Traditional Data Networks Research Articles

Congestion-aware delay-guaranteed scheduling and routing with renewal optimization

The emergence of time-critical applications imposes great challenges on traditional best-effort data networks. Such applications demand delay-guaranteed services with different granularity. In this paper, we propose a novel fully distributed approach that provides delay-guaranteed services at the packet level within an autonomous system. Specifically, we adopt priority queues with fixed buffer sizes to provide differentiated services and per-hop delay upper bound and explore path diversity in the network to achieve multiplex gain. Network congestion is a major cause of long delay. To address this issue, a virtual queue manager is deployed at each node in the network to exchange their local queue information with neighbors periodically. The exchanged queue information reflects the congestion status of the neighborhood so the nodes can avoid congested routes in making routing decisions. Given the rich control space including routing and queuing decisions, we aim at maximizing the overall network utility. Due to the randomness caused by network dynamics, we transform the utility maximization problem into renewal optimization which is solved at each node. A delay laxity-based reward function and a weighted queue time cost are designed to characterize each decision. To solve the renewal optimization problem, an algorithm named DSROpt is proposed using an iterative approach. Extensive experiments are conducted to verify the performance of the proposed solution using NS-3. Simulation results show that the proposed solution can guarantee packet-level delay while achieving significant performance improvements in goodput and network utility over the state-of-the-art.

Data communications network for real-time industrial control systems

The advancements in network technologies and the evolution of the Internet of Things (IoT) have made supporting industrial control systems over probabilistic data networks promising. However, control systems’ communication over the traditional data networks is faced with problems of instability in feedback control and poor quality of performance due to time-varying data propagation delay. This paper presents two approaches that can enable real-time industrial control over non-deterministic computer networks allowing control system designers to take advantage of the existing communication infrastructures. The first approach is based on system-level interaction over two wires network called the collaboration network. The second approach is based on the implementation of the virtual local area network (VLAN). This method allows real-time control of industrial equipment or systems over IP-based networks while other computers are connected. Nodes providing real-time control services have the same PortID on the VLAN switch. This approach minimizes data traffic and reduces time-varying delay in system control over IP networks. The first approach was modeled and simulated using Proteus ISIS software. Two PIC16F877A microcontrollers were used to represent two nodes. CISCO packet tracer was used in the second approach to model and simulate IP-based control system communications over the traditional data network. Results indicate that the use of a two-wire collaborative network approach to a real-time control system is effective but requires an additional network alongside the main data traffic channel. VLAN, therefore, presents a more flexible approach that relies on the same infrastructures.

Service Oriented Virtual Machine for Maximising Quality of Service in Wireless Networks

A traditional big data network is a wireless multimedia network, as multiple video/audio streaming account for 70 percent of mobile traffic and the fifth generation wireless networks are projected to rise 500 times. However, it does raise various new and transparent challenges for multimedia big data communication over 5G wireless systems because multimedia big data services provide timely, throughput broadcasts through time-sensitive communication networks with restricted wireless resources. In order to address the above issues, we suggest in this paper information-centric virtualization architectures for a statistical latency consistency of content delivery across 5G wireless large media platforms for technology. In particular, three successful nominee strategies to promise the mathematical time limit for interactive large-data communications are implemented in our proposed scheme: information-centered network which extracts an optimum in-network storage location for multimedia big data; a virtualization of the network feature which transforms PHY architecture into many virtualized channels. In our architectures we build the 3 primary computer-generated machine collection besides power distribution plans to collectively simplify the application of NFV and SDN techniques in the ICN architecture: to improve performance for single users, to integrate effective combining capability with equity allocation for all users besides under non-cooperative betting Via models and computational assesses, we prove that our suggested designs and applications greatly perform better other existing systems to enable QoS provisioning with statistical delays over 5G immersive Large Data Wireless communication.

