| 1. |
- Smirnova, Anna, et al.
(författare)
-
Increased apoptosis, reduced Wnt/beta-catenin signaling, and altered tail development in zebrafish embryos exposed to a human-relevant chemical mixture
- 2021
-
Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 264:1
-
Tidskriftsartikel (refereegranskat)abstract
- A wide variety of anthropogenic chemicals is detected in humans and wildlife and the health effects of various chemical exposures are not well understood. Early life stages are generally the most susceptible to chemical disruption and developmental exposure can cause disease in adulthood, but the mechanistic understanding of such effects is poor. Within the EU project EDC-MixRisk, a chemical mixture (Mixture G) was identified in the Swedish pregnancy cohort SELMA by the inverse association between levels in women at around gestational week ten with birth weight of their children. This mixture was composed of mono-ethyl phthalate, mono-butyl phthalate, mono-benzyl phthalate, mono-ethylhexyl phthalate, mono-isononyl phthalate, triclosan, perfluorohexane sulfonate, perfluorooctanoic acid, and perfluorooctane sulfonate. In a series of experimental studies, we characterized effects of Mixture G on early development in zebrafish models. Here, we studied apoptosis and Wnt/beta-catenin signaling which are two evolutionarily conserved signaling pathways of crucial importance during development. We determined effects on apoptosis by measuring TUNEL staining, caspase-3 activity, and acridine orange staining in wildtype zebrafish embryos, while Wnt/beta-catenin signaling was assayed using a transgenic line expressing an EGFP reporter at beta-catenin-regulated promoters. We found that Mixture G increased apoptosis, suppressed Wnt/beta-catenin signaling in the caudal fin, and altered the shape of the caudal fin at water concentrations only 20-100 times higher than the geometric mean serum concentration in the human cohort. These findings call for awareness that pollutant mixtures like mixture G may interfere with a variety of developmental processes, possibly resulting in adverse health effects.
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| 2. |
- Mandalari, Anna Maria, et al.
(författare)
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Experience: Implications of Roaming in Europe
- 2018
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Ingår i: MobiCom '18. Proceedings of the 24th Annual International Conference on Mobile Computing and Networking. - New York, USA : ACM Publications. - 9781450359030 ; , s. 179-189
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Konferensbidrag (refereegranskat)abstract
- "Roam like Home" is the initiative of the European Commission (EC) to end the levy of extra charges when roaming within the European region. As a result, people are able to use data services more freely across Europe. However, the implications roaming solutions have on performance have not been carefully examined. This paper provides an in-depth characterization of the implications of international data roaming within Europe. We build a unique roaming measurement platform using 16 different mobile networks deployed in six countries across Europe. Using this platform, we measure different aspects of international roaming in 3G and 4G networks, including mobile network configuration, performance characteristics, and content discrimination. We find that operators adopt common approaches to implementing roaming, resulting in additional latency penalties of ∼60 ms or more, depending on geographical distance. Considering content accessibility, roaming poses additional constraints that leads to only minimal deviations when accessing content in the original country. However, geographical restrictions in the visited country make the picture more complicated and less intuitive.
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| 3. |
- Mattsson, Anna, et al.
(författare)
-
Developmental exposure to a mixture of perfluoroalkyl acids (PFAAs) affects the thyroid hormone system and the bursa of Fabricius in the chicken
- 2019
-
Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 9:1
-
Tidskriftsartikel (refereegranskat)abstract
- Perfluoroalkyl acids (PFAAs) are ubiquitous environmental contaminants and eggs and nestlings of raptors and fish-eating birds often contain high levels of PFAAs. We studied developmental effects of a mixture of ten PFAAs by exposing chicken embryos to 0.5 or 3 μg/g egg of each compound in the mixture. Histological changes of the thyroid gland were noted at both doses and increased expression of mRNA coding for type III deiodinase was found at 0.5 μg/g egg. Serum concentrations of the free fraction of thyroid hormones (T3 and T4) were reduced by the PFAA mixture at 3 µg/g egg, which is in line with a decreased synthesis and increased turnover of thyroid hormones as indicated by our histological findings and the decreased mRNA expression of type III deiodinase. The relative weight of the bursa of Fabricius increased at a dose of 3 μg/g egg in females. The bursa is the site of B-cell development in birds and is crucial for the avian adaptive immune system. Analysis of plasma and liver concentrations of the mixture components showed differences depending on chain length and functional group. Our results highlight the vulnerability of the thyroid hormone and immune systems to PFAAs.
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| 4. |
- Mattsson, Anna, et al.
(författare)
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Metabolic Profiling of Chicken Embryos Exposed to Perfluorooctanoic Acid ( PFOA) and Agonists to Peroxisome Proliferator-Activated Receptors
- 2015
-
Ingår i: PLOS ONE. - : Public Library Science. - 1932-6203. ; 10:12
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Tidskriftsartikel (refereegranskat)abstract
- Untargeted metabolic profiling of body fluids in experimental animals and humans exposed to chemicals may reveal early signs of toxicity and indicate toxicity pathways. Avian embryos develop separately from their mothers, which gives unique possibilities to study effects of chemicals during embryo development with minimal confounding factors from the mother. In this study we explored blood plasma and allantoic fluid from chicken embryos as matrices for revealing metabolic changes caused by exposure to chemicals during embryonic development. Embryos were exposed via egg injection on day 7 to the environmental pollutant perfluorooctanoic acid (PFOA), and effects on the metabolic profile on day 12 were compared with those caused by GW7647 and rosiglitazone, which are selective agonists to peroxisome-proliferator activated receptor a (PPAR alpha) and PPAR gamma, respectively. Analysis of the metabolite concentrations from allantoic fluid by Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) showed clear separation between the embryos exposed to GW7647, rosiglitazone, and vehicle control, respectively. In blood plasma only GW7647 caused a significant effect on the metabolic profile. PFOA induced embryo mortality and increased relative liver weight at the highest dose. Sublethal doses of PFOA did not significantly affect the metabolic profile in either matrix, although single metabolites appeared to be altered. Neonatal mortality by PFOA in the mouse has been suggested to be mediated via activation of PPAR alpha. However, we found no similarity in the metabolite profile of chicken embryos exposed to PFOA with those of embryos exposed to PPAR agonists. This indicates that PFOA does not activate PPAR pathways in our model at concentrations in eggs and embryos well above those found in wild birds. The present study suggests that allantoic fluid and plasma from chicken embryos are useful and complementary matrices for exploring effects on the metabolic profile resulting from chemical exposure during embryonic development.
