Analysis of a Priority Stack Random Access Protocol In W-CDMA Systems
Résumé
The stack protocol (called also tree protocol) can be used in order to introduce a priority mechanism on the random access stage in W-CDMA. Indeed, after second generation networks supporting voice service only, the third generation systems (UMTS) should offer more services with quality and priority. However, all priorities in the UMTS system are based on the dedicated channel and after the random access mechanism that use the weak access protocol: slotted aloha. In this paper, we analyze the possibility to apply the tree random access protocol for the W-CDMA part in the UTRA radio interface proposition. We study also a priority system applied on the random access directly. The analytical model use generating functions and an algebraic method in order to show the stack protocol performance. Also, numerical and simulation results are presented and show the predominance of this protocol compared with the slotted aloha mechanism.