A Neural Network-Based Sustainable Data Dissemination through Public Transportation for Smart Cities

In recent years, there has been a big data revolution in smart cities dues to multiple disciplines such as smart healthcare, smart transportation, and smart community. However, most services in these areas of smart cities have become data-driven, thus generating big data that require sharing, storing, processing, and analysis, which ultimately consumes massive amounts of energy. The accumulation process of these data from different areas of a smart city is a challenging issue. Therefore, researchers have started aiming at the Internet of vehicles (IoV), in which smart vehicles are equipped with computing and storage capabilities to communicate with surrounding infrastructure. In this paper, we propose a subcategory of IoV as the Internet of buses (IoB), where public buses enable a service as a data carrier in a smart city by introducing a neural network-based sustainable data dissemination system (NESUDA), where opportunistic sensing comprises delay-tolerant data collection, processing and disseminating from one place to another place around the city. The objective was to use public transport to carry data from one place to another and to reduce the traffic from traditional networks and energy consumption. An advanced neural network (NN) algorithm was applied to locate the realistic arrival time of public buses for data allocation. We used the Auckland transport (AT) buses data set from the transport agency to validate our model for the level of accuracy in predicted bus arrival time and scheduled arrival time to disseminate data using bus services. Data were uploaded onto buses as per their dwelling time at each stop and terminals within the coverage area of deployed RSU. The offloading capacity of our proposed data dissemination system showed that it could be utilized to effectively complement traditional data networks. Moreover, the maximum offloading capacity at each parent stop could reach up to 360 GB with a huge saving of energy consumption.

Adaptive Avatar Handoff in the Cloudlet Network

In a traditional big data network, data streams generated by User Equipments (UEs) are uploaded to the remote cloud (for further processing) via the Internet. However, moving a huge amount of data via the Internet may lead to a long End-to-End (E2E) delay between a UE and its computing resources (in the remote cloud) as well as severe traffic jams in the Internet. To overcome this drawback, we propose a cloudlet network to bring the computing and storage resources from the cloud to the mobile edge. Each base station is attached to one cloudlet and each UE is associated with its Avatar in the cloudlet to process its data locally. Thus, the E2E delay between a UE and its computing resources in its Avatars is reduced as compared to that in the traditional big data network. However, in order to maintain the low E2E delay when UEs roam away, it is necessary to hand off Avatars accordingly-it is not practical to hand off the Avatars' virtual disks during roaming as this will incur unbearable migration time and network congestion. We propose the LatEncy Aware Replica placemeNt (LEARN) algorithm to place a number of replicas of each Avatar's virtual disk into suitable cloudlets. Thus, the Avatar can be handed off among its cloudlets (which contain one of its replicas) without migrating its virtual disk. Simulations demonstrate that LEARN reduces the average E2E delay. Meanwhile, by considering the capacity limitation of each cloudlet, we propose the LatEncy aware Avatar hanDoff (LEAD) algorithm to place UEs' Avatars among the cloudlets such that the average E2E delay is minimized. Simulations demonstrate that LEAD maintains the low average E2E delay.

Special issue on age of information

Information freshness at the monitoring station is of fundamental importance in the dissemination of time-critical information. Applications that rely on information freshness include networked monitoring, situational awareness and automated control (e.g., tactical networks, sensor networks, airplane/vehicular control, and Cyber-Physical Systems) applications. Other commercial applications include data analytics (e.g., crowdsourcing, financial trading, social networks, and Internet of Things) applications. Age of Information (AoI) is a concept that has recently gained prominence as a performance metric for characterizing information freshness at the receiver. It is interesting to note that improving first-order metrics such as, providing high throughput and / or low delay, that lead to improved performance in traditional data networks, are inadequate when it comes to improving information freshness. Therefore, there is a critical need to re-examine existing metrics and develop new ones for current and future real-time applications.

Coordinated and Unified Control Scheme of IP and Optical Networks for Smart Power Grid

As new services of the smart power grid emerge with diversity and complexity, great challenge and demand is presented for traditional IP data network and optical network to realize coordinated control. Benefiting from advantages of concentration, open, manageability and controllability, this paper proposes a power-grid oriented concentrated unification control architecture of IP and optical networks, together with coordinated services control mechanism, with the aim to achieve highly efficient coordination between IP network and optical network. Under this concentrated unification control architecture, an OpenFlow protocol based unified control scheme is also proposed and designed, by making full use of existing connections on optical layer to reach fast establishment for services produced by smart power grid. Therefore, the support ability of IP and optical networks to power-grid services can be greatly improved.

