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Publications (10 of 311) Show all publications
Cheng, Y., Lin, R., De Andrade, M., Wosinska, L. & Chen, J. (2019). Disaggregated Data Centers: Challenges and Tradeoffs. IEEE Communications Magazine
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2019 (English)In: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896Article in journal (Other academic) Submitted
Abstract [en]

Resource utilization of modern data centers is significantly limited by the mismatch between the diversity of the resources required by running applications and the fixed amount of hardwired resources (e.g., number of central processing unit CPU cores, size of memory) in the server blades. In this regard, the concept of function disaggregation is introduced, where the integrated server blades containing all types of resources are replaced by the resource blades including only one specific function. Therefore, disaggregated data centers can offer high flexibility for resource allocation and hence their resource utilization can be largely improved. In addition, introducing function disaggregation simplifies the system upgrade, allowing for a quick adoption of new generation components in data centers. However, the communication between different resources faces severe problems in terms of latency and transmission bandwidth required. In particular,the CPU-memory interconnects in fully disaggregated data centers require ultra-low latency and ultra-high transmission bandwidth in order to prevent performance degradation for running applications. Optical fiber communication is a promising technique to offer high capacity and low latency, but it is still very challenging for the state-of-the-art optical transmission technologies to meet the requirements of the fully disaggregated data centers. In this paper, different levels of function disaggregation are investigated. For the fully disaggregated data centers, two architectural options are presented, where optical interconnects are necessary for CPU-memory communications. We review the state-of-the-art optical transmission technologies and carry out performance assessment when employing them to support function disaggregation in data centers. The results reveal that function disaggregation does improve the efficiency of resource usage in the data centers, although the bandwidth provided by the state-of-the-art optical transmission technologies is not always sufficient for the fully disaggregated data centers. It calls for research in optical transmission to fully utilize the advantages of function disaggregation in data centers.

National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-244839 (URN)
Note

QC 20190301

Available from: 2019-02-28 Created: 2019-02-28 Last updated: 2019-03-01Bibliographically approved
Natalino, C., Idzikowski, F., Chiaraviglio, L., Wosinska, L. & Monti, P. (2019). Energy- and fatigue-aware RWA in optical backbone networks. Optical Switching and Networkning Journal, 31, 193-201
Open this publication in new window or tab >>Energy- and fatigue-aware RWA in optical backbone networks
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2019 (English)In: Optical Switching and Networkning Journal, ISSN 1573-4277, E-ISSN 1872-9770, Vol. 31, p. 193-201Article in journal (Refereed) Published
Abstract [en]

Connection provisioning in Wavelength Division Multiplexing (WDM) networks needs to account for a number of crucial parameters. On the one hand, operators need to ensure the connection availability requirements defined in Service Level Agreements (SLAs). This is addressed by selecting an appropriate amount of backup resources and recovery strategies for the connections over which services are provisioned. Services requiring less strict availability requirements can be routed over unprotected lightpaths. Services with more strict availability requirements are provisioned over protected lightpaths in order to cope with possible failures in the network. Another important aspect to consider during the provisioning process is energy efficiency. Green strategies leverage on setting network devices in Sleep Mode (SM) or Active Mode (AM) depending on whether or not they are needed to accommodate traffic. However, frequent power state changes introduce thermal fatigue which in turn has a negative effect on the device lifetime. Finally, in multi-period traffic scenarios, it is also important to minimize the number of reconfigurations of lightpaths already established in the network in order to avoid possible traffic disruptions at higher layers. The work presented in this paper tackles the connection provisioning paradigm in an optical backbone network with a multi-period traffic scenario. More specifically the paper looks into the interplay among (i) energy efficiency, (ii) thermal fatigue, and (iii) lightpath reconfiguration aspects. To this end, the Energy and Fatigue Aware Heuristic with Unnecessary Reconfiguration Avoidance (EFAH-URA) is introduced, showing that it is possible to balance the three aspects mentioned above in an efficient way. When compared to the pure energy-aware strategies, EFAH-URA significantly improves the average connection availability for both unprotected and protected connections. On the other hand, it is done at the expense of reduced energy saving.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE BV, 2019
Keywords
Acceleration factor, Connection availability, Device lifetime, Green provisioning, Lightpath reconfiguration, Optical backbone network operation, Thermal fatigue
National Category
Communication Systems
Identifiers
urn:nbn:se:kth:diva-241188 (URN)10.1016/j.osn.2018.10.007 (DOI)000454380100016 ()2-s2.0-85056257635 (Scopus ID)
Note

