Estimation of interference variation caused by the addition or deletion of a connection

Abstract

A method for determining whether a connection event between a base station and a wireless transmit/receive unit (WTRU) should be accepted or rejected, comprises measuring the interference level I 0 in a candidate timeslot; measuring the path loss L between the base station and the WTRU; measuring the total transmit power P 0 of the base station; determining a thermal noise level θ; determining a fading average signal-to-interference ratio (SIR); and calculating a ratio R, wherein if the ratio R is above a certain threshold the connection event will be accepted and if the call is below the threshold it will be rejected.

1 . A base station for wireless communications comprising:
 a processor configured to determine a total transmission power P 0  and reporting the total transmission power to a Radio Network Controller (RNC);   a controller configured to determine whether a connection with a wireless transmit receive unit (WTRU) is to be added or deleted; and   on a condition that a connection is to be added, adding a connection between with the WTRU on the condition that a predicted interference level does not exceed a predetermined maximum value, using measurements from the WTRU.   
     
     
         2 . The base station of  claim 1  wherein the controller determines whether to add or delete based on comparison to a ratio R calculated using a determined transmission power P 0 , a connection transmission power P C  of the connection to be added or deleted, and a determined interference I 0  in the candidate time slot. 
     
     
         3 . The base station of  claim 2  wherein the ratio R is calculated based on a thermal noise level θ of the connection to be added or deleted, and a link gain value G c  which relates to the link gain between a BS and a WTRU operating in an adjacent cell. 
     
     
         4 . The base station of  claim 3  further comprising
 a receiver configured to receive reports of signal parameters, and 
 the processor configured to determine the thermal noise level θ of the connection to be added or deleted, the fading-averaged signal-to-interference ratio (SIR) and the link gain value G c .