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| 5. |
- Mentor, Anna, 1989-, et al.
(författare)
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Bisphenol AF and Bisphenol F Induce Similar Feminizing Effects in Chicken Embryo Testis as Bisphenol A
- 2020
-
Ingår i: Toxicological Sciences. - OXFORD ENGLAND : Oxford University Press (OUP). - 1096-6080 .- 1096-0929. ; 178:2, s. 239-250
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Tidskriftsartikel (refereegranskat)abstract
- The plastic component bisphenol A (BPA) impairs reproductive organ development in various experimental animal species. In birds, effects are similar to those caused by other xenoestrogens. Because of its endocrine disrupting activity, BPA is being substituted with other bisphenols in many applications. Using the chicken embryo model, we explored whether the BPA alternatives bisphenol AF (BPAF), bisphenol F (BPF), and bisphenol S (BPS) can induce effects on reproductive organ development similar to those induced by BPA. Embryos were exposed in ovo from embryonic day 4 (E4) to vehicle, BPAF at 2.1, 21, 210, and 520 nmol/g egg, or to BPA, BPF, or BPS at 210 nmol/g egg and were dissected on embryonic day 19. Similar to BPA, BPAF and BPF induced testis feminization, manifested as eg testis-size asymmetry and ovarian-like cortex in the left testis. In the BPS-group, too few males were alive on day 19 to evaluate any effects on testis development. We found no effects by any treatment on ovaries or Mullerian ducts. BPAF and BPS increased the gallbladder-somatic index and BPAF, BPF and BPS caused increased embryo mortality. The overall lowest-observed-adverse-effect level for BPAF was 210 nmol/g egg based on increased mortality, increased gallbladder-somatic index, and various signs of testis feminization. This study demonstrates that the BPA replacements BPAF, BPF, and BPS are embryotoxic and suggests that BPAF is at least as potent as BPA in inducing estrogen-like effects in chicken embryos. Our results support the notion that these bisphenols are not safe alternatives to BPA.
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| 6. |
- Mentor, Anna, et al.
(författare)
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Developmental exposure to a human relevant mixture of endocrine disruptors alters metabolism and adipogenesis in zebrafish (Danio rerio)
- 2020
-
Ingår i: Chemosphere. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0045-6535 .- 1879-1298. ; 238
-
Tidskriftsartikel (refereegranskat)abstract
- Exposure to endocrine disrupting chemicals has been suggested to contribute to the ongoing globally increasing obesity trend. The complex chemical mixtures that humans and wildlife are exposed to include a number of compounds that may have obesogenic properties. In this study we examined a mixture consisting of phthalate-monoesters, triclosan, and perfiuorinated compounds. The mixture was designed within the EDC-MixRisk project based on serum levels of the compounds in pregnant women of a Swedish mother-child cohort. The compounds were negatively associated with birth weight of the children. We assessed whether developmental exposure to this mixture in combination with a calorie-rich diet affected metabolic rate, blood lipids, adipogenesis and lipid storage, and the whole-body level of neutral lipids in zebrafish (Danio rerio). Wildtype zebrafish were exposed to the mixture from 3 h post fertilization to 5, 14 or 17 days post fertilization (dpf) at water concentrations corresponding to 1, 10, 20, or 100 times the geometrical mean of the serum concentration (hsc) in the women. Exposure to the mixture at 20 times hsc lowered metabolic rate at 2-5 dpf, and increased the number of adipocytes and the amount of visceral adipose tissue at 14 and 17 dpf respectively. Also, mRNA expression of fatty acid binding protein a was increased at 17 dpf by 10 and 20 times hsc of the mixture. This study shows that a human-relevant mixture of environmental pollutants affects metabolic rate, adipogenesis and lipid storage in young zebrafish fed a calorie-rich diet, thus demonstrating its potential to disrupt metabolism.
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| 7. |
- Mentor, Anna, 1989-, et al.
(författare)
-
Metabolic disruption by a human-relevant chemical mixture, triclosan, and tributyltin in larval zebrafish (Danio rerio)
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Exposure to metabolism disrupting compounds during development may have short- and long-term health consequences. We have studied the effects of a mixture that consists of perfluoroalkyl acids, phthalate monoesters, and triclosan (TCS) on metabolic endpoints in developing zebrafish (Danio rerio). The mixture has previously been negatively associated with birth weight in the Swedish pregnancy cohort SELMA. We also studied one of the mixture components (TCS) and the known obesogen tributyltin (TBT). Water concentrations of the mixture and TCS corresponded to 1, 20, 60, and 100 times the geometrical mean of the gestational week 10 serum concentration in the SELMA women. The fish were exposed from 3 hours post fertilization and effects on metabolic rate were assessed at 2-5 days post fertilization (dpf) and lipid content in the blood, whole-body neutral lipid content, and adiposity were determined at 7 dpf. Exposure to the mixture and TCS altered metabolic rate. The mixture and both single compounds reduced lipid levels in whole-body samples and in the blood. A higher proportion of fish in the mixture- and TBT-exposed groups had visible adipocytes at 7 dpf compared with the control group and a similar tendency was observed in TCS-exposed fish. Our results demonstrate metabolism disrupting properties of the mixture and its component TCS that were similar to those of TBT. The results further indicate that TCS contributes to, but is not solely responsible for, the effect by the mixture.
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| 8. |
- Scholz, Birger, et al.
(författare)
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Neuropeptidomic analysis of the embryonic Japanese quail diencephalon
- 2010
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Ingår i: BMC Developmental Biology. - 1471-213X. ; 10, s. 30-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Endogenous peptides such as neuropeptides are involved in numerous biological processes in the fully developed brain but very little is known about their role in brain development. Japanese quail is a commonly used bird model for studying sexual dimorphic brain development, especially adult male copulatory behavior in relation to manipulations of the embryonic endocrine system. This study uses a label-free liquid chromatography mass spectrometry approach to analyze the influence of age (embryonic days 12 vs 17), sex and embryonic day 3 ethinylestradiol exposure on the expression of multiple endogenous peptides in the developing diencephalon.Results: We identified a total of 65 peptides whereof 38 were sufficiently present in all groups for statistical analysis. Age was the most defining variable in the data and sex had the least impact. Most identified peptides were more highly expressed in embryonic day 17. The top candidates for EE2 exposure and sex effects were neuropeptide K (downregulated by EE2 in males and females), gastrin-releasing peptide (more highly expressed in control and EE2 exposed males) and gonadotropin-inhibiting hormone related protein 2 (more highly expressed in control males and displaying interaction effects between age and sex). We also report a new potential secretogranin-2 derived neuropeptide and previously unknown phosphorylations in the C-terminal flanking protachykinin 1 neuropeptide.Conclusions: This study is the first larger study on endogenous peptides in the developing brain and implies a previously unknown role for a number of neuropeptides in middle to late avian embryogenesis. It demonstrates the power of label-free liquid chromatography mass spectrometry to analyze the expression of multiple endogenous peptides and the potential to detect new putative peptide candidates in a developmental model.
