| 1. |
- Abbas, Muhammad Tahir, et al.
(author)
-
Energy-Saving Solutions for Cellular Internet of Things - A Survey
- 2022
-
In: IEEE Access. - IEEE : IEEE. - 2169-3536. ; 10, s. 62096-62096
-
Journal article (peer-reviewed)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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| 2. |
- Abbas, Muhammad Tahir, et al.
(author)
-
Guidelines for an Energy Efficient Tuning of the NB-IoT Stack
- 2020
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In: 45th IEEE Conference on Local Computer Networks (LCN). - : IEEE Communications Society. ; , s. 60-69
-
Conference paper (peer-reviewed)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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| 3. |
- Abbas, Muhammad Tahir, et al.
(author)
-
Impact of Tunable Parameters in NB-IoT Stack onthe Energy Consumption
- 2019
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In: Proceedings of Fifteenth Swedish National Computer Networking Workshop (SNCNW).
-
Conference paper (peer-reviewed)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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| 4. |
- Abbas, Muhammad Tahir
(author)
-
Improving the Energy Efficiency of Cellular IoT Device
- 2023
-
Licentiate thesis (other academic/artistic)abstract
- Cellular Internet of Things (CIoT) has emerged as a promising technology to support applications that generate infrequent data. One requirement on these applications, often battery-powered devices, is low energy consumption to enable extended battery life. Narrowband IoT (NB-IoT) is a promising technology for IoT due to its low power consumption, which is essential for devices that need to run on battery power for extended periods. However, the current battery life of NB-IoT devices is only a few years, which is insufficient for many applications. This thesis investigates the impact of energy-saving mechanisms standardized by 3GPP on battery life of NB-IoT devices. The main research objective is to classify and analyze existing energy-saving solutions for CIoT and examine their limitations, to study the impact of standardized energy-saving mechanisms on the battery life of NB-IoT devices, both in isolation and combined, and to provide guidelines on how to configure NB-IoT devices to reduce energy consumption efficiently. The research aims to provide a deeper understanding of the effect of energy-saving mechanisms and best practices to balance energy efficiency and performance of NB-IoT devices. Applying the proposed solutions makes it possible to achieve a battery life of 10~years or more for CIoT devices.
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| 5. |
- Abbas, Muhammad Tahir, et al.
(author)
-
On the Energy-efficient Use of Discontinuous Reception and Release Assistance in NB-IoT
- 2022
-
Conference paper (peer-reviewed)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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| 6. |
- Abbas, Muhammad Tahir, et al.
(author)
-
Towards zero-energy : Navigating the future with 6G in Cellular Internet of Things
- 2024
-
In: Journal of Network and Computer Applications. - : Elsevier. - 1084-8045 .- 1095-8592. ; 230
-
Journal article (peer-reviewed)abstract
- The Cellular Internet of Things (CIoT) has seen significant growth in recent years. With the deployment of 5G, it has become essential to reduce the power consumption of these devices for long-term sustainability. The upcoming 6G cellular network introduces the concept of zero-energy CIoT devices, which do not require batteries or manual charging. This paper focuses on these devices, providing insight into their feasibility and practical implementation. The paper examines how CIoT devices use simultaneous wireless information and power transfer, beamforming, and backscatter communication techniques. It also analyzes the potential use of energy harvesting and power management in zero-energy CIoT devices. Furthermore, the paper explores how low-power transceivers can lower energy usage while maintaining dependable communication functions.
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| 7. |
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| 8. |
- Eklund, Johan, 1966-, et al.
(author)
-
Delay Penalty during SCTP Handover
- 2011
-
Conference paper (peer-reviewed)abstract
- The rapidly growing interest in untethered Internet connections such as WLAN and 3G/4G mobile connections,calls for intelligent session management, not least in terms of handovers. As part of an effort to develop a SCTP-based session management framework, we are studying ways of improving the SCTP handover delay forreal-time traffic by optimizing the startup delay on the handover-target path. We have developed a theoretical model that predicts the transfer times of SCTP messages during the startup on a new path. This paper validates our model. It shows that the model can be used to predict message transfer times in variable bitrate flows. The paper further employs our model to study the startup delay penalty during handover for the spectrum of network conditions considered relevant for real-time traffic over mobile connections.
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| 9. |
- Eklund, Johan, 1966-, et al.
(author)
-
Efficient Scheduling to Reduce Latency for Signaling Traffic using CMT-SCTP
- 2016
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In: 27th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), September 4-7, Valencia, Spain. - : IEEE. - 9781509032549 ; , s. 2127-2132
-
Conference paper (peer-reviewed)abstract
- To mitigate delay spikes during transmission of bursty signaling traffic, concurrent multipath transmission (CMT) over several paths in parallel could be an option. Still, unordered delivery is a well known problem when concurrently transmitting data over asymmetric network paths, leading to extra delay due to Head-of-Line Blocking (HoLB). The Stream Control Transmission Protocol (SCTP), designed as a carrier for signaling traffic over IP, is currently being extended with support for CMT (CMT-SCTP). To reduce the impact of HoLB, SCTP has support for transmission of separate data flows, called SCTP streams. In this paper, we address sender scheduling to optimize latency for signaling traffic using CMT-SCTP. We present dynamic stream-aware (DS) scheduling, which utilizes the SCTP stream concept, and continuously considers the current network status as well as the data load to make scheduling decisions. We implement a DS scheduler and compare it against some existing schedulers. Our investigation suggests that DS scheduling could significantly reduce latency compared to dynamic path scheduling that does not consider streams. Moreover, we show that naive round-robin scheduling may provide low latency over symmetric network paths, but may transmit data on non-beneficial asymmetric network paths leading to increased latency. Finally, our results show that a static stream based approach, found beneficial for bulk traffic, is not appropriate for bursty signaling traffic.
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| 10. |
- Eklund, Johan, 1966-, et al.
(author)
-
Impact of slow start on SCTP handover performance
- 2011
-
In: Proc Int Conf Comput Commun Networks ICCCN. - : IEEE conference proceedings. - 9781457706387
-
Conference paper (peer-reviewed)abstract
- The rapidly growing interest in untethered Internet connections, especially in terms of WLAN and 3G/4G mobile connections, calls for intelligent session management: a mobile device should be able to provide a reasonable end-user experience despite location changes, disconnection periods and, not least, handovers. As part of an effort to develop a SCTP-based session management framework that meets these criteria, we are studying ways of improving the SCTP handover delay for real-time traffic; especially the startup delay on the connection between a mobile device and the target access point. To obtain an appreciation of the theoretically feasible gains of optimizing the startup delay on the handover-target path, we have developed a model that predicts the transfer times of SCTP messages during slow start. This paper experimentally validates our model and demonstrates that it could be used to predict the message transfer times in a variable bitrate flow by approximating the variable flow with a constant dito. It also employs our model to obtain an appreciation of the startup delay penalties incured by slow start during handovers in typical mobile, real-time traffic scenarios.
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| 11. |
- Eklund, Johan, 1966-, et al.
(author)
-
Implications of using a Large Initial Congestion Window to Improve mSCTP Handover Delay
- 2012
-
In: MOBILITY 2012 : The Second International Conference on Mobile Services, Resources, and Users. - : IARIA. - 9781612082295 ; , s. 116-121
-
Conference paper (peer-reviewed)abstract
- The currently rather heterogeneous wireless landscape makes handover between different network technologies, so-called vertical handover, a key to a continued success for wireless Internet access. Recently, an extension to the Stream Control Transmission Protocol (SCTP) – the Dynamic Address Reconfiguration (DAR) extension – was standardized by IETF. This extension enables the use of SCTP for vertical handover. Still, the way vertical handover works in SCTP with DAR makes it less suitable for real-time traffic. Particularly, it takes a significant amount of time for the traffic to ramp up to full speed on the handover target path. In this paper, we study the implications of an increased initial congestion window for real-time traffic on the handover target path when competing traffic is present. The results clearly show that an increased initial congestion window could significantly reduce the transfer delay for real-time traffic, provided the fair share of the available capacity on the handover target path is sufficiently higher than the send rate required by the real-time flow. Additionally, we notice that this performance gain comes without penalizing the competing traffic.
