Abstract-Network throughput and packet delay are two important parameters in the design and the evaluation of routing protocols for ad-hoc networks. While mobility has been shown to increase the capacity of a network, it is not clear whether the delay can be kept low without trading off the throughput. We consider a theoretical framework and propose a routing algorithm which exploits the patterns in the mobility of nodes to provide guarantees on the delay. Moreover, the throughput achieved by the algorithm is only a poly-logarithmic factor off from the optimal. The algorithm itself is fairly simple. In order to analyze its feasibility and the performance guarantee, we used various techniques of probabilistic analysis of algorithms. The approach taken in this paper could be applied to the analyses of some other routing algorithms for mobile ad hoc networks proposed in the literature.

Abstract-We consider the steady state distribution of the end-to-end delay of a tagged flow in queueing networks where the queues have self-similar cross traffic. We assume that such cross traffic at each queue, say queue i,is modeled by fractional Brownian Motion (FBM) with Hurst parameter Hi ∈ [1/2, 1), and is independent of other queues.The arrival process of the tagged flow is renewal. Two types of queueing networks are considered. We show that the end-to-end delay of the tagged flow in a tandem queueing network, and more generally in a tree network, is completely dominated by one of the queues. The dominant queue is the one with the maximal Hurst parameter. If several queues have the same maximal Hurst parameter, then we have to compare the ratio (1−ρ)H σ to determine the dominant queue, where ρ is the load of the queue, and σ is the coefficient of variation of the cross traffic at the queue.In the case that the tagged flow is controlled through a window based congestion control mechanism, the end-to-end delay is still asymptotically Weibullian with the same shape parameter. We provide upper and lower bounds on the constant that determines the scale parameter of the corresponding Weibull distribution.

In this paper, we present Harmony, a holistic messaging middleware for distributed, event-driven systems. Harmony supports various communication paradigms and heterogeneous networks. The key novelty of Harmony is the unified provision of endto-end quality of service, security, and resiliency, which shields the applications from the underlying network dynamics, failures, and security configurations. We describe the Harmony architecture in the context of cyber-physical business applications and elaborate on the design of its critical system components, including routing, security, and mobility support.

No abstract

No abstract