Equal-cost multi-path routing

About: Equal-cost multi-path routing is a research topic. Over the lifetime, 10472 publications have been published within this topic receiving 249362 citations.

A prediction-based link availability estimation for routing metrics in MANETs

Abstract: A Mobile Ad hoc Network (MANET) is a collection of wireless mobile terminals that are able to dynamically form a temporary network without any aid from fixed infrastructure or centralized administration. One critical issue for routing in MANETs is how to select reliable paths that can last as long as possible since terminal mobility may cause radio links to be broken frequently. To solve this problem, a criterion that can judge path reliability is needed. The reliability of a path depends on the number of links and the reliability of each link constituting the path. Many routing metrics in terms of number of links have been proposed, such as the shortest path routing. However, how to measure link availability or reliability in order to find more reliable paths has not been addressed adequately in the literature. (By a link being available, we mean that the radio quality of the link satisfies the minimum requirement for successful communication. Link availability is used to measure probability or degree that a link is available. The terms availability and reliability are used interchangeable in this paper.) This paper first introduces a prediction-based link availability estimation to quantify the link reliability. This quantity makes use of some instantly available information and also considers the dynamic nature of link status in order to properly reflect the link reliability. Then, this quantity has been further used to develop routing metrics for path selection in terms of path reliability to improve routing performances. The proposed schemes have been investigated through computer simulation.

Spectrum-Aware Opportunistic Routing in Multi-Hop Cognitive Radio Networks

Abstract: In this paper, cognitive routing coupled with spectrum sensing and sharing in a multi-channel multi-hop cognitive radio network (CRN) is investigated. Recognizing the spectrum dynamics in CRN, we propose an opportunistic cognitive routing (OCR) protocol that allows users to exploit the geographic location information and discover the local spectrum access opportunities to improve the transmission performance over each hop. Specifically, based on location information and channel usage statistics, a secondary user (SU) distributedly selects the next hop relay and adapts its transmission to the dynamic spectrum access opportunities in its neighborhood. In addition, we introduce a novel metric, namely, cognitive transport throughput (CTT), to capture the unique properties of CRN and evaluate the potential relay gain of each relay candidate. A heuristic algorithm is proposed to reduce the searching complexity of the optimal selection of channel and relay. Simulation results are given to demonstrate that our proposed OCR well adapts to the spectrum dynamics and outperforms existing routing protocols in CRN.

The extent of AS path inflation by routing policies

Abstract: A route in the Internet may take a longer AS (autonomous systems) path than the shortest AS path due to routing policies. We systematically analyze AS paths and quantify the extent to which routing policies inflate AS paths. The results show that AS path inflation in the Internet is more prevalent than expected. We first present the extent of AS path inflation observed from the route view routing tables. From an ISP, at least 55% of AS paths are inflated by at least one AS hop and AS paths can be inflated by as long as 6 AS hops. We then employ two typical routing policies to show the extent of AS path inflation for all AS pairs; we find that at least 45% of AS paths are inflated by at least one AS hop and AS paths can be inflated by as many as 9 AS hops. Quantifying AS path inflation in the Internet has important implications on the extent of routing policies and traffic engineering performed on the Internet, and on BGP (border gateway protocol) convergence speed.

Adaptive proportional routing: a localized QoS routing approach

Abstract: Most of the QoS routing schemes proposed so far require periodic exchange of QoS state information among routers, imposing both communication overhead on the network and processing overhead on core routers. Furthermore, stale QoS state information causes the performance of these QoS routing schemes to degrade drastically. In order to circumvent these problems, we focus on localized QoS routing schemes where the edge routers make routing decisions using only "local" information and thus reducing the overhead at core routers. We first describe virtual capacity-based routing (VCR), a theoretical scheme based on the notion of virtual capacity of a route. We then propose proportional sticky routing (PSR), an easily realizable approximation of VCR and analyze its performance. We demonstrate through extensive simulations that adaptive proportional routing is indeed a viable alternative to the global QoS routing approach.

Cooperative Routing in UWB Wireless Networks

Abstract: There is recently an increasing popularity in the use of wireless ad hoc networks, especially for sensor networks. However, these networks are susceptible to fading, interference and limited power supply. In this paper, we consider the issue of cooperative routing under the effect of both multi-user interference (MUI) and fading in ultra-wideband (UWB) networks. We first generate a single path route from any available routing algorithms. Based on this single path route, our cooperative routing algorithm is executed to see whether nodes which 'overhear' the information should cooperate to alleviate the effect of fading, and thus improve outage performance. From our result, it is shown that our cooperative routing algorithm reduces the average transmit energy by 8dB at 3% of outage.