Effect of Transmission Opportunity Limit on Transmission Time Modeling in 802.11e (original) (raw)
Related papers
Transmission Time Analysis and Modeling in 802.11e Contention Free Burst Mode
2007 First International Global Information Infrastructure Symposium, 2007
Several analytical models have been developed for both 802.11 Distributed Coordinated Function (DCF) and 802.11e Enhanced Distributed Channel Access (EDCA). However, none of these models considers the 802.11e Contention Free Burst (CFB) mode which allows a given station to transmit more than one frame for each access to the channel. In spite of its influence on the global performance and its role as a main differentiation parameter in 802.1le, Transmission Opportunity (TXOP) bursting is ignored in all already existing models. These latter consider, for the sake of simplicity, that a particular station transmits a unique frame when having data to be transmitted. The main objective of the current work is to analyze the TXOP bursting procedure and to propose a simple model allowing us to calculate the transmission time occupied by a particular AC when using the CFB mode. It will be shown that this transmission time is directly a function of the number of transmitted frames which depends on the queue size and on the TXOP limit. CFB performance analysis as well as the proposed model are discussed, demonstrated and validated by means of simulations. I.
Journal of Computer …, 2011
Extensive research addressing IEEE 802.11e enhanced distributed channel access (EDCA) performance analysis, by means of analytical models, exist in the literature. Unfortunately, the currently proposed models, even though numerous, do not reach this accuracy due to the great number of simplifications that have been done. Particularly, none of these models considers the 802.11e contention free burst (CFB) mode which allows a given station to transmit a burst of frames without contention during a given transmission opportunity limit (TXOPLimit) time interval. Despite its influence on the global performance, TXOPLimit is ignored in almost all existing models. To fill in this gap, we develop in this paper a new and complete analytical model that (i) reflects the correct functioning of EDCA, (ii) includes all the 802.11e EDCA differentiation parameters, (iii) takes into account all the features of the protocol, and (iv) can be applied to all network conditions, going from nonsaturation to saturation conditions. Additionally, this model is developed in order to be used in admission control procedure, so it was designed to have a low complexity and an acceptable response time. The proposed model is validated by means of both calculations and extensive simulations.
TransmissionTime Analysisand Modeling in 802. le Contention FreeBurstMode
Several analytical modelshavebeendeveloped for both802.11 Distributed Coordinated Function (DCF)and802.11e Enhanced Distributed Channel Access (EDCA). However, noneof these models considers the802.11e Contention FreeBurst(CFB) modewhichallows a givenstation totransmit morethanone frameforeachaccess tothechannel. Inspite ofitsinfluence on theglobal performance anditsroleasa maindifferentiation parameter in 802.1le, Transmission Opportunity (TXOP) bursting isignored inallalready existing models. Theselatter consider, forthesakeofsimplicity, thata particular station transmits auniqueframewhenhaving datatobetransmitted. Themainobjective ofthecurrent workistoanalyze theTXOP bursting procedure andtopropose asimple modelallowing usto calculate thetransmission timeoccupied byaparticular AC when using theCFBmode.Itwill beshownthatthis transmission time isdirectly afunction ofthenumberoftransmitted frames which dependson thequeuesizeandon theTXOP limit. CFB performance analysis aswellasthepro...
Analytical Modeling of the IEEE 802.11e EDCA Network
2014
Contention Free Burst (CFB) is a promising burst transmission scheme defined in the IEEE 802.11e Medium Access Control (MAC) protocol to achieve differentiated Quality of Service (QoS) and improve the utilization of the wireless scarce bandwidth. Although modeling and performance analysis of the IEEE 802.11e network have attracted tremendous research efforts from both the academia and industry, most existing analytical models do not give attention to the CFB QoS parameter. In this paper, we aim to propose a simple analytical model of the IEEE 802.11e Enhanced Distributed Channel Access (EDCA) function including mainly the CFB, in order to study its effect on the improvement of the achievable throughput of Video and Voice Access Categories (ACs). Therefore, we propose a new two-dimensional Markov chain model of the IEEE 802.11e EDCA function with CFB. Then, we develop a mathematical model to derive the saturation throughput. Finally, performance analysis has allowed us to estimate th...
