airBridge and airNIC

By Brien M. Posey

July 25, 2002

smartBridges offers two different wireless solutions for users on the go -- one for USB ports, another for PCs already with Ethernet, and both with long ranges.

Model Number: airBridge - SB2100 ($239); airNIC - SB2000 ($179)

smartBridges' airBridge is a bridge designed for connecting a PC with a standard Ethernet network card to a wireless network -- no USB or PC Card slot needed. airNIC is a USB-based 802.11b NIC that can be used to attach a desktop or laptop PCs to a wireless network.

This review looks at both products from a performance and practicality standpoint.

Pros

  • Easy to install NICs
  • Very long ranges

Cons

  • airBridge is tedious to configure
  • Dependant on a power cord (or optional power-over-Ethernet accessory)

BASIC FEATURES

The airNIC is nothing more than a USB based wireless NIC. It offers the same features as any other 802.11B wireless NIC, including 40, 64, and 128 bit WEP encryption. The airNIC's biggest selling point is its range -- it claims to have a 600 meter range (3/8 mile) at 11Mbps, and a 1200 meter (3/4 mile) range at slower speeds.

The airBridge is designed to connect a PC with a standard network card to a wireless network. The unit features a changeable IP address and a completely automated setup procedure (on some networks). The airBridge claims for range are even greater -- a half mile range at 11Mbps speed and up to a one mile at lower speeds.

SETUP/INSTALLATION

airBridge

The airBridge requires a desktop or laptop computer that already contains a 10Mbps or 10/100Mbps Ethernet card. The PC must be running Windows 98, ME, NT, 2000, or XP. For my airBridge test, I used an old Toshiba Pentium 133 laptop with 32 MB of RAM. The laptop was running Windows NT 4.0, and used a 3Com 10/100 PCMCIA-based NIC for interfacing with the airBridge.

The airBridge is designed for an automatic setup. According to the directions, the unit can simply plug directly into your existing NIC via a supplied patch cable and be ready to use. However, this wasn't the case with my test unit. It came preconfigured to use the IP address 192.168.0.2, and that address wasn't compatible with my existing network. Fortunately, the enclosed installation software allows you to change the unit's internal IP address.

The IP address is required because of the way that the unit works. The client maintains its own individual IP address. When a packet needs to go to the client, the packet is sent to the bridge's IP address. The bridge then forwards the packet to the client's IP address.

Once the software is installed and the hardware is connected, it's a bit tedious to change the unit's IP address. The process works the way that it's supposed to, there are just a lot of steps involved, and the airBridge software isn't very intuitive.

In a nut shell, the process involves opening a utility called Simple Monitor, and clicking on a Search button to see if the software can detect the airBridge. When the detection process fails, you must assign the PC a temporary IP address (something in the 192.168.0.x range) and then try the search again. This time the software will detect the unit. Once the unit is detected, you must log in to assign the unit a new IP address and subnet mask and then download your configuration changes to the unit. This will log you out of the unit.

Because your PC is using a temporary IP address, it will no longer be able to communicate with the airBridge (which now has a valid address). You must now re-assign the PC a valid IP address and then redetect the unit, login, and finally assign the necessary wireless parameters. If your network already uses the 192.168.0.x IP address range, you won't have to go through any of this. Although the configuration process was tedious, the directions that came with the unit provided somewhat (but not completely) clear step by step instructions.

Once I had the unit configured, it ran with no problems.

airNIC

The airNIC is designed to be used on desktops or laptops that are running Windows 98, ME, 2000, or XP. For my tests, I used an 800 MHz Sony laptop with 256 MB of RAM that was running Windows XP Professional.

The airNIC is USB based. However, unlike most USB devices, you must begin the driver installation procedure before attaching the unit. The majority of the software installation process is automated. The software does a quick hardware compatibility check and then begins copying the necessary files. When the installation process completes, the software prompts you to attach the airNIC. From here, the installation process is identical to that used for installing any other USB NIC. Once I had assigned the unit an IP address (I was not using DHCP for this review), channel, SSID, and WEP configuration, the unit was up and running. The setup process didn't give me any problems at all.

PERFORMANCE

For my performance testing I used NetIQ's Qcheck to measure the throughput from the wireless client to a machine on the wired network. The tests involved testing the throughput at various distances and under various conditions, first with WEP disabled and then with 128 bit WEP. All of the measurements that I've listed are averages based on three sequential throughput tests. For the tests, wireless clients are connecting to a standard 3Com Air Connect access point.

airBridge

I began testing the airBridge by testing the throughput from about 10 feet across the room. I tested the speed three times and received an average measurement of 4.7Mbps. I then enabled 128-bit WEP and the throughput dropped only slightly.

Next, I took the laptop down the hall to the room on the same floor that was furthest from the unit. I ran several tests in this room and throughput ranged anywhere from 200 Kbps to 5.2Mbps, with the average being about 4.7Mbps. With WEP enabled, the throughput was about 4.2Mbps

I then took the laptop down a floor to a location directly below the wireless gateway. The average throughput was 5.0Mbps without WEP and 4.6 with WEP.

Down another floor into a room with lots of metal duct work -- This room has been notorious for signal degradation in past tests. This time, the throughput averaged 4.5 Mbps and 4.0 with WEP enabled. Not bad.

Although the airBridge boasts an exceptionally long range, it was impossible to test the longer ranges because the unit must be plugged into an electrical outlet, and I didn't have any electrical outlets available to me at the longer distances.

airNIC

I began testing the airNIC throughput from about 10 feet across the room. I tested the speed three times and received an average measurement of 4.3Mbps. I then enabled 128-bit WEP and the throughput dropped only to an average of 4.0Mbps.

Down the hall to the room on the same floor that was furthest from the unit, I ran several tests with the average being about 3.9Mbps. With WEP enabled, the throughput was about 3.8Mbps.

Down a floor to a location directly below the wireless gateway, the average throughput was 3.8 Mbps. With WEP enabled, the average throughput didn't change.

Next, into the room with metal duct work notorious for signal degradation, I consistently received a 4.0 Mbps throughput.

Because this NIC's biggest selling point is range, I decided to test it on the road. Initially, I climbed a large hill in front of my home, just over a quarter of a mile away. There were lots of trees and houses in between. In spite of the distance and the obstacles, I was able to sustain a throughput of about 1Mbps. WEP didn't work at this distance, however.

Staying on top of the hill, but now at half a mile away, I couldn't get a signal at all. Back down to level ground, an eighth of a mile away with lots of obstacles, I got only a 500Kbps signal; again WEP didn't work.

SUMMARY

All in all, both products performed very well. I was especially impressed by the superior range that these products offered. Too bad the Bridge is limited to needing AC electrical power or Power over Ethernet (PoE) using the optional powerShot product from smartBridges, but if its range is anything like that of the airNIC, it is a worthwhile investment for those with no open USB ports or PC Card slots.



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