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Land Ops - The Off Road, Navigation and Amateur Radio Search Club
LandOps conducted a land navigation exercise near Cuddeback Dry Lake in the Mojave Desert on January 17, 2015. Participants communicated with each other via FRS, 2 meter ham radio, APRS and for the first time, by broadband mesh. (21 of the 28 participants in the exercise were licensed ham radio operators; seven of the ham operators brought a total of 15 mesh nodes which were deployed at various locations around the lakebed).
Terrain: Cuddeback Dry Lake is located in the northern Mojave Desert at an elevation of approximately 2500’ MSL. The lakebed is approximately 6 miles long and 2-1/2 miles wide at its widest point. LandOps base camp for this operation was located on a plateau approximately 4 miles northeast of the lakebed at an elevation of about 3500’. The ground slopes down toward the dry lakebed except that there are low hills of about 3300’ elevation (about 300’ higher than the surrounding terrain) midway between base camp and the dry lakebed. The edge of the plateau has direct line of sight to about half of the lakebed however, the base camp was located several hundred yards from the edge of the plateau, so it did not have direct line of sight to the lakebed.
Mesh Node Deployment: Based on an analysis of the terrain, a plan was developed to pre-position mesh nodes at various locations around the area in order to provide mesh connectivity between basecamp and mobile mesh nodes during the land navigation exercise.
Unfortunately, we only had time to establish a mesh node at location Bravo before the start of the exercise. Location Bravo was on high ground approximately ¼ mile from basecamp and it had line of sight to the lakebed (about four miles away). The node consisted of a Linksys router with a vertically polarized Yagi antenna connected to one antenna port and an omnidirectional antenna connected to the other antenna port. The node had good connectivity to the nodes located at basecamp, however, we were unable to establish a connection to it from the mobile mesh nodes on the lakebed. As a result, the mobile nodes were able to connect to each other but were unable to connect to the nodes at basecamp.
Wi-Fi Access Points: Two fixed Wi-Fi access points were located at basecamp and connected to mesh nodes. One laptop computer was used as a mobile Wi-Fi access point and connected to a mobile node.
Node Range: While enroute to basecamp, my Ubiquiti Bullet M2 with an Engenius EAG-2408 Omni antenna was able to make contact with KJ6DGG’s Ubiquiti Nanostation M2 at a distance of 12 miles. I was located on high ground west of the dry lakebed and KJ6DGG was at basecamp. As I descended to the dry lakebed, we lost the connection due to the terrain, and I was unable to regain the connection until I was one mile from basecamp.
The next day, I attempted to establish a connection between my Ubiquiti Nanostation M2 located at Bravo and a Linksys node with a vertically polarized Yagi antenna located on the lakebed four miles away. We were able to connect to each other’s nodes. However, when we attempted to experiment with two Yagi antenna, one vertically polarized and one horizontally polarized, we lost the connection and could not regain the connection even when we switched back to one antenna. We need to conduct more testing to determine the practical range of mesh nodes using various combinations of hardware, directional and omnidirectional antennas.
This mesh status screen shows 11 of the 15 mesh nodes online at basecamp. The other four nodes were offline.
Foscam webcam at basecamp:
KJ6DGG's mobile node setup:
KI6MLU's mobile node setup: