When the goal is to link two devices or networks which may be remote, there is an important decision to be made up front: Do you go with a wired solution that guarantees speed but is expensive and potentially damage-prone, or do you opt for a wireless solution, which may cost less, but could slow down your network?
Suppose you choose wireless, and purchase two 802.11n routers and two high-gain antennas plus specialty RF cables to create a wireless Ethernet bridge. What might you encounter when you begin to implement the solution?
Pain #1: Is there power at the site?
Installing outlets at one or both sites could be a fun several hours of do-it-yourself work, or expensive (approximately $100 per hour) to hire a union electrician. Don't forget to add the $100 of materials (enclosure, outlet, wire, conduit etc) on each end.
Pain #2: Configuring is easy, right?
Configuring your bridge means wading through access point/router network configuration fields, assigning a static IP, creating SSID, and establishing security settings and naming conventions. If you're a glutton for punishment and want to take this on, it'll probably take 45 minutes to 2 hours, depending on your technical expertise. If not, paying someone else to do it will be in the $100 per hour range.
Pain #3: Hmmm. This antenna should work...
You've gone through all the settings to turn your access point into a bridge. The next challenge is to make the antennas work. Your access point may not be outdoor-rated, so you'll have to weatherproof it to keep it close to the antenna. You'll also need to identify and purchase the right mounting bracket and accessories.
Many designers, however, are either light on network expertise, or simply don't want to spend time struggling through configuring and installing a wireless solution. What if you could wirelessly link remote sites, support mobile devices, overcome physical obstacles and distances, and still maintain the speed of your network without these pains?
A viable solution is an out-of-the-box, point-and-play wireless Ethernet bridge called GhostBridge, that leverages 802.11n chipsets, Multiple-input Multiple-output (MIMO), and Power Over Ethernet (PoE)--all pre-configured and with a built-in sector antenna and a pole mount included as well.
Here's how to take care of the basic configuration pains with GhostBridge:
Having 24V PoE adapters for both AC and DC power gives users the freedom to choose installation sites, and no power outlets are required. The cat5 cable handles both data and power. GhostBridge units inject 24VDC onto the unused pair. A LAN2 port bridges the 24V from the main port so that the secondary port can output 24VDC on the unused pair.
The GhostBridge units are pre-configured into a secure bridge. There's an available web server, but it's really not necessary. Users simply mount the units, plug them into the network using the PoE adapters, point them at each other, and in less than 20 seconds they automatically pair up into a transparent, secure, high-speed (up to 150 Mpbs) Ethernet link. The bridge is also pre-configured with WPA2, 128-bit security.
An 80-degree antenna with 15-dBi gain is fully integrated into the housing and functions as a sector antenna. With 80 degrees of coverage, it's easy to line up the units even without a clear line of sight. A pole mount is also part of the molded, outdoor-rated (IP54 for water and dust), UV-stabilized plastic enclosure. Users can easily mount it onto a pole or use an optional wall-mount kit.
A 5 GHz radio built from the 802.11n 2x2 MIMO technology provides the long-range (up to 15km, about 9 miles) connectivity between remote stations and a central office. Or, users can easily bridge two networks or hard-to-reach nodes together. A PoE pass-through Ethernet port allows for the connection of remote devices (IP camera, or other) to a LAN.
When Walter Horigan, president of Vortechs Automation, a Huntingdon Valley, PA-based system integrator, needed high-speed Ethernet/Internet connectivity in a remote building across state park land, he looked to GhostBridge as a solution.
Horigan installed one GhostBridge unit locally and the other on his remote building, and then pointed them at each other through medium-dense foliage.
"I went from Dixie cups and strings to super-fast Ethernet with the GhostBridge punching through 700 ft. of trees to beam the signal to my remote site," said Horigan. "The GhostBridge was wicked fast, pumping the full 60 Mbps available from the ISP on my first test out of the box. The cat5 cable carrying both data and power saved me from having to install power, which would've easily taken 5 to 6 hours, and cost about $100 of materials, for each site," said Horigan.
Horigan estimates that the solution cost approximately a dollar per foot, far cheaper and easier than laying cable, not to mention that laying a cable across a state park would have potentially invited some trouble. "Installing GhostBridge was as easy as hanging a picture," said Horigan.
The GhostBridge includes a pre-configured base station and node, two AC PoE adapters with power cords, two DC PoE adapters with barrel plug adapters, and four heavy-duty cable ties.
About the Author:
Mike Fahrion is the director of engineering at B&B Electronics where he oversees development of next-generation industrial control wireless products. He has 12 years of experience designing data communications products for M2M applications, with particular expertise making USB and other physical-layer communications protocols reliable in harsh environments. Fahrion holds a BSEE from Iowa State University.