Increasing user demand for more bandwidth over wireless communications has motivated a new challenge to utilize the benefits of wireless ATM technology. This paper focuses on how to provide IP services to a mobile user over wireless ATM networks. It seems to be able to support the mobility by combining the existing schemes developed by the IETF and ATM Forum such as Mobile IP, IP over ATM, Next Hop Resolution Protocol (NHRP), mobile PNNI, and LR (location register) schemes. They may be so called "Mobile IP over ATM" or "IP over WATM". However, these naive combinations of existing schemes may result in shortcomings such as inefficiency, duplication of functions and waste of resources. Thus, a new efficient scheme called mobile NHRP is proposed to provide IP mobility support over wireless ATM networks. Also, the fault tolerant routing with mobile NHRP is described.

In packet switching using multistage interconnection networks (MIN's), it is generally assumed that the packet movements successively propagate from the last stage to the first stage in one network cycle. Ding and Bhuyan (1994), however, have shown that the network performance can be significantly improved if the packet movements are confined within each pair of adjacent stages using small clock cycles. In this short note, we present a model for estimating the performance of multibuffered MIN's employing the approach. Using the model, the relative effectiveness of the approach is identified compared to the traditional design.>

Multistage interconnection networks (MIN's) have a number of applications in the areas of computer and communication. While several analytical models have been proposed for the performance evaluation of MIN's, they are either not very accurate or too complex to be generalized. The authors propose a new model for evaluating multibuffered MIN's with 2/spl times/2 switching elements. It effectively and realistically models the correlation of packet movements between two adjacent stages as well as subsequent network cycles. As a result, the proposed model is very accurate for any size and traffic conditions of MIN's. It is also simple and can be easily generalized.>

Call packing has been recognized as a routing scheme that significantly reduces the blocking probability of connection requests in a circuit-switched Clos multistage interconnection network. In this paper, for the first time, we develop general analytical models for the point-to-point blocking probability of the call-packing scheme applied to Clos networks. By introducing a new parameter called the degree of call packing, the models can correctly estimate the blocking probability of both call-packing and random routing schemes. The models are verified by computer simulation for various size networks and traffic conditions.>

A new relationship is derived between blocking probability and the rearrangement probability density for a three stage switch. A novel analytical model for call packing is developed. The model confirms previous results from simulation and shows that packing/repacking reduces blocking and hence the required rearrangements, compared to the random routing method. The probability density of rearrangements is also derived.>

The authors present a model which can accurately evaluate the performance of single-buffered and multibuffered MINs (multistage interconnection networks) with 2*2 switching elements (SESs). Earlier models were inaccurate because of the simplicity, or hard to expand for larger SEs or buffer sizes due to their complexity. The proposed model for single-buffered MINs has only three states, including the blocked state, while it is very accurate by realistically modeling the transactions between buffers in adjacent stages and network cycles. The model was expanded for multibuffered MIN, and it was found to be still very accurate. Comparisons with simulation and the YLL model (see H.Y. Yoon et al., 1990) revealed that the proposed models are consistently much more accurate irrespective of the size of the network, buffer, and traffic condition. The proposed model can be easily expanded for any other structures and operation conditions of MINs.>