Saturation Throughput Analysis of IEEE 802.11e Enhanced Distributed Coordination Function
IEEE Journal on Selected Areas in Communications, 2004
The 802.11 WLAN legacy standard cannot provide Quality of Service (QoS) support for multimedia applications because the 802.11 was initially developed for Best Effort services. Hence, the 802.11e amendment was published in order to provide the QoS support to WLANs. One of the most important functions in 802.11e is the contention based channel access mechanism called Enhanced Distributed Channel Access (EDCA), which provides a priority scheme by differentiating the Arbitration Inter Frame Space (AIFS), initial window size and Transmission OPportunity limit (TXOPlimit). In this paper, we propose a novel analytical model for the performance analysis of the IEEE 802.11e EDCA network with Contention Free Burst under fading channel and saturated traffic conditions. This new model captures all of the major QoS specific features, namely AIFS, minimum contention window size, maximum contention window size, virtual collision and TXOPlimit. So, we have analyzed the saturation system throughput of the basic access method of the IEEE 802.11e EDCA network.
Saturation Throughput Analysis of IEEE 802.11 e EDCA Through Analytical Model
The 802.11 WLAN legacy standard cannot provide Quality of Service (QoS) support for multimedia applications because the 802.11 was initially developed for Best Effort services. Hence, the 802.11e amendment was published in order to provide the QoS support to WLANs. One of the most important functions in 802.11e is the contention based channel access mechanism called Enhanced Distributed Channel Access (EDCA), which provides a priority scheme by differentiating the Arbitration Inter Frame Space (AIFS), initial window size and Transmission OPportunity limit (TXOPlimit). In this paper, we propose a novel analytical model for the performance analysis of the IEEE 802.11e EDCA network with Contention Free Burst under fading channel and saturated traffic conditions. This new model captures all of the major QoS specific features, namely AIFS, minimum contention window size, maximum contention window size, virtual collision and TXOPlimit. So, we have analyzed the saturation system throughput of the basic access method of the IEEE 802.11e EDCA network.
Efficiency analysis of burst transmissions with block ACK in contention-based 802.11e WLANs
2005
The channel utilization efficiency of the standard 802.11 networks is severely compromised when high data transmission rates are employed since physical layer headers and control frames are transmitted at low rate, thus wasting more channel time proportionally. The extensions defined in the emerging 802.11e for quality-of-service (QoS) provisioning include some new mechanisms developed in order to improve the efficiency. Those include data transmission bursting (referred to as TXOP operation) and acknowledgment aggregation (referred to as block ACK). These two features allow to offer new data transmission services, in which the data delivery and acknowledgment unit is not a single frame, but a block of frames. In this paper, we evaluate the performance of these operations for both basic and RTS/CTS access cases. We quantify how the data bursting and block ACK mechanisms can affect the system efficiency for different environments, and derive the maximum achievable throughput. We also discuss the operating conditions at which the switch from a channel utilization method to another is desired.
Throughput and delay analysis for the IEEE 802.11e enhanced distributed channel access
IEEE Transactions on Communications, 2000
In this letter, we propose a three-dimensional Markov chain model for the 802.11e enhanced distributed channel access (EDCA) mode. This model can be used to compute the maximum sustainable throughput and service delay distribution for each priority class when under saturation load. The new framework models the performance impact of major quality-of-service (QoS)specific features (e.g., CWMin, CWMax, AIFS, internal collision resolution) of the 802.11e EDCA mode, and hence can provide an analytical approach to pick the parameter values associated with EDCA to meet the QoS requirements of each priority.
Performance analysis of transmissions opportunity limit in 802.11 e WLANs
2008
Abstract Transmission opportunity (TXOP) is a channel control mechanism introduced in the IEEE802. 11e wireless LAN standard to improve channel utilization. In a previous paper, we have proposed a novel scheme to effectively predict the throughput of various TXOP classes based on a common threshold. In this paper, we extend this solution to incorporate the impact of the contention window (CW) size.
An analytical model for the IEEE 802.11e EDCF
The 13th IEEE Workshop on Local and Metropolitan Area Networks, 2004. LANMAN 2004.
The IEEE 802.11e protocol is designed to enhance the QoS capability of wireless local area networks (WLAN). In this paper, we propose a multidimensional Markov model for the 802.11e enhanced distributed coordination function (EDCF)' mode and compute the maximum sustainable throughput and service delay distribution for each priority class when under heavy load. Since the QoS mechanisms and their associated parameters in IEEE 802.11e interact with each other in a complex way, it is important to model the aggregate effect of all the mechanisms. The approach we present does so and therefore provides an analytical approach to pick the parameter values associated with EDCF to meet the QoS requirements of each priority. 'In the latest IEEE 802.11e draft, enhanced distributed channel access (EDCA) replaces EDCF. However, since the major QoS schemes remain the same in EDCA, we will still call it EDCF throughout this paper.