QC 20190121

Available from: 2019-01-21 Created: 2019-01-21 Last updated: 2019-01-21Bibliographically approved
Natalino, C., Yayimli, A., Wosinska, L. & Furdek, M. (2019). Infrastructure upgrade framework for Content Delivery Networks robust to targeted attacks. Optical Switching and Networkning Journal, 31, 202-210
Open this publication in new window or tab >>Infrastructure upgrade framework for Content Delivery Networks robust to targeted attacks
2019 (English)In: Optical Switching and Networkning Journal, ISSN 1573-4277, E-ISSN 1872-9770, Vol. 31, p. 202-210Article in journal (Refereed) Published
Abstract [en]

Content Delivery Networks (CDNs) are crucial for enabling delivery of services that require high capacity and low latency, primarily through geographically-diverse content replication. Optical networks are the only available future-proof technology that meets the reach and capacity requirements of CDNs. However, the underlying physical network infrastructure is vulnerable to various security threats, and the increasing importance of CDNs in supporting vital services intensifies the concerns related to their robustness. Malicious attackers can target critical network elements, thus severely degrading network connectivity and causing large-scale service disruptions. One way in which network operators and cloud computing providers can increase the robustness against malicious attacks is by changing the topological properties of the network through infrastructure upgrades. This work proposes a framework for CDN infrastructure upgrade that performs sparse link and replica addition with the objective of maximizing the content accessibility under targeted link cut attacks. The framework is based on a newly defined content accessibility metric denoted as mu-ACA which allows the network operator to gauge the CDN robustness over a range of attacks with varying intensity. Two heuristics, namely Content-Accessibility Aware Link Addition Heuristic (CAA-LAH), and Content-Accessibility-Aware Replica Addition Heuristic (CAA-RAH) are developed to perform strategic link and replica placement, respectively, and hamper attackers from disconnecting users from the content even in severe attack scenarios. Extensive experiments on real-world reference network topologies show that the proposed framework effectively increases the CDN robustness by adding a few links or replicas to the network.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE BV, 2019
Keywords
Content delivery networks, Content replica addition, Infrastructure upgrade, Link addition, Network robustness, Optical networks, Targeted attacks
National Category
Communication Systems
Identifiers
urn:nbn:se:kth:diva-241189 (URN)10.1016/j.osn.2018.10.006 (DOI)000454380100017 ()2-s2.0-85056237720 (Scopus ID)
Note

QC 20190121

Available from: 2019-01-21 Created: 2019-01-21 Last updated: 2019-01-21Bibliographically approved
Wiatr, P., Chen, J., Monti, P., Wosinska, L. & Yuan, D. (2019). Routing and wavelength assignment vs. EDFA reliability performance in optical backbone networks: An operational cost perspective. Optical Switching and Networkning Journal, 31, 211-217
Open this publication in new window or tab >>Routing and wavelength assignment vs. EDFA reliability performance in optical backbone networks: An operational cost perspective
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2019 (English)In: Optical Switching and Networkning Journal, ISSN 1573-4277, E-ISSN 1872-9770, Vol. 31, p. 211-217Article in journal (Refereed) Published
Abstract [en]

A failure in optical backbone network can cause tremendous consequences as a substantial number of connections often each carrying a large amount of data can be interrupted. Therefore, high reliability performance is essential for the network operators. Many existing works that aim at improving network reliability performance implicitly assume that the lifetime of devices is constant and independent of the traffic load. However, the reliability performance of a device is related to its occupancy. For example, the failure rate of erbium doped fiber amplifier (EDFA) can be expressed as a function of the number of amplified wavelengths. On the other hand, the choice of routing and wavelength assignment (RWA) algorithm impacts the link load and, as a consequence, can influence the number of EDFA failures in the network. In this paper we examine how RWA can impact the failure reparation related network operational costs. Several types of RWA approaches are considered, namely load-balancing, energy-awareness, and reliability-awareness. Among all the considered RWA algorithms, the reliability-aware RWA (RA-RWA) approach leverages on EDFA reliability profile to reduce the number of EDFA failures in the network and the related operational costs. The simulation results show that the RWA algorithm impacts in a significant way the operational costs caused by EDFA failures. The cost associated with reparation of an EDFA decreases by 7.8% (in case of RA-RWA) and increases by up to 40% (in case of a load-balancing approach) compared to the classical Shortest Path (SP) approach. Moreover, the cost caused by connection rerouting due to link unavailability triggered by EDFA failure exhibits a 20% decrease (RA-RWA) and up to 94% increase (energy-aware algorithm). We also analyze some key network performance metrics that may be affected by RWA, including blocking probability, link occupancy distribution, and path length.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE BV, 2019
Keywords
Device reliability performance, Device reliability profile, Routing and wavelength assignment (RWA), Erbium doped fiber amplifier (EDFA), Optical backbone networks
National Category
Computer Systems
Identifiers
urn:nbn:se:kth:diva-241190 (URN)10.1016/j.osn.2018.10.005 (DOI)000454380100018 ()2-s2.0-85056245448 (Scopus ID)
Note

QC 20190121

Available from: 2019-01-21 Created: 2019-01-21 Last updated: 2019-01-21Bibliographically approved
Raza, M. R., Natalino, C., Öhlen, P., Wosinska, L. & Monti, P. (2018). A Slice Admission Policy Based on Reinforcement Learning for a 5G Flexible RAN. In: : . Paper presented at 44th European Conference and Exhibition on Optical Communication (ECOC).
Open this publication in new window or tab >>A Slice Admission Policy Based on Reinforcement Learning for a 5G Flexible RAN
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2018 (English)Conference paper, Published paper (Refereed)
National Category
Communication Systems
Identifiers
urn:nbn:se:kth:diva-235258 (URN)
Conference
44th European Conference and Exhibition on Optical Communication (ECOC)
Note

QC 20180920

Available from: 2018-09-19 Created: 2018-09-19 Last updated: 2018-10-19Bibliographically approved
Yaghoubi, F., Mahloo, M., Wosinska, L., Monti, P., Farias, F. d., Weyl Albuquerque Costa, J. C. & Chen, J. (2018). A TECHNO-ECONOMIC FRAMEWORK FOR 5G TRANSPORT NETWORKS. IEEE wireless communications, 25(5), 56-63
Open this publication in new window or tab >>A TECHNO-ECONOMIC FRAMEWORK FOR 5G TRANSPORT NETWORKS
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2018 (English)In: IEEE wireless communications, ISSN 1536-1284, E-ISSN 1558-0687, Vol. 25, no 5, p. 56-63Article in journal (Refereed) Published
Abstract [en]

Wireless heterogeneous networks (HetNets) are a cost- and energy-efficient alternative to provide high capacity to end users in the future 5G communication systems. However, the transport segment of a RAN poses a big challenge in terms of cost and energy consumption. In fact, if not planned properly, its resulting high cost might limit the benefits of using small cells and impact the revenues of mobile network operators. Therefore, it is essential to be able to properly assess the economic viability of different transport technologies as well as their impact on the cost and profitability of a HetNet deployment (i.e., RAN plus transport). This article first presents a general and comprehensive techno-economic framework able to assess not only the TCO but also the business viability of a HetNet deployment. The framework is then applied to the specific case study of a backhaul-based transport segment. In the evaluation work two technology options for the transport network are considered (i.e., microwave and fiber) assuming both a homogeneous (i.e., macrocells only) and a HetNet deployment. Our results demonstrate the importance of selecting the right technology and deployment strategy in order not to impact the economic benefits of a HetNet deployment. Moreover, the results also reveal that a deployment solution with the lowest TCO does not always lead to the highest profit.

