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Santos, R. (2020). Towards Resilient and Reconfigurable Software-defined Wireless Backhaul Networks. (Doctoral dissertation). Karlstad: Karlstads universitet
Open this publication in new window or tab >>Towards Resilient and Reconfigurable Software-defined Wireless Backhaul Networks
2020 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The increase of mobile devices and services over the last decade has led to unprecedented mobile traffic growth. To cope with the increasing demands, fifth generation (5G) network architectures have been designed to provide the required capacity using a large number of small cells (SCs). However, a dense deployment of SCs requires a robust and scalable backhaul to transport the access traffic towards the Internet. In this thesis, we explore the application of the Software-defined Networking (SDN) paradigm for the management of a wireless backhaul. With SDN, the data and control planes are separated and the network is managed by a centralized entity. To that end, we provide multiple contributions that focus on achieving resilient and reconfigurable wireless backhaul networks. Firstly, we propose an SDN-based architecture to manage the wireless backhaul. Our architecture is integrated in practical testbed environments, where we use an SDN controller to configure the forwarding plane and wireless backhaul links. Secondly, we evaluate SDN-based resiliency in the wireless backhaul. We achieve that by implementing fast-failover resiliency with OpenFlow group tables and by using the bidirectional-forwarding detection protocol (BFD) to monitor the state of the backhaul links. Finally, we develop algorithms that calculate the necessary reconfiguration operations to transition between different wireless backhaul topologies, while minimizing the impact on existing user traffic. We consider that the backhaul nodes can be powered on/off and are equipped with steerable antennas that can be aligned to form links with different neighbors. Our optimization problems are modeled as mixed integer linear programs (MILP) that are optimally solved using exact mathematical programming methods. In addition, we develop greedy-based heuristic algorithms that solve the same problems and obtain good quality solutions in short time.

Abstract [en]

The increase of mobile devices and services over the last decade has led to unprecedented mobile traffic growth. To cope with the increasing demands, fifth generation (5G) network architectures have been designed to provide the required capacity using a large number of small cells (SCs). However, a dense deployment of SCs requires a robust and scalable backhaul to transport the access traffic towards the Internet.

In this thesis, we explore the application of the Software-defined Networking (SDN) paradigm for the management of a wireless backhaul. To that end, we provide multiple contributions that focus on achieving resilient and reconfigurable wireless backhaul networks. Firstly, we propose an SDN-based architecture to manage the wireless backhaul. Our architecture is integrated in practical testbed environments, where we use an SDN controller to configure the forwarding plane and wireless backhaul links. Secondly, we evaluate SDN-based fast-failover resiliency in the wireless backhaul. Finally, we develop several algorithms that orchestrate different backhaul reconfiguration operations with minimal impact on existing user traffic.

Place, publisher, year, edition, pages
Karlstad: Karlstads universitet, 2020. p. 42
Series
Karlstad University Studies, ISSN 1403-8099 ; 2020:9
Keywords
5G, heterogeneous networks, mmWave, resiliency, SDN, wireless backhaul
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-76286 (URN)978-91-7867-092-5 (ISBN)978-91-7867-102-1 (ISBN)
Public defence
2020-03-06, 21A342, Karlstad, 09:15 (English)
Opponent
Supervisors
Available from: 2020-02-14 Created: 2020-01-13 Last updated: 2020-02-14Bibliographically approved
Santos, R., Koslowski, K., Daube, J., Ghazzai, H., Kassler, A., Sakaguchi, K. & Haustein, T. (2019). mmWave Backhaul Testbed Configurability Using Software-Defined Networking. Wireless Communications & Mobile Computing, 1-24, Article ID 8342167.
Open this publication in new window or tab >>mmWave Backhaul Testbed Configurability Using Software-Defined Networking
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2019 (English)In: Wireless Communications & Mobile Computing, ISSN 1530-8669, E-ISSN 1530-8677, p. 1-24, article id 8342167Article in journal (Refereed) Published
Abstract [en]

