A fair packet scheduler to support QoS in HSDPA

This paper proposes a novel packet scheduling algorithm for delay constraint traffic on high speed down link packet access (HSDPA) and also a packet scheduler for this algorithm. In this packet scheduling algorithm, we consider both the delay constraint and the throughput for each traffic class while maximizing the system capacity. Considering the delay constraint and the throughput simultaneously, our method can guarantee different quality of service (QoS) for each traffic class. Finally, in order to demonstrate the performance of our proposed algorithm, we compare our algorithm with the proportional fairness (PF) method and round robin (RR) method by system simulations. Numerical results show that system performance can be significantly improved employing our algorithm compared to that with the PF or RR method.

This paper provides methods for packet scheduling that designed for VoIP in a mixed traffic scenario over high-speed downlink packet access (HSDPA) in WCDMA. In the interested mixed traffic scenario voice packets are transmitted together with 5 background best-effort (BE) data users. The proposed packet scheduling schemes in such a mixed traffic environment are based on a proportional fair (PF) packet scheduling algorithm, to be more specifically, they are two resource allocation methods for BE data user. The performance is evaluated with a quasi-static system level simulator. Performance with a LMMSE advanced receivers is also addressed. The results indicate that with the proposed scheduling algorithm 2 in this paper the VoIP capacity in a mixed traffic scenario can be up to 106 users with a delay budget 80 ms, which is approximately maintained as that of VoIP single mode. At the same time, a rather good background BE performance can be obtained. With the proposed algorithm 1 the VoIP capacity can reach 101 users per cell. However a better background BE performance than algorithm 2 can be obtained.

The 3G UMTS is currently undergoing inherent changes. The expected release 5&6 of UMTS will contain a new set of features known collectively as high speed downlink packet access (HSDPA). In this paper, we propose two packet scheduling algorithms for HSDPA, shortest queue first (SQF) and longest queue first (LQF), to provide priority scheduling between services of different quality of service (QoS) classes and fairness between users within the same class. Simulation results show that the proposed algorithms meet QoS requirements of different traffic classes, with the SQF algorithm having a better performance compared to the LQF algorithm.

Fast packet scheduling is a key feature of packet-based data services which are 3G/4G wireless networks such as Enhanced Data rates for GSM Evolution, High-Speed Downlink Packet Access (HSDPA), and High Data Rate. In this paper, we propose Anticipated Proportionally Optimal (APO), a new packet scheduling scheme with Quality of Service (QoS) support for hybrid of real and non-real-time services over HSDPA networks. The APO scheduling algorithm is based on the effective channel anticipation model. In contrast to the traditional schemes, the proposed method is implemented based on a cyclic non-work-conserving discipline. Simulation results indicate capability of proposed scheme to maximize the channel usage efficiency compared to other exist scheduling methods. Results also present fair tradeoff between channel capacity and desired QoS for real-time services.

High speed downlink packet access (HSDPA) is a packet-based data service that supports downlink data rates of up to 14 Mbps in the WCDMA (wideband code division multiple access) system. In HSDPA, the packet scheduler is a key element for high-speed and efficient transmissions. In addition, hybrid automatic request (HARQ) plays a significant role in improving system performance. We propose an enhanced scheduling algorithm combined with HARQ to reduce transfer delay without the degradation of system throughput.

Simple wireless scheduling techniques, such as maximum carrier-to-interference ratio (Max. C/I) or round robin (RR), fail to take into account all aspects of quality of service (QoS) provisioning. The fundamentals of evolutionary computation (genetic algorithms) and conventional wireless scheduling techniques are combined and the weaknesses of the existing known techniques are exploited to propose a novel hybrid genetic packet scheduler (HGPS) for high speed downlink packet access (HSDPA). The proposed HGPS outperforms the Max. C/I packet scheduler in terms of total delivered throughput within low delay thresholds.

High-speed downlink packet access (HSDPA) achieves high data rates and high spectral efficiency by using adaptive modulation and coding schemes and employing multicode CDMA. In this paper, we present opportunistic algorithms for scheduling HSDPA users and selecting modulation/coding and multicode schemes that exploit channel and buffer variations to increase the probability of uninterrupted media play-out. First, we introduce a stochastic discrete event model for a HSDPA system. By employing the discrete event model, we transform the scheduling problem of providing uninterrupted play-out to a feasibility problem that considers two sets of stochastic quality-of-service (QoS) constraints: stability constraints and robustness constraints. A methodology for obtaining a feasible solution is then proposed by starting with a so-called stable algorithm that satisfies the stability QoS constraints. Next, we present stochastic approximation algorithms that adapt the parameters of the stable algorithm in a way that a feasible point for the robustness QoS is reached within the feasibility region of the stability QoS

This article investigates the efficient transmission of file download services to several users simultaneously in 3G mobile networks with HSDPA (High-Speed Downlink Packet Access) and MBMS (Multimedia Broadcast Multicast Services). HSDPA supports high speed point-to-point (p-t-p) transmissions (up to several Mb/s), whereas with MBMS the same content can be transmitted with a point-to-multipoint (p-t-m) connection to multiple users in a unidirectional fashion. Multicast delivery can be implemented through only p-t-p transmissions with HSDPA, a single p-t-m transmission with MBMS, or using both jointly in a hybrid approach by employing HSDPA for error repair of the MBMS p-t-m transmission. We investigate the optimum HSDPA and MBMS transmission configuration when they are used separately, and the trade-off between the initial MBMS file p-t-m transmission and the HSDPA error repair for the hybrid delivery. The approach of minimizing the transmission energy (product of the transmit power times the transmission time) to achieve a target file acquisition probability (percentage of users that successfully receive the file) has been adopted.

High speed downlink packet access (HSDPA) was originally introduced in release 5 of WCDMA to boost data rates of packet switched traffic in the downlink. With increasing demand for streaming services and recent efforts to provide mobile TV, the standard has also been considered for delivering streaming services over cellular networks. While much attention has been paid to optimizing transmission of non real time application, this paper aims at providing a comprehensive study of particular requirements and performance aspects of transmission of streaming services over HSDPA. We compare performances of different scheduling algorithms in pure streaming scenarios for constant bit rate as well as variable bit rate streams and different streaming rates. We further study the impact of code multiplexing of different streaming users on the system performance and examine the system behavior when both streaming and best effort services are present.

We consider modeling the statistical behavior of interactive and streaming traffics in high-speed downlink packet access (HSDPA) networks. Two important applications in these traffic categories are web-browsing (interactive service) and video streaming (streaming service). Web-browsing is characterized by its important sensitivity to delay. Video streaming on the other hand is less sensitive to delay, however, due to its large frame sizes, video traffic is more affected by the packet loss resulting from a limited buffer size at the base station. Taking these characteristics into account, we consider modeling the queuing delay probability density function (PDF) of the Web-browsing traffic, and modeling the queuing buffer size distribution of video streaming traffic. Specifically, we show that the queuing delay of the Web-browsing traffic follows an exponential distribution and that the queuing buffer size of video streaming traffic follows a weighted Weibull distribution. Model fitting based on simulated data is used to provide simple mathematical formulations for the different parameters that characterize the PDFs under consideration. The provided equations could be used, directly, in HSDPA network dimensioning and, as a reference, to satisfy a certain quality of service (QoS).

The provision of data services in 3G systems requires spectral efficiency solutions to increase the capacity of the radio access network as well as support for high data rates. In this context, the 3GPP introduces a new feature in the release 5 specifications denominated high speed downlink packet access (HSDPA). The HSDPA concept appears as an umbrella of features to improve both user and system performance. The concept includes a reduction of the transmission time interval (TTI) to 2 ms, an adaptive modulation and coding (AMC) scheme, and a fast physical layer hybrid ARQ mechanism. In this paper the objective is to analyze the HSDPA performance for streaming, interactive, and background services. Relevant characteristics such as the QoS demands of the different traffic classes, the throughput and delay characteristics has been analyzed and compared with shared channel. We also propose a new packet-scheduling scheme for HSDPA transmission, which improves the overall performance and fairness among the packet users.