DDoS attacks in VoIP: a brief review of detection and mitigation techniques

Voice communication in recent trends has shown rapid growth in homes and businesses with the development of Voice over Internet Protocol (VoIP). The growth in VoIP subscribers was determined by the increase in VoIP flexibility, Quality of Service and monetary savings. The fall in public switched telephone network and raise in phone portability migrated PSTN to VoIP. The Session initiation protocol being an application layer protocol helps to create session between the caller and the called for bidirectional communication using SIP messages. The VoIP became targeted victim of different attacks as internet became the medium of transmission. The security vulnerabilities arise from new protocols and the existing infrastructure of traditional data network. Flood-based attacks are more threatening and annoying than other attacks. This brief review paper discusses on different types of VoIP attacks along with the existing VoIP detection and mitigation techniques based on Entropy, Wavelet, Sketch and Hellinger distance, Sunshine and RQA are presented.

Multicast Routing for Decentralized Control of Cyber Physical Systems with an Application in Smart Grid

In cyber physical systems, communication is needed for conveying sensor observations to controllers; thus, the design of the communication sub-system is of key importance for the stabilization of system dynamics. In this paper, multicast routing is studied for networking of decentralized sensors and controllers. The challenges of uncertain destinations and multiple routing modes, which are significantly different from traditional data networks, are addressed by employing the theories of hybrid systems and linear matrix inequalities, thus forming a novel framework for studying the communication sub-system in cyber physical systems. Both cases of neglible delay and non-negligible delay are discussed. The proposed framework is then applied in the context of voltage control in smart grid. Numerical simulations using a 4-bus power grid model show that the proposed framework and algorithm can effectively stabilize cyber physical systems.

A Dual Buffer Scheme for Combating Frame Erasure Problems in VoIP Communication

paper refers to the transmission of speech across data- style networks. This form of transmission is conceptually superior to conventional circuit switched communication in many ways. Quality of service (QoS) is fundamental to the operation of a VoIP network that meets users' quality expectations. However, the implementation of various security measures can cause a marked deterioration in QoS. These complications range from firewalls delaying or blocking call setups to encryption-produced latency and delay variation (jitter). Because of the time-critical nature of VoIP, and its low tolerance for disruption and packet loss, many security measures implemented in traditional data networks are simply not applicable to VoIP in their current form' firewalls, intrusion detection systems, and other components must be specialized for VoIP. To address the QoS issue of packet loss, this research work develops a new model making use of adative buffering technique. Our model implements dual buffers, strategically placed to manage and ameliorate frame erasure problem amongst other QoS factors. With this implementation, the new model achieved a better reduction in the amount of packet loss.

Utility optimal scheduling in processing networks

We consider the problem of utility optimal scheduling in general processing networks with random arrivals and network conditions. These are generalizations of traditional data networks where commodities in one or more queues can be combined to produce new commodities that are delivered to other parts of the network, and can be used to model problems such as in-network data fusion, stream processing, MapReduce scheduling, and grid computing. Scheduling actions are complicated by the underflow problem that arises when some queues with required components go empty. In this paper, we develop a novel methodology for constructing and analyzing online algorithms for such processing networks. Specifically, we develop the Perturbed Max-Weight algorithm (PMW) to achieve optimal utility. The idea of PMW is to perturb the weights used by the usual Max-Weight algorithm to “push” queue levels toward non-zero values (avoiding underflows). We then show, using a novel combination of Lyapunov drift analysis and duality theory, that when the perturbations are carefully chosen, PMW is able to achieve a utility that is within O ( 1 / V ) of the optimal value for any V ≥ 1 , while ensuring an average network backlog of O ( V ) . The methodology developed here is very general and can also be applied to other problems that involve such underflow constraints.