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| 9. |
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| 10. |
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| 11. |
- Abbas, Muhammad Tahir, et al.
(författare)
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Energy-Saving Solutions for Cellular Internet of Things - A Survey
- 2022
-
Ingår i: IEEE Access. - IEEE : IEEE. - 2169-3536. ; 10, s. 62096-62096
-
Tidskriftsartikel (refereegranskat)abstract
- The Cellular Internet of Things (CIoT), a new paradigm, paves the way for a large-scale deployment of IoT devices. CIoT promises enhanced coverage and massive deployment of low-cost IoT devices with an expected battery life of up to 10 years. However, such a long battery life can only be achieved provided the CIoT device is configured with energy efficiency in mind. This paper conducts a comprehensive survey on energy-saving solutions in 3GPP-based CIoT networks. In comparison to current studies, the contribution of this paper is the classification and an extensive analysis of existing energy-saving solutions for CIoT, e.g., the configuration of particular parameter values and software modifications of transport- or radio-layer protocols, while also stressing key parameters impacting the energy consumption such as the frequency of data reporting, discontinuous reception cycles (DRX), and Radio Resource Control (RRC) timers. In addition, we discuss shortcomings, limitations, and possible opportunities which can be investigated in the future to reduce the energy consumption of CIoT devices.
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| 12. |
- Abbas, Muhammad Tahir, et al.
(författare)
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Guidelines for an Energy Efficient Tuning of the NB-IoT Stack
- 2020
-
Ingår i: 45th IEEE Conference on Local Computer Networks (LCN). - : IEEE Communications Society. ; , s. 60-69
-
Konferensbidrag (refereegranskat)abstract
- In this paper, we study the energy consumptionof Narrowband IoT devices. The paper suggests that key tosaving energy for NB-IoT devices is the usage of full Discontinuous Reception (DRX), including the use of connected-mode DRX (cDRX): In some cases, cDRX reduced the energy consumption over a 10-year period with as much as 50%. However, the paper also suggests that tunable parameters, such as the inactivity timer, do have a significant impact. On the basis of our findings, guidelines are provided on how to tune the NB-IoT device so that it meets the target of the 3GPP, i.e., a 5-Wh battery should last for at least 10 years. It is further evident from our results that the energy consumption is largely dependent on the intensity and burstiness of the traffic, and thus could be significantly reduced if data is sent in bursts with less intensity,irrespective of cDRX support.
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| 13. |
- Abbas, Muhammad Tahir, et al.
(författare)
-
Impact of Tunable Parameters in NB-IoT Stack onthe Energy Consumption
- 2019
-
Ingår i: Proceedings of Fifteenth Swedish National Computer Networking Workshop (SNCNW).
-
Konferensbidrag (refereegranskat)abstract
- This paper studies the impact of tunable parametersin the NB-IoT stack on the energy consumption of a user equipment(UE), e.g., a wireless sensor. NB-IoT is designed to enablemassive machine-type communications for UE while providing abattery lifetime of up to 10 years. To save battery power, most oftime the UE is in dormant state and unreachable. Still, duringthe CONNECTED and IDLE state, correct tuning of criticalparameters, like Discontinuous reception (DRX), and extendedDiscontinuous reception (eDRX), respectively, are essential to savebattery power. Moreover, the DRX and eDRX actions relate tovarious parameters which are needed to be tuned in order toachieve a required UE battery lifetime. The objective of thispaper is to observe the influence of an appropriate tuning ofthese parameters to reduce the risk of an early battery drainage
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| 14. |
- Abbas, Muhammad Tahir, et al.
(författare)
-
On the Energy-efficient Use of Discontinuous Reception and Release Assistance in NB-IoT
- 2022
-
Konferensbidrag (refereegranskat)abstract
- Cellular Internet of Things (CIoT) is a Low-Power Wide-Area Network (LPWAN) technology. It aims for cheap, lowcomplexity IoT devices that enable large-scale deployments and wide-area coverage. Moreover, to make large-scale deployments of CIoT devices in remote and hard-to-access locations possible, a long device battery life is one of the main objectives of these devices. To this end, 3GPP has defined several energysaving mechanisms for CIoT technologies, not least for the Narrow-Band Internet of Things (NB-IoT) technology, one of the major CIoT technologies. Examples of mechanisms defined include CONNECTED-mode DRX (cDRX), Release Assistance Indicator (RAI), and Power Saving Mode (PSM). This paper considers the impact of the essential energy-saving mechanisms on minimizing the energy consumption of NB-IoT devices, especially the cDRX and RAI mechanisms. The paper uses a purpose-built NB-IoT simulator that has been tested in terms of its built-in energy-saving mechanisms and validated with realworld NB-IoT measurements. The simulated results show that it is possible to save 70%-90% in energy consumption by enabling the cDRX and RAI. In fact, the results suggest that a battery life of 10 years is only achievable provided the cDRX, RAI, and PSM energy-saving mechanisms are correctly configured and used
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| 15. |
- Abrahamsson, Henrik, et al.
(författare)
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Connected Vehicles in Cellular Networks : Multi-Access Versus Single-Access Performance
- 2018
-
Ingår i: TMA 2018 - Proceedings of the 2nd Network Traffic Measurement and Analysis Conference. - : Institute of Electrical and Electronics Engineers Inc.. - 9783903176096
-
Konferensbidrag (refereegranskat)abstract
- Connected vehicles can make roads traffic safer and more efficient, but require the mobile networks to handle time-critical applications. Using the MONROE mobile broadband measurement testbed we conduct a multi-access measurement study on buses. The objective is to understand what network performance connected vehicles can expect in today's mobile networks, in terms of transaction times and availability. The goal is also to understand to what extent access to several operators in parallel can improve communication performance. In our measurement experiments we repeatedly transfer warning messages from moving buses to a stationary server. We triplicate the messages and always perform three transactions in parallel over three different cellular operators. This creates a dataset with which we can compare the operators in an objective way and with which we can study the potential for multi-access. In this paper we use the triple-access dataset to evaluate single-access selection strategies, where one operator is chosen for each transaction. We show that if we have access to three operators and for each transaction choose the operator with best access technology and best signal quality then we can significantly improve availability and transaction times compared to the individual operators. The median transaction time improves with 6% compared to the best single operator and with 61% compared to the worst single operator. The 90-percentile transaction time improves with 23% compared to the best single operator and with 65% compared to the worst single operator.
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| 16. |
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| 17. |
- Afzal, Zeeshan, 1991-, et al.
(författare)
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Slice Distance : An Insert-Only Levenshtein Distance with a Focus on Security Applications
- 2018
-
Ingår i: Proceedings of NTMS 2018 Conference and Workshop. - New York : IEEE. - 9781538636626 - 9781538636633 ; , s. 1-5
-
Konferensbidrag (refereegranskat)abstract
- Levenshtein distance is well known for its use in comparing two strings for similarity. However, the set of considered edit operations used when comparing can be reduced in a number of situations. In such cases, the application of the generic Levenshtein distance can result in degraded detection and computational performance. Other metrics in the literature enable limiting the considered edit operations to a smaller subset. However, the possibility where a difference can only result from deleted bytes is not yet explored. To this end, we propose an insert-only variation of the Levenshtein distance to enable comparison of two strings for the case in which differences occur only because of missing bytes. The proposed distance metric is named slice distance and is formally presented and its computational complexity is discussed. We also provide a discussion of the potential security applications of the slice distance.
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| 18. |
- Afzal, Zeeshan, 1991-, et al.
(författare)
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Towards Multipath TCP Aware Security Technologies
- 2016
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Ingår i: 2016 8th IFIP International Conference onNew Technologies, Mobility and Security (NTMS). - New York : IEEE. - 9781509029143 ; , s. 1-8
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Konferensbidrag (refereegranskat)abstract
- Multipath TCP (MPTCP) is a proposed extension to TCP that enables a number of performance advantages that have not been offered before. While the protocol specification is close to being finalized, there still remain some unaddressed challenges regarding the deployment and security implications of the protocol. This work attempts to tackle some of these concerns by proposing and implementing MPTCP aware security services and deploying them inside a proof of concept MPTCP proxy. The aim is to enable hosts, even those without native MPTCP support, to securely benefit from the MPTCP performance advantages. Our evaluations show that the security services that are implemented enable proper intrusion detection and prevention to thwart potential attacks as well as threshold rules to prevent denial of service (DoS) attacks.
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| 19. |
- Afzal, Zeeshan, 1991-, et al.
(författare)
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Using Features of Encrypted Network Traffic to Detect Malware
- 2021
-
Ingår i: 25th Nordic Conference on Secure IT Systems, NordSec 2020. - Cham : Springer Science and Business Media Deutschland GmbH. ; , s. 37-53
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Konferensbidrag (refereegranskat)abstract
- Encryption on the Internet is as pervasive as ever. This has protected communications and enhanced the privacy of users. Unfortunately, at the same time malware is also increasingly using encryption to hide its operation. The detection of such encrypted malware is crucial, but the traditional detection solutions assume access to payload data. To overcome this limitation, such solutions employ traffic decryption strategies that have severe drawbacks. This paper studies the usage of encryption for malicious and benign purposes using large datasets and proposes a machine learning based solution to detect malware using connection and TLS metadata without any decryption. The classification is shown to be highly accurate with high precision and recall rates by using a small number of features. Furthermore, we consider the deployment aspects of the solution and discuss different strategies to reduce the false positive rate.
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| 20. |
- Afzal, Zeeshan, 1991-, et al.
(författare)
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Using Partial Signatures in Intrusion Detection for Multipath TCP
- 2019
-
Ingår i: Secure IT-systems. - Cham, Switzerland : Springer. ; , s. 71-86
-
Konferensbidrag (refereegranskat)abstract
- Traditional security mechanisms such as signature basedintrusion detection systems (IDSs) attempt to find a perfect match of aset of signatures in network traffic. Such IDSs depend on the availabilityof a complete application data stream. With emerging protocols such asMultipath TCP (MPTCP), this precondition cannot be ensured, result-ing in false negatives and IDS evasion. On the other hand, if approximatesignature matching is used instead in an IDS, a potentially high numberof false positives make the detection impractical. In this paper, we showthat, by using a specially tailored partial signature matcher and knowl-edge about MPTCP semantics, the Snort3 IDS can be empowered withpartial signature detection. Additionally, we uncover the type of Snort3rules suitable for the task of partial matching. Experimental results withthese rules show a low false positive rate for benign traffic and highdetection coverage for attack traffic.
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| 21. |
- Ahlgren, Bengt, et al.
(författare)
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Are MIRCC and Rate-based Congestion Control in ICN READY for Variable Link Capacity?
- 2017
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Information-centric networking (ICN) has been introduced as a potential future networking architecture. ICN promises an architecture that makes information independent from lo- cation, application, storage, and transportation. Still, it is not without challenges. Notably, there are several outstanding issues regarding congestion control: Since ICN is more or less oblivious to the location of information, it opens up for a single application flow to have several sources, something which blurs the notion of transport flows, and makes it very difficult to employ traditional end-to-end congestion control schemes in these networks. Instead, ICN networks often make use of hop-by-hop congestion control schemes. How- ever, these schemes are also tainted with problems, e.g., several of the proposed ICN congestion controls assume fixed link capacities that are known beforehand. Since this seldom is the case, this paper evaluates the consequences in terms of latency, throughput, and link usage, variable link capacities have on a hop-by-hop congestion control scheme, such as the one employed by the Multipath-aware ICN Rate-based Congestion Control (MIRCC). The evaluation was carried out in the OMNeT++ simulator, and demonstrates how seemingly small variations in link capacity significantly deterio- rate both latency and throughput, and often result in inefficient network link usage.
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| 22. |
- Ahlgren, Bengt, et al.
(författare)
-
ICN congestion control for wireless links
- 2018
-
Ingår i: IEEE WCNC 2018 Conference Proceedings. - New York : IEEE.
-
Konferensbidrag (refereegranskat)abstract
- Information-centric networking (ICN) with its design around named-based forwarding and in-network caching holds great promises to become a key architecture for the future Internet. Many proposed ICN hop-by-hop congestion control schemes assume a fixed and known link capacity, which rarely - if ever - holds true for wireless links. Firstly, we demonstrate that although these congestion control schemes are able to fairly well utilise the available wireless link capacity, they greatly fail to keep the delay low. In fact, they essentially offer the same delay as in the case with no hop-by-hop, only end-to-end, congestion control. Secondly, we show that by complementing these schemes with an easy-to-implement, packet-train capacity estimator, we reduce the delay to a level significantly lower than what is obtained with only end-to-end congestion control, while still being able to keep the link utilisation at a high level.
