 a short period of high-volume data activity. If the bursts are short, then there is not even time for power control to react, just a moment of re- duced Eb/No and higher BER. There will be more of these brief hiccups as 3G services become more popular, but the interruptions should be so brief that voice callers barely detect them or do not notice them at all. When an extra call appears on the CDMA carrier, the effect may be longer than a data burst. The power-control process will try to compensate, but sometimes there will be too much traffic on the CDMA carrier for everybody to have a good call. Then how long will it take, on average, for some call to end and to relieve the overload? Well, con- Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Turning User Complaints into Useful Data Turning User Complaints into Useful Data sider a fully loaded cdmaOne carrier with 20 calls. 1 And consider the average voice call direction on a cell sector being about 1 minute before somebody hangs up or the call is handed off.' 2 This means that the average time until some call goes away is 3 seconds. This is longer than a syllable, long enough that somebody listening for it might hear it, but not long enough to create a bad impression unless it happens frequently. A wide- band CDMA (W-CDMA) carrier with 130 voice calls brings the average call ending time down below half a second, not a problem unless it is very frequent. Calls that are lousy and stay lousy are a warning that something other than an OC- casional brief CDMA carrier overload is happening. Sustained poor sound quality is a sign that something more is wrong. It is these calls that should get our highest level of attention. 40.5 Slow-Data-Link Complaints Slow response is a data link's equivalent to poor speech quality in voice calls. A slow data link simply could be a slow server at the other end