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| 12. |
- Eklund, Johan, 1966-, et al.
(author)
-
Improving mSCTP-based Vertical Handovers by Increasing the Initial Congestion Window
- 2011
-
Conference paper (peer-reviewed)abstract
- Wireless networks play an increasingly important role in our daily lives. However, the wireless landscape comprises serveralnetwork technologies, and which technology to use is often context dependent and varies over time: In urban areas, WiFi viaa WiFi hotspot might be the preferred access technology, while in rural areas 3G, HSPA or some other 3GPP technologymight be the only viable alternative. To this end, a large number of vertical handover solutions, ranging from link-level toapplication-level solutions, has been proposed in the past several years.We believe that the Stream Control Transmission Protocol and its extension for Dynamic Address Reconfiguration (mSCTP)make up an attractive vertical handover solution, especially in cases where there are little or no economic incentives to modify orupgrade the existing network infrastructure. Currently, we are implementing an mSCTP-based mobility management frameworkfor Android smartphones and tablets, and as part of that work we are considering ways of mitigating the effects of a handoveron ongoing transport sessions.A mobile terminal with several network interfaces may traverse different types of networks (WLAN, UMTS, HSPA).A seamless handover between these networks may be achieved by the transport protocol, Stream Control TransmissionProtocol(SCTP), with its multihoming facility (mSCTP), in conjunction with a mobility manager monitoring the availablenetwork interfaces. SCTP, a reliable transport protocol, closely related to TCP, encompasses slow-start in the beginning of asession. This slow-start phase is also activated to probe for network capacity on the target path after a handover, which couldresult in unncessarily reduced throughput in case of spare capacity in the network. The throughput degradation in could becrucial for an ongoing real time session, like video conferencing. In this study we have conducted experiments on the benefitof increasing the initial congestion window to reduce the negative impact of the slow start phase. We have by experimentsquantified the performance gain from an increasd initial window, and have seen that there a reduction in maximum transfertime for a message of about 50 % in scenarios with real-time video, compared to the default initial congestion window. Theimprovement is most prominent in sessions with high transfer delays. One easy, and thus very attractive, way to improveon the handover performance is to increase the initial congestion window on the handover target path. Although a seeminglycontroversal proposition, one should bear in mind that researchers at Google and other cloud computing companies are currentlystrongly promoting a drastic increase of TCP’s initial congestion window within IETF.
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| 13. |
- Eklund, Johan, 1966-, et al.
(author)
-
On the Impact of Data Scheduling to Reduce Latency for Telephony Signaling Traffic using CMT-SCTP
- 2015
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In: The 11th Swedish National Computer Networking Workshop (SNCNW), Karlstad, Sweden, May 28-29, 2015..
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Conference paper (other academic/artistic)abstract
- SCTP is a transport protocol targeted for telephony signaling traffic. Although SCTP from its inception supported multihoming, it has until now not supported concurrent mul- tipath transfer. However, this is about to change: Currently a standard for concurrent multipath transfer is underway. Since it is unclear whether concurrent multipath transfer could reduce transmission latency, this paper evaluates two algorithms for scheduling signaling traffic for transmission. We find that the mechanisms may provide good performance and to some extent enables for service differentiation. Still, the results indicate that unpredictable traffic require dynamic scheduling.
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| 14. |
- Eklund, Johan, 1966-, et al.
(author)
-
On the Relation Between SACK Delay and SCTP Failover Performance for Different Traffic Distributions
- 2008
-
In: Proceedings on the Fifth International Conference on Broadband Communications, Networks and Systems. - : IEEE. - 9781424423910 ; , s. 577-584
-
Conference paper (peer-reviewed)abstract
- The stream control transmission protocol (SCTP) is an important component in the ongoing evolution towards IP in the fixed and mobile telephone networks. It is the transport protocol being used in the ongoing deployment of IETFpsilas signaling transport (SIGTRAN) architecture for tunneling of traditional telephony signaling traffic over IP. Further SCTP represents an alternative for future SIP signaling traffic. Key to the success of SCTP is its ability to recover from network failures, in particular failed network paths. SCTP includes multihoming and a failover mechanism which should swiftly shift from a failed or unavailable network path to a backup path. However, several studies have shown that SCTPpsilas failover performance is dependent on factors both related to protocol parameters and network conditions. This paper complements these studies by providing a comprehensive evaluation of the impact of SACK delay under various traffic distributions. The results show a clear relation between the traffic distribution and the impact of the SACK delay on SCTP failover performance. Severe negative effects are observed for low intensity traffic composed of individual signaling messages. On the other hand, our results show limited impact of SACK delay for high intensity and bursty traffic. Furthermore, the results show a limited increase in network traffic by reducing the SACK delay at low traffic intensities and even less impact on network traffic at high traffic intensities. Based on these results we recommend a decrease of the SCTP SACK timer to a small value in signaling scenarios
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| 15. |
- Eklund, Johan, 1966-, et al.
(author)
-
On the Use of an Increased Initial Congestion Window to Improve mSCTP Handover Performance
- 2012
-
In: WAINA 2012. - : IEEE Press. - 9780769546520 ; , s. 1101-1106
-
Conference paper (peer-reviewed)abstract
- With the wireless landscape being ratherheterogeneous, handover between different networktechnologies, so-called vertical handover, becomes keyto a continued success for wireless Internet access.Recently, an extension to the Stream Control Trans-mission Protocol (SCTP) – the Dynamic Address Re-configuration (DAR) extension – was standardized bythe IETF. This extension enables the use of SCTPfor vertical handover. Still, the way vertical handoverworks in SCTP with DAR makes it less suitable for real-time traffic. Particularly, it takes a significant amountof time for the traffic to ramp up to full speed on thehandover target path. In this paper, we study the ex-tent to which an increased initial congestion window onthe handover target path decreases the transfer delayspikes in real-time video traffic experienced during avertical handover. The impact on both standard andhigh-definition video traffic is considered. The resultsof our study suggest that an increased initial congestionwindow does indeed significantly decrease the spikes inthe video traffic. However, the results also indicate thatit does not resolve the problem altogether.
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| 16. |
- Eklund, Johan, 1966-, et al.
(author)
-
Stream-aware Scheduling to Improve Latency for Signaling Traffic using CMT-SCTP
- 2016
-
Conference paper (peer-reviewed)abstract
- To mitigate delay spikes during transmission ofbursty signaling traffic, concurrent multipath transmission(CMT) over several paths in parallel could be an option. Still,unordered delivery is a well known problem when transmittingover asymmetric network paths, leading to extra delay due toHead-of-Line Blocking (HoLB). The Stream Control TransmissionProtocol (SCTP) is designed as a carrier for signaling trafficover IP to reduce the impact of HoLB. SCTP has support fortransmission of separate flows, called SCTP streams. SCTP iscurrently being extended with support for CMT (CMT-SCTP). Inthis paper, we address sender scheduling to optimize latency forsignaling traffic over CMT-SCTP. We present dynamic streamaware(DS) scheduling, which utilizes the SCTP stream concept,and continuously considers the current network status as well asthe data load to make scheduling decisions. We implement a DSScheduler and compare it against a dynamic path (DP) schedulerthat does not consider streams. Our investigation shows that DSscheduling could significantly reduce latency compared to a DPscheduler.
