How to render page on demand ( for a pdf) using byte-range request?

I use Ember PDFJS addon to render a pdf document. (http://ift.tt/2sG2uam) It uses byte range request but requests go on for the entire pdf document. I want to preload few pages say 5 at first and then load pages as user requests either by entering the page number or scrolling. How can I do it using byte-range requests? and It should be done on the server side or client side?