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| 23. |
- Ahlgren, Bengt, et al.
(författare)
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Latency-aware Multipath Scheduling inInformation-centric Networks
- 2019
-
Ingår i: Proceedings of the Fifteenth Swedish National Computer Networking Workshop (SNCNW), Luleå, Sweden. 4-5 June 2019..
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Konferensbidrag (refereegranskat)abstract
- We present the latency-aware multipath schedulerZQTRTT that takes advantage of the multipath opportunities ininformation-centric networking. The goal of the scheduler is touse the (single) lowest latency path for transaction-oriented flows,and use multiple paths for bulk data flows. A new estimatorcalled zero queue time ratio is used for scheduling over multiplepaths. The objective is to distribute the flow over the paths sothat the zero queue time ratio is equal on the paths, that is,so that each path is ‘pushed’ equally hard by the flow withoutcreating unwanted queueing. We make an initial evaluation usingsimulation that shows that the scheduler meets our objectives.
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| 24. |
- Alay, Özgü, et al.
(författare)
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Experience : An open platform for experimentation with commercial mobile broadband networks
- 2017
-
Ingår i: MobiCom '17 Proceedings of the 23rd Annual International Conference on Mobile Computing and Networking. - New York : Association for Computing Machinery (ACM). - 9781450349161 ; , s. 70-78
-
Konferensbidrag (refereegranskat)abstract
- Open experimentation with operational Mobile Broadband (MBB) networks in the wild is currently a fundamental requirement of the research community in its endeavor to address the need of innovative solutions for mobile communications. Even more, there is a strong need for objective data about stability and performance of MBB (e.g., 3G/4G) networks, and for tools that rigorously and scientifically assess their status. In this paper, we introduce the MONROE measurement platform: an open access and flexible hardware-based platform for measurements and custom experimentation on operational MBB networks. The MONROE platform enables accurate, realistic and meaningful assessment of the performance and reliability of 11 MBB networks in Europe. We report on our experience designing, implementing and testing the solution we propose for the platform. We detail the challenges we overcame while building and testing the MONROE testbed and argue our design and implementation choices accordingly. We describe and exemplify the capabilities of the platform and the wide variety of experiments that external users already perform using the system
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| 25. |
- Alay, Özgü, et al.
(författare)
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Measuring and Assessing Mobile Broadband Networks with MONROE
- 2016
-
Ingår i: 2016 IEEE International Symposium on a World of Wireless, Mobile, and Multimedia Networks (WoWMoM). - Red Hook : IEEE. - 9781509021864 - 9781509021857
-
Konferensbidrag (refereegranskat)abstract
- Mobile broadband (MBB) networks underpin numerous vital operations of the society and are arguably becoming the most important piece of the communications infrastructure. In this demo paper, our goal is to showcase the potential of a novel multi-homed MBB platform for measuring, monitoring and assessing the performance of MBB services in an objective manner. Our platform, MONROE, is composed of hundreds of nodes scattered over four European countries and a backend system that collects the measurement results. Through a user-friendly web client, the experimenters can schedule and deploy their experiments. The platform further embeds traffic analysis tools for real-time traffic flow analysis and a powerful visualization tool.
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| 26. |
- Alay, Özgü, et al.
(författare)
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Monitoring and Analytics (Release B)
- 2021
-
Rapport (refereegranskat)abstract
- This document describes the design and implementation of the 5GENESIS Monitoring & Analytics (M&A) framework in its Release B, developed within Task T3.3 of the project work plan. M&A Release B leverages and extends M&A Release A, which has been documented in the previous Deliverable D3.5 [1]. In particular, we present new features and enhancements introduced in this new Release compared to the Release A. We also report some examples of usage of the M&A framework, in order to showcase its integrated in the 5GENESIS Reference Architecture.
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| 27. |
- Alay, Özgü, et al.
(författare)
-
MONROE, a distributed platform to measure and assess mobile broadband networks : demo
- 2016
-
Ingår i: Proceedings of the Tenth ACM International Workshop on Wireless Network Testbeds, Experimental Evaluation, and Characterization. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450342520 ; , s. 85-86
-
Konferensbidrag (refereegranskat)abstract
- This demo presents the MONROE distributed platform and how it can be used to implement measurement and assessment experiments with operational mobile broadband networks (MBBs). MONROE provides registered experimenters with open access to hundreds of nodes, distributed over several European countries and equipped with multiple MBB connections, and a backend system that collects the measurement results. Experiments are scheduled through a user-friendly web client, with no need to directly access the nodes. The platform further embeds tools for real-time traffic flow analysis and a powerful visualization tool.
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| 28. |
- Alfredsson, Stefan, 1976-
(författare)
-
A Cross-Layer Perspective on Transport Protocol Performance in Wireless Networks
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Communication by wireless technologies has seen a tremendous growth in the last decades. Mobile phone technology and wireless broadband solutions are rapidly replacing the last-hop wireline connectivity for telephones and Internet access. Research has, however, shown that Internet traffic can experience a performance degradation over wireless compared to wired networks. The inherent properties of radio communication lead to a higher degree of unreliability, compared to communication by wire or fiber. This can result in an increased amount of transmission errors, packet loss, delay and delay variations, which in turn affect the performance of the main Internet transport protocols TCP and UDP. This dissertation examines the cross-layer relationship between wireless transmission and the resulting performance on the transport layer. To this end, experimental evaluations of TCP and UDP over a wireless 4G downlink system proposal are performed. The experiment results show, in a holistic scenario, that link-level adaptive modulation, channel prediction, fast persistent link retransmissions, and channel scheduling, enables the transport protocols TCP and UDP to perform well and utilize the wireless link efficiently. Further, a novel approach is proposed where a modified TCP receiver can choose to accept packets that are corrupted by bit errors. Results from network emulation experiments indicate that by accepting and acknowledging even small amounts of corrupted data, a much higher throughput can be maintained compared to standard TCP.