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| 17. |
- Eklund, Johan, 1966-, et al.
(author)
-
Theoretical Analysis of an Ideal Startup Scheme in Multihomed SCTP
- 2010
-
In: Networked Services and Applications - Engineering, Control and Management. - Berlin, Heidelberg : Springer. - 9783642139703 ; , s. 155-166
-
Conference paper (peer-reviewed)abstract
- SCTP congestion control includes the slow-start mechanism to probe the network for available bandwidth. In case of a path switch in a multihomed association, this mechanism may cause a sudden drop in throughput and increased message delays. By estimating the available bandwidth on the alternate path it is possible to utilize a more efficient startup scheme. In this paper, we analytically compare and quantify the degrading impact of slow start in relation to an ideal startup scheme. We consider three different scenarios where a path switch could occur. Further, we identify relevant traffic for these scenarios. Our results point out that the most prominent performance gain is seen for applications generating high traffic loads, like video conferencing. For this traffic, we have seen reductions in transfer time of more than 75% by an ideal startup scheme. Moreover, the results show an increasing impact of an improved startup mechanism with increasing RTTs
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| 18. |
- Eklund, Johan, 1966-, et al.
(author)
-
Using multiple paths in SCTP to reduce latency for signaling traffic
- 2018
-
In: Computer Communications. - : Elsevier. - 0140-3664 .- 1873-703X. ; 129, s. 184-196
-
Journal article (peer-reviewed)abstract
- The increase in traffic volumes as well as the heterogeneity in network infrastructure in the upcoming 5G cellular networks will lead to a dramatic increase in volumes of control traffic, i.e., signaling traffic, in the networks. Moreover, the increasing number of low-power devices with an on-off behavior to save energy will generate extra control traffic. These increased traffic volumes for signaling traffic, often generated as bursts of messages, will challenge the signaling application timing requirements on transmission. One of the major transport protocols deployed for signaling traffic in cellular networks is the Stream Control Transmission Protocol (SCTP), with support for multiple paths as well as for independent data flows. This paper evaluates transmission over several paths in SCTP to keep the latency low despite increasing traffic volumes. We explore different transmission strategies and find that concurrent multipath transfer over several paths will significantly reduce latency for transmission over network paths with the same or similar delay. Still, over heterogeneous paths, careful, continuous sender scheduling is crucial to keep latency low. To this end, we design and evaluate a sender scheduler that considers path characteristics as well as queuing status and data flows of different priority to make scheduling decisions. Our results indicate that by careful dynamic sender scheduling, concurrent multipath transfer could lead to reduced latency for signaling traffic irrespective of path or traffic characteristics.
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| 19. |
- Grinnemo, Karl-Johan, 1968-, et al.
(author)
-
A Taxonomy and Survey of Retransmission Based Partially Reliable Transport Protocols
- 2002
-
Reports (other academic/artistic)abstract
- The mismatch between the services offered by the two standard transport protocols inthe Internet, TCP and UDP, and the services required by distributed multimedia applicationshas led to the development of a large number of partially reliable transportprotocols. That is, protocols which in terms of reliability places themselves betweenTCP and UDP. This paper presents a taxonomy for retransmission based, partially reliabletransport protocols, i.e., the subclass of partially reliable transport protocols thatperforms error recovery through retransmissions. The taxonomy comprises two classificationschemes: one that classifies retransmission based, partially reliable transportprotocols with respect to the reliability service they offer and one that classifies themwith respect to their error control scheme. The objective of our taxonomy is fourfold:to introduce a unified terminology; to provide a framework in which retransmissionbased, partially reliable transport protocols can be examined, compared, and contrasted;to make explicit the error control schemes used by these protocols; and, finally, to gainnew insights into these protocols and thereby suggest avenues for future research. Basedon our taxonomy, a survey was made of existing retransmission based, partially reliabletransport protocols. The survey shows how protocols are categorized according to ourtaxonomy, and exemplifies the majority of reliability services and error control schemesdetailed in our taxonomy.
