@zoltan thanks for the link. I had seen that and their website said you need a clear view of the sky for it to work. To verify, I've scheduled a phone call with their support team this morning. I'll report back here.
UDPATE: notes from call with Rock7:
- Iridium’s Short Burst Delivery is perfect for small packets sent sporadically.
- Satellites (66 total) travel North-South.
- Retries if not sent. (Frequency of retries will affect battery power)
- Do not rely on signal strength returned by unit via AT command. While accurate, it only happens every 20 seconds so it will have changed by the time you read it and do something about it. Instead, just try to send and if it doesn’t go through, retry.
- Patch vs. Helical
- Patch has ground plane. Larger = better. Eliminates interfernce better than helical. Has a half-dome reception pattern.
- Helical has radial reception pattern and better for orientations that are not fixed or need a wider view of sky. Recommended for our purposes due to flexibility of orientation when mounting.
- All of their boards can be ordered with SMA connectors for antenna
9602 vs. 9603. Both the same functionality and price. 9603 is smaller/lighter and has smaller/more finicky headers. Both 5V, UART, no microcontroller or logic - just the AT commands and responses.
- RockBlock + is waterproof unit, runs on 9-30V and uses RS232. Ideal for longer-cable situations.
- When building housing, avoid metal, carbon fiber, and fire-retardant plastics (due to high carbon content). Also, if using a patch antenna, leave at least 5mm distance between antenna and case walls.
- Supercapacitor on the board is for storing energy needed in bursts for transmission. In sleep mode, this still draws power. Some people add a FET transistor inline with the cap so that it is completely shut off during sleep.
Since this forum is dedicated to OUTERNET and related projects, I'll stop posting anything related to competitor projects but will continue to discuss general concepts like antenna design, etc. for anyone interested. Just wanted to follow through on the info for anyone else like me looking for a 2-way solution.