Pricing-based call admission control for wireless MPEG-4 traffic

Next generation wireless technologies will need to incorporate new sets of traffic control procedures in order to cope with the challenges related to supporting both the existing and the ever-increasing new multimedia services. The work presented in this paper focuses on traffic control for MPEG-4 videoconference over cellular networks, and is twofold. We first introduce a traffic model for medium quality MPEG-4 videoconference traffic. We then proceed to use this model, as well as a previously developed model for high quality MPEG-4 traffic, in the implementation of a new Call Admission Control (CAC) mechanism. Providers need to use efficient resource management mechanisms in order to keep existing clients satisfied and attract new customers, so that they can increase their revenue. Towards this goal, our CAC mechanism makes decisions on the acceptance/rejection of a new video call not only based on the predicted capacity that users will consume, but also on the possible revenue gained for the provider when degrading current users in order to accommodate new ones. Our mechanism is implemented with both a static and a dynamic pricing policy and is shown, via an extensive simulation study, to provide excellent Quality of Service (QoS) to wireless videoconference users.     

On Multiple Traffic Type Integration over Wireless TDMA Channels with Adjustable Request Bandwidth

A new medium access control (MAC) protocol for mobile wireless communications is presented and investigated. We explore, via an extensive simulation study, the performance of the protocol when integrating voice, video and data packet traffic over a wireless channel of high capacity (referring to an indoor microcellular environment). Depending on the number of video users admitted into the system, our protocol varies: a) the request bandwidth dedicated to resolving the voice users contention, and b) the probability with which the base station grants information slots to voice users, in order to preserve full priority for video traffic. We evaluate the maximum voice capacity and mean access delay, as well as the aggregate channel throughput, for various voice and video load conditions, and the maximum voice capacity, aggregate channel throughput and average data message delays, for various video, voice and data load conditions. As proven by the comparison with a recently introduced efficient MAC scheme (DPRMA), when integrating voice and video traffic our scheme obtains higher voice capacity and aggregate channel throughput. When integrating all three traffic types, our scheme achieves high aggregate channel throughput in all cases of traffic load.     

A new bandwidth allocation mechanism for next generation wireless cellular networks

In this paper we design and study the performance of a Medium Access Control (MAC) scheme for the multiplexing and the integrated delivery of voice, mobile messaging, IP, gaming and H.264 videoconference traffic over a high-speed cellular TDMA channel with errors and capture. To the best of our knowledge, this is one of the first papers in the literature investigating the integration of actual H.264 video traces and gaming traffic with other types of traffic over wireless networks. Our results show that the proposed scheme achieves high throughput results while preserving the strict Quality of Service (QoS) requirements of each traffic type, and outperforms two efficient schemes previously proposed in the literature.     

Energy Efficient H.263 Video Transmission in Power Saving Wireless LAN Infrastructure

Wireless local area networks (WLANs) are now being used in places where access point (AP) power saving would be very desirable. Although this is not currently possible, modifications to the IEEE 802.11 protocol have recently been proposed which would permit this functionality. A difficult problem that arises is to maintain good client power saving when AP power saving is introduced. This is especially true when carrying multiple real-time traffic flows such as H.263 video, where the payload size varies randomly over short time periods. In this paper, we first present protocol modifications for power saving quality-of-service (QoS) enabled access points (PSQAP). We then focus on the transmission of bursty real-time H.263 video over a PSQAP. A variety of mechanisms are proposed for this purpose, which result in various tradeoffs between station and PSQAP power saving performance. Analytical models and simulation experiments are used to assess the performance of the video scheduling algorithms. The best overall performance is obtained using a mechanism that combines a novel variant of the Power Save Multi-Poll (PSMP) protocol with a scheduling mechanism based on a discrete autoregressive video prediction model.      

Scheduling and Traffic Policing for Variably Demanding Video Traffic Integrated with Voice and Data Traffic in 4th Generation Wireless Networks

In this paper, we present an effective mechanism for scheduling and traffic policing in 4th generation wireless networks. More specifically, we: a) extend our previous work on a Multiple Access Control (MAC) scheme for the multiplexing of voice, video and bursty data traffic over a very high-speed wireless TDMA channel, and we study our scheme's performance when MPEG-4 videoconference users of various traffic characteristics are present in the system, and b) we combine the MAC mechanism with an improved version of an efficient traffic policing mechanism. Our results are derived for cases with and without handoff traffic in the uplink channel, and it is shown that although the burstiness of MPEG-4 traffic and channel errors impedes the maximization of channel throughput, our scheme still achieves high channel throughput for all the combined voice/video/data loads examined. This research was supported by the Operational Programme for Education and Initial Vocational Training “PYTHAGORAS: Funding of research groups in Technical University of Crete”, M 2.2 MIS 89192, co-funded by the EU through the Third Community Support Framework. Polychronis Koutsakis was born in Hania, Greece, in 1974. He received his 5-year Diploma in Electrical Engineering in 1997 from the University of Patras, Greece and his MSc and Ph.D. degrees in Electronic and Computer Engineering in 1999 and 2002, respectively, from the Technical University of Crete, Greece. He is currently a Visiting Assistant Professor at the Electronic and Computer Engineering Department of the same University. His research interests focus on the design, modeling and performance evaluation of wireless personal communication networks, and especially on the design and evaluation of multiple access schemes for multimedia integration over wireless and mobile satellite networks, on call admission control and traffic policing schemes for both wireless and wired networks and on traffic modeling. Dr. Koutsakis has authored more than 25 peer-reviewed papers in the above mentioned areas, and serves as a reviewer for many of the major journal publications focused on his research field. He is a member of the Greek Chamber of Professional Engineers and of the Greek Association of Electrical and Mechanical Engineers.     

Integrating high quality video streams with FTP traffic over a noisy high capacity wireless cellular channel

In this paper we propose and evaluate a Medium Access Control (MAC) protocol for the efficient integration of high quality video traffic with ftp data packet traffic over a wireless cellular channel of very high capacity. We envision a system where the mobile terminals are considered to be high performance devices with extended storage capabilities which can act like cache memories streaming multimedia material. Via an extensive simulation study we evaluate the system’s performance under a variety of possible loads which consist of actual MPEG-4 streams and ftp sessions, and we show that our scheme outperforms another, well-known MAC protocol for cellular networks.     

A New Call Admission Control Mechanism for Multimedia Traffic over Next-Generation Wireless Cellular Networks

The subject of Call Admission Control (CAC) for wireless networks has been studied extensively in the literature. Another subject on which many researchers have focused their attention is that of video traffic modeling. However, user mobility, combined with the rapidly growing number of "greedy" multimedia applications, in terms of bandwidth and Quality of Service (QoS) requirements, form a challenging and yet unresolved problem for third and fourth-generation wireless networks. In recent work, we have built a Discrete Autoregressive (DAR (1)) model to capture the behavior of multiplexed H.263 videoconference movies from variable bit rate (VBR) coders. Based on this model, we propose in this work a new efficient CAC scheme for wireless cellular networks, which differs from the existing proposals in the literature in that it uses precomputed traffic scenarios combined with online simulation for its decision making. Our scheme is shown, via an extensive simulation study comparison and a conceptual comparison with well-known existing approaches, to clearly excel in terms of QoS provisioning to users receiving videoconference videoconference and Web traffic. To the best of our knowledge, this is the first work in the relevant literature where such an approach has been proposed.     

Satellite bandwidth allocation based on MPEG-4 videoconference traffic prediction

The provision of acceptable Quality-of- Service for multimedia traffic over a geosynchronous earth orbit satellite network demands the existence of a well-designed Medium Access Control protocol. This paper proposes a new dynamic satellite bandwidth allocation technique which is based on accurate MPEG-4 videoconference traffic prediction. The use of the prediction in our protocol is shown via a simulation study to provide very good throughput and delay results.     

Medium Access Control for Integrated Multimedia Wireless Access with the Use of a Video Packet Discard Scheme

A well designed Medium Access Control (MAC) protocol for wireless networks should provide an efficient mechanism to share the limited bandwidth resources, and satisfy the diverse and usually contradictory Quality of Service (QoS) requirements of each traffic class. In this paper a new MAC protocol for next generation wireless communications is presented and investigated. The protocol uses a combined Packet Discard/Forward Error Correction scheme in order to efficiently integrate MPEG-4 videoconference packet traffic with voice, SMS data and web packet traffic over a noisy wireless channel of high capacity. Our scheme achieves high aggregate channel throughput in all cases of traffic load, while preserving the Quality of Service (QoS) requirements of each traffic type, and is shown to clearly outperform DPRMA, another efficient MAC protocol proposed in the literature for multimedia traffic integration over wireless networks. Dr. Polychronis Koutsakis was born in Hania, Greece, in 1974. He received his 5-year Diploma in Electrical Engineering in 1997 from the University of Patras, Greece and his MSc and Ph.D. degrees in Electronic and Computer Engineering in 1999 and 2002, respectively, from the Technical University of Crete, Greece. He was a Visiting Lecturer at the Electronic and Computer Engineering Department of the same University for three years (2003–2006). He is currently an Assistant Professor at the Electrical and Computer Engineering Department of McMaster University, Canada. His research interests focus on the design, modeling and performance evaluation of computer communication networks, and especially on the design and evaluation of multiple access schemes for multimedia integration over wireless networks, on call admission control and traffic policing schemes for both wireless and wired networks, on multiple access control protocols for mobile satellite networks, wireless sensor networks and powerline networks, and on traffic modeling. Dr. Koutsakis has authored more than 45 peer-reviewed papers in the above mentioned areas, has served as a Guest Editor for an issue of the ACM Mobile Computing and Communications Review, as a TPC member for conferences such as IEEE GLOBECOM, IEEE LCN and IEEE PerCom, will serve as Session Chair for the IEEE GLOBECOM 2006 Symposium on Satellite & Space Communications and serves as a reviewer for most of the major journal publications focused on his research field. Moisis Vafiadis was born in Elefsina, Greece, in 1980. He has recently completed his studies towards the Diploma in Electronic Engineering at the Technological Educational Institute of Crete, Greece. His research interests focus on wireless personal communication networks, and especially on the MAC layer and on the development and testing of wireless multimedia applications.     

Call-admission-control and traffic-policing mechanisms for the transmission of videoconference traffic from MPEG-4 and H.263 video coders in wireless ATM networks

In this paper, we explore, via an extensive simulation study, the performance of a call-admission-control (CAC) and traffic-policing mechanisms proposed for transmitting multiple quality encoded videoconference movies over a wireless asynchronous transfer mode channel of high capacity, depending on the user's needs and requests. Both the CAC algorithm and the traffic-policing mechanism are novel mechanisms proposed for the first time in this paper. For their implementation, we use an estimation of the equivalent bandwidth of the movies, which has been introduced in the past. We focus on both MPEG-4 and H.263 coded movies, as the integration of such video streams has not been studied in the relevant literature. In the case of H.263 movies, our scheme achieves high aggregate channel throughput, while preserving the very strict quality-of-service requirements of the video traffic.