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| 29. |
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| 30. |
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| 31. |
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| 32. |
- Alfredsson, Stefan, 1976-
(författare)
-
TCP in Wireless Networks: Challenges, Optimizations and Evaluations
- 2005
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis presents research on transport layer behavior in wireless networks. As the Internet is expanding its reach to include mobile devices, it has become apparent that some of the original design assumptions for the dominant transport protocol, TCP, are approaching their limits. A key feature of TCP is the congestion control algorithm, constructed with the assumption that packet loss is normally very low, and that packet loss therefore is a sign of network congestion. This holds true for wired networks, but for mobile wireless networks non-congestion related packet loss may appear. The varying signal power inherent with mobility and handover between base-stations are two example causes of such packet loss. This thesis provides an overview of the challenges for TCP in wireless networks together with a compilation of a number of suggested TCP optimizations for these environments. A TCP modification called TCP-L is proposed. It allows an application to increase its performance, in environments where residual bit errors normally give a degraded throughput, by making a reliability tradeoff. The performance of TCP-L is experimentally evaluated with an implementation in the Linux kernel. The transport layer performance in a 4G scenario is also experimentally investigated, focusing on the impact of the link layer design and its parameterization. Further, for emulation-based protocol evaluations, controlled packet loss and bit error generation is shown to be an important aspect.
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| 33. |
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| 34. |
- Ali, Usman, et al.
(författare)
-
Data-Driven Analysis of Outdoor-to-Indoor Propagation for 5G Mid-Band Operational Networks
- 2022
-
Ingår i: Future Internet. - : MDPI. - 1999-5903. ; 14:8, s. 1-27
-
Tidskriftsartikel (refereegranskat)abstract
- The successful rollout of fifth-generation (5G) networks requires a full understanding of the behavior of the propagation channel, taking into account the signal formats and the frequencies standardized by the Third Generation Partnership Project (3GPP). In the past, channel characterization for 5G has been addressed mainly based on the measurements performed on dedicated links in experimental setups. This paper presents a state-of-the-art contribution to the characterization of the outdoor-to-indoor radio channel in the 3.5 GHz band, based on experimental data for commercial, deployed 5G networks, collected during a large scale measurement campaign carried out in the city of Rome, Italy. The analysis presented in this work focuses on downlink, outdoor-to-indoor propagation for two operators adopting two different beamforming strategies, single wide-beam and multiple synchronization signal blocks (SSB) based beamforming; it is indeed the first contribution studying the impact of beamforming strategy in real 5G networks. The time and power-related channel characteristics, i.e., mean excess delay and Root Mean Square (RMS) delay spread, path loss, and K-factor are studied for the two operators in multiple measurement locations. The analysis of time and power-related parameters is supported and extended by a correlation analysis between each pair of parameters. The results show that beamforming strategy has a marked impact on propagation. A single wide-beam transmission leads, in fact, to lower RMS delay spread and lower mean excess delay compared to a multiple SSB-based transmission strategy. In addition, the single wide-beam transmission system is characterized by a smaller path loss and a higher K-factor, suggesting that the adoption of a multiple SSB-based transmission strategy may have a negative impact on downlink performance.
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| 35. |
- Ali, Usman, et al.
(författare)
-
Large-Scale Dataset for the Analysis of Outdoor-to-Indoor Propagation for 5G Mid-Band Operational Networks
- 2022
-
Ingår i: Data. - : MDPI. - 2306-5729. ; 7:3, s. 34-34
-
Tidskriftsartikel (refereegranskat)abstract
- Understanding radio propagation characteristics and developing channel models is fundamental to building and operating wireless communication systems. Among others uses, channel characterization and modeling can be used for coverage and performance analysis and prediction. Within this context, this paper describes a comprehensive dataset of channel measurements performed to analyze outdoor-to-indoor propagation characteristics in the mid-band spectrum identified for the operation of 5th Generation (5G) cellular systems. Previous efforts to analyze outdoor-to-indoor propagation characteristics in this band were made by using measurements collected on dedicated, mostly single-link setups. Hence, measurements performed on deployed and operational 5G networks still lack in the literature. To fill this gap, this paper presents a dataset of measurements performed over commercial 5G networks. In particular, the dataset includes measurements of channel power delay profiles from two 5G networks in Band n78, i.e., 3.3–3.8 GHz. Such measurements were collected at multiple locations in a large office building in the city of Rome, Italy by using the Rohde & Schwarz (R&S) TSMA6 network scanner during several weeks in 2020 and 2021. A primary goal of the dataset is to provide an opportunity for researchers to investigate a large set of 5G channel measurements, aiming at analyzing the corresponding propagation characteristics toward the definition and refinement of empirical channel propagation models.
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| 36. |
- Amend, Markus, et al.
(författare)
-
A Framework for Multiaccess Support for Unreliable Internet Traffic Using Multipath DCCP
- 2019
-
Ingår i: Proceedings of the 44th IEEE Conference on Local Computer Networks (LCN), October 14-17, 2019, Osnabrück, Germany. - : IEEE.
-
Konferensbidrag (refereegranskat)abstract
- Mobile nodes are typically equipped with multiple radios and can connect to multiple radio access networks (e.g. WiFi, LTE and 5G). Consequently, it is important to design mechanisms that efficiently manage multiple network interfaces for aggregating the capacity, steering of traffic flows or switching flows among multiple interfaces. While such multi-access solutions have the potential to increase the overall traffic throughput and communication reliability, the variable latencies on different access links introduce packet delay variation which has negative effect on the application quality of service and user quality of experience. In this paper, we present a new IP-compatible multipath framework for heterogeneous access networks. The framework uses Multipath Datagram Congestion Control Protocol (MP-DCCP) - a set of extensions to regular DCCP - to enable a transport connection to operate across multiple access networks, simultaneously. We present the design of the new protocol framework and show simulation and experimental testbed results that (1) demonstrate the operation of the new framework, and (2) demonstrate the ability of our solution to manage significant packet delay variation caused by the asymmetry of network paths, by applying pluggable packet scheduling or reordering algorithms.
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| 37. |
- Amend, Markus, et al.
(författare)
-
In-network Support for Packet Reordering for Multiaccess Transport Layer Tunneling
- 2022
-
Ingår i: 2022 IEEE 11th IFIP International Conference on Performance Evaluation and Modeling in Wireless and Wired Networks, PEMWN 2022. - : IEEE. - 9783903176508
-
Konferensbidrag (refereegranskat)abstract
- Networked systems have recently aimed to use multiple access networks in parallel to increase resiliency, availability and capacity. However, different paths may have different latency characteristics, which may lead to out-of-order packet delivery. This may severely impact both the end-to-end application performance and the capacity utilisation of multiaccess systems. In this paper, we show that in-network support for packet reordering for multiaccess systems that are based on multiple transport layer tunnels is beneficial for several application types. Our findings are applicable to TCP and QUIC traffic in the 3GPP ATSSS context, where we use the MP-DCCP tunneling framework with a buffer-based packet reordering approach that uses a dynamic timing threshold to cope with variation of path delays over time. We demonstrate achievable performance gains for a wide range of path latency differences and end-to-end round trip times when using different in-network reordering algorithms.
