Stability and Distributed Power Control in MANETs with Outages and Retransmissions

In the current work the effects of hop-by-hop packet loss and retransmissions via ARQ protocols are investigated within a Mobile Ad-hoc NET-work (MANET). Errors occur due to outages and a success probability function is related to each link, which can be controlled by power and rate allocation. We first derive the expression for the network’s capacity region, where the success function plays a critical role. Properties of the latter as well as the related maximum goodput function are presented and proved. A Network Utility Maximization problem (NUM) with stability constraints is further formulated which decomposes into (a) the input rate control problem and (b) the scheduling problem. Under certain assumptions problem (b) is relaxed to a weighted sum maximization problem with number of summants equal to the number of nodes. This further allows the formulation of a non-cooperative game where each node decides independently over its transmitting power through a chosen link. Use of supermodular game theory suggests a price based algorithm that converges to a power allocation satisfying the necessary optimality conditions of (b). Implementation issues are considered so that minimum information exchange between interfering nodes is required. Simulations illustrate that the suggested algorithm brings near optimal results.

💡 Research Summary

The paper investigates the impact of hop‑by‑hop packet loss and automatic repeat‑request (ARQ) retransmissions on the performance and stability of Mobile Ad‑hoc Networks (MANETs). Unlike traditional models that treat link reliability as a fixed function of signal‑to‑noise ratio, the authors introduce a success probability function (p_{ij}(P_{ij},R_{ij})) that depends explicitly on the transmit power (P_{ij}) and the transmission rate (R_{ij}) of each link ((i,j)). This function is monotone non‑decreasing in power and initially increasing then saturating in rate, thereby capturing both physical‑layer fading effects and the stochastic nature of ARQ retransmissions.

From the success probability they define the goodput of a link as
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