ACCESS-CONTROL OF DATA IN INTEGRATED VOICE DATA CDMA SYSTEMS - BENEFITS AND TRADEOFFS/

In previous work, access control for data has been proposed as a metho d to ensure adequate quality of service (QoS) in an integrated voice/d ata CDMA system, The motivation behind access control is to schedule d ata packet transmissions in slots when voice activity is low and to cu rtail data transmissions when the voice load is heavy, In this work, t he class of probabilistic access control schemes, wherein data transmi ssions are controlled by dynamically changing the permission probabili ty, are considered. The trigger for changing the permission probabilit y is a measure of the current uplink load, Perfect power control is as sumed first, and the trigger for access control is the power control f easibility condition, Schemes based on prediction are analyzed, While prediction schemes are complex to implement, they do provide an upper bound for performance of access control schemes, A simple and practica l access control scheme, proposed earlier in the literature, is then e xtended. It controls the permission probability for data based on upli nk load and a 1-bit broadcast feedback to all of the mobiles, The perf ormance of this scheme depends on the choice of three parameters, It i s demonstrated that, through a combined choice of these parameters, ac cess control can be tuned to perform as desired and to yield significa nt capacity gains over not using access control, Results are then exte nded to the case of imperfect power control, where the outage criterio n is based on limiting the total received power at the base station, I n this case, too, the simple control scheme is shown to work well.