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| 38. |
- Arvidsson, Åke, 1957-, et al.
(författare)
-
Web metrics for the next generation performance enhancing proxies
- 2019
-
Ingår i: 2019 27TH INTERNATIONAL CONFERENCE ON SOFTWARE, TELECOMMUNICATIONS AND COMPUTER NETWORKS (SOFTCOM). - : IEEE. - 9789532900880 ; , s. 171-176
-
Konferensbidrag (refereegranskat)abstract
- The fast growth of Internet traffic, the growing importance of cellular accesses and the escalating competition between content providers and network operators result in a growing interest in improving network performance and user experience. In terms of network transport, different solutions ranging from tuning TCP to installing middleboxes are applied. It turns out, however, that the practical results sometimes are disappointing and we believe that poor testing is one of the reasons for this. Indeed, many cases in the literature limit testing to the simple and rare use case of a single file download, while common and complex use cases like web browsing often are ignored or modelled only by considering smaller files. To facilitate better testing, we present a broader view which includes domain counts, flow counts and different forms of concurrency to better characterise the complexity around web pages, and from which the potential for different optimisation techniques can be estimated. We also derive numerical values of these metrics for a small set of popular web pages and study similarities and differences between pages with the same kind of content (newspapers, e-commerce and video) and between pages designed for the same platform (computer and smartphone).
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| 39. |
- Arvidsson, Åke, et al.
(författare)
-
Web metrics for the next generation performance enhancing proxies
- 2019
-
Ingår i: 2019 International Conference on Software, Telecommunications and Computer Networks (SoftCOM). - : IEEE. - 9789532900880 - 9781728137117 ; , s. 171-176
-
Konferensbidrag (refereegranskat)abstract
- The fast growth of Internet traffic, the growingimportance of cellular accesses and the escalating competitionbetween content providers and network operators result in agrowing interest in improving network performance and userexperience. In terms of network transport, different solutionsranging from tuning TCP to installing middleboxes are applied.It turns out, however, that the practical results sometimes aredisappointing and we believe that poor testing is one of thereasons for this. Indeed, many cases in the literature limittesting to the simple and rare use case of a single file download,while common and complex use cases like web browsing oftenare ignored or modelled only by considering smaller files. Tofacilitate better testing, we present a set of metrics by whichthe complexity around web pages can be characterised andthe potential for different optimisations can be estimated. Wealso derive numerical values of these metrics for a small set ofpopular web pages and study similarities and differences betweenpages with the same kind of content (newspapers, e-commerceand video) and between pages designed for the same platform(computer and smartphone).
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| 40. |
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| 41. |
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| 42. |
- Asplund, Katarina
(författare)
-
Implementation and Experimental Evaluation of a Partially Reliable Transport Protocol
- 2004
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the last decade, we have seen an explosive growth in the deployment of multimedia applications on the Internet. However, the transport service provided over the Internet is not always feasible for these applications, since the network was originally designed for other types of applications. One way to better accommodate the service requirements of some of these applications is to provide a partially reliable transport service. A partially reliable transport service does not insist on recovering all, but just some of the packet losses, thus providing a lower transport delay than a reliable transport service. The work in this thesis focuses on the design, implementation, and evaluation of a partially reliable transport protocol called PRTP. PRTP has been designed as an extension to TCP in order to show that such a service could be effectively integrated with current protocol standards. An important feature of PRTP is that all modifications for PRTP are restricted to the receiver side, which means that it could be very easily deployed. The thesis presents performance results from various experiments on a Linux implementation of PRTP. The results suggest that transfer times can be decreased significantly when using PRTP as opposed to TCP in networks in which packet loss occurs. Furthermore, the thesis includes a study that investigates how users perceive an application that is based on a partially reliable service. Specifically, how users select the trade-off between image quality and latency when they download Web pages is explored. The results indicate that many of the users in the study could accept less than perfect image quality if the latency could be shortened.
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| 43. |
- Asplund, Katarina, et al.
(författare)
-
Partially Reliable Multimedia Transport
- 2004
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The ongoing deployment of applications that transmit multimedia data makes it important for the Internet to better accommodate the service requirements of this type of applications. One approach is to provide a partially reliable service, i.e. a service that does not insist on recovering all but only some of the packet losses, thus providing less delay than a reliable transport service. This technical report describes a transport protocol that provides a partially reliable service. The protocol, called PRTP, is especially aimed at applications with soft real-time requirements. The report also presents performance results from a number of different experiments investigating different aspects of PRTP. The results indicate that transfer times can be significantly decreased when using PRTP as opposed to TCP when packets are lost in the network.
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| 44. |
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| 45. |
- Atxutegi, Eneko, et al.
(författare)
-
On the move with TCP in current and future mobile networks
- 2017
-
Ingår i: Proceedings of the 2017 8th International Conference on the Network of the Future (NOF).. - New York, USA : IEEE. - 9781538605547 ; , s. 66-72
-
Konferensbidrag (refereegranskat)abstract
- Mobile wireless networks constitute an indispensable part of the global Internet, and with TCP the dominating transport protocol on the Internet, it is vital that TCP works equally well over these networks as over wired ones. This paper identifies the performance dependencies by analyzing the responsiveness of TCP NewReno and TCP CUBIC when subject to bandwidth variations related to movements in different directions. The presented evaluation complements previous studies on 4G mobile networks in two important ways: It primarily focuses on the behavior of the TCP congestion control in medium- to high-velocity mobility scenarios, and it not only considers the current 4G mobile networks, but also low latency configurations that move towards the overall potential delays in 5G networks. The paper suggests that while both CUBIC and NewReno give similar goodput in scenarios where the radio channel continuously degrades, CUBIC gives a significantly better goodput in scenarios where the radio channel quality continuously increases. This is due to CUBIC probing more aggressively for additional bandwidth. Important for the design of 5G networks, the obtained results also demonstrate that very low latencies are capable of equalizing the goodput performance of different congestion control algorithms. Only in low latency scenarios that combine both large fluctuations of available bandwidths and a mobility pattern in which the radio channel quality continuously increases can some performance differences be noticed.
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| 46. |
- Atxutegi, Eneko, et al.
