Strong positive cash flow throughout the year enabled us to pay down our debt by $9 million. And at the end of the year in a net cash position of $2.6 million, which is the first time in five years that we have had a positive net cash balance. Focused on deinvestments across all of our operations resulted in 24 new product introductions during fiscal 2012 and we expect these products to drive continued growth in market expansion. Total R&D investment in fiscal 2012 was $11.3 million, which more than $9 million was in our wireless datacom segment.
Now but – I would like to review our operational highlights for the quarter. Our wireless datacom segment maintained a near-record revenue run rate in the fourth quarter with continued momentum across multiple markets compensating for the expected lowered revenue from our positive train control development project. We continue to experience strong demand for our MRM products and services, as well as increased demand for products targeting smart grid and oil and gas applications. Similar to recent past quarters, MRM applications accounted for approximately two thirds of total wireless datacom revenue with wireless networks applications accounting for one third.
In MRM applications, we continue to see strong demand in market share gains for our products and solutions in a market that is estimated to be growing at about 20% per year. Sales to our core customers for fleet management, trailer tracking, stolen vehicle recovery and vehicle finance applications, we are very strong resulting in full year, year-over-year, excuse me, in full year-over-year revenue growth in these segments of 25%. We are seeing steady international market penetration particularly in Latin America and we were poised for further wins in Asia-Pacific and EMEA region.