I can help i'm in a similar situation
Ok I'm currently in a similar situation except i see her 2 times a week max <------ I'm busy and so is she. This is an opportunity to drive her interest level sky high because u are forced to see her so infrequently.
Tip 1
Control yourself man
This is probably the hardest thing to do because you are forced to only see her once a week rather than choosing to do so. you have no choice in the matter meaning the same thing is happening to you as we all do to girls at the beginning. I have found it difficult to control my AFCness (wanting to skip things just to see her, high priority things) this is especially hard if you skip a week or something like that.
Tip 2
Long and frequent phone conversations are for girl friends
You will probably find this harder than me because you seem to have already developed a trend of talking a long time on the phone
i feel as though we talk about the same **** all the time on the phone
This is evidence of that. Talk for 20 mins max fluff 2 times a week
Now if your girl gets cranky because your not talking as long, state that you would rather hear about her life to her face (throw in some C+F here)......... u want her to be bursting with things to tell you when you do see her....... while she is thinking about these things she is thinking about you
<--- this is a good thing. This also filters un important cra p well some anyway
Tip 3
Be unpredictable on the weekends
Now the weekend has arrived you want her giddy with anticipation
Your dates must vary from climbing up a mountain to hanging out doing nothing. I always send a message stating what type of attire is suitable, but over time she should be message/ringing you wondering what is happening. If you can hold out try and give hints to what the date is going to be through the brief conversations on the phone during the week.
Tip 4
Do "Sh it" with your mates on weekends as well
You have a life and that includes doing stuff with your mates on the weekend; some things she is welcome to attend... if she wants ie. house warming party and others not welcome ie. beer drinking fishing trips/strip bars
Having said all this, it is difficult to progress in the relationship because there is a barrier to you taking it to the next level without some sort of sacrifices
Oh and I almost forgot
Have fun