(författare)
-
On the use of TCP BBR in cellular networks
- 2018
-
Ingår i: IEEE Communications Magazine. - New York, USA : IEEE. - 0163-6804 .- 1558-1896. ; :3, s. 172-179
-
Tidskriftsartikel (refereegranskat)abstract
- TCP BBR (Bottleneck Bandwidth and Round-trip propagation time) is a new TCP variant developed at Google, and which, as of this year, is fully deployed in Googles internal WANs and used by services such as Google.com and YouTube. In contrast to other commonly used TCP variants, TCP BBR is not loss-based but model-based: It builds a model of the network path between communicating nodes in terms of bottleneck bandwidth and minimum round-trip delay and tries to operate at the point where all available bandwidth is used and the round-trip delay is at minimum. Although, TCP BBR has indeed resulted in lower latency and a more efficient usage of bandwidth in fixed networks, its performance over cellular networks is less clear. This paper studies TCP BBR in live mobile networks and through emulations, and compares its performance with TCP NewReno and TCP CUBIC, two of the most commonly used TCP variants. The results from these studies suggest that in most cases TCP BBR outperforms both TCP NewReno and TCP CUBIC, however, not so when the available bandwidth is scarce. In these cases, TCP BBR provides longer file completion times than any of the other two studied TCP variants. Moreover, competing TCP BBR flows do not share the available bandwidth in a fair way, something which, for example, shows up when shorter TCP BBR flows struggle to get its fair share from longer ones.
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| 47. |
- Atxutegi, Eneko, et al.
(författare)
-
TCP behaviour in LTE : impact of flow start-up and mobility
- 2016
-
Ingår i: Wireless and Mobile Networking Conference (WMNC), 2016 9th IFIP. - : IEEE Communications Society. - 9781467387460 - 9781467387477 ; , s. 73-80
-
Konferensbidrag (refereegranskat)abstract
- Mobile internet has been widely adopted and it is expected to rise to almost 4 billion users by 2020. Despite the research effort dedicated to the enhancement of its performance, there still exists a gap in the understanding of how TCP and its many variants work over LTE. To this end, this paper evaluates the extent to which five common TCP variants, CUBIC, NewReno,Westwood+, Illinois, and CAIA Delay Gradient (CDG), are able to utilise available radio resources under hard conditions, such as during start-up and in mobile scenarios at different speeds. The paper suggests that CUBIC, due to its Hybrid Slow-Start mechanism, enters congestion avoidance prematurely, and thus experiences a prolonged start-up phase. As a result, it is unable to efficiently utilise radio resources during shorter transmissionsessions. Besides, CUBIC, Illinois and NewReno, i.e., the loss-based TCP implementations, offer better throughput, and are able to better utilise available resources during mobility than Westwood+ and CDG - the delay-based variants do.
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| 48. |
- Atxutegi, Eneko, et al.
(författare)
-
TCP behaviour in LTE : impact of flow start-up and mobility
- 2016
-
Ingår i: Wireless and Mobile Networking Conference (WMNC), 2016 9th IFIP. - : IEEE. ; , s. 73-80
-
Konferensbidrag (refereegranskat)abstract
- Nowadays, more than two billion people uses the mobile internet, and it is expected to rise to almost 4 billion by 2020. Still, there is a gap in the understanding of how TCP and its many variants work over LTE. To this end, this paper evaluates the extent to which five common TCP variants, CUBIC, NewReno, Westwood+, Illinois, and CAIA Delay Gradient (CDG), are able to utilise available radio resources under hard conditions, such as during start-up and in mobile scenarios at different speeds. The paper suggests that CUBIC, due to its Hybrid Slow- Start mechanism, enters congestion avoidance prematurely, and thus experiences a prolonged start-up phase, and is unable to efficiently utilise radio resources during shorter transmission sessions. Still, CUBIC, Illinois and NewReno, i.e., the loss-based TCP implementations, offer better throughput, and are able to better utilise available resources during mobility than Westwood+ and CDG – the delay-based variants do.
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| 49. |
- Atxutegi, Eneko, et al.
(författare)
-
TCP Performance over Current Cellular Access : A Comprehensive Analysis
- 2018
-
Ingår i: Autonomous Control for a Reliable Internet of Services. - Cham : Springer. - 9783319904146 ; , s. 371-400, s. 371-400
-
Bokkapitel (refereegranskat)abstract
- Mobile internet usage has significantly raised over the last decade and it is expected to grow to almost 4 billion users by 2020. Even after the great effort dedicated to the improvement of the performance, there still exist unresolved questions and problems regarding the interaction between TCP and mobile broadband technologies such as LTE. This chapter collects the behavior of distinct TCP implementation under various network conditions in different LTE deployments including to which extent the performance of TCP is capable of adapting to the rapid variability of mobile networks under different network loads, with distinct flow types, during start-up phase and in mobile scenarios at different speeds. Loss-based algorithms tend to completely fill the queue, creating huge standing queues and inducing packet losses both under stillness and mobility circumstances. On the other side delay-based variants are capable of limiting the standing queue size and decreasing the amount of packets that are dropped in the eNodeB, but they are not able under some circumstances to reach the maximum capacity. Similarly, under mobility in which the radio conditions are more challenging for TCP, the loss-based TCP implementations offer better throughput and are able to better utilize available resources than the delay-based variants do. Finally, CUBIC under highly variable circumstances usually enters congestion avoidance phase prematurely, provoking a slower and longer start-up phase due to the use of Hybrid Slow-Start mechanism. Therefore, CUBIC is unable to efficiently utilize radio resources during shorter transmission sessions.
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| 50. |
- Aumayr, E., et al.
(författare)
-
Service-based Analytics for 5G open experimentation platforms
- 2022
-
Ingår i: Computer Networks. - : Elsevier B.V.. - 1389-1286 .- 1872-7069. ; 205
-
Tidskriftsartikel (refereegranskat)abstract
- A scalable, flexible and reliable Analytics service has become a requirement toward building efficient Fifth Generation (5G) experimental platforms that can support a suite of end-user experiments and verticals. Our paper presents the challenges that come with designing such a service-based Analytics component, and shows how we have used it in the context of open experimental platforms in the 5GENESIS project. Our Analytics service was designed both for enabling the efficient setup and configuration of the underlying platform, and also for ensuring that it provides useful insights into the experimentation Key Performance Indicators (KPIs) toward the end-user. Thus, Analytics proved to be a useful tool across several stages, starting from ensuring correct operation during the initial phases of the network setup and continuing into the normal day-to-day experimentation. Our experiments show how the tool was used in our setup and provide information on how to apply it to different environments. The Analytics component, designed as a set of microservices that serve several goals in the analytics workflow, is also provided as open source, being part of the Open5Genesis suite.
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