In this paper, we investigate a call-admission and handoffcontrol framework for multi-tier cellular networks. We first propose and compare Call-Admission Control (CAC) algorithms based on the cell-dwelling time, by studying their impact on the handoff-call dropping and new-call blocking probabilities and the channel partitioning between the two tiers. Our results show that a simple, cell-dwelli...

Networked applications require good performance from the network along with a high level of predictability. One of the factors that affects application performance is the packet dropping policy adopted in the switch or router. In this paper, we evaluate the absolute performance of various packet dropping policies, and also the predictability they can provide to an application. The packet droppi...

| The performance analyses of selective packet dropping policies have usually been performed using homogeneous traac sources and under one node scenarios. In this paper we focus our attention not only to heterogeneous sources but also heterogeneous environments. We present simulation results of application level performance for heterogeneous traac sources under three diierent packet dropping sc...

As the DiffServ architecture is gaining ground, traffic engineering requires major adjustments. In addition, the measurement-based strategy has been widely adopted owing to its advantages of flexibility and easy adaptation. This article reviews measurement-based dropping schemes. Based on the definition and investigation of the “packet shortage” phenomenon, an enhanced dropping scheme for the p...

Traffic engineering issues require major adjustments, as the DiffServ architecture is gaining ground. In addition, the measurementbased strategy shows the advantages of flexibility and easy adaptation. This article reviews measurement-based packet/cell dropping schemes. Based on the definition and investigation of a “packet shortage” phenomenon, a new dropping scheme for proportionally differen...

In this paper‎, ‎an efficient dropping criterion has been used to compute the IUL factorization obtained from Backward Factored APproximate INVerse (BFAPINV) and ILU factorization obtained from Forward Factored APproximate INVerse (FFAPINV) algorithms‎. ‎We use different drop tolerance parameters to compute the preconditioners‎. ‎To study the effect of such a dropping on the quality of the ILU ...

one studies the $hx$-hypergroups, corresponding to the chinese hypergroups associated with the direct products of some ${bf z}/n {bf z},$ calculating their fuzzy grades.