Determination of the Traffic Properties of Cells with Mobile Users Using a Mixed Traffic

Abstract

This paper presents a two-dimensional Markov traffic model of the mobile users' network where there exist handover calls from the surrounding cells to the considered cell and where, also, primary calls are generated. The two emphasized types of calls form together mixed traffic. The new, two-dimensional model allows us to calculate some characteristic variables for the systems, which may not be determined based on the analysis of one-dimensional model. The developed simulation program is verified comparing the obtained system state probabilities as also primary and handover calls loss rate to the corresponding values from the calculation process. We analyzed cells with a number of channels reserved only for handover calls. This system performances are compared to the performances of some other systems from literature and it is proved that their characteristics are comparable whereby our system improves handover calls dropping rate. It is also proved that users' speed increase and cell radius decrease cause both primary and, especially, handover calls loss rate increase. The results of calculation and simulation are obtained after a number of iterations (calculation or simulation cycles), where the new loss probability values from one iteration become the input values for the next iteration. In the case that call loss values do not converge during simulation, we implemented the original algorithm for input call loss probability estimation for the next iteration.

Influence of channel reservation on the handover calls flow in mobile network

“…This is proved by the simulation program which comprises simulations for each cell separately, as described in Section 6. The parts of simulation program, which correspond to one cell, are presented in [7]. The results of simulation program in [7] are verified by their comparison to the calculation results.…”

“…The number of traffic channels is N = 5 , the offered traffic is A p = 2E and the number of channels reserved for handover calls is r = 2 . It is calculated that [12], [7]. The probability of primary traffic loss is B p = 0.269 and the probability of handover traffic loss is B h = 0.00111 in this case.…”

“…As already stated, simulation program is based on the similar simulation of the system with handover calls, which is presented in detail in [7]. The program version from [7] is modified in such a way that it realizes the simulation for 7 cells of mobile telephony network in the same time (1 central cell and 6 surrounding cells), in accordance to the model presented in the Fig, 3.…”

“…As already stated, simulation program is based on the similar simulation of the system with handover calls, which is presented in detail in [7]. The program version from [7] is modified in such a way that it realizes the simulation for 7 cells of mobile telephony network in the same time (1 central cell and 6 surrounding cells), in accordance to the model presented in the Fig, 3. The first addition to the program from [7] is generation of one more random number with uniform distribution (RN2) whose value determines the ordinal number of the cell (among total 7 cells) for which the following simulation step is intended.…”

“…These cells inevitably cause a high number of handovers of existing connections [1]. Handover calls loss is considered very undesirable and many techniques are developed which decrease probability of handover calls loss [2]- [7]. One common measure is channel reservation for handover calls that reduces the handover calls loss at the expense of primary calls loss increasing.…”