Packet Scheduling for VOIP Over HSDPA in Mixed Traffic Scenarios

Third generation (3G) packet switched WCDMA networks with high-speed downlink packet access (HSPDA) are currently being deployed worldwide to provide wireless broadband connectivity. When introducing HSDPA in 3G networks the end user experience and system capacity with voice over IP applications improve considerably. When later on adding also high-speed packet uplink access (HSUPA), the system capacity and end user experience will improve even further. This paper analyzes with measurements the VoIP quality over current Release 5 HSDPA networks. The results show that even though the introduction of HSDPA significantly reduces the user-to-user voice delay, the performance is satisfactory only for selected devices, the overall end user experience is still significantly worse than with circuit switched solutions and not acceptable. The current limitations with VoIP in HSDPA networks with a too large delay can be improved by using the RLC UNACK mode, potentially decreasing the jitter buffer size and reducing the terminal processing delay. In the longer term, HSUPA and several features in 3GPP Release 7 standards will bring further performance improvements in both user plane latency and system capacity.

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“…However, since this variable is merely subjective it is recommended to be ignored. The simplified algorithm is depicted in equation (2).…”

Section: A Voip Quality Methodologymentioning

confidence: 99%

“…93 (2) The R value can be associated with the Mean Opinion Score (MOS) values, which is a subjective grade for voice quality based on studies carried out by ITU-T. However, even though the R-value can match a MOS value, it cannot predict the absolute opinion of an individual user.…”

Section: A Voip Quality Methodologymentioning

confidence: 99%

Towards High Quality VoIP in 3G Networks - An Empirical Study

Arjona

Westphal²,

Ylä-Jääski³

et al. 2008

2008 Fourth Advanced International Conference on Telecommunications

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“…Before this work, [3] used the Weighted Proportional Fair (WPF) [2]. With WPF, the (single) scheduled flow is the one with highest priority.…”

Section: B Schedulingmentioning

confidence: 99%

“…One strategy to guarantee the desired QoS for RT services is the utilization of prioritization among services such as scheduling [2]. However, when the system is near to be overloaded scheduling alone cannot guarantee QoS for RT services.…”

Section: Introductionmentioning

confidence: 99%

Overload Prediction Based on Delay in Wireless OFDMA Systems

Lucena

Lima

Freitas

et al. 2010

2010 IEEE Global Telecommunications Conference GLOBECOM 2010

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In this work we deal with Congestion Control (CC) strategies to protect the Quality of Service (QoS) of Real Time (RT) services in Orthogonal Frequency Division Multiple Access (OFDMA)-based and packet-switched networks such as Long Term Evolution (LTE) and Worldwide Interoperability forMicrowave Access (WiMAX). Specifically, the first contribution of this paper is the adaptation of a CC strategy previously proposed for High-Speed Downlink Packet Access (HSDPA) to these modern systems. This CC strategy comprises in a coordinated manner the functionalities scheduling, Admission Control (AC) and Load Control (LC). The second contribution is the proposal of a new feature to be added to this CC strategy in order to allow for an early detection of overload situations based on the packet delay of RT flows. In the results we show that our proposed overload prediction based on delay can efficiently prevent QoS degradation of RT flows.

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“…Scheduling multiple services amounts to managing priority between these services according to their quality-of-service (QoS) requirements. These issues have already been extensively developed in literature, e.g., [12][13][14]. This paper is organized as follows: In Section 2, the system model and assumptions are given.…”

Section: Paper Scope and Outlinementioning

confidence: 99%

Analytical evaluation of multicast packet delivery and user-clustering schemes in high-speed cellular networks

Heni

Lagrange

2009

Ann. Telecommun.

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Transmission on data-oriented radio interfaces of cellular networks has been primarily designed for unicast applications. Nevertheless, unicast may not optimize the resource usage when the same content has to be transmitted to several users in the same cell. In this context, multicast seems to be an efficient means to convey data. In this paper, we develop an analytical model that allows the computation of the mean bitrate for both multicast and multiple-unicast transmission schemes. Furthermore, we propose a multicast transmission scheme called the equal-bitrate (EB) algorithm that allocates bandwidth to mobiles according to their instantaneous channel quality. We compare it to adaptations of the well-known max-signal-to-noise ratio and round robin to multicast. We propose to group users into clusters. The clustering method combines multicast and unicast transmission schemes according to the user's average channel conditions. We use the analytical model to evaluate the proposed solutions. We compare the resulting performance against pure multicast and multiple-unicast approaches. We show that the EB algorithm offers a good trade-off between throughput and fairness. Also, we show that mixed clustering achieves good performance compared to conventional clustering methods.

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Packet Scheduling for VOIP Over HSDPA in Mixed Traffic Scenarios

Cited by 20 publications

References 4 publications

Towards High Quality VoIP in 3G Networks - An Empirical Study

Towards High Quality VoIP in 3G Networks - An Empirical Study

Overload Prediction Based on Delay in Wireless OFDMA Systems

Analytical evaluation of multicast packet delivery and user-clustering schemes in high-speed cellular networks

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