Less than 1 percent of the 4,000-mile northern border between the U.S. and Canada is under the operational control of the U.S. Border Patrol. The large scale, relative openness, and severe environmental conditions pose unique technical challenges to securing this border. Solutions must detect, localize and track people in wooded terrain using mesh networks comprised of low power, covert, RF sensors based on standard, inexpensive commercial off the shelf (COTS) products used widely in wireless data networks. IAI has been awarded a follow-on contract to develop scalable and reliable RF sensing for long-duration personnel tracking. A novel mesh networked Radio Frequency (RF) sensor, ARGUS-HS2 is being developed, based on IAI’s proven RF perimeter monitoring ARGUS™ system, which uses low cost COTS radios to establish radio links between nodes. Intruders near nodes are detected by changes in the RF channel due to motion, and resulting changes in received signal strength. ARGUS™ is easy to use, portable and scalable, and deploys wireless nodes for long-term unattended operations. IAI has demonstrated the technical feasibility of adapting ARGUS™ to the DHS border application in the wooded US-Canada border, using modeling and analysis and two levels of hardware and software design, low power COTS radio and processor platforms in conjunction with advanced signal processing software. Optimal operational frequency band and distance for the RF links, and optimal antenna mounting methods procedures have been determined. ARGUS-HS2 can provide robust, cost-effective perimeter security under (Non) Line of Sight conditions at both northern and southern borders.