Place, publisher, year, edition, pages
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2018
National Category
Telecommunications
Identifiers
urn:nbn:se:kth:diva-239826 (URN)10.1109/MWC.2018.1700233 (DOI)000450162600009 ()2-s2.0-85056548451 (Scopus ID)
Note

QC 20181217

Available from: 2018-12-18 Created: 2018-12-18 Last updated: 2019-02-22Bibliographically approved
Yaghoubi, F. (2018). A Techno-Economic Framework for 5G Transport Networks. IEEE wireless communications, 25(5), pp. 56-63
Open this publication in new window or tab >>A Techno-Economic Framework for 5G Transport Networks
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2018 (English)In: IEEE wireless communications, ISSN 1536-1284, E-ISSN 1558-0687, Vol. 25, no 5, p. 56-63Article in journal, News item (Refereed) Published
Abstract [en]

Wireless heterogeneous networks (HetNets) are a cost- and energy-efficient alternative to provide high capacity to end users in the future 5G communication systems. However, the transport segment of a RAN poses a big challenge in terms of cost and energy consumption. In fact, if not planned properly, its resulting high cost might limit the benefits of using small cells and impact the revenues of mobile network operators. Therefore, it is essential to be able to properly assess the economic viability of different transport technologies as well as their impact on the cost and profitability of a HetNet deployment (i.e., RAN plus transport). This article first presents a general and comprehensive techno-economic framework able to assess not only the TCO but also the business viability of a HetNet deployment. The framework is then applied to the specific case study of a backhaul-based transport segment. In the evaluation work two technology options for the transport network are considered (i.e., microwave and fiber) assuming both a homogeneous (i.e., macrocells only) and a HetNet deployment. Our results demonstrate the importance of selecting the right technology and deployment strategy in order not to impact the economic benefits of a HetNet deployment. Moreover, the results also reveal that a deployment solution with the lowest TCO does not always lead to the highest profit.

National Category
Engineering and Technology
Identifiers
urn:nbn:se:kth:diva-244610 (URN)
Note

QC 20190304

Available from: 2019-02-22 Created: 2019-02-22 Last updated: 2019-03-04Bibliographically approved
Tremblay, C., Archambault, E., Be´langer, M. P., Littlewood, P., Clelland, W., Furdek, M. & Wosinska, L. (2018). Agile optical networking: Beyond filtered solutions. In: Optics InfoBase Conference Papers: . Paper presented at Optical Fiber Communication Conference, OFC 2018, 11 March 2017 through 15 March 2017. Optics Info Base, Optical Society of America
Open this publication in new window or tab >>Agile optical networking: Beyond filtered solutions
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2018 (English)In: Optics InfoBase Conference Papers, Optics Info Base, Optical Society of America, 2018Conference paper, Published paper (Refereed)
Abstract [en]

Filterless optical networks based on broadcast-and-select nodes and coherent transceivers are attractive cost-effective and flexible solutions in core networks. In this paper, we explore the suitability of filterless architectures in metropolitan core and aggregation networks.

Place, publisher, year, edition, pages
Optics Info Base, Optical Society of America, 2018
National Category
Communication Systems
Identifiers
urn:nbn:se:kth:diva-228661 (URN)10.1364/OFC.2018.M1A.5 (DOI)2-s2.0-85047134241 (Scopus ID)9781557528209 (ISBN)
Conference
Optical Fiber Communication Conference, OFC 2018, 11 March 2017 through 15 March 2017
Note

