Dynamic Bandwidth Allocation Technique Research Articles

A Joint CAC and Dynamic Bandwidth Allocation Technique for Capacity and QoS Analysis in Heterogeneous LTE based BWA Network: Few Case Studies

Broadband Wireless Access (BWA) network such as LTE brings heterogeneity in terms of different radio access technologies, multi-tier architectures and co-implementation of various protocols to support various types of services with desired Quality of Service (QoS) for the subscribers. However, due to limited bandwidth and high demand of LTE-BWA networks, effective network planning is required to utilize the available radio resources in an efficient way. To achieve this target, this paper aims to implement a unique Radio Resource Management scheme for a heterogeneous LTE based BWA network (BWA Het-Nets) which consists of Small cells along with Macro cells. The proposed analysis has two components: (1) Received Signal Strength (RSS) based CAC policy; and (2) Dynamic Bandwidth Allocation (DBA) scheme for QoS provisioning. The novelty of this work lies on the integration of the RSS based CAC policy with DBA scheme for improved performance in terms of different QoS parameters like New Call Blocking Probability (NCBP), Hand off Call Dropping Probability (HCDP) and Bandwidth Utilization (BU). A Continuous Time Markov Chain based mathematical model is also developed for the realistic analysis of those QoS parameters. The Joint CAC and DBA scheme (JCAC-DBA) in two-tier LTE BWA Het-Nets significantly improves NCBP, HCDP, BU and overall capacity of the network under different combinations of macro/small cells for heterogeneous multimedia services.

Dynamic Bandwidth Allocation Supporting Diversified Queue Status Reporting for EPON Systems

Dynamic bandwidth allocation (DBA) is an indispensable function in Ethernet passive optical networks (EPONs). The DBA function implemented in an optical line terminal utilizes REPORT messages to learn about the upstream queue statuses in optical network units (ONUs). However, the methods for describing the REPORT messages are not fully standardized, which results in a lack of interoperability. This paper proposes a diversity DBA technique that can support different types of ONUs with diverse REPORT description methods. The diversity DBA technique is comprised of an identification process to differentiate REPORT description methods and an interpretation process to convert the content of different REPORT description methods. We provide simulation results to demonstrate the validity of the proposed DBA technique.

Low-Latency Dynamic Bandwidth Allocation for 100 km Long-Reach EPONs

We propose a new dynamic bandwidth allocation (DBA) method for long-reach passive optical networks that can reduce the upstream latency. With this method, an optical line terminal allocates bandwidth to long-distance (up to 100 km) optical network units (ONUs) with a transmission request prediction and reduces the latency of the long-distance ONUs. This has no influence on the latency of short-distance ONUs even if they coexist with long-distance ONUs. The results of real machine experiments show that this new DBA method achieves a smaller latency with long-distance ONUs than the conventional DBA technique, and that there is no influence on short-distance ONUs. The latency time and jitter are kept below 1300 μs and 1000 μs, respectively, for both long- and short-distance ONUs. The experimental results also reveal the effect of the proposed method on bandwidth utilization efficiency and fairness. The degradation in bandwidth utilization efficiency when one long-distance ONU is added is small (0.3%), and the fairness index degradation is negligible (less than 0.1%), when the parameters are optimized. These results indicate the validity of the proposed DBA method.

Redball: Throttling Shrew Attack in Cloud Data Center Networks

In homeland security and defense, cloud security is critical. As an increasing number of governments and organizations outsource their computing to the cloud, they at the same time make it an attractive target for terrorists and hackers. Cloud computing offers a great opportunity for improved productivity and lowered cost, however, it meanwhile raises potential security issues as attackers from around the nation or world could be its legal tenants. This paper studies one of the potential security problem, namely, legal yet malicious tenants would launch low-rate DoS (Denial of Service) attack (or Shrew attack for short) to the co-residents once they rent and control a part of computing resources. To explore the feasibility and understand the possible attack pattern, we try to identify bottlenecks in the underlying DCNs (Data Center Networks), and then attack the victim with as little traffic. Moreover, an analytical model is built to quantitatively analyze the necessary and sufficient traffic for an effective attack. Finally, we propose a universal receiver-enforced dynamic bandwidth allocation technique named Redball to enhance defense capabilities of the cloud. Redball could intelligently throttle shrew attack in DCNs by decomposing its group behavior, enforce an average fair share of bandwidth among tenants in a workconserving way, and yet sacrifice only a small proportion of flows by delaying allocating bandwidth for them. Further, our proposal modifies only the endpoints, leaving the network gears untouched.

Iterative resource pooling for bandwidth allocation in TDM-PON: algorithm, convergence and experimental evaluation

In this paper, we propose a new dynamic bandwidth allocation technique, SLIding Cycle Time (SLICT) for TDM-PON, specifically focused on ethernet passive optical network (EPON). Based on the sliding cycle time constraint, the proposed algorithm guarantees the maximum polling interval, an essential property for delay-sensitive applications and interactive services. We then introduce an iterative resource pooling that processes bursty best-effort traffic and achieves high throughput even under non-uniform upstream traffic distribution. We prove that greedy iterative resource pooling converges to equal resource allocation exponentially fast. Extensive numerical simulations show that SLICT outperforms existing techniques in all aspects: throughput, delay, packet loss and average queue size. Finally, SLICT has been implemented on an EPON FPGA board and the performance is confirmed under real traffic.

Dynamic bandwidth allocation in GEO satellite networks: A predictive control approach

The paper presents a novel approach for dynamic bandwidth allocation (DBA) in GEO satellite networks based on adaptive predictive control. In the proposed DBA scheme each satellite gateway (SG) uses an adaptive predictor to forecast the future input traffic flow along with a bandwidth controller to generate a bandwidth request to the bandwidth manager (BM) according to a receding-horizon policy, via solution of an optimal control problem. A multi-service traffic scenario is considered with a careful eye to guarantee differentiated quality of service requirements. Simulation experiments demonstrate that the predictive DBA technique proposed in this work outperforms fixed allocation as well as existing reactive DBA methods.

Dynamic bandwidth allocation technique for high speed LANs

A modified time division multiplexing scheme using a slotted ring local area network combined with token passing is proposed. The hybrid scheme allows for multiple classes of data to be transmitted over a single optical fibre simultaneously. The bandwidth allocation can be changed dynamically, thereby accommodating real-time traffic as well as large file transfers. Simulation experiments have been carried out to demonstrate the feasibility of such a scheme.