A novel use for the Apple (4th generation) iPod Touch in the operating room

There are many potential uses of video technology in the operating room; however, few have been implemented. Uses include using video for teaching best practice, monitoring team performance, skills training and operating room command and control [1]. We wish to report an innovative use of two iPod Touch™ devices (Apple, Cupertino, CA, USA) in the operating room environment that we believe have the potential to improve patient safety. The latest (4th generation) Apple iPod Touch has two built-in high definition cameras. There is a feature built into the device, called FaceTime™, that allows the devices to be used for live video-conferences. Each party can decide to use either the front-facing or rear-facing cameras, depending on what image they wish to show. The devices do not use a conventional phone signal to carry the FaceTime transmission, rather they use any local WiFi network, which is often present in healthcare facilities. An iPod Touch was mounted on a GorillaPodTM flexible tripod (Joby, San Francisco, CA, USA) using velcro. The tripod was wrapped around a standard intravenous pole mount. The rear-facing camera was pointed to a ‘patient’ monitor (we used a simulated patient to avoid transferring patient data over an unsecured internal network; Fig. 2). A FaceTime connection was established between the two devices. The second device was at a remote location within the same theatre suite (Fig. 3), but could have functioned identically anywhere else in the hospital. The ‘patient’ data were displayed on the second iPod Touch that was secured under a second ‘patient’ monitor. The patient in this case was one of the authors. We found the quality of the video display of the iPod Touch to be acceptable for viewing the vital signs of our simulated patient. There was no perceptible lag, although data transfer rates were not formally measured. The audio quality was also found to be acceptable; a conversation could be held at normal volumes. Our second test involved remote monitoring of a simulated infant undergoing tracheal intubation, and again we found the quality of both video and audio to be acceptable. iPod Touch attached to GorillaPod pointing at the ‘patient monitor’. Second iPod Touch at remote location monitoring the first patient’s vital signs. Remote supervision is routinely practiced in anaesthesia worldwide. In the UK, consultants provide junior anaesthetists with either local or distant supervision. In the USA model, one attending anaesthetist may be supervising multiple theatres, but needs to maintain situational awareness in order to be able to plan multiple operating lists. We have described an effective and relatively cheap method to conduct videoconferences in the theatre environment (iPod Touch $229, Gorillapod $30, Superglue $1.50, ¼ inch nut $0.25 and zero ongoing costs). One of the advantages of this setup is the use of a completely mobile device. The remote iPod Touch can easily be carried from location to location allowing constant situational awareness of the case in progress. As FaceTime includes video and audio, it would be easy to discuss in real time any important changes occurring during a case. Furthermore, the local iPod Touch could easily be redirected to display other pertinent information. Traditional data networks involve more ‘hardwired’ connections with less mobility and often require IT support. They also use more expensive equipment. Although this is not a substitute for an anaesthetist’s presence during a case, such a system could prove beneficial during cases without constant senior presence, thus improving supervision levels, coordination of patient flow and ultimately patient safety. Dr Low is the medical director and founder of iMobileMedic.com Ltd that makes medical software for Apple iPhones and iPods. No other external funding or competing interest declared.

Security and delay issues in SIP systems

AbstractThe deployment of multimedia over IP (MoIP), and in particular voice over IP services, requires to solve new security issues they introduce, before completely exploiting the great opportunities they offer to telecommunication market. Furthermore, the implementation of various security measures can cause a marked deterioration in quality of service, which is fundamental to the operation of an MoIP network that meets users' quality expectations. In particular, because of the time‐critical nature of MoIP and its low tolerance for disruption and packet loss, many security measures implemented in traditional data networks are simply not applicable in their current form. This paper presents an analysis of the security options of Session Initiation Protocol‐ (SIP)‐based MoIP architecture aimed at evaluating their impact on delay. In particular, each security option is analyzed in terms of clock cycles needed to perform the related operations. This parameter could be used to estimate the delay introduced by the security mechanisms. Moreover the paper proposes a rigorous definition of five security profiles, which provide different levels of security to a MoIP system. Copyright © 2009 John Wiley & Sons, Ltd.

