Survey of traffic control schemes and error control schemes for ATM networks

Among the techniques proposed for B-ISDN transfer mode, ATM concept is considered to be the most promising transfer technique because of its flexibility and efficiency. This paper surveys and reviews a number of topics related to ATM networks. Those topics cover congestion control, provision of multiple classes of traffic, and error control. Due to the nature of ATM networks, those issues are far more challenging than in conventional networks. Sorne of the more promising solutions to those issues are surveyed, and the corresponding results on performance are summarized. Future research problems in ATM protocol aspect are also presented

Final report on the evaluation of RRM/CRRM algorithms

Deliverable public del projecte EVERESTThis deliverable provides a definition and a complete evaluation of the RRM/CRRM algorithms selected in D11 and D15, and evolved and refined on an iterative process. The evaluation will be carried out by means of simulations using the simulators provided at D07, and D14.Preprin

Quality of Service over Specific Link Layers: state of the art report

The Integrated Services concept is proposed as an enhancement to the current Internet architecture, to provide a better Quality of Service (QoS) than that provided by the traditional Best-Effort service. The features of the Integrated Services are explained in this report. To support Integrated Services, certain requirements are posed on the underlying link layer. These requirements are studied by the Integrated Services over Specific Link Layers (ISSLL) IETF working group. The status of this ongoing research is reported in this document. To be more specific, the solutions to provide Integrated Services over ATM, IEEE 802 LAN technologies and low-bitrate links are evaluated in detail. The ISSLL working group has not yet studied the requirements, that are posed on the underlying link layer, when this link layer is wireless. Therefore, this state of the art report is extended with an identification of the requirements that are posed on the underlying wireless link, to provide differentiated Quality of Service

Future benefits and applications of intelligent on-board processing to VSAT services

The trends and roles of VSAT services in the year 2010 time frame are examined based on an overall network and service model for that period. An estimate of the VSAT traffic is then made and the service and general network requirements are identified. In order to accommodate these traffic needs, four satellite VSAT architectures based on the use of fixed or scanning multibeam antennas in conjunction with IF switching or onboard regeneration and baseband processing are suggested. The performance of each of these architectures is assessed and the key enabling technologies are identified

Simulation of ATM multiplexer for bursty sources

Asynchronous transfer mode ( ATM ) is a promising multiplexing and switching technique for implementing an integrated access as well as transport network and has been adopted by CCITT as a basis for the future broadband integrated services digital network ( BISDN ). The ATM technique allows digital communication of any type to share common transmission links and switching devices on a statistical multiplexing basis. Information is transmitted in the form of constant length cells. In an ATM network, the major parameters to cause ATM network performance deterioration are the cell loss and the cell delay at the buffer queue in the ATM multiplexer. Therefore, the performance parameters of an ATM multiplexer are specifically focused on the cell loss probability, the cell delay, and the distribution of queueing length at buffer m this study. The performance of an ATM multiplexer is studied, whose input consists of the superposition of homogeneous bursty ( ON/OFF ) sources, 1e , all the superposed sources are characterized by the bursty sources of the same parameter values. The cell loss probability and the distribution of queuing length at buffer under different offered load and buffer size conditions are evaluated. An ATM multiplexer with three priority classes is simulated using the priority assignment control method of [15]. Under the priority assignment period P and the priority assignment ratio WD in this method have been defined, the relationship between the traffic balance of classes and buffer size of each is studied. The cell loss probability and delay time of each class ( same sources and different sources between classes ) are evaluated. The results are useful to design a economic and effective ATM multiplexer

Network capacity and quality of service management in F/TDMA cellular systems

As a consequence of rapidly increasing mobile communications, efficient utilization of the scarce radio resources becomes one of the most important issues in the system evolution. Increase of the system capacity has been investigated in two ways. The first way is to replace the fixed channel allocation (FCA), with the more efficient dynamic channel allocation (DCA). The second way is to utilize those traffic channels not being used by voice services to provide a packet data service, like general packet radio service (GPRS) and cellular digital packet data (CDPD). In this thesis, the author have proposed two DCA schemes and developed an analysis method to investigate the GPRS impact on the GSM voice services. In addition, the GPRS downlink performance is investigated and some guidelines or principles for GPRS network planning have been presented. In the proposed DCA algorithms, the effect of the channel allocation on existing calls is considered by the evaluation of the call outage rate or a cost function. In the first proposed algorithm, in order to evaluate the call outage caused by those candidate channels, a method of estimating the average signal to interference ratio (SIR) variation of on-going calls due to the assignment of a coming call has been developed. This algorithm improves the capacity or QoS performance compared with the first available and maximum SIR schemes. In the second proposed algorithm, a cost function has been introduced to estimate the cost of the assignment of a candidate channel. The performance evaluation shows that by using the cost-function for channel pre-selection the problem of high intracell handover rate for the first available based scheme can be decreased to an adequate level and the time of the call set-up can be shortened. An analysis method to calculate the outage probability of the GSM-GPRS network for both the non-frequency hopping and frequency hopping systems has been presented to investigate the GPRS impact on GSM voice services. It is found that: GPRS affects more on the QoS of voice services of the network with small reuse factor; GPRS will reduce the cell service area, but the reduction percentage of the cell service area for the system with small reuse factor is higher than that for the system with large reuse factor; those channels unused by voice services might not all be used for carrying GPRS traffic; the number of unused voice channels which can be allocated to GPRS depends on the difference between the outage level of the existing GSM network and the maximum acceptable level. From final part of this work, it is found that: GPRS capacity performance in downlink is quite different from that in uplink because of the difference in the transmission protocols; multiple-slot allocation does not show a gain of the mean throughput neither a decrease on the mean delay compared to single slot allocation. This result is different from the result of the uplink performance. In multi-rate services, the multi-slot services significantly increase the delay of the single-slot service, consequently, a control of the multi-slot services is needed.reviewe