Guard Channel Scheme Research Articles

Adaptive resource allocation for prioritized call admission over an ATM-based wireless PCN

In future personal communications networks (PCNs) supporting network-wide handoffs, new and handoff requests will compete for connection resources in both the mobile and backbone networks. Forced call terminations due to handoff call blocking are generally more objectionable than new call blocking. The previously proposed guard channel scheme for radio channel allocation in cellular networks reduces handoff call blocking probability substantially at the expense of slight increases in new call blocking probability by giving resource access priority to handoff calls over new calls in call admission control. While the effectiveness of a fixed number of guard channels has been demonstrated under stationary traffic conditions, with nonstationary call arrival rates in a practical system, the achieved handoff call blocking probability may deviate significantly from the desired objective. We propose a novel dynamic guard channel scheme which adapts the number of guard channels in each cell according to the current estimate of the handoff call arrival rate derived from the current number of ongoing calls in neighboring cells and the mobility pattern, so as to keep the handoff call blocking probability close to the targeted objective while constraining the new call blocking probability to be below a given level. The proposed scheme is applicable to channel allocation over cellular mobile networks, and is extended to bandwidth allocation over the backbone network to enable a unified approach to prioritized call admission control over the ATM-based PCN.

Cutoff priority scheduling in mobile cellular communication systems

A mobile cellular communication system is considered. The calls arriving at the base station of each cell are modeled by a queueing system with two arrival streams. Stream 1 (also called class 1) arrivals are those calls in progress that are handed over to the cell from other cells, and class a arrivals are those calls that are originating in the cell. The guard channel scheme is considered in which arriving calls are indiscriminately assigned channels within a cell as long as the number of busy channels in the cell is below a predefined threshold. When this number reaches the threshold, only arriving class 1 calls are assigned channels immediately; arriving class 2 calls are queued. When all the channels are busy, then arriving class 1 calls are lost while class 2 calls continue to be queued. The system is analysed by a generating function method which utilizes the structure of the model to give a very concise solution.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>