In this paper, we propose an adaptive compensation algorithm to compensate cell delay variation (CDV) occurring during ATM/TDMA transition in a satellite ATM network. The proposed CDV compensation algorithm uses two types of additional information: cell position information (Cp)--indicating the number of cells (N) arriving within a control unit time (Tc) and positions of cells at a given time--and the number of cells in bursts--to take into account the characteristics of localized bursts. To evaluate the performance of the proposed algorithm, we performed a computer simulation based on an OPNET environment, using the Markov modulated Poisson process (MMPP) traffic model and assessed its effectiveness from varied standpoints. The results of the performance testing indicate that the proposed algorithm, while requiring significantly less additional information than previous CDV compensation algorithms, is able to more efficiently compensate CDV in localized burst traffic than the previous ones.

This paper proposes a new MAC scheme for ATM based Passive Optical Network (APON) which follows the ITU-T recommendation G.983.1. MAC schemes for APON mostly adopt single-side scheduling in which only OLT (Optical Line Termination) schedules upstream access order for ONUs (Optical Network Units) that inform cell arrival information to OLT. In this paper, we propose a MAC scheme called double-side scheduling protocol (DSP) in which both OLT and ONU participate in scheduling process. Through the computer simulation we find out that the CDV (cell delay variation) performance of the real-time service can be improved remarkably using fewer overhead slots than that of the MAC schemes adopting CDV control algorithm. For the proposed MAC scheme, we present grant field format, minislot format, divided slot format, and scheduling algorithm.

This paper proposes a new failure-resistant ATM transport method for real-time applications (FRAT-RA). This method can prevent not only cell loss but also cell delay variation (CDV) even when a network failure occurs. First, a general overview of the existing fault-resistant method is briefly described and its problems for real-time applications are discussed. Next, the proposed FRAT-RA method is described in detail. Finally, evaluation results on the CDV of FRAT-RA and its QoS improvement are presented. The results show that failure-resistant and high-quality transmission of real-time signals can be achieved with FRAT-RA.

Recent progress in the optical transmission technology makes an ATM passive optical network (APON) a good candidate for access networks. APON based on tree topology requires efficient medium access control (MAC) to multiplex upstream data flows efficiently while not disturbing the original pattern. In this paper, we proposed a Window-based permit distribution scheme for the MAC protocol of APON. It derives the rate of generated cell during one spacing window by the unit called time segment, and spaces permits not to cluster the cells in upstream transmission. The purpose of the proposed scheme is to make the permit arrival rate close to the cell arrival rate, so, reduces the CDV even if under the various kinds of bursty traffic. In addition, the proposed scheme does not require the additional MAC overhead for cell arrival timing information. The result of simulation shows that the performance of proposed protocol is better than current protocols in terms of transfer delay and 1-point CDV.

Recent progress in the optical transmission technology makes an ATM passive optical network (APON) a good candidate for access networks. APON based on tree topology requires efficient medium access control (MAC) to multiplex upstream data flows efficiently while not disturbing the original pattern. In this paper, we proposed a Window-based permit distribution scheme for the MAC protocol of APON. It derives the rate of generated cell during one spacing window by the unit called time segment, and spaces permits not to cluster the cells in upstream transmission. The purpose of the proposed scheme is to make the permit arrival rate close to the cell arrival rate, so, reduces the CDV even if under the various kinds of bursty traffic. In addition, the proposed scheme does not require the additional MAC overhead for cell arrival timing information. The result of simulation shows that the performance of proposed protocol is better than current protocols in terms of transfer delay and 1-point CDV.

In ATM networks, a usage parameter control (UPC) strategy must regulate incoming traffic according to the characteristics of the sources declared at call set-up. Among various UPC schemes, Leaky Bucket is a conventionally method having been discussed extensively. This paper examines the characteristics of the multiplexer with a sufficient buffer in which cell arrivals are policed by Enhanced Leaky-Bucket (ELB) before entering the system. In addition to the factor of mean rate, peak rate and cell delay variation (CDV) are also considered for each ELB. We find out the worst output pattern from the ELB and derive the upper bound on average waiting time as a function of the ELB parameters.

Due to the Cell Delay Variation (CDV) at User Network Interface (UNI), it is very hard for an ATM network to perform Usage Parameter Control (UPC), which is an important job for congestion control. Based on the Generic Cell Rate Algorithm (GCRA), ATM Forum has proposed a procedure to perform the UPC. However, the severe problem is that a user has to specify the CDV Tolerance at the UNI by itself. Such a nearly unreachable constraint makes the GCRA unsuitable for UPC. In this paper, we point out that the CDV comprises two parts in which the customer and a network provider should be responsible. Thus, we propose a concept of Innocent Public Network and an Agent Protocol to realize the principle and facilitate UPC. In addition, a shaper is suggested for the customer to employ so as to prevent its performance degradation. In the proposed system, the network is no longer suffered from CDV at the UNI and the UPC can be easily preformed.

This letter proposes a new shaping algorithm (CRSA: CDV Reduction Shaping Algorithm) that can freely reduce the maximum CDV value of a cell stream to any predetermined value. There is a trade off between shaping delay and the maximum CDV value reduction achieved when using CRSA. The shaper using CRSA (CR-shaper) output satisfies the Peak Cell Rate Reference Algorithm set with the CR-shaper parameters.

This letter presents SAM, a multiplexer for ATM's circuit emulation services that can precisely control the cell clumping at the connection-level. Compared with a FIFO (First In First Out) multiplexer, it also improves the connection-level diffusion and CDV (Cell Delay Variation) performance. SAM can therefore significantly increase the number of connections accepted by CAC (Call Admission Control) procedures in the subsequent multiplexer.

For a CBR (Constant Bit Rate) connection in an ATM (Asynchronous Transfer Mode) network, we determine the CDV (Cell Delay Variation) tolerance for the mapping of ATM cells from the ATM Layer onto the Physical Layer. Our result will be useful to properly allocate resources to connections and to accurately enforce the contract governing the user's cell traffic by UPC (Usage Parameter Control).