In order to provide the growing demand of data services, several wireless standards are evolving to support packet data more efficiently. In particular 3rd generation partnership project (3GPP) is studying a new access technique called high speed downlink packet access (HSDPA) to support UMTS users with high speed data services. The present paper is focused on scheduling problems for video streaming services in the HSDPA. Two classical scheduling algorithms (weighted first queuing and earliest deadline first) are applied to this access technique and a new algorithm, based on an hybrid procedure between the above, is also designed. Furthermore two strategies for radio resource allocation are introduced: frame-by-frame assignment and fast scheduling, respectively. A software simulation using OPNET modeler is performed in order to compare and find out benefits and drawbacks in the application of each above mentioned strategy.

HSDPA (high-speed downlink packet access), introduced in WCDMA release 5, provides a high-bandwidth shared channel with short transmission time interval (TTI). The short TTI together with appropriate scheduling enable HSDPA to support efficient multiplexing of traffic. We explain the performance of four scheduling algorithms when transmitting a traffic mix consisting of both conversational (VoIP) traffic and background (Web) traffic over the high-speed downlink shared channel (HS-DSCH) of HSDPA. We consider both cell throughput and user satisfaction. The proportional fair (PF), the maximum rate (MR) scheduler and two extended versions of MR, are tested for different VoIP scheduling delay budgets and varying load. To understand the behaviour of the schedulers, we use the ns-2 simulator extended with a model of HS-DSCH to simulate a mixed traffic scenario. Our results show that a scheduler that gradually increases the VoIP priority and considers the user's current possible rate, performs well. A more drastic increase in VoIP priority is however needed when the delay budget is short. Furthermore, attempting to uphold quality for both VoIP and Web traffic makes the system sensitive to overload situations.

Long Term Evolution (LTE) network deploys Orthogonal Frequency Division Multiple Access (OFDMA) technology for downlink multi-carrier transmission. To meet the Quality of Service (QoS) requirements for LTE networks, packet scheduling has been employed. Packet scheduling determines when and how the user’s packets are transmitted to the receiver. Therefore effective design of packet scheduling algorithm is an important discussion. The aims of packet scheduling are maximizing system throughput, guaranteeing fairness among users, andminimizing either or both PacketLoss Ratio (PLR)and packet delay. Inthis paper, the performance of two packet scheduling algorithms namely Log Maximum-Largest Weighted Delay First (LOG-MLWDF) and Max Delay Unit (MDU), developed for OFDM(Orthogonal Frequency Division Multiplexing)networks, has been investigated in LTE downlink networks, and acomparison of those algorithmswith a well-known scheduling algorithm namely Maximum-Largest Weighted Delay First(MLWDF) has been studied.The performance evaluation was in terms of system throughput, PLR and fairness index. This study was performed forboth real time (voice and video streaming)and non-real time (best effort)perspectives. Results show that for streaming flows,LOG-MLWDF shows best PLR performance among the considered scheduling schemes, and for best effort flows, it outperforms theother two algorithms in terms of packet delay and throughput.

Nowadays you can see everyone holding mobile phones on the street, used to be with only purely voice service till now, as the progress of the technology, function of wireless internet surfing is more and more valued. Whether video call, on-line browsing, or navigation is to provide consumer a multiple service. To fulfill most users’ request, high-speed downloading of 3G broadband system is needed. Telecom Operators start to create mass HSPA (High Speed Packet Access) system in 2009, meaning HSDPA (High Speed Downlink Packet Access) could reach 14.4Mbps and HSUPA (High Speed Uplink Packet Access) could reach 2Mbps. In order to fulfill this mass transportation, Telecom Operator not only has to upgrade the software and hardware of base stations (aka. Node B), the flow of physical circuit’s transmission also has to reach certain bandwidth. Considering investment cost and quality of service, fixed Telecom operators has take a new generation NG-SDH (Next Generation-Synchronous Digital Hierarchy). Using Ethernet to provide physical transmission of wireless internet browsing. This thesis is mainly discussing new generation Ethernet NG-SDH’s usage, while current base station using physical fiber circuit to provide transmission internet service quality. Through the result if the experiment, we will have a better reference for transmission service quality and solution when future operators planning transmission of HSPA+, 4G LTE (Long Term Evolution).