Effectiveness of segment routing technology in reducing the bandwidth and cloud resources provisioning times in network function virtualization architectures

Network Function Virtualization is a new technology allowing for a elastic cloud and bandwidth resource allocation. The technology requires an orchestrator whose role is the service and resource orchestration. It receives service requests, each one characterized by a Service Function Chain, which is a set of service functions to be executed according to a given order. It implements an algorithm for deciding where both to allocate the cloud and bandwidth resources and to route the SFCs. In a traditional orchestration algorithm, the orchestrator has a detailed knowledge of the cloud and network infrastructures and that can lead to high computational complexity of the SFC Routing and Cloud and Bandwidth resource Allocation (SRCBA) algorithm. In this paper, we propose and evaluate the effectiveness of a scalable orchestration architecture inherited by the one proposed within the European Telecommunications Standards Institute (ETSI) and based on the functional separation of an NFV orchestrator in Resource Orchestrator (RO) and Network Service Orchestrator (NSO). Each cloud domain is equipped with an RO whose task is to provide a simple and abstract representation of the cloud infrastructure. These representations are notified of the NSO that can apply a simplified and less complex SRCBA algorithm. In addition, we show how the segment routing technology can help to simplify the SFC routing by means of an effective addressing of the service functions. The scalable orchestration solution has been investigated and compared to the one of a traditional orchestrator in some network scenarios and varying the number of cloud domains. We have verified that the execution time of the SRCBA algorithm can be drastically reduced without degrading the performance in terms of cloud and bandwidth resource costs

Association of kidney disease measures with risk of renal function worsening in patients with type 1 diabetes

Background: Albuminuria has been classically considered a marker of kidney damage progression in diabetic patients and it is routinely assessed to monitor kidney function. However, the role of a mild GFR reduction on the development of stage 653 CKD has been less explored in type 1 diabetes mellitus (T1DM) patients. Aim of the present study was to evaluate the prognostic role of kidney disease measures, namely albuminuria and reduced GFR, on the development of stage 653 CKD in a large cohort of patients affected by T1DM. Methods: A total of 4284 patients affected by T1DM followed-up at 76 diabetes centers participating to the Italian Association of Clinical Diabetologists (Associazione Medici Diabetologi, AMD) initiative constitutes the study population. Urinary albumin excretion (ACR) and estimated GFR (eGFR) were retrieved and analyzed. The incidence of stage 653 CKD (eGFR < 60 mL/min/1.73 m2) or eGFR reduction > 30% from baseline was evaluated. Results: The mean estimated GFR was 98 \ub1 17 mL/min/1.73m2 and the proportion of patients with albuminuria was 15.3% (n = 654) at baseline. About 8% (n = 337) of patients developed one of the two renal endpoints during the 4-year follow-up period. Age, albuminuria (micro or macro) and baseline eGFR < 90 ml/min/m2 were independent risk factors for stage 653 CKD and renal function worsening. When compared to patients with eGFR > 90 ml/min/1.73m2 and normoalbuminuria, those with albuminuria at baseline had a 1.69 greater risk of reaching stage 3 CKD, while patients with mild eGFR reduction (i.e. eGFR between 90 and 60 mL/min/1.73 m2) show a 3.81 greater risk that rose to 8.24 for those patients with albuminuria and mild eGFR reduction at baseline. Conclusions: Albuminuria and eGFR reduction represent independent risk factors for incident stage 653 CKD in T1DM patients. The simultaneous occurrence of reduced eGFR and albuminuria have a synergistic effect on renal function worsening

Performance evaluation of TTEthernet-based architectures for the VEGA launcher

The objective of the paper is to propose and evaluate the performance of a TTEthernet network architecture applied in small launchers in order to interconnect the terminals (on-board computer, telemetry apparatus, Inertial Reference System,...) performing the Guide, Navigation and Control (GNC) operations and producing/receiving telemetry traffic. The work described in the paper was been funded by Italian Space Agency (ASI) within the research agreement titled 'Advanced Avionic Architecture (AAA)'. Time-Triggered Ethernet (TTEthernet) improved the performance of Avionic Full Duplex Ethernet in terms of delay determinism by introducing time-triggered mechanism and by introducing a static allocation of the network capacity for the messages needing hard delay constraints. The strongest points of the TTEthernet solution applied to small launcher with respect to the classical one based on 1553B technology can be summarized as follows: i) the connections between flight stages can be limited to switch to switch connections and this reduces greatly the connectors and harness in the launcher with the consequence to reduce single points of failure, weight and complexity of assembly and integration activities during production; ii) the compatibility with Ethernet technology allows for the use of standard mass devices (PC) to perform checks and tests in standard ground operations during launch campaign; iii) the possibility to interconnect critical and non-critical equipment on the same network without the need for a physical segregation allows for cost reduction; iv) the increase in available bandwidth allows for the support of additional functional and telemetry data We propose a TTEthernet-based architecture ad hoc for small launchers and compare it to a benchmark TTEthernet architecture in which all of the traffic (GNC and telemetry) is classified as Time-Triggered. Conversely the proposed architecture operates a traffic classification in which only GNC messages with hard delay requirements are classified as Time Triggered. The remaining telemetry messages are classified as rate constrained so as to guarantee a maximum delay only. We show how the proposed traffic classification allows for advantages in terms of bandwidth efficiency and routing computational complexity. The comparison is performed when the compared communication networks handle messages extrapolated by the message set of VEGA, a small launcher jointly designed by Italian Space Agency and European Space Agency. The type and characteristic of the messages considered allows for achieving realistic results and for evaluating the effectiveness of the TTEthernet solution applied to small launchers. The results are provided in the case of star network topology with two redundant channels. We show how the adoption of a TTEthernet as launcher network allows to satisfy all of the delay requirements of GNC messages. The achieved results show how the proposed architecture allows for a 75% bandwidth saving in the most critical network link and a 50% routing table complexity reduction with respect to the benchmark architecture