QC 20180529

Available from: 2018-05-29 Created: 2018-05-29 Last updated: 2018-05-29Bibliographically approved
Tremblay, C., Archambault, E., Belanger, M. P., Littlewood, P., Clelland, W., Furdek, M. & Wosinska, L. (2018). Agile Optical Networking: Beyond Filtered Solutions. In: 2018 Optical Fiber Communications Conference and Exposition, OFC 2018 - Proceedings: . Paper presented at 2018 Optical Fiber Communications Conference and Exposition, OFC 2018, San Diego, United States, 11 March 2018 through 15 March 2018. IEEE
Open this publication in new window or tab >>Agile Optical Networking: Beyond Filtered Solutions
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2018 (English)In: 2018 Optical Fiber Communications Conference and Exposition, OFC 2018 - Proceedings, IEEE , 2018Conference paper, Published paper (Refereed)
Abstract [en]

Filterless optical networks based on broadcast-and-select nodes and coherent transceivers are attractive cost-effective and flexible solutions in core networks. In this paper, we explore the suitability of filterless architectures in metropolitan core and aggregation networks.

Place, publisher, year, edition, pages
IEEE, 2018
National Category
Communication Systems
Identifiers
urn:nbn:se:kth:diva-232646 (URN)000437286300005 ()2-s2.0-85050022817 (Scopus ID)9781943580385 (ISBN)
Conference
2018 Optical Fiber Communications Conference and Exposition, OFC 2018, San Diego, United States, 11 March 2018 through 15 March 2018
Note

QC 20180802

Available from: 2018-08-02 Created: 2018-08-02 Last updated: 2018-08-02Bibliographically approved
Yaghoubi, F., Furdek, M., Rostami, A., Ohlen, P. & Wosinska, L. (2018). Consistency-Aware Weather Disruption-Tolerant Routing in SDN-Based Wireless Mesh Networks. IEEE Transactions on Network and Service Management, 15(2), 582-595
Open this publication in new window or tab >>Consistency-Aware Weather Disruption-Tolerant Routing in SDN-Based Wireless Mesh Networks
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2018 (English)In: IEEE Transactions on Network and Service Management, ISSN 1932-4537, E-ISSN 1932-4537, Vol. 15, no 2, p. 582-595Article in journal (Refereed) Published
Abstract [en]

Wireless network solutions, a dominant enabling technology for the backhaul segment, are susceptible to weather disturbances that can substantially degrade network throughput and/or delay, compromising the stringent 5G requirements. These effects can be alleviated by centralized rerouting realized by software defined networking architecture. However, careless frequent reconfigurations can lead to inconsistencies in the network states due to asynchrony between different switches, which can create congestion and limit the rerouting gain. The aim of this paper is to minimize the total data loss during rain disturbance by proposing an algorithm that decides on the timing, the sequence, and the paths for rerouting of network flows considering the imposed congestion during reconfiguration. At each time sample, the central controller decides whether to adopt the optimal routes at a switching cost, defined as the imposed congestion, or to keep using existing, sub-optimal routes at a throughput loss. To find optimal solutions with minimal data loss in a static scenario, we formulate a dynamic programming problem that utilizes perfect knowledge of rain attenuation for the whole rain period. For dynamic scenarios with unknown future rain attenuation, we propose an online consistency-aware rerouting algorithm, called consistency-aware rerouting with prediction (CARP), which uses the temporal correlation of rain fading to estimate future rain attenuation. Simulation results on synthetic and real networks validate the efficiency of our CARP algorithm, substantially reducing data loss and increasing network throughput with a fewer number of rerouting actions compared to a greedy and a regular rerouting benchmarking approaches.

Place, publisher, year, edition, pages
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2018
Keywords
5G, wireless software-defined networking, routing, rain disturbance, model predictive control
National Category
Communication Systems
Identifiers
urn:nbn:se:kth:diva-231716 (URN)10.1109/TNSM.2018.2795748 (DOI)000435177300007 ()2-s2.0-85040925980 (Scopus ID)
Note

QC 20180817

Available from: 2018-08-17 Created: 2018-08-17 Last updated: 2019-02-22Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-6704-6554

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