Future mobile data traffic predictions expect a significant increase in user data traffic, requiring new forms of mobile network infrastructures. Fifth generation (5G) communication standards propose the densification of small cell access base stations (BSs) in order to provide multigigabit and low latency connectivity. This densification requires a high capacity backhaul network. Using optical links to connect all the small cells is economically not feasible for large scale radio access networks where multiple BSs are deployed. A wireless backhaul formed by a mesh of millimeter-wave (mmWave) links is an attractive mobile backhaul solution, as flexible wireless (multihop) paths can be formed to interconnect all the access BSs. Moreover, a wireless backhaul allows the dynamic reconfiguration of the backhaul topology to match varying traffic demands or adaptively power on/off small cells for green backhaul operation. However, conducting and precisely controlling reconfiguration experiments over real mmWave multihop networks is a challenging task. In this paper, we develop a Software-Defined Networking (SDN) based approach to enable such a dynamic backhaul reconfiguration and use real-world mmWave equipment to setup a SDN-enabled mmWave testbed to conduct various reconfiguration experiments. In our approach, the SDN control plane is not only responsible for configuring the forwarding plane but also for the link configuration, antenna alignment, and adaptive mesh node power on/off operations. We implement the SDN-based reconfiguration operations in a testbed with four nodes, each equipped with multiple mmWave interfaces that can be mechanically steered to connect to different neighbors. We evaluate the impact of various reconfiguration operations on existing user traffic using a set of extensive testbed measurements. Moreover, we measure the impact of the channel assignment on existing traffic, showing that a setup with an optimal channel assignment between the mesh links can result in a 44% throughput increase, when compared to a suboptimal configuration.

Place, publisher, year, edition, pages
Hindawi Publishing Corporation, 2019
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-71786 (URN)10.1155/2019/8342167 (DOI)000465345700001 ()
Available from: 2019-04-09 Created: 2019-04-09 Last updated: 2020-01-13Bibliographically approved
Santos, R. (2018). 5G Backhauling with Software-defined Wireless Mesh Networks. (Licentiate dissertation). Karlstad: Karlstads universitet
Open this publication in new window or tab >>5G Backhauling with Software-defined Wireless Mesh Networks
2018 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Current technological advances have caused an exponential growth of the number of mobile Internet-connected devices, along with their respective traffic demands. To cope with this increase of traffic demands, fifth generation (5G) network architectures will need to provide multi-gigabit capacity at the access base stations (BSs), through the deployment of ultra-dense small cells (SCs) operating with millimeter-wave (mmWave) frequencies, e.g. 60 GHz. To connect the BSs to the core network, a robust and high capacity backhaul infrastructure is required. As it is unfeasible to connect all the SCs through optical fiber links, a solution for the future 5G backhaul relies on the usage of mmWave frequencies to interconnect the SCs, forming multi-hop wireless mesh topologies. In this thesis, we explore the application of the Software-defined Networking (SDN) paradigm for the management of a SC wireless backhaul. With SDN, the data and control planes are separated and the network management is done by a centralized controller entity that has a global network view. To that end, we provide multiple contributions. Firstly, we provide an SDN-based architecture to manage SC backhaul networks, which include an out-of-band Long Term Evolution (LTE) control channel and where we consider aspects such as energy efficiency, resiliency and flexible backhaul operation. Secondly, we demonstrate the benefit of the wireless backhaul configuration using the SDN controller, which can be used to improve the wireless resource allocation and provide resiliency mechanisms in the network. Finally, we investigate how a SC mesh backhaul can be optimally reconfigured between different topologies, focusing on minimizing the network disruption during the reconfiguration.

Abstract [en]

The growth of mobile devices, along with their traffic demands, is expected to saturate the current mobile networks soon. To cope with such demand increase, fifth generation (5G) network architectures will need to provide multi-gigabit capacity at the access level, through the deployment of a massive amount of ultra-dense small cells (SCs). To connect the access and core networks, a robust and high capacity backhaul is required. To that end, mmWave links that operate at e.g. 60 GHz, can be used to interconnect the SCs, forming multi-hop wireless mesh topologies.

