 core and access networks with the newer NEs. Of course, some vendors are innovatively addressing such concerns by introducing newer 3G network elements that are LTE ready in the sense that they reduce the network deployment costs to just upgrades-for-LTE kind of solutions. Yet, predominantly, operators are required to invest upfront to make and deploy the LTE networks. In times of financial turmoil, as existed in much of 2012 in international markets, this would mean that a majority of these decisions cannot be absorbed by operators because huge investments in such a financial climate may not be feasible. Also, unless operators are of such a size as to have surplus cash available to plan and make such deployments, they are going to be dependent on external funding to enable such deployments. Such borrowings, however, carry periods for interest calculations and need to be factored into the plans for deployment, and they further constrain the timelines by which operators can plan and execute their deployment and to be able to fulfill commercial obligations to the creditors in a timely manner. Coupled with the inherent challenges discussed in the previous section, this really is an arduous task. Average Revenue per User and Return on Investment Periods To make any business plan work, there needs to be elements of cost and modeling of expected revenue to be worked out so that subsequent periods of business can be simulated and some sort of profit projections can be made. In the cellular world, the most common key performance indicator from revenues perspective is average revenue per user (ARPU). In simple terms, this could equate to the revenue generated by an operator divided by the number of users or subscribers supported by the operator. Hence, there is a way to find out how much one user is contributing to the margins of the operator and also determine business health through the service offering. The return of investment (ROI) is the period over which a business needs to be operational to be able to start makin