5860855
A distributed buffer management approach supporting IPv6 mobility
In wireless local area networks (WLAN), mobility support is essential for providing seamless services. The current Mobile IP standard suffers several problems, especially for accommodating real-time media applications. Most of the existing studies focus on improving the performance between the home agent (HA) and foreign agent (FA). In this work, we propose a buffer management approach to enhance the performance between the mobility agent (HA or FA) and the mobile node (MN). The proposed scheme deals with the packet delivery between MA and MN in Layer 2. Through the simulation, we show that our scheme improves TCP throughput as well as reducing the UDP packet loss rate. Moreover, its implementation is feasible in both IPv4 and IPv6, and suitable for supporting quality of service (QoS).
894881
Performance improvement of TCP Vegas over heterogeneous networks
Current IP network has become the dominant paradigm for all networking environments. The significant cause of packet losses in such heterogenous networks is no longer limited to network congestion. Traditional TCP interprets every packet loss as caused by congestion which may be not the case in the current Internet. Misinterpretation of wireless random loss as an indication of network congestion results in TCP slowing down its sending rate unnecessarily. We propose a new variant of TCP Vegas named RedVegas. By using the innate nature of Vegas and congestion indications marked by routers, RedVegas may detect random packet losses precisely. Through the packet loss differentiation, RedVegas reacts appropriately to the losses, and therefore the throughput of connection over heterogeneous networks can be significantly improved.
18849054
An enhanced buffer management scheme for fast handover protocol
The integration of IEEE 802.11 wireless LAN and mobile IP technologies offers an affordable and high bandwidth solution for host mobility. When applying the hierarchical mobile IP for fast handover, the performance bottleneck on mobile IP and potential disconnection during handoff period can be greatly improved. However, the fast handover protocol suffers several problems such as scalability and QoS support for lacking a buffer management mechanism. We propose an enhanced buffer management scheme for fast handover. By means of the proposed scheme, we are able to improve the buffer utilization on routers as well as to support QoS services during a handoff process. Using the ns-2 simulator, we have demonstrated the significance and effectiveness of our proposed scheme.
45017187
An Agent-Based Metric for Quality of Services over Wireless Networks
In a wireless LAN environment, wireless stations with the strongest received signal can not be guaranteed to have the best quality of service if the population sharing the network capacity was not considered. In other words, within the same access point, the more the population, the less the shared bandwidth, and the worse the quality of service will be. In this paper, we proposed an Anticipative Agent Assistance which is an agent-based metric for evaluating and managing the resource of the wireless access points, computing the potential AP list, and providing clients with resource information of APs. We also propose a novel QoS feedback mechanism which allows users to promptly adjust the service quality with AAA according to the throughput and delay requirements. We evaluate the performance of our proposed method using the ns-2 simulator. Numerical results show that AAA help reduce the transmission delay, increase the throughput, improve the network utilization, accommodate more users, and provide load-balancing.
14989858
Logic of Global Synchrony
An intermediate-level specification notation, Logs, is presented for PRAM/BSP-style programming. It extends pre-post style semantics to reveal state at points of global synchronization before termination (if that occurs). The result is an integration of the pre-post, finite and reactive-process styles of specification and in particular an extension of standard BSP. The language is provided with a complete set of laws, formulated to benefit from a simple predicative semantics and to be quite close to programming intuition. The language is compositional, and parallel composition is simply logical conjunction. Use of Logs, and of the laws for reasoningab out it, is demonstrated on the problem of the dining philosophers.
8852685
Generic Composition
Abstract. This paper presents a technique called generic composition to provide a uniform basis for modal operators, sequential composition, different kinds of parallel compositions and various healthiness conditions appearing in a variety of semantic theories. The weak inverse of generic composition is defined. A completeness theorem shows that any predicate can be written in terms of generic composition and its weak inverse. A number of algebraic laws that support reasoning are derived.
8394681
ViteX: a streaming XPath processing system
We present ViteX, an XPath processing system on XML streams with polynomial time complexity. ViteX uses a polynomial-space data structure to encode an exponential number of pattern matches (in the query size) which are required to process queries correctly during a single sequential scan of XML. Then ViteX computes query solutions by probing the data structure in a lazy fashion without enumerating pattern matches.
14597615
Priority assignment optimization for minimization of current surge in high performance power efficient clock-gated microprocessor
We propose an integrated architectural/physical-planning approach named priority assignment optimization to minimize the current surge in high performance power efficient clock-gated microprocessors. The proposed approach balances the current demands across the floorplan by assigning optimized priorities to the functional units (FUs). Two complementary methods -- physical planning with soft modules and issue pattern management - to enhance our proposed approach are also discussed for various applications. Experimental results show that the proposed approach reduces the peak noise by 11.75% and consequently, the decoupling capacitance (Decap) requirement by 24.22% without any degradation in IPC (Instruction Per Cycle). We also show that our approach does not increase the clock period for the 0.18μm technology and beyond.