Gateway Handover Research Articles

A Practical Q/V Band Smart Gateway Diversity Scheme for Very High Throughput Satellite Systems

The use of Q/V band feeder links and Ka band user links is a feasible solution to support the next iteration of High Throughput Satellite. The gateway transmit diversity technique is a way to compensate the rain attenuation of Q/V band feeder links. This paper analyzes a practical combination scheme that combinates N-active (K=2) with N+1 diversity method in detail from the working principle, gateway handover status transfer process, evaluation of system availability and implementation complexity. Compared with the existing N+P scheme, the proposed scheme can provide higher system availability and more stable user experience under the condition of properly increasing the complexity of payload design. Compared with N-active scheme that has been reported, it is much easier to implement in engineering and more cost-effective. As a result, the combination scheme is an optimized solution based on a tradeoff between performance improvement and complexity of the payload.

QoS Support in SGD-Based High Throughput Satellite Networks

This paper proposes a quality of service (QoS) management framework for high throughput satellite (HTS) systems using extremely high frequency (EHF) frequency bands, which can achieve high capacity provided that feeder link outage events caused by severe weather conditions can be properly counteracted. To this regard, smart gateway diversity architectures implementing advanced gateway handover procedures are certainly attractive, although they can only partly mitigate the negative effects of adverse weather conditions in terms of packet losses, delays, and jitters, which significantly degrade the performance of delay-sensitive and delay-insensitive traffic flows. To cope with these technical challenges, we propose an incremental rerouting scheme to control congestion events because of capacity reduction during the transient phase, consisting of offloading high-priority QoS traffic flows from the affected gateway towards gateways operating in more favorable conditions. Moreover, we apply inter-flow network coding at the gateways to protect delay-insensitive flows from packet losses occurring during feeder link outage. Finally, extra capacity is reserved at the gateways to handle the additional traffic resulting from gateway handover. The theoretical analysis (validated by simulation campaigns) allowed characterizing network coding performance and confirming the potentialities of our QoS management framework for HTS systems.

Improving session continuity through user mobility tracking for EPS inter‐serving gateway handover

ABSTRACTThe Evolved Packet System (EPS) is standardized to support a common IP‐based core network with heterogeneous radio accesses in the latest 3GPP release. In the EPS, the Policy and Charging Control (PCC) framework provides dynamic policy control combined with real‐time charging management. Long core network signaling for PCC degrades session continuity performance during handover. In this paper, we investigate the handover for an EPS session. Based on the results, we propose a proactive scheme along with a user mobility tracking model to improve session continuity. More specifically, our proposed scheme attempts to reduce PCC reauthorization signaling delay during the handover procedure. Then, we formulate a Markov process to model the user mobility pattern and to derive the session continuity probability. Numerical results show that our scheme can significantly keep the session continuity at a user acceptable level even when the mobility pattern is high. We also provide guidelines for operators to set up the network configuration parameters according to various traffic conditions. Copyright © 2011 John Wiley & Sons, Ltd.