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| 20. |
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| 21. |
- Nguyen, Van-Giang, 1989-, et al.
(author)
-
On Auto-scaling and Load Balancing for User-plane Functions in a Softwarized 5G Core
- 2021
-
In: Proceedings of the 2021 17th International Conference on Network and Service Management: Smart Management for Future Networks and Services, CNSM 2021. - : IEEE. - 9783903176362 ; , s. 132-138
-
Conference paper (peer-reviewed)abstract
- In the fifth generation (5G) mobile networks, the number of user plane functions has increased, and, in contrast to previous generations. They can be deployed in a decentralized way and auto-scaled independently from their control plane functions. Moreover, the performance of the user plane functions can be boosted with the adoption of advanced acceleration techniques such as Vector Packet Processing (VPP). However, the increased number of user plane functions has also made load balancing a necessity, something we find has so far received little attention. Moreover, the introduction of VPP poses a challenge to the design of the auto-scaling of user-plane functions. In this paper, we address these two challenges by proposing a novel performance indicator for making better auto-scaling decisions, and by proposing three new dynamic load-balancing algorithms for the user plane of a VPP-based, softwarized 5G network. The novel performance indicator is estimated based on the VPP vector rate, and is used as a threshold for the auto-scaling process. The dynamic load-balancing algorithms take into account the number of bearers allocated for each user plane function and their VPP vector rate. We validated and evaluated our proposed solution in a 5G testbed. Our experiment results show that the scaling helps to reduce the packet latency for the user plane traffic, and our proposed load-balancing algorithms seem to give a better distribution of traffic load as compared to traditional static algorithms.
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| 22. |
- Nguyen, Van-Giang, 1989-, et al.
(author)
-
On Auto-scaling and Load Balancing for User-plane Gateways in a Softwarized 5G Network
- 2021
-
In: Proceedings of the 2021 17th International Conference on Network and Service Management. - : IEEE. - 9783903176362 ; , s. 132-138
-
Conference paper (peer-reviewed)abstract
- In the fifth generation (SG) mobile networks, the number of user-plane gateways has increased, and, in contrast to previous generations they can be deployed in a decentralized way and auto-scaled independently from their control-plane functions. Moreover, the performance of the user-plane gateways can be boosted with the adoption of advanced acceleration techniques such as Vector Packet Processing (VPP). However, the increased number of user-plane gateways has also made load balancing a necessity, something we find has so far received little attention. Moreover, the introduction of VPP poses a challenge to the design of the auto-scaling of user- plane gateways. In this paper, we address these two challenges by proposing a novel performance indicator for making better auto-scaling decisions, and by proposing three new dynamic load- balancing algorithms for the user plane of a VPP-based, softwarized SG network. The novel performance indicator is estimated based on the VPP vector rate and is used as a threshold for the auto-scaling process. The dynamic load-balancing algorithms take into account the number of bearers allocated for each user-plane gateway and their VPP vector rate. We validate and evaluate our proposed solution in a SG testbed. Our experiment results show that the scaling helps to reduce the packet latency for the user-plane traffic, and that our proposed load-balancing algorithms can give a better distribution of traffic load as compared to traditional static algorithms.
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| 23. |
- Oljira, Dejene Boru, et al.
