the user and network context is derived, adopting Analytical Hierarchical Process (AHP) for weighting the importance of the selection criteria and TOPSIS for ranking the available RATs. The proposed CRAT was implemented and validated in NS3 simulation environment. The performance of the proposed mechanism was tested using two different scenarios within a smart city environment, called a shopping mall and urban city scenarios. The obtained results showed that CRAT outperforms the conventional approach namely A2A4 of RAT selection in terms of the number of handovers, average network delay, throughput, and packet delivery ratio.

  • Context-Aware Radio Access Technology Selection in 5G Ultra Dense Networks
    IEEE Access, 2017
    Co-Authors: Adib Habbal, Swetha Indudhar Goudar, Suhaidi Hassan
    Abstract:

    Ultra dense network (UDN) is the extreme densification of heterogeneous Radio Access technologies (RATs) that are deployed closely in a coordinated or uncoordinated manner. The densification of RATs forms an overlapping zone of signal coverage, leading user equipment (UE) to frequent signal handovers among the available RATs. Consequently, this degrades the overall system performance. The traditional approach of RAT selection is network-centric and the decision is primarily focused on the signal aspect. However, the next generation of digital wave is a paradigm shift to being user-centric. In this paper, a context-aware multi-attribute RAT (CMRAT) selection approach is proposed to eliminate unnecessary handover of UE among RATs and determine the best RAT as the next point of attachment among the available ones in the UDN. CMRAT integrates the context-aware concept with multi-attribute decision making (MADM) theory in RAT selection. CMRAT is formed with two mechanisms, including, first, a context-aware analytical hierarchy process mechanism to prioritize the criteria for obtaining the weight. Then, a context-aware technique for order preference by similarity to an ideal solution mechanism is employed to choose the best RAT amongst the available RATs. The proposed CMRAT mechanism was implemented and validated using MATLAB. The obtained simulation findings demonstrate that the proposed CMRAT approach outperforms classic MADM methods, namely TOPSIS, SAW, and GRA with respect to the number of handovers and ranking abnormality metrics. Hence, this paper paves the way to choose RAT based on context information comprising network and user preference criteria information.

Xavier Gelabert - One of the best experts on this subject based on the ideXlab platform.

  • Investigation on MDP-based Radio Access Technology selection in heterogeneous wireless networks
    Computer Networks, 2015
    Co-Authors: Elissar Khloussy, Xavier Gelabert, Yuming Jiang
    Abstract:

    The new generation of wireless networks is characterized by heterogeneity i.e. the coexistence of two or more Radio Access technologies (RAT) in the same geographical area. While this coexistence of RATs offers various advantages, it also imposes many challenges for the network operator, whose aim is to maximize the generated revenue while satisfying the customers' increasing demands. One important mechanism in heterogeneous wireless networks (HWN) is the RAT selection. It is normally triggered when a new call arrives, and provides the decision on whether the call can be admitted or not, and by which RAT it has to be served. Different approaches can be used to tackle the problem of RAT selection in HWNs. In this paper, we study Markov Decision Process (MDP)-based RAT selection in a cellular/WLAN heterogeneous network where the maximization of the revenue is considered as objective. An optimal RAT selection policy is therefore derived. The performance of the optimal scheme is evaluated in comparison with two other policies, namely Cellular-First policy and Load Balancing policy.

  • A Revenue-Maximizing Scheme for Radio Access Technology Selection in Heterogeneous Wireless Networks with User Profile Differentiation
    2013
    Co-Authors: Elissar Khloussy, Xavier Gelabert, Yuming Jiang
    Abstract:

    In this paper, the problem of Radio Access Technology (RAT) selection in heterogeneous wireless networks (HWNs) is tackled from an operator’s perspective, with the objective of maximizing the generated revenue. Two user profiles are considered with different priority levels. An integrated 3GPP Long Term Evolution (LTE) and Wireless Fidelity (WiFi) network is considered as an example of HWN, where LTE is used mainly for the high-priority class, while a portion of its resources, defined by a load threshold, can be shared by the low-priority class. A Markovian model is defined and validated by simulation. Subsequently, the value of the load threshold for resource sharing in LTE is investigated, and an optimization problem is formulated to find the optimal threshold for which the revenue is maximized.

  • EUNICE - A Revenue-Maximizing Scheme for Radio Access Technology Selection in Heterogeneous Wireless Networks with User Profile Differentiation
    Lecture Notes in Computer Science, 2013
    Co-Authors: Elissar Khloussy, Xavier Gelabert, Yuming Jiang
    Abstract:

    In this paper, the problem of Radio Access Technology (RAT) selection in heterogeneous wireless networks (HWNs) is tackled from an operator’s perspective, with the objective of maximizing the generated revenue. Two user profiles are considered with different priority levels. An integrated 3GPP Long Term Evolution (LTE) and Wireless Fidelity (WiFi) network is considered as an example of HWN, where LTE is used mainly for the high-priority class, while a portion of its resources, defined by a load threshold, can be shared by the low-priority class. A Markovian model is defined and validated by simulation. Subsequently, the value of the load threshold for resource sharing in LTE is investigated, and an optimization problem is formulated to find the optimal threshold for which the revenue is maximized.

  • a markovian approach to Radio Access Technology selection in heterogeneous multiAccess multiservice wireless networks
    IEEE Transactions on Mobile Computing, 2008
    Co-Authors: Xavier Gelabert, Oriol Sallent, J Perezromero, R Agusti
    Abstract:

    This paper addresses the problem of Radio Access Technology (RAT) selection in heterogeneous multi-Access/multi-service scenarios. For such purpose, a Markov model is proposed to compare the performance of various RAT selection policies within these scenarios. The novelty of the approach resides in the embedded definition of the aforementioned RAT selection policies within the Markov chain. In addition, the model also considers the constraints imposed by those users with terminals that only support a subset of all the available RATs (i.e. multi-mode terminal capabilities). Furthermore, several performance metrics may be measured to evaluate the behaviour of the proposed RAT selection policies under varying offered traffic conditions. In order to illustrate the validation and suitability of the proposed model, some examples of operative Radio Access networks are provided, including the GSM/EDGE Radio Access Network (GERAN) and the UMTS Radio Access Network (UTRAN), as well as several service-based, load-balancing and terminal-driven RAT selection strategies. The flexibility exhibited by the presented model enables to extend these RAT selection policies to others responding to diverse criteria. The model is successfully validated by means of comparing the Markov model results with those of system-level simulations.

  • A Markovian Approach to Radio Access Technology Selection in Heterogeneous MultiAccess/Multiservice Wireless Networks
    IEEE Transactions on Mobile Computing, 2008
    Co-Authors: Xavier Gelabert, Jordi Pérez-romero, Oriol Sallent, Ramon Agusti
    Abstract:

    This paper addresses the problem of Radio Access Technology (RAT) selection in heterogeneous multi-Access/multi-service scenarios. For such purpose, a Markov model is proposed to compare the performance of various RAT selection policies within these scenarios. The novelty of the approach resides in the embedded definition of the aforementioned RAT selection policies within the Markov chain. In addition, the model also considers the constraints imposed by those users with terminals that only support a subset of all the available RATs (i.e. multi-mode terminal capabilities). Furthermore, several performance metrics may be measured to evaluate the behaviour of the proposed RAT selection policies under varying offered traffic conditions. In order to illustrate the validation and suitability of the proposed model, some examples of operative Radio Access networks are provided, including the GSM/EDGE Radio Access Network (GERAN) and the UMTS Radio Access Network (UTRAN), as well as several service-based, load-balancing and terminal-driven RAT selection strategies. The flexibility exhibited by the presented model enables to extend these RAT selection policies to others responding to diverse criteria. The model is successfully validated by means of comparing the Markov model results with those of system-level simulations.

Abhay Karandikar - One of the best experts on this subject based on the ideXlab platform.

  • Low Complexity Online Radio Access Technology Selection Algorithm in LTE-WiFi HetNet
    IEEE Transactions on Mobile Computing, 2020
    Co-Authors: Arghyadip Roy, Vivek S. Borkar, Prasanna Chaporkar, Abhay Karandikar
    Abstract:

    In an offload-capable Long Term Evolution (LTE)- Wireless Fidelity (WiFi) Heterogeneous Network (HetNet), we consider the problem of maximization of the total system throughput under voice user blocking probability constraint. The optimal policy is threshold in nature. However, computation of optimal policy requires the knowledge of the statistics of system dynamics, viz., arrival processes of voice and data users, which may be difficult to obtain in reality. Motivated by the Post-Decision State (PDS) framework to learn the optimal policy under unknown statistics of system dynamics, we propose, in this paper, an online Radio Access Technology (RAT) selection algorithm using Relative Value Iteration Algorithm (RVIA). However, the convergence speed of this algorithm can be further improved if the underlying threshold structure of the optimal policy can be exploited. To this end, we propose a novel structure-aware online RAT selection algorithm which reduces the feasible policy space, thereby offering lesser storage and computational complexity and faster convergence. This algorithm provides a novel framework for designing online learning algorithms for other problems and hence is of independent interest. We prove that both the algorithms converge to the optimal policy. Simulation results demonstrate that the proposed algorithms converge faster than a traditional scheme. Also, the proposed schemes perform better than other benchmark algorithms under realistic network scenarios.

  • Optimal Radio Access Technology Selection Algorithm for LTE-WiFi Network
    IEEE Transactions on Vehicular Technology, 2018
    Co-Authors: Arghyadip Roy, Prasanna Chaporkar, Abhay Karandikar
    Abstract:

    Heterogeneous network (HetNet) comprises multiple Radio Access technologies (RATs) allowing a user to associate with a specific RAT and steer to other RATs in a seamless manner. To cope up with the unprecedented growth of data traffic, mobile data can be offloaded to wireless fidelity (WiFi) in a long term evolution (LTE) based HetNet. In this paper, an optimal RAT selection problem is considered to maximize the total system throughput in an LTE-WiFi system with offload capability. Another formulation is also developed where maximizing the total system throughput is subject to a constraint on the voice user blocking probability. It is proved that the optimal policies for the association and offloading of voice/data users contain threshold structures. As a policy search over the entire policy space may become computationally inefficient, we propose computationally efficient algorithms based on the threshold structures for the association and offloading of users in LTE-WiFi HetNet. Simulation results are presented to demonstrate the voice user blocking probability and the total system throughput performance of the proposed algorithms in comparison with other benchmark algorithms.

  • Performance Evaluation of Optimal Radio Access Technology Selection Algorithms for LTE-WiFi Network.
    arXiv: Networking and Internet Architecture, 2017
    Co-Authors: Arghyadip Roy, Prasanna Chaporkar, Abhay Karandikar
    Abstract:

    A Heterogeneous Network (HetNet) comprises of multiple Radio Access Technologies (RATs) allowing a user to associate with a specific RAT and steer to other RATs in a seamless manner. To cope up with the unprecedented growth of data traffic, mobile data can be offloaded to Wireless Fidelity (WiFi) in a Long Term Evolution (LTE) based HetNet. In this paper, an optimal RAT selection problem is considered to maximize the total system throughput in an LTE-WiFi system with offload capability. Another formulation is also developed where maximizing the total system throughput is subject to a constraint on the voice user blocking probability. It is proved that the optimal policies for the association and offloading of voice/data users contain threshold structures. Based on the threshold structures, we propose algorithms for the association and offloading of users in LTE-WiFi HetNet. Simulation results are presented to demonstrate the voice user blocking probability and the total system throughput performance of the proposed algorithms in comparison to another benchmark algorithm.

  • WCNC - An On-Line Radio Access Technology Selection Algorithm in an LTE-WiFi Network
    2017 IEEE Wireless Communications and Networking Conference (WCNC), 2017
    Co-Authors: Arghyadip Roy, Prasanna Chaporkar, Abhay Karandikar
    Abstract:

    In a Heterogeneous Network (HetNet) comprising of multiple Radio Access Technologies (RATs), a user can be associated with a particular RAT and can be steered to other RATs in a seamless manner. To handle the rapid growth of data traffic, offloading of mobile data to Wireless Fidelity (WiFi) has been proposed in a Long Term Evolution (LTE) based HetNet. In this paper, we consider an optimal RAT selection problem in an offload-capable LTE-WiFi system with an objective of maximizing the total system throughput subject to a constraint on the voice user blocking probability. An on-line algorithm for optimal RAT selection is proposed based on a Relative Value Iteration Algorithm (RVIA) centric Q-learning approach. The proposed algorithm can be implemented without any explicit knowledge of arrival processes of voice and data users. Simulation results are presented to exhibit the convergence behavior of the proposed scheme to the optimal policy.

  • optimal Radio Access Technology selection policy for lte wifi network
    Modeling and Optimization in Mobile Ad-Hoc and Wireless Networks, 2015
    Co-Authors: Arghyadip Roy, Abhay Karandikar
    Abstract:

    As a part of Fourth Generation (4G) wireless communication system, a user can associate with any Radio Access Technology (RAT) when there are multiple RATs available and can move seamlessly among them. To handle the explosive growth of traffic in cellular network, the idea of mobile data traffic offloading to Wireless Fidelity (WiFi) has been proposed. In this paper, we focus on mobile data offload assisted optimal association problem in a heterogeneous network. The problem has been formulated under the framework of constrained Markov decision process (CMDP). Value iteration and gradient descent algorithm has been used to determine the optimal policy. We aim to maximize the expected average per-user throughput of the system subject to a constraint on blocking probability of voice users. In our model, we consider the possibility of mobile data user offload from one RAT to another during association or departure of a user. Optimal policy has been found to follow a threshold structure. Numerical results are presented to show how the average per-user throughput of the system varies under different load conditions.

Stefan Parkvall - One of the best experts on this subject based on the ideXlab platform.

  • SPAWC - 5G Evolution and Beyond
    2019 IEEE 20th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC), 2019
    Co-Authors: Erik Dahlman, Janne Peisa, Stefan Parkvall, Hugo Tullberg
    Abstract:

    This paper provides an overview of the evolution of the 5G NR Radio-Access Technology, starting with 3GPP release 16 but also including potential further evolution steps. It also provides a discussion about the use of AI and machine learning as important components of the future evolution of wireless communication

  • What Is 5G
    5G NR: the Next Generation Wireless Access Technology, 2018
    Co-Authors: Erik Dahlman, Stefan Parkvall, Johan Sköld
    Abstract:

    Abstract The chapter gives background to 5G mobile communication, describing the earlier generations and the justification for a new generation. It describes the high-level 5G use cases, eMBB, mMTC, and URLLC. It also describes the 3GPP process for developing the new 5G/NR Radio-Access Technology.

  • VTC Spring - NR - The New 5G Radio-Access Technology
    2018 IEEE 87th Vehicular Technology Conference (VTC Spring), 2018
    Co-Authors: Erik Dahlman, Stefan Parkvall
    Abstract:

    This paper provides a detailed overview of the key Technology features of the new 5G/NR Radio-Access Technology, the first release of which has recently been published by 3GPP release 15, of the NR specifications finalized by the end of 2017. This first release is limited to non-standalone NR operation, implying that NR devices rely on LTE for initial Access and mobility. The final release-15 specifications, to be available in June 2018, will also support stand-alone NR operation. The difference between stand-alone and non-standalone operation is primarily affecting higher layers and the interface to the core network; the basic Radio Technology is the same in both cases. This paper will give a detailed overview of the NR RadioAccess Technology with focus on the key features that distinguish it from 4G LTE.

  • NR: The New 5G Radio Access Technology
    IEEE Communications Standards Magazine, 2017
    Co-Authors: Stefan Parkvall, Anders Furuskar, Erik Dahlman, Mattias Frenne
    Abstract:

    This article provides an overview of the Technology components and capabilities of the New Radio (NR) Radio interface standard currently under development by 3GPP. NR will enable new use cases, requiring further enhanced data rates, latency, coverage, capacity, and reliability. This needs to be accomplished with improved network energy performance and the ability to exploit spectrum in very high frequency bands. Key Technology components to reach these targets include flexible numerology, latency-optimized frame structure, massive MIMO, interworking between high and low frequency bands, and ultra-lean transmissions. Preliminary evaluations indicate that, with these Technology components, NR can reach the 5G targets.

  • New 5G Radio-Access Technology
    4g LTE Evolution and the Road to 5G, 2016
    Co-Authors: Erik Dahlman, Stefan Parkvall, Johan Sköld
    Abstract:

    This chapter goes more into the details of the new 5G Radio-Access Technology to be developed by 3GPP. It begins with a discussion of some key design principles that needs to be followed in order to ensure a high performance, flexible, and future proof air interface. It then goes more into the details on the key 5G Technology components including but not limited to duplex arrangement, 5G waveform, massive MIMO, multi-site connectivity, flexible system plane, and Access/backhaul integration.