queens-satellite-team / comms

Repository for all communication related projects related to the satellite. Location for both hardware and software files.

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Motivation ⛰️

The data characteristics are important to the overall success of the satellite. In this issue we will need to define some characteristics of the data so that we obey all requirements for CSDC and ITU regulations.

Next Steps 🚶

This issue will have more steps than others since there is a lot that will need to be determined for the transmitted data.

[x] Determine an Uplink and Downlink Frequency
[x] Data Rate
[ ] How is Data Encoded?
[x] What communication protocol will be used?
[x] How much Data can be uplinked/downlinked?
[ ] What communications protocol overhead as a percentage of useable data transmitted?

Supporting Material and Resources 📖

If any links, resources, or past work would be useful include the links here

Markdown Style Guide for Creating Issues

Definition of Done 💯

This issue will be completed when each of the steps has a been completed. That means for frequency, data rate, total data transferred, and overhead percentage will have a numerical value associated. And for the communication protocol and how the data will be encoded will have a specific method chosen.

Tags

tag people that should know about this issue

Uplink

Uplink frequency is the frequency of transmission from the ground station to the satellite. It will be 144 MHz. This frequency that is allowed to be used by amateur satellites. https://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf10759.html#t2

Downlink

Downlink frequency is the frequency of transmission from the satellite to ground station. It will be higher than the uplink since it will need to hold more data. It will be 433MHz, this frequency is also allowed to be used by amateur satellites. https://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf10759.html#t2

Data Rate

As outlined by CSDC-0270 the downlink must be 9600 bps (bits per second), so to keep it simple, the uplink and downlink data rate will be 9600 bps.

Communication Protocol

As outlined by CSDC-0270 we must use AX.25 Communication Protocol.

How Much Data Can Be Downlinked

As per CSDC-0290 we have 90 second s to downlink data, and at a rate to 9800 bps: