11793175
Internet Traffic Characterization Using Packet-Pair Probing
This paper presents an edge-based Internet traffic characterization approach. Our objective is to estimate the marginal distribution and the correlation structure of the packet arrival process at a queue, by sending probe packet pairs with a specific dispersion to sample the traffic. The aggregate work load process inferred from the output dispersions is a compound process of the packet arrival process and the packet size distribution. We show that the packet arrival marginal distribution and the packet size distribution can be decoupled by using the probability generating function; given one of the distributions, the other can then be estimated. We use the fact that the Internet packet size follows a known multi-modal distribution. Moreover, multiple series of packet pairs with different input dispersions can be used to estimate the packet arrival process at different time scales, and therefore to estimate the Hurst parameter, which characterizes the long-range dependence, by generating the variance-time plot. While the traffic characterization techniques are developed and validated in a single-queue context, we indicate how the techniques can be applied to a black box system for end-to-end quality of service provisioning along a multi-hop path.
31421692
Efficient resource allocation for SLA based wireless/wireline interworking
This paper proposes efficient resource allocation techniques for a domain-based wireless/wireline interworking architecture. Resource allocation is driven by the service level agreement (SLA). Each wireless domain can freely choose its internal resource management schemes to guarantee the customer access SLA (CASLA), while the border-crossing traffic is served by a DiffServ/MPLS core network according to the transit domain SLA (TRSLA). Specifically, we propose an engineered priority scheme for a cellular wireless domain, where the CASLA for each service class is met with efficient resource utilization and the interdomain TRSLA bandwidth requirement can be obtained conveniently. In the transit domain, the traffic load fluctuation from upstream access domains is tackled with an inter-TRSLA resource sharing technique, where the spare capacity from underloaded TRSLAs can be exploited by the overloaded TRSLAs to improve resource utilization.
15761102
Dynamic inter-SLA resource sharing in path-oriented differentiated services networks
This paper proposes novel resource sharing schemes for differentiated services (DiffServ) networks, to achieve both high resource utilization and quality of service (QoS) guarantee. Service level agreements (SLAs) are negotiated at network boundaries and supported by path-oriented resource mapping within the network. The recently proposed SLA management scheme based on virtual partitioning (Bouillet et al., 2002) allows overloaded SLAs to exploit the spare capacity of underloaded SLAs for efficient resource utilization, however, at the the cost of possible SLA violation of the underloaders. In the bandwidth borrowing scheme proposed here, the dedicated bandwidth for underloaded SLAs is determined and adaptively adjusted at network boundaries according to the actual traffic load and QoS policies; the available spare capacity is then properly distributed to related links for lending to others. On the other hand, the traffic flows admitted with borrowed bandwidth are tagged and may be preempted later when the original bandwidth owner needs to claim back the resources. Through a detailed implementation design and extensive computer simulation results we show that, by bandwidth borrowing, both SLA compliance and high resource utilization can be achieved in various load conditions, with some side benefits such as call-level service differentiation, small admission overhead, and convenience for policy-based management. In addition, we propose a distributed bandwidth pushing scheme that can dynamically adjust the spare bandwidth distribution over the network. Combining bandwidth pushing with bandwidth borrowing, the resource utilization can be further improved
3117733
Efficient Resource Allocation for Policy-Based Wireless/Wireline Interworking
This paper proposes efficient resource allocation techniques for a policy-based wireless/wireline interworking architecture, where quality of service (QoS) provisioning and resource allocation is driven by the service level agreement (SLA). For end-to-end IP QoS delivery, each wireless access domain can independently choose its internal resource management policies to guarantee the customer access SLA (CASLA), while the border-crossing traffic is served by a core network following policy rules to meet the transit domain SLA (TRSLA). Particularly, we propose an engineered priority resource sharing scheme for a voice/data integrated wireless domain, where the policy rules allow cellular-only access or cellular/WLAN interworked access. By such a resource sharing scheme, the CASLA for each service class is met with efficient resource utilization, and the interdomain TRSLA bandwidth requirement can be easily determined. In the transit domain, the traffic load fluctuation from upstream access domains is tackled by an inter-TRSLA resource sharing technique, where the spare capacity from underloaded TRSLAs can be exploited by the overloaded TRSLAs to improve resource utilization. Advantages of the inter-SLA resource sharing technique are that the core network service provider can freely design the policy rules that define underload and overload status, determine the bandwidth reservation, and distribute the spare resources among bandwidth borrowers, while all the policies are supported by a common set of resource allocation techniques.