Feature article: Definition and performance evaluation of an advanced avionic TTEthernet architecture for the support of launcher networks

Standard Ethernet has been well established and widely used in office and home networks known as Local Area Networks (LAN). In the recent decade, standard Ethernet has been widely adopted into other network domains such as industrial automation, automotive, railway, and aerospace domains [1], [2]. One of the main attractions of Ethernet is its high bandwidth, a bandwidth that is much higher than in other communication networks. Another one is that the prices of commercial-off-the-shelf standard Ethernet components are relatively low [3], [4]. Since standard Ethernet was not originally designed to be capable of providing temporal guarantees for real-time communication, there have been many protocol designs adapting standard Ethernet to being capable of providing such temporal guarantees. Some examples are: EtherCAT, Ethernet/ IP, PROFINET [5], Avionic Full Duplex Ethernet, and Time- Triggered (TT) Ethernet (TTEthernet) [6]

Dimensioning Models of Optical WDM Rings in Xhaul Access Architectures for the Transport of Ethernet/CPRI Traffic

The Centralized Radio Access Network (C-RAN) provides a valid solution to overcome the problem of traditional RAN in scaling up to the needed processing resource and quality expected in 5G. The Common Public Rate Interface has been defined to transport traffic flows in C-RAN and recently some market solutions are available. Its disadvantage is to increase by at least 10 times the needed bandwidth and for this reason its introduction will be gradual and will coexist with traditional RAN solutions in which Ethernet traffic is carried towards the radio base stations. In this paper, we propose an Xhaul optical network architecture based on Optical Transport Network (OTN) and Dense Wavelength Division Multiplexing (DWDM) technologies. The network allows for a dynamic allocation of the bandwidth resources according to the current traffic demand. The network topology is composed of OTN/DWDM rings and the objective of the paper is to evaluate the best configuration (number of rings and number of wavelengths needed) to both to minimize the cost and to provide an implementable solution. We introduce an analytical model for the evaluation of the number of wavelengths needed in each optical ring and provide some results for 5G case studies. We show how, although the single ring configuration provides the least cost solution due to the high statistical multiplexing advantage, it is not implementable because it needs switching apparatus with a too high number of ports. For this reason, more than one ring is needed and its value depends on several parameters as the offered traffic, the number of Radio Remote Units (RRU), the percentage of business sub-area and so on. Finally, the analytical model allows us to evaluate the advantages of the proposed dynamic resource allocation solution with respect to the static one in which the network is provided with a number of wavelengths determined in the scenario in which the radio station works at full load. The bandwidth saving can be in the order of 90% in a 5G traffic scenario

Performance Evaluation of 5G Access Technologies and SDN Transport Network on an NS3 Simulator

In this article, we deal with the enhanced Mobile Broadband (eMBB) service class, defined within the new 5G communication paradigm, to evaluate the impact of the transition from 4G to 5G access technology on the Radio Access Network and on the Transport Network. Simulation results are obtained with ns3 and performance analyses are focused on 6 GHz radio scenarios for the Radio Access Network, where an Non-Standalone 5G configuration has been assumed, and on SDN-based scenarios for the Transport Network. Inspired by the 5G Transformer model, we describe and simulate each single element of the three main functional plains of the proposed architecture to aim a preliminary evaluation of the end-to-end system performances

Evaluation of bandwidth and power consumption in reconfigurable fronthaul network architecture

The introduction of the Common Public Radio Interface (CPRI) technology allows for a centralization in Base Bandwidth Unit (BBU) of some access functions with advantages in terms of power consumption saving when switching off algorithms are implemented. Unfortunately the advantages of the CPRI technology is to be paid with an increase in bandwidth to be carried between the BBU and the Radio Remote Unit (RRU) in which only the radio functions are implemented. Bandwidth saving can be achieved with the use of a reconfigurable network carrying the traffic generated by the RRUs towards the Central Office (CO) where the BBUs are located. We introduce an analytical model to evaluate the bandwidth and power consumptions and observe how, due to statistical multiplexing effects, the savings increase when the number of RRUs managed by each of the Access Nodes of the reconfigurable network increases. For instance we show how in 5G traffic scenarios, this percentage saving can vary from 30% to 50% according to total traffic amount handled by a switching node of the reconfigurable network

Digital Twin Manager: A Novel Framework to Handle Conflicting Network Applications

In recent years, a higher number of emerging network applications boosted the adoption of new managing technology, like Digital Twin (DT). Also in networking scope, DT starts to be largely considered to model network behaviours to efficiently manage their resources. DT can be exploited to find optimal solutions, even in context where disjoint objectives are envisaged. For instance, this is the case of network application handled by an SDN Controller that pursue possibly conflicting goals. Nowadays, SDN Controller has no feature to manage this kind of contentions. This paper proposes a novel module, called Digital Twin Manager, that aims at evaluating the effects of operational changes provided by concurrent network applications by means of a Digital Twin Network, i.e., an interconnection of several DTs. DT Manager updates the digital network status in real-time and evaluates the feedback information provided by the digital applications. The proof-of-concept shows the feasibility of the proposed solution