3,029 research outputs found
A low complexity resource allocation algorithm for multicast service delivery in OFDMA networks
Allocating and managing radio resources to multicast transmissions in Orthogonal Frequency-Division Multiple Access (OFDMA) systems is the challenging research issue addressed by this paper. A subgrouping technique, which divides the subscribers into subgroups according to the experienced channel quality, is considered to overcome the throughput limitations of conventional multicast data delivery schemes. A low complexity algorithm, designed to work with different resource allocation strategies, is also proposed to reduce the computational complexity of the subgroup formation problem. Simulation results, carried out by considering the Long Term Evolution (LTE) system based on OFDMA, testify the effectiveness of the proposed solution, which achieves a near-optimal performance with a limited computational load for the system
DyMo: Dynamic Monitoring of Large Scale LTE-Multicast Systems
LTE evolved Multimedia Broadcast/Multicast Service (eMBMS) is an attractive
solution for video delivery to very large groups in crowded venues. However,
deployment and management of eMBMS systems is challenging, due to the lack of
realtime feedback from the User Equipment (UEs). Therefore, we present the
Dynamic Monitoring (DyMo) system for low-overhead feedback collection. DyMo
leverages eMBMS for broadcasting Stochastic Group Instructions to all UEs.
These instructions indicate the reporting rates as a function of the observed
Quality of Service (QoS). This simple feedback mechanism collects very limited
QoS reports from the UEs. The reports are used for network optimization,
thereby ensuring high QoS to the UEs. We present the design aspects of DyMo and
evaluate its performance analytically and via extensive simulations.
Specifically, we show that DyMo infers the optimal eMBMS settings with
extremely low overhead, while meeting strict QoS requirements under different
UE mobility patterns and presence of network component failures. For instance,
DyMo can detect the eMBMS Signal-to-Noise Ratio (SNR) experienced by the 0.1%
percentile of the UEs with Root Mean Square Error (RMSE) of 0.05% with only 5
to 10 reports per second regardless of the number of UEs
Virtual RTCP: A Case Study of Monitoring and Repair for UDP-based IPTV Systems
IPTV systems have seen widespread deployment, but often lack robust mechanisms for monitoring the quality of experience. This makes it difficult for network operators to ensure that their services match the quality of traditional broadcast TV systems, leading to consumer dissatisfaction. We present a case study of virtual RTCP, a new framework for reception quality monitoring and reporting for UDP-encapsulated MPEG video delivered over IP multicast. We show that this allows incremental deployment of reporting infrastructure, coupled with effective retransmission-based packet loss repair
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