28212950
Life is sharable: blogging life experience with RFID embedded mobile phones
Recent development and proliferation of mobile devices, wireless communication, and sensor technologies have prompted a new vision of social interactions in the world in which we inhabit. For example, the number of mobile phones that are capable of capturing users' spontaneous life experiences not only in pictures but also in audio and video clips is on the increase. In addition, captured experiences can be sent and shared with others over wireless networks such as WiFi, GSM, GPRS, EDGE, or recently commenced third-generation (3G) protocols. Other technology trends such as weblog and peer-to-peer communication provide a ubiquitous platform and a model of motivating users to share life experiences with other people. The hypothesis is that everyone can be an owner of a weblog which records their experience about place, people, and things that interest them. Initial form of peer-to-peer communication, centralized directory service, can help authors of weblogs attain widespread of popularity and increase the level of participation in this type of interaction. The convergence of these technologies provides new design opportunities for computer-mediated communications. The aim of this paper is to share our experiences in designing and implementing a novel physical prototype which incorporates peer-to-peer communication, weblog, RFID, wireless networking, and mobile phone technologies to enhance social quality of shared life experience.
40703514
On weakly symmetric graphs of order twice a prime
Abstract A graph is weakly symmetric if its automorphism group is both vertex-transitive and edge-transitive. In 1971, Chao characterized all weakly symmetric graphs of prime order and showed that such graphs are also transitive on directed edges. In this paper we determine all weakly symmetric graphs of order twice a prime and show that these graphs too are directed-edge transitive.
3320962
Track seeking hybrid fuzzy controller for the compact disc player
A hybrid track seeking fuzzy controller for an optical compact disc player is proposed. It is shown that the proposed hybrid fuzzy controller smoothes the applied voltage to the sled motor and improves the track seeking efficiency. The proposed hybrid fuzzy controller consists of three subsystems including parking time controller, driving force controller and parameter tuner. All three of subsystems are designed based on fuzzy inference. The hybrid fuzzy controller will on one hand drive the pickup head as fast as possible to the neighborhood of target track, it will on the other hand smoothly park the pickup head so that the fine seek controller can take over the control of pickup head.
6228406
Distributed and parallel execution of Java programs on a DSM system
The paper focuses on the loop-level parallelism of bytecode on a distributed shared memory (DSM) system, which is built on a cluster of multiprocessors. We define a new attribute called 'Loop Attribute' to record the information of Java loops. When first loading a Java program, our Java virtual machine, called ES-JVM, checks and analyzes the loops of the bytecode dynamically, handles the data dependence of loops, and records the information as the loop attributes. ES-JVM uses the virtual shared memory and synchronization mechanisms provided by the DSM system to maintain the memory consistency. Before ES-JVM interprets the loops of the bytecodes, it dispatches the workload of loops to the interpreter threads at all nodes according to the loop attributes and the number of threads. After distributed and parallel execution of the loops, ES-JVM continues to interpret the rest of the bytecodes of the Java program. Finally, ES-JVM saves the loop attributes in a new class file for the next run. Our research shows that distributed and parallel execution of loops of a Java program could improve performance.
10297562
Computational Models for the Helix Tilt Angle
The concept of hydrophobic imbalance and that of hydrophobic and hydrophilic centers are used along with side chain models in the computation of helix orientation and tilt angle in or near a membrane. Rotamer statistics are used to infer typical side chain positions and chain length for each amino acid, and the results are used in fast computation of helix orientation. Sliding windows are used to compute local tilt angles on long alpha-helices that defy idealized modeling and generate tilt angle profiles. Seven different procedures based on different formulas and hydrophobicity scales are used for comparison. These procedures generated very similar tilt angle profiles. These profiles provide insights into helix deformation, membrane destabilization, and similarity and differences between membrane proteins.