Browsing by Author "Akyildiz, IF"

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A new random walk model for PCS networks
(2000-07-01)
Akyildiz, IF
;
Lin, YB
;
Lai, WR
;
Chen, RJ
;
資訊工程學系
This paper proposes a new approach to simplify the two-dimensional random walk models capturing the movement of mobile users in Personal Communications Services (PCS) networks. Analytical models are proposed for the new random walks. For a PCS network with hexagonal configuration, our approach reduces the states of the two-dimensional random walk from (3n(2) + 3n - 5) to n(n + 1)/2, where n is the layers of a cluster. For a mesh configuration, our approach reduces the states from (2n(2) - 2n + 1) to (n(2) + 2n + 4)/4 if n is even and to (n(2) + 2n + 5)/4 if n is odd. Simulation experiments are conducted to validate the analytical models. The results indicate that the errors between the analytical and simulation models are within 1%, Three applications (i.e., microcell/macrocell configuration, distance-based location update, and GPRS mobility management for data routing) are used to show how our new model can be used to investigate the performance of PCS networks.
Movement-based location update and selective paging for PCS networks
(1996-08-01)
Akyildiz, IF
;
Ho, JSM
;
Lin, YB
;
資訊工程學系
;
Department of Computer Science
This paper introduces a mobility tracking mechanism that combines a movement-based location update policy with a selective paging scheme, Movement-based location update is selected for its simplicity. It does not require each mobile terminal to store information about the arrangement and the distance relationship of all cells, In fact, each mobile terminal only keeps a counter of the number of cells visited, A location update is performed when this counter exceeds a predefined threshold value, This scheme allo cvs the dynamic selection of the movement threshold on a per-user basis, This is desirable as different users may have very different mobility patterns, Selective paging reduces the cost for locating a mobile terminal in the expense of an increase in the paging delay, In this paper, we propose a selective paging scheme which significantly decreases the location tracking cost under a small increase in the allowable paging delay, We introduce an analytical model for the proposed location tracking mechanism which captures the mobility and the incoming call arrival patterns of each mobile terminal, Analytical results are provided to demonstrate the cost-effectiveness of the proposed scheme under various parameters.
Movement-based location update and selective paging for PCS networks
(1996-08-01)
Akyildiz, IF
;
Ho, JSM
;
Lin, YB
;
資訊工程學系
;
Department of Computer Science
This paper introduces a mobility tracking mechanism that combines a movement-based location update policy with a selective paging scheme, Movement-based location update is selected for its simplicity. It does not require each mobile terminal to store information about the arrangement and the distance relationship of all cells, In fact, each mobile terminal only keeps a counter of the number of cells visited, A location update is performed when this counter exceeds a predefined threshold value, This scheme allo cvs the dynamic selection of the movement threshold on a per-user basis, This is desirable as different users may have very different mobility patterns, Selective paging reduces the cost for locating a mobile terminal in the expense of an increase in the paging delay, In this paper, we propose a selective paging scheme which significantly decreases the location tracking cost under a small increase in the allowable paging delay, We introduce an analytical model for the proposed location tracking mechanism which captures the mobility and the incoming call arrival patterns of each mobile terminal, Analytical results are provided to demonstrate the cost-effectiveness of the proposed scheme under various parameters.