(author)
-
MDTCP: Practical Latency-Aware Multipath Con- gestion Control for Datacenter Networks
-
Other publication (other academic/artistic)abstract
- Datacenter applications generate a mix of short and long flows, which have often contrasting network performance requirements. While short flows are typically sensitive to their completion time, long flows are more or less deadline agnostic but demand high throughput. Despite the availability of multiple, parallel high-capacity paths inside a datacenter network, the achievable transport-layer performance for both latency-sensitive and capacity-demanding applications is far from optimal. The reason is partly due to the inefficiency of transport protocols deployed inside datacenters. Existing transport protocols are either not capable of utilizing multiple paths offered by datacenter topologies, e.g., Datacenter TCP (DCTCP) or unsuitable for latency-sensitive applications, e.g., Multipath TCP (MPTCP), due to the employed congestion detection schemes. To address this problem, we have designed a coupled multipath congestion control algorithm called Multipath Datacenter TCP (MDTCP). MDTCP builds upon MPTCP and uses Explicit Congestion Notification (ECN) signals to detect and react to congestion before queues overflow as in DCTCP, offering both reduced latency and higher network utilization. The MDTCP congestion control has been implemented in the Linux kernel and in a packet- level network simulator. We evaluate MDTCP’s performance extensively both in a programmable datacenter network testbed andin large-scale simulations. The obtained results show that MDTCP outperforms DCTCP by reducing the average Flow Completion Time (FCT) by more than 1.6× at high load, and achieves similar performance as DCTCP at moderate network load. Moreover, it outperforms MPTCP by always achieving a lower average FCT. MDTCP also improves network utilization by 7% and 12% compared to MPTCP and DCTCP, respectively.
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| 24. |
- Söderman, Pehr, et al.
(author)
-
Handover in the Wild : The feasibility of vertical handover in commodity smartphones
- 2013
-
In: Communications (ICC), 2013 IEEE International Conference on. - : IEEE conference proceedings. - 9781467331227 ; , s. 6401-6406
-
Conference paper (peer-reviewed)abstract
- Today commodity mobile devices are equipped withmultiple wireless access technologies. To enable continuous connectivityit is vital that these terminals provide for vertical handover between different technologies. Particularly, they should provide a vertical handover that complies with the timeliness requirements of soft real-time applications. Considering aspects such as cost- and ease-of-deployment, application neutrality, and, not least, the emergence of transport protocols that support multi-homing such as mobile SCTP and multi-path TCP, we think it would be beneficial to handle vertical handover in thetransport layer of the mobile terminal. This paper demonstrates through several real-world experiments, the feasibility of using a lightweight vertical handover scheme in smart mobile terminals for live video streaming. The vertical handover criteria is basedon the received signal strength. Our experiments suggest that thescheme indeed provides for seamless vertical handover at walking speed – our target scenario. However, the experiments also suggest that the scheme gives significant reductions in handovertime, as compared to mobile SCTP without improvements, at higher speeds.
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| 25. |
- Vestin, Jonathan, 1989-, et al.
(author)
-
Programmable Event Detection for In-Band Network Telemetry
- 2019
-
In: Proceeding of the 2019 IEEE 8th International Conference on Cloud Networking, CloudNet 2019. - : IEEE.
-
Conference paper (peer-reviewed)abstract
- In-Band Network Telemetry (INT) is a novel framework for collecting telemetry items and switch internal state information from the data plane at line rate. With the suppor programmable data planes and programming language P4,switches parse telemetry instruction headers and determine which telemetry items to attach using custom metadata. At the network edge, telemetry information is removed and the original packets are forwarded while telemetry reports are sent to a distributed stream processor for further processing by a network monitoring platform. In order to avoid excessive load on the stream processor, telemetry items should not be sent for each individual packet but rather when certain events are triggered. In this paper, we develop a programmable INT event detection mechanism in P4 that allows customization of which events to report to the monitoring system, on a per-flow basis, from the control plane. At the stream processor, we implement a fast INT report collector using the kernel bypass technique AF XDP, which parses telemetry reports and streams them to a distributed Kafka cluster, which can apply machine learning, visualization and further monitoring tasks. In our evaluation, we use realworld traces from different data center workloads and show that our approach is highly scalable and significantly reduces the network overhead and stream processor load due to effective event pre-filtering inside the switch data plane. While the INT report collector can process around 3 Mpps telemetry reports per core, using event pre-filtering increases the capacity by 10-15x.
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