Elsa AirLancer MC-2

Although the wireless network has taken far too long to mature, it's still a solid alternative for companies that don't want to invest in structured cabling. Farallon's SkyLine PC Cards (reviewed issue 65, p178) worked well enough during testing but were plagued with installation problems. Elsa's AirLancer MC-2 proved to be far more amenable as we found the PC Cards worked first time. PCs can also join the wireless club as Elsa offers the ISA-2 package (£167), including an MC-2 and an ISA card with a PC Card slot.

The MC-2 is a Type II PC Card conforming to the IEEE 802.11 wireless specification and supporting DSSS (direct sequence spread spectrum), which uses a range of frequencies to transmit a low power signal. Configuration of the AirLