congestion control and quality of service

... 24-1 DATA TRAFFIC The main focus of congestion control and quality of service is data traffic In congestion control we try to avoid traffic congestion In quality of service, we try to create an appropriate ... Four cases of congestion 24.22 24-5 QUALITY OF SERVICE Quality of service (QoS) is an internetworking issue that has been discussed more than defined We can informally define quality of service ... understand the concept of congestion control, let us give two examples: one in TCP and the other in Frame Relay Topics discussed in this section: Congestion Control in TCP Congestion Control...

Ngày tải lên: 06/03/2014, 12:20

... article we start out with a detailed review and discussion of available CLDs for both power control and MUD Eventually, we are concerned with the Quality of Service (QoS) achieved with the different ... first part of the frame is related to a contention phase and consists of several pairs of minislots Each minislot is divided into the transmission of an RTS and a CTS signal The second part of the ... 11times increase of bandwidth In the 802.11b protocol, the same spreading gain of 11 is applied against out-ofband interferers However, PBOA assumes only a single band transmission and is thus naturally...

Ngày tải lên: 21/06/2014, 03:20

... of retransmissions for web-browsing and data services (x) Web-browsing and data services are equipped with finite buffer of buffer sizes B3 and B4 , respectively, both in unit of packets Voice and ... amount of interference and retransmissions, the lengthened activity factors of each mobile can be different even for the same class of service Let us denote the average on and off periods of webbrowsing ... retransmission and overflow statistics For example, in Qlength (t | l), N of , ξ, and ξ are used to replace Nof , ξ, and χ, respectively The value of ξ is estimated using the average number of retransmissions...

Ngày tải lên: 22/06/2014, 22:20

... Costs and Improve Quality of Service Improving Grade of Service (GOS) While Reducing RF Channels Wireless service providers are adopting new deployment strategies to reduce network costs and improve ... or more of the total number of RF channels required on a multiple link transport system for a specified amount of user grade of service The percentage reduction depended on the number of radiating ... to reduce network costs and improve quality of service In one urban market, a major national wireless service provider has improved network traffic loading and significantly boosted network RF...

Ngày tải lên: 10/12/2013, 19:15

... are wider service organization agendas than simply service quality: improving access to existing services; equity and equality of service provision; providing efficient and effective services ... customers perceive the service quality and being able to measure service quality can benefit industry professionals in quantitative and qualitative ways The measurement of service quality can provide ... management", Managing Service Quality, Vol.9, No.3, pp 180-190 Dotchin, J.A and Oakland, J.S (1994a), "Total quality management in services: Part Service quality" , International Journal of Quality & Reliability...

Ngày tải lên: 23/12/2013, 02:16

... initial bandwidth, UGS, rtPS, nrtPS and BE, based on the requested bandwidth of UGS, the required minimum bandwidth of rtPS and nrtPS and the queue length of BE service respectively If remaining bandwidth ... classified and associated with a service class The IEEE 802.16 standards define five service classes: Unsolicited Grant Service (UGS), extended real-time Polling Service (ertPS), real-time Polling Service ... synthesis table of the main scheduling mechanisms and highlights the main points of each of them Section does the final consideration of this chapter WiMAX MAC scheduling and QoS: Issues and challenges...

Ngày tải lên: 21/06/2014, 05:20

... scheduling services have different and sometimes conflicting requirements UGS services must always have their delay and bandwidth commitment met, so simply reserving enough bandwidth for those services ... Algorithm and Bandwidth Allocation in WiMAX fixed allocation for UGS, EDF for rtVR, WFQ for nrtVR, and equal division of remaining bandwidth for BE Although EDF takes care of the delay requirement of ... connection and then sent to BS, and BS sorts the SC of all the connections and assigns bandwidth according to the descending order of SC SC is derived according to the buffer occupancy and waiting...

Ngày tải lên: 21/06/2014, 05:20

... (resp C) and user k of cell A at subcarrier n and OFDM block m Of course, the average channel gains A B C E | Hk (n, m)|2 , E | Hk (n, m)|2 and E | Hk (n, m)|2 depend on the position of user k ... enhancement (IEEE802.16e, 2006), that allows the quality- of- service management Service and performance metric The main objective of this chapter is to derive and compare the performance provided by a ... on the vertical handovers management, in order to optimize the resource usage, maintaining an adequate quality- of- service and acting seamlessly (i.e., automatically and without service interruptions)...

Ngày tải lên: 21/06/2014, 05:20

... words, if we consider an offered capacity system equal to C and types of service class (class and 2) If class (i.e aggreagted calls) uses I units then 154 Quality of Service and Resource Allocation ... the format of the OFDMA slot is data subcarriers of OFDM symbols The total number of OFDMA slots in a mobile WiMAX frame corresponds to S × Ts where S = Ld and Ts is the number of OFDM symbol ... following the call admission control mechanism decision 152 Quality of Service and Resource Allocation in WiMAX Will-be-set-by-IN-TECH Call admission control (CAC) and Bandwidth Allocation As in...

Ngày tải lên: 21/06/2014, 05:20

... S1, the service time of an REQ is X1 = Y, and the Laplace-Stieltjes transform of X1 is therefore given by that of Y Thus the service time of an REQ is given by X= X0 w.p 1−ρ Y w.p ρ (14) and the ... studying the impact of different parameters on the performance of contention-based services of IEEE 802.16 We evaluate the impact of the number of SSs (N) and the initial backoff window (W) on ... Control and Resource Allocation for H.264 SVC Transmission Over OFDMA Networks, Proceedings of VTC’2010, pp 1-5, 15502252, Taipei, may 2010, IEEExplorer Mukul, R and Singh, P and Jayaram, D and...

