Because one of the most popular fixed wireless applications is as a replacement for T1 or T3 leased-line services, we asked Proxim to estimate the ROI from fixed wireless versus leased lines. Information on leased-line costs was acquired through Telco Exchange, a Web-based information service that tracks telecommunication circuit costs nationwide. We selected 18 representative locations from three geographic regions: East, Midwest and West. Half of the locations were urban; the other half, suburban. We considered both circuit-installation costs and recurring monthly charges. After spreading the installation costs over a three-year period, the average monthly cost of a T1 was $382, with a total three-year cost of $13,768. For T3 service, the average monthly cost was $3,550; total three-year cost, $127,824.
We then selected appropriate systems offered by Proxim, using street prices provided by the vendor. For T1 comparisons, we used the Proxim QuickBridge 20, which has a raw data rate of 20 Mbps and a street price of approximately $2,500. We added installation costs of $1,000 per end, leading to a total system cost of $4,500. Over a three-year period, the monthly cost would be $125. In comparison with T1, the wireless system would pay for itself within one year, while providing LAN-interconnection performance that would far exceed a T1 line. And if you consider that the wireless bridge's Ethernet connection makes it easier to integrate into a LAN backbone (no need for special serial routers or CSU/ DSUs), the payback period can be reduced to less than one year.
For our T3 comparison, we used Proxim's QuickBridge 60 (see our review), which has a raw data rate of up to 54 Mbps. With an estimated street price of $4,000 and installation costs of $1,000 per end, the monthly cost is $167. Although a T3 link is likely to provide slightly better overall performance than the QuickBridge 60, in comparison to T3 service, the system pays for itself in less than two months.
While the above scenarios are representative of typical environments, accurate ROI calculations must consider your organization's unique needs and installation costs. For example, the cost to install a wireless bridge may be substantially higher than the $1,000 estimate we have provided. On the other hand, given efforts by Proxim and others to simplify installation by using such features as Power-over-Ethernet, integrated antennas, flexible mounting brackets and functional antenna-aiming software, installation costs may be even lower.
- Does your organization have a point-to-point wireless system?