Last fall, Aerohive introduced Online Wi-Fi Planner, a Web-based predictive tool intended to help prospective customers quickly draft and budget upcoming deployments. Freely available to anyone for 60 days (or forever to HiveManager customers), Planner made it easy to supply a floor plan, drag/drop new APs, and visualize predicted results. But the initial release didn't design WLANs: Positioning APs was up to the user. With this week's HiveManager 3.5 update, that limitation is lifted.
"As more organizations rely on wireless to support voice, video and data networks, ensuring proper AP density for performance and reliability is essential and must be factored in during the deployment stages," said Adam Conway, Aerohive's Vice President of Product Management. By adding auto-placement and richer design parameters to Online Wi-Fi Planner, Aerohive is making it easier to propose WLANs designed to meet coverage, signal, and data rate goals for a given site.
Plan and Budget
With 802.11n, coverage is far more difficult to predict. Possible data rates and channels have spiked, and dual-band APs mean mapping twice: once at 2.4 GHz, again at 5 GHz. Multiple streams and multi-path make uplink/downlink throughputs not only different, but more variable over time. Given this, experts debate whether pre-deployment site surveys are worthwhile for 802.11n. However, customers still need a rough idea of how many APs to buy and where to place them. This is where Online Wi-Fi Planner fits.
Aerohive's first release Planner generated signal strength heatmaps by using algorithms to predict RF behavior using floorplans -- images overlaid by lines indicating building materials that attenuate Wi-Fi signal -- and manually-added APs. Predictions reflect both user input -- for example, characterizing environments as open space or office -- and tool assumptions (e.g., typical client Tx power/Rx sensitivity, AP model). Output accuracy varies but depends heavily on input accuracy.
A predicted RSSI heatmap is no substitute for in-situ throughput measurements, but it can be a "roadmap" for budgeting, purchasing and installing new APs. To help users share that roadmap with others, Aerohive added PDF reports. Each PDF includes one predicted RSSI, data rate, or channel heatmap for a single band, followed by an AP inventory list of names, models, types, and channel/power assignments. For example, Planner can now generate PDFs to show a layout estimated to deliver 2.4 and 5GHz at least -70 dBm -- and an alternative layout for -80 dBm. Such reports will help customers consider cost/design tradeoffs prior to purchase.
Fast and Free
Of course, many companies are reluctant to spend money on formal WLAN planning or lack RF expertise to fully-use a sophisticated predictive planner. Aerohive's first release Planner provided a free alternative for those with small/simple WLANs. However, manual placement made it hard to optimize large WLANs and drawing tools were very basic.
This week's update includes several enhancements that improve ease of use and facilitate automated design and human optimization. Those who need to model complex buildings will appreciate color-coded materials that can now be applied faster using connected and auto-closed lines. Plans are still only 2D and the materials list is still pre-defined, but there's quite a bit here for a free tool. Anyone new to Planner will benefit from a redesigned interface that makes usage and workflow more obvious.
After importing drawing a perimeter and walls, it's time to start placing APs. This is where the updated Planner shines. Those who want to place their own APs still can, but Planner can now populate a floorplan with APs, auto-positioned to meet a specified RSSI goal. APs can then be added, removed or adjusted to reflect other needs, such as power or aesthetics. Want to compare coverage at 2.4 vs. 5 GHz? Just click a button. Want to see estimated data rates above a specified threshold? Just click another button. Want to see what happens when you increase 5 GHz channel width to 40 MHz? Click another button.
The Bottom Line
These enhancements make Planner far more useful without becoming too complicated. For example, Aerohive has added a 20/40 toggle at 5 GHz but implicitly assumes 20 MHz at 2.4 GHz. Noise and data rate thresholds can now be applied when visualizing design output, but cannot be specified as design inputs. In short, enhancements focus on making Planner more accessible to non-RF-engineers who need to perform quick what-ifs by clicking just a few buttons to see and share results.
Note that Planner's proposed channels and power levels are for reference only -- plans are not used to auto-configure APs after deployment. And, while Planner can only predict Aerohive AP performance, plans can include several different Aerohive AP types. Those with other-vendor APs may still find Planner useful for what-ifs, although not a precise representation of their own WLAN gear.
Aerohive customers will find the latest version of On-line Wi-Fi Planner included in HiveManager release 3.5 at no additional cost. Others can visit Aerohive's website to register for free access to On-line Wi-Fi Planner, receiving a login valid for 60 days.
Lisa Phifer owns Core Competence, a consulting firm focused on business use of emerging network and security technologies. After working with 802.11 for nearly a decade, Lisa has drawn numerous wireless LANs, using everything from pen-and-paper to commercial predictive plan-and-survey suites.