It's really tough to identify strong 5G players here. Your best opportunity in Canada is likely just a Big 3 telecom, our favorite being Telus.
Down south is where you're going to find much more exposure in terms of the infrastructure, chips, technology etc.
However, Sierra Wireless (SW.TO) is an option you could potentially look at too. The company is currently developing quite a bit of 5G tech, and it does expect revenue generation from it in 2021. This is very much a turnaround project though. Sierra has been relatively inconsistent for a while now.
In terms of cloud platforms, couple you could look at is Dye and Durham (DND.TO), although they're pretty niche for law firms, and Converge Technology Solutions (CTS.V), and Quisitive Technology (QUIS.V)
Of note, I do own Telus and Dye and Durham.