Data Networking

Current Links

Mount Seymour & Nanaimo NARA Repeater Site

This link is the first link our club made with older 2.4GHz VINE technology. This link proved to work quite well with a typical 10dB of head room and speeds of at least 2Mbps. While larger gain antennas and more tuning may have further increased margins, this link may soon be recycled to a shorter more direct route to its "IP destination".


Devices: WiLan VIP 110-24 Transceivers
Antennas: 24dBi Parabolic Grid Dish & 30dBi Parabolic Grid Dish
Transmit Power: 23dBm/200mW
Receive Sensitivity: -84dBm
Distance: 76km
Free Space Path Loss (@2.4GHz): 137.7dB
Best Predicted Received Signal Strength: -64.3dBm

Newcastle Ridge NIARS Repeater Site - Nanaimo NARA Repeater Site

Between the Newcastle Ridge repeater site near Sayward and the Nanaimo repeater site lies 198km of distance and a significant earth curvature. In an attempt to deliver BCWARN IP services to North Vancouver Island, our club has chosen to try an unheard of 200km on 5.8GHz ISM band.


Devices: Ubiquiti Rocket M5 MIMO
Antennas: Dual Polarized 30dBi Parabolic Dishes with Radomes
Transmit Power (@MCS0): 27dBm/500mW
Receive Sensitivity (@MCS0): -96dBm
Estimated ERP: 305W
Distance: 198km
Free Space Path Loss (@5800): 153.6dB
Free Space Path Loss (@2400): 146dB (7.6dBm less than 5.8GHz)
Best Predicted Receive Signal Strength: -71.1dBm

These figures take into account the topography (ASL) and appropriate tower heights (AGL). Based on these calculations, we could expect a best case of -71.1dBm or 25dB of margin. Reality always says otherwise but these numbers certainly make it worth "trying the impossible". Note the figures on 2.4GHz FSPL which say that we must make up for 7.6dBm of losses at 5.8GHz vs 2.4GHz. This is generally achieved with higher gain antennas in smaller packages equating to larger system gains.

This link has now been installed and is in test mode. 5.8ghz signal levels over the long path of 200km (125mi) tend to be quite variable ranging from the mid -80's to signal levels as high as -68db. After weathering one of the most intense North Island rain events in recent memory, the system has continued to operate with 99.9% reliability @5mhz bandwidth. This gives the system a reliable data rate of 1.6mbps. Higher rates *may* be possible with fine tuning and careful system "tweaking". It is possible that we have the longest terrestrial ISM 5.8ghz path ever attempted in Canada.

Below is a current test setup between the NARA repeater site and a NIARS club member's residence in Comox, a distance of 90km and quite obstructed as you can see! The Comox end is a 24dBi parabolic and the current link sites ~ -80 to -90dBm. While not production grade, it is quite usable for testing.

UBC to Nanaimo NARA Repeater Site

Future planned 5.8GHz TDMA link between the Nanaimo NARA repeater and UBC site. More details to come.