SAT04-3: ELB: An Explicit Load Balancing Routing Protocol for Multi-Hop NGEO Satellite Constellations

Abstract

Due to geographical and/or climatic constraints, the community of future satellite users will exhibit a significant variance in its density over the Globe. This density variance will yield a scenario where some satellite links are congested while others are underutilized. To ensure an intelligent engineering of traffic over satellite networks, this paper proposes a routing protocol that enables neighboring satellites to explicitly exchange information on their congestion status. A "soon-to-be-congested" satellite requests its neighboring satellites to decrease their data forwarding rates. In response, the neighboring satellites search for less congested paths that do not include the satellite in question and communicate a portion of data, primarily destined to the satellite, via the retrieved paths. By so doing, congestion, and the resulting packet drops, can be avoided. A better distribution of traffic among satellites can be guaranteed as well. The proposed scheme is dubbed "Explicit Load Balancing" (ELB) scheme. A set of simulations is conducted to evaluate the performance of the ELB scheme using the Network Simulator. In terms of Quality of Service, encouraging results are obtained: better traffic distribution, higher throughput, and lower packet drops.

Explicit Load Balancing Technique for NGEO Satellite IP Networks With On-Board Processing Capabilities

“…We assume that routing tables are updated periodically every interval time. At time , the instant path cost is defined as (8) where denotes the one-way propagation delay. denotes a predicted value of the queuing delay at time and is computed as follows: (9) where denotes the ISL capacity.…”

“…In this paper, we describe an easy-to-implement mathematical model for a dynamic setting of the system parameters. While an abridged version of the proposed scheme can be found in [8], the major improvements presented in this paper consists in the application of the proposed scheme in more general scenarios where both delay-sensitive and delay-insensitive applications coexist. Furthermore, we investigate the effect of packet reordering on the working of the Transmission Control Protocol (TCP) when ELB is in use.…”

Cross-layer design and ant-colony optimization based routing algorithm for low earth orbit satellite networks

“…But sometimes the optimal path cannot be found because the static routing algorithm is not able to adapt the diversification of the inter-satellite links and network load. The dynamic routing algorithm [2][3][4][5][6][7][8] can adaptively update its path when network traffic or link delay changes, thus it can ensure the efficiency of packet forwarding.…”

Multiservice on-demand routing in LEO satellite networks

“…Additional downside includes reduced reliability, in case of link failures, and scalability, since signaling overhead depends on network size and the period of the protocol. To eliminate such disadvantages some researchers have introduced load balancing mechanisms that apportion traffic between two [7], [8] or more different paths [5] or switch a selected path whenever an involved satellite becomes congested [9]. However, the limitation of using periodically computed paths still holds in those studies.…”