SI
SI
discoversearch

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor.  We ask that you disable ad blocking while on Silicon Investor in the best interests of our community.  If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.
Technology Stocks : Winstar Comm. (WCII)
 Public ReplyPrvt ReplyMark as Last ReadFilePrevious 10Next 10PreviousNext  
To: SteveG who wrote (10012)1/16/1999 9:13:00 PM
From: wonk  Read Replies (1) of 12468
 
Steve:

The conservative limits of 38 GHz is a 1.5 mile radius? 28 GHz =2.5 miles? and 24 GHz = 3? In the loss of reach in higher freq's, how exactly is the equivalencies that you've previously discussed realized?

The only way to answer your question is to specify 1) the modulation 2) the total path loss that the link must tolerate 3) a grade of service.

Presuming the following:

1. QPSK modulation
2. Point to multipoint (90 degree sector antennas at hub) — (to Bernard's point, I have presumed that the antennas scale down as frequency increases, i.e., all frequency bands have the same antenna gain)
3. 99.999% availability (5.3 minutes per year outage due to rain)

the three frequency bands look something like this for the best and worst rain regions in the continental US;

28 GHz

.49 to 1.3 miles

for 38 GHz

.42 to 1.0 miles

for 24 GHz

.57 to 1.5 miles

If you drop down to 99.9% availability (536 minutes or about 8.75 hours) 38 GHz performance looks like this:

1.0 to 4.0 miles

Also, if one presumes point-to-point (add about 20 dB to the tolerable path loss), 38 GHz looks like this:

99.999%
.65 to 1.8 miles

99.9%
2.15 to 9.8 miles

My calculations do not have all the "bell's and whistles" which should be there for total accuracy but the general ratios should be right given the above parameters.

ww
Report TOU ViolationShare This Post
 Public ReplyPrvt ReplyMark as Last ReadFilePrevious 10Next 10PreviousNext  

HomeMailHotSubjectMarksPeopleMarksKeepersSettings
Terms Of UseContact UsCopyright/IP PolicyPrivacy PolicyAbout UsFAQAdvertise on SI
© 2025 Knight Sac Media.  Data provided by Twelve Data, Alpha Vantage, and CityFALCON News