Ngày tải lên: 21/06/2014, 05:20

... the growing demands of fixed and mobile users, while increasing the profits of the content providers With regard to Quality of Service (QoS) control, the WiMAX system provides service differentiation ... seamless handover, when the video 210 Quality of Service and Resource Allocation in WiMAX quality was maintained during the change of BS The SS that experienced a hard handover did not receive 5% of ... delay rate and throughput, are generally used to measure the impact on the quality level of multimedia streaming from the 194 Quality of Service and Resource Allocation in WiMAX perspective of the...

Ngày tải lên: 21/06/2014, 05:20

... DV and CTC – Map 231 232 Quality of Service and Resource Allocation in WiMAX Fig Blocking probabilities for DV and CTC – Map1 Fig 10 System throughput for DV and CTC – Map2 Evaluation of QoS and ... results of assessing quality of VoIP (Voice Over IP) conversations CTC and nbLDPC codes are compared in terms of system capacity and resulting quality of experience (QoE) performance of VoIP ... example of the process of estimating resources for four frames 226 Quality of Service and Resource Allocation in WiMAX Value of guard channel (threshold) is adjusted based on the value of the...

Ngày tải lên: 21/06/2014, 05:20

... safety and healthcare 246 Quality of Service and Resource Allocation in WiMAX E (electronic)-health terminology lumps a variety of medicine and communication services associated with rendering of ... Mobility factor enhances efficiency of treatment decision-making, patients care and makes e-health services more comfortable and accessible 248  Quality of Service and Resource Allocation in WiMAX ... purpose of its utilization across e-health mobile applications Although, the standard is incapable of suiting real-time video and voice traffic demands on account of no priority provision and lack of...

Ngày tải lên: 21/06/2014, 05:20

... 276 Quality of Service and Resource Allocation in WiMAX WiMAX and IP handoff management (Chen & Hsieh, 2007) and in that way reduce the number of control messages For further general examples of ... hoc and mesh networks), and resource management In WiMAX multicast mode, scheduling decisions for the real-time Polling Service (rtPS) queue, one of the WiMAX quality of service queues (Andrews ... increased bandwidth compared to 3G systems, which bandwidth capacity will be further expanded in part ‘m’ of the standard (Ahmandi, 2011, written by Intel’s chief technology officer) Broadband wireless...

Ngày tải lên: 21/06/2014, 05:20

... of video applications Like every other wireless environment, transmitting video signals in a VANET poses concerns Handling 294 Quality of Service and Resource Allocation in WiMAX congestion and ... WireShark software is set to access the “capture” folder in the control centre before 302 Quality of Service and Resource Allocation in WiMAX streaming the video The WireShark software is turned on and ... are routed and given priority due to the service class name associated with them and the scheduling type, which handles the bandwidth request/grant mechanism The silver service class and the Real-time...

Ngày tải lên: 21/06/2014, 05:20

... initial bandwidth, UGS, rtPS, nrtPS and BE, based on the requested bandwidth of UGS, the required minimum bandwidth of rtPS and nrtPS and the queue length of BE service respectively If remaining bandwidth ... Table Taxonomy of Bandwidth request mechanisms 30 Quality of Service and Resource Allocation in WiMAX control is not efficient to guarantee QoS of different types of connections and in the same ... we conclude the chapter in section 26 Quality of Service and Resource Allocation in WiMAX Quality of services provisioning in WiMAX networks 2.1 Services and parameters In WiMAX (Jeffrey,2007)(Labiod...

Ngày tải lên: 27/06/2014, 01:20

... increases The quality of high-strength concrete is controlled by the quality and uniformity of the ingredients, and by the mixing, placing, and curing conditions A high level of quality control is ... magnitude of the strengths obtained and is more useful in comparing the degree of control for a wide range of strength levels Suggested standards of quality control are listed in Table 5.1.1 These standards ... differential of 20 C (36F) was found to be acceptable for the 0.5 m (1.5 ft) thick walls CHAPTER 3 QUALITY ASSURANCE AND QUALITY CONTROL 3.1—Introduction Quality assurance (QA) and quality control...

Ngày tải lên: 24/10/2014, 21:59

... 1.1 Overview of Quality of Service 1.2 Application-level Quality of Service 1.3 Overview of Sensor Networks 1.4 Overview of loosely coupled distributed 1.5 Motivation and Contribution ... situation, the question of the quality of service for these applications will become important This thesis addresses some of the issues of provisioning of application-level quality of service either for ... INTRODUCTION of loosely coupled distributed systems in Section 1.4 In Section 1.1 Overview of Quality of Service The term Quality of Service in the context of a computer system refers to the ability of...

Ngày tải lên: 11/09/2015, 14:22

... rest of the thesis, we will focus primarily on JET OBS 1.3 Need for Quality of Service Support in Optical Burst Switched Networks and Challenges Due to the extreme popularity and success of the ... requirements of network performance or Quality of Service (QoS) Non-interactive and semi-interactive applications such as email, web browsing can cope with a wide range of QoS On the other hand, highly ... WR-OBS improves network throughput and includes explicit Quality of Service (QoS) provisioning However, the centralised nature of this scheme does not scale well and makes it unsuitable for large...

Ngày tải lên: 15/09/2015, 21:52