 

In this thesis, we study the application of the Software-defined Networking (SDN) paradigm for the management of a SC wireless backhaul. Firstly, we provide an SDN-based architecture to manage SC backhaul networks, which includes an out-of-band control channel and where we consider aspects such as energy efficiency, resiliency and flexible backhaul operation. Secondly, we show the benefits of the wireless backhaul configuration using the SDN controller, which can be used to improve the wireless resource allocation and provide network resiliency. Finally, we investigate how a SC mesh backhaul can be optimally reconfigured between different topologies, while minimizing the network disruption during the reconfiguration.

Place, publisher, year, edition, pages
Karlstad: Karlstads universitet, 2018. p. 95
Series
Karlstad University Studies, ISSN 1403-8099 ; 2018:44
Keywords
SDN, wireless backhaul, heterogeneous networks, mmWave, 5G, resiliency
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-69437 (URN)978-91-7063-881-7 (ISBN)978-91-7063-976-0 (ISBN)
Presentation
2018-10-22, 09:15 (English)
Opponent
Supervisors
Available from: 2018-10-26 Created: 2018-10-02 Last updated: 2018-10-26Bibliographically approved
Tran, G. K., Santos, R., Ogawa, H., Nakamura, M., Sakaguchi, K. & Kassler, A. (2018). Context-based dynamic meshed backhaul construction for 5G heterogeneous networks. Journal of Sensor and Actuator Networks, 7(4), Article ID 43.
Open this publication in new window or tab >>Context-based dynamic meshed backhaul construction for 5G heterogeneous networks
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2018 (English)In: Journal of Sensor and Actuator Networks, ISSN 2224-2708, Vol. 7, no 4, article id 43Article in journal (Refereed) Published
Abstract [en]

Five-G heterogeneous network overlaid by millimeter-wave (mmWave) access employs mmWave meshed backhauling as a promising cost-efficient backhaul architecture. Due to the nature of mobile traffic distribution in practice which is both time-variant and spatially non-uniform, dynamic construction of mmWave meshed backhaul is a prerequisite to support the varying traffic distribution. Focusing on such scenario of outdoor dynamic crowd (ODC), this paper proposes a novel method to control mmWave meshed backhaul for efficient operation of mmWave overlay 5G HetNet through Software-Defined Network (SDN) technology. Our algorithm is featured by two functionalities, i.e., backhauling route multiplexing for overloaded mmWave small cell base stations (SC-BSS) and mmWave SC-BSS' ON/OFF status switching for underloaded spot. In this paper, the effectiveness of the proposed meshed network is confirmed by both numerical analyses and experimental results. Simulations are conducted over a practical user distribution modeled from measured data in realistic environments. Numerical results show that the proposed algorithm can cope with the locally intensive traffic and reduce energy consumption. Furthermore, a WiGig (Wireless Gigabit Alliance certified) device based testbed is developed for Proof-of-Concept (PoC) and preliminary measurement results confirm the proposed dynamic formation of the meshed network's efficiency.

Place, publisher, year, edition, pages
MDPI AG, 2018
Keywords
5G heterogeneous network, Dynamic construction, Experimental validation, Meshed backhaul, Mmwave, Numerical analysis, Outdoor dynamic crowd, SDN, Testbed
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-70358 (URN)10.3390/jsan7040043 (DOI)000455415600002 ()2-s2.0-85056267796 (Scopus ID)
Available from: 2018-11-29 Created: 2018-11-29 Last updated: 2019-04-26Bibliographically approved
Santos, R., Ghazzai, H. & Kassler, A. (2018). Optimal Steerable mmWave Mesh Backhaul Reconfiguration. In: 2018 IEEE GLOBAL COMMUNICATIONS CONFERENCE (GLOBECOM): . Paper presented at IEEE Global Communications Conference (GLOBECOM). IEEE
Open this publication in new window or tab >>Optimal Steerable mmWave Mesh Backhaul Reconfiguration
2018 (English)In: 2018 IEEE GLOBAL COMMUNICATIONS CONFERENCE (GLOBECOM), IEEE, 2018Conference paper, Published paper (Refereed)
Abstract [en]

Future 5G mobile networks will require increased backhaul (BH) capacity to connect a massive amount of high capacity small cells (SCs) to the network. Because having an optical connection to each SC might be infeasible, mmWave-based (e.g. 60 GHz) BH links are an interesting alternative due to their large available bandwidth. To cope with the increased path loss, mmWave links require directional antennas that should be able to direct their beams to different neighbors, to dynamically change the BH topology, in case new nodes are powered on/off or the traffic demand has changed. Such BH adaptation needs to be orchestrated to minimize the impact on existing traffic.This paper develops a Software-defined networking-based framework that guides the optimal reconfiguration of mesh BH networks composed by mmWave links, where antennas need to be mechanically aligned.By modelling the problem as a Mixed Integer Linear Program (MILP), its solution returns the optimal ordering of events necessary to transition between two BH network configurations. The model creates backup paths whenever it is possible, while minimizing the packet loss of ongoing flows. A numerical evaluation with different topologies and traffic demands shows that increasing the number of BH interfaces per SC from 2 to 4 can decrease the total loss by more than 50%. Moreover, when increasing the total reconfiguration time, additional backup paths can be created, consequently reducing the reconfiguration impact on existing traffic.

Place, publisher, year, edition, pages
IEEE, 2018
Series
IEEE Global Communications Conference (GLOBECOM), ISSN 2334-0983, E-ISSN 2576-6813
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-69436 (URN)10.1109/GLOCOM.2018.8647747 (DOI)000465774303123 ()978-1-5386-4727-1 (ISBN)
Conference
IEEE Global Communications Conference (GLOBECOM)
Projects
Socra, 4840
Funder
Knowledge Foundation
Available from: 2018-10-02 Created: 2018-10-02 Last updated: 2020-01-13Bibliographically approved
Mesodiakaki, A., Zola, E., Santos, R. & Kassler, A. (2018). Optimal User Association, Backhaul Routing and Switching off in 5G Heterogeneous Networks with Mesh Millimeter Wave Backhaul Links. Ad hoc networks, 78, 99-114
Open this publication in new window or tab >>Optimal User Association, Backhaul Routing and Switching off in 5G Heterogeneous Networks with Mesh Millimeter Wave Backhaul Links
2018 (English)In: Ad hoc networks, ISSN 1570-8705, E-ISSN 1570-8713, Vol. 78, p. 99-114Article in journal (Refereed) Published
Abstract [en]

Next generation, i.e., fifth generation (5G), cellular networks will provide a significant higher capacity per area to support the ever-increasing traffic demands. In order to achieve that, many small cells need to be deployed that are connected using a combination of optical fiber links and millimeter-wave (mmWave) backhaul architecture to forward heterogeneous traffic over mesh topologies. In this paper, we present a general optimization framework for the design of policies that optimally solve the problem of where to associate a user, over which links to route its traffic towards which mesh gateway, and which base stations and backhaul links to switch off in order to minimize the energy cost for the network operator and still satisfy the user demands. We develop an optimal policy based on mixed integer linear programming (MILP) which considers different user distribution and traffic demands over multiple time periods. We develop also a fast iterative two-phase solution heuristic, which associates users and calculates backhaul routes to maximize energy savings. Our strategies optimize the backhaul network configuration at each timeslot based on the current demands and user locations. We discuss the application of our policies to backhaul management of mmWave cellular networks in light of current trend of network softwarization (Software-Defined Networking, SDN). Finally, we present extensive numerical simulations of our proposed policies, which show how the algorithms can efficiently trade-off energy consumption with required capacity, while satisfying flow demand requirements.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
5G; Energy efficiency; Green networks; Mesh backhaul; Millimeter wave; Optimization; Routing; Software defined networking (SDN); Switching off; User association
National Category
Computer Sciences Communication Systems Telecommunications Computer Systems Computer Engineering
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-67393 (URN)10.1016/j.adhoc.2018.05.008 (DOI)000441653100009 ()
Available from: 2018-05-29 Created: 2018-05-29 Last updated: 2019-10-28Bibliographically approved
Koslowski, K., Santos, R., Keusgen, W., Haustein, T., Kassler, A., Sakaguchi, K., . . . Tao, Y. (2018). SDN Orchestration to Optimize Meshed Millimeter-Wave Backhaul Networks for MEC-enhanced eMBB Use Cases. In: 2018 13th IEEE International Symposium on Broadband Multimedia Systems and Broadcasting (BMSB): . Paper presented at 13th IEEE International Symposium on Broadband Multimedia Systems and Broadcasting (BMSB), JUN 06-08, 2018, Valencia, SPAIN. IEEE
Open this publication in new window or tab >>SDN Orchestration to Optimize Meshed Millimeter-Wave Backhaul Networks for MEC-enhanced eMBB Use Cases
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2018 (English)In: 2018 13th IEEE International Symposium on Broadband Multimedia Systems and Broadcasting (BMSB), IEEE, 2018Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents a novel concept for enhanced mobile broadband (eMBB) communication using millimeter-wave radio technologies enhanced by mobile edge computing to support a new class of applications requiring low latency and high data rates at the same time. The concept developed in the joint European/Japanese collaboration project 5G-MiEdge [1] builds on meshed backhaul topologies using millimeter wave links with beam forming capabilities and smart routing units for dynamic route, link and power management to be orchestrated by SDN. It is shown that dynamic changes in the topology at run time can be realized without experiencing losses in latency or throughput.

Place, publisher, year, edition, pages
IEEE, 2018
Series
IEEE International Symposium on Broadband Multimedia Systems and Broadcasting, ISSN 2155-5044
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-70431 (URN)000450290900017 ()978-1-5386-4729-5 (ISBN)
Conference
13th IEEE International Symposium on Broadband Multimedia Systems and Broadcasting (BMSB), JUN 06-08, 2018, Valencia, SPAIN
Projects
Socra, 4840
Funder
Knowledge Foundation
Available from: 2018-12-06 Created: 2018-12-06 Last updated: 2019-11-10Bibliographically approved
Santos, R., Bozakov, Z., Mangiante, S., Brunström, A. & Kassler, A. (2017). A NEAT framework for application-awareness in SDN environments. In: 2017 IFIP Networking Conference (IFIP Networking) and Workshops: . Paper presented at 16th International IFIP TC6 Networking Conference, Networking 2017, Stockholm, June 12-15, 2017. IEEE
Open this publication in new window or tab >>A NEAT framework for application-awareness in SDN environments
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2017 (English)In: 2017 IFIP Networking Conference (IFIP Networking) and Workshops, IEEE, 2017Conference paper, Published paper (Refereed)
Abstract [en]

Software-Defined Networking (SDN) has led to a paradigm shift in the way how networks are managed and operated. In SDN environments the data plane forwarding rules are managed by logically centralized controllers operating on global view of the network. Today, SDN controllers typically posses little insight about the requirements of the applications executed on the end-hosts. Consequently, they rely on heuristics to implement traffic engineering or QoS support. In this work, we propose a framework for application-awareness in SDN environments where the end-hosts provide a generic interface for the SDN controllers to interact with. As a result, SDN controllers may enhance the end-host’s view of the attached network and deploy policies into the edge of the network. Further, controllers may obtain information about the specific requirements of the deployed applications. Our demonstration extends the OpenDaylight SDN controller to enable it to interact with end-hosts running a novel networking stack called NEAT. We demonstrate a scenario in which the controller distributes policies and path information to manage bulk and low-latency flows. 

Place, publisher, year, edition, pages
IEEE, 2017
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-64539 (URN)10.23919/IFIPNetworking.2017.8264887 (DOI)000425452000064 ()978-3-901882-94-4 (ISBN)
Conference
16th International IFIP TC6 Networking Conference, Networking 2017, Stockholm, June 12-15, 2017
Projects
NEAT
Funder
EU, Horizon 2020
Note

Demo paper

Available from: 2017-10-13 Created: 2017-10-13 Last updated: 2018-09-05
Bozakov, Z., Mangiante, S., Hernandez Benet, C., Brunström, A., Santos, R., Kassler, A. & Buckley, D. (2017). A NEAT framework for enhanced end-host integration in SDN environments. In: 2017 IEEE Conference on Network Function Virtualization and Software Defined Networks (NFV-SDN): . Paper presented at 2017 IEEE Conference on Network Function Virtualization and Software Defined Networks (NFV-SDN). 6-8 Nov. 2017, Berlin, Germany. IEEE
Open this publication in new window or tab >>A NEAT framework for enhanced end-host integration in SDN environments
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2017 (English)In: 2017 IEEE Conference on Network Function Virtualization and Software Defined Networks (NFV-SDN), IEEE, 2017Conference paper, Published paper (Refereed)
Abstract [en]

SDN aims to facilitate the management of increasingly complex, dynamic network environments and optimize the use of the resources available therein with minimal operator intervention. To this end, SDN controllers maintain a global view of the network topology and its state. However, the extraction of information about network flows and other network metrics remains a non-trivial challenge. Network applications exhibit a wide range of properties, posing diverse, often conflicting, demands towards the network. As these requirements are typically not known, controllers must rely on error-prone heuristics to extract them. In this work, we develop a framework which allows applications deployed in an SDN environment to explicitly express their requirements to the network. Conversely, it allows network controllers to deploy policies on end-hosts and to supply applications with information about network paths, salient servers and other relevant metrics. The proposed approach opens the door for fine grained, application-aware resource optimization strategies in SDNs

Place, publisher, year, edition, pages
IEEE, 2017
Keywords
computer network management, optimisation, quality of service, resource allocation, software defined networking, telecommunication traffic
National Category
Computer Sciences Computer Engineering Telecommunications Communication Systems
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-65783 (URN)10.1109/NFV-SDN.2017.8169828 (DOI)000426936400006 ()978-1-5386-3285-7 (ISBN)
Conference
2017 IEEE Conference on Network Function Virtualization and Software Defined Networks (NFV-SDN). 6-8 Nov. 2017, Berlin, Germany
Available from: 2018-01-22 Created: 2018-01-22 Last updated: 2019-08-02Bibliographically approved
Grinnemo, K.-J., Bozakov, Z., Brunström, A., Isabel Bueno, M., Damjanovic, D., Rikter Evensen, K., . . . Welzl, M. (2017). Deliverable D3.1 - Initial Report on the Extended Transport System.
Open this publication in new window or tab >>Deliverable D3.1 - Initial Report on the Extended Transport System
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2017 (English)Report (Refereed)
Abstract [en]

The NEAT System offers an enhanced API for applications that disentangles them from the actual transport protocol being used. The system also enables applications to communicate their service requirements to the transport system in a generic, transport-protocol independent way. Moreover, the architecture of the NEAT System promotes the evolution of new transport services. Work Package 3 (WP3) enhances and extends the core parts of the NEAT Transport. Efforts have been devoted to developing transport-protocol mechanisms that enable a wider spectrum of NEAT Transport Services, and that assist the NEAT System in facilitating several of the commercial use cases. Work has also started on the development of optimal transport-selection mechanisms; mechanisms that enable for the NEAT System to make optimal transport selections on the basis of application requirements and network measurements. Lastly, another research activity has been initiated on how to use SDN to signal application requirements to routers, switches, and similar network elements. This document provides an initial report on all these WP3 activities—both on completed and on near-termplanned work.

Publisher
p. 144
National Category
Telecommunications
Research subject
Computer Science
Identifiers
urn:nbn:se:kau:diva-70624 (URN)
Projects
A New, Evolutive API and Transport-Layer Architecture for the Internet (NEAT)
Funder
EU, Horizon 2020, 644334
Available from: 2018-12-22 Created: 2018-12-22 Last updated: 2019-06-17Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-4961-5087

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