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Map of PERN's connectivity to Universities in the Islamabad region. |
Legend for the map |
We calculated the lat/long of Islamabad nodes (from http://itouchmap.com/latlong.html) and calculated the distance using formula
(courtesy of http://www.meridianworlddata.com/Distance-Calculation.asp):
d=_6378.7 * arccos[sin(lat1/57.2958) * sin(lat2/57.2958) + cos(lat1/57.2958) * cos(lat2/57.2958) * cos(lon2/57.2958 -lon1/57.2958)]
and the Round Trip Distance RTD = 2 * d.
Using the RTD and the minimum Round Trip Time (min_RTT) we can derive alpha from
RTD[km] = alpha * min_rtt [msec] * 100 km/msec
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Plot of alpha between Universities in the Islamabad region. We use the log of alpha to enable easy visualization of the wide range of alphas found. the x-axis shows the monitoring host followed by > followed by the remote host, followed by an equal sign (=) and the great circle distance between the hosts. Spreadsheet. |
