No abstract

Satellite networks provide complete connectivity and worldwide data transmission capability for constructing the Internet of Things. However, because of the varying Internet of Things traffic density, satellite networks may endure imbalanced traffic requirements and frequent link congestion. To effectively resolve these problems and optimally transmit Internet of Things data, a novel hybrid global-local load balancing routing scheme for Low Earth Orbit satellite networks is proposed in this article. Hybrid global-local load balancing routing scheme enables satellites to route Internet of Things traffic through global planning and local real-time adjustments in two steps. In hybrid global-local load balancing routing scheme, given the predictive nature of Internet of Things traffic distribution and Low Earth Orbit satellite networks, the inter-satellite traffic demand is decomposed into a predictable long-range baseline and unpredictable shortrange fluctuations. A global strategy is employed first for preliminary global traffic allocation based on long-range baselines, and a local strategy is then employed for route adjustments based on short-range fluctuations. With the combination of global planning and local real-time adjustments, network traffic can eventually obtain a near-optimal allocation. Numerical simulations indicate that in contrast to single-strategy schemes, hybrid global-local load balancing routing scheme can more thoroughly eliminate congestion, and it performs better in measures such as packet loss rate, average queuing delay, traffic distribution, route oscillation, and communication overhead.

No abstract

Satellite networks provide global coverage and can take a wide range of multimedia services. Routing algorithm performance is critical for satellite network business and is always considered an important step for using the satellite networks. Although a lot of research has been done on the performance of satellite routing algorithm in normal condition, the performance under node failure scenarios is seldom discussed. In this paper, number of tests is designed to evaluate delay, loss rate performances of routing algorithms that include SPF, DRA, and SGRP. The key of the tests is focusing on the performance in single satellite node failure and random node failures scenarios. Moreover, a novel error path measure is proposed and realized to analyze the convergence performance of these algorithms. It is found that, node failure in the minimum horizontal ring may bring about more error paths. DRA performance may suffer severe degeneration at large damage condition.