Assessing the technical efficiency, service effectiveness, and technical effectiveness of the world’s railways through NDEA analysis

This paper presents an approach to include both the unstorable feature of transportation service and the technological differences within railway companies in efficiency and effectiveness measurements. We explore efficiency and effectiveness for a group of 40 global railways in the year 2002, using traditional data development analysis (TDEA) and network data development analysis (NDEA). Comparing the results obtained from the NDEA model with those from the TDEA indicate that performance measures are quite different in terms of the magnitude, and even using different DEA type models to evaluate railway system performance does not distort the ranking of their performance. We also analyze the inter-related effects among three performance measures, finding that transportation service characteristics have positive effects on the evaluation of performance. Generally speaking, the NDEA model provides deeper insight regarding the sources of inefficiency and process-specific guidance to railway managers so as to help them improve their railway’s performance.

Hybrid network management

To support the phenomenal growth in data bandwidth demand in carrier networks, synchronous optical network (SONET) and synchronous digital hierarchy (SDH) products are increasingly being given data interfaces. In addition, data products are providing SONET, SDH, and optical networking (ON) interfaces. These hybrid network elements, providing both data and optical transport, are being asked to deliver bandwidth and service enhancements more rapidly than ever before. Consequently, carriers need management tools to enable them to deploy new equipment and services expeditiously. Traditional optical network management systems and data network management systems address different needs, use different tools and protocols, and have different operations philosophies. To enable integration of data and transmission management and provide a scalable solution, management platforms for hybrid networks will use Common Object Request Broker Architecture (CORBA∗), develop management packages that can be distributed over a variety of management hardware, and use standard information models and protocols. These techniques will also enable multivendor network management solutions and encourage the use of third-party management applications.

A Learning Approach to Quality-of-Service Routing for Supporting Multimedia Applications

Multimedia applications such as digital video and audio often have stringent quality-of-Service (QoS) requirements. In recent years, several new architectures have been developed for supporting such applications. One Important element that is still missing from these architectures is QoS routing, namely routing based on QoS requirements.In traditional data networks, routing has been primarily concerned with connectivity. Routing Protocols usually characterize the network with a single metric such as hop-count or delay. However to support a wide range of QoS requirements, there is a need to consider multiple metrics such as bandwidth, delay and loss probability while making routing decisions. The problem of determining a path that satisfies multiple constraints is computationally very demanding and in most cases, such problems have been shown to be NP complete.In this paper, we first examine the basic problem of QoS routing and then propose a new, efficient learning algorithm for selection of the optimum path. This algorithm is subsequently utilized to make routing decisions in various routing architectures.

Protocol Conversion in Multimedia Networks: Simulation and Algorithm

Out of recently proposed high speed networks such as DQDB, FDDI, ATM, etc., various issues have been examined to determine the most suitable type of backbone network for multimedia networks[1]. At this point in time, evaluations are still inconclusive. As a result, different high speed networks using different protocols will co exist in an integrated multimedia network in the near future. Like the traditional heterogeneous data networks, the inter-operability among the interconnected heterogeneous high speed networks will be the key to success for integrated multimedia networks. On the other hand, unlike the traditional heterogeneous data networks, a simulation study presented in this paper shows that, due to the special characteristics (e.g., high speed and high connectivity) of these integrated multimedia networks, the traditional protocol conversion model will introduce long transmission delays and render a network system useless. Thus, in addition to the simulation study, efforts are made in this paper to modify the previously proposed Synchronizing Transition Set (STS)[2] algorithm to accommodate the high speed and high connectivity of a multimedia network. For the modified algorithm, the protocol compensation model is used instead of the traditional intermediate converter model while all the desirable strengths of the original STS approach are retained.

Topological and Architectural Designs for Pre-ISDN Integration of Fiber Optic Voice and Data Networks

Several inter-LATA carriers in the United States are implementing fiber optic networks. The geographic coverage of these networks coupled with the bias to choose fiber as backbone links via traditional data network design yields an opportunity for pre-ISDN integration of voice and data. This paper presents three transitional models for pre-ISDN integration of voice and data. The impact of incorporating a fiber optic network in the traditional data design formulation is demonstrated. Based upon the theoretical considerations of fiber optic incorporation, data routing, delay, throughput, and reliability are redefined, yielding an inverse design problem formulation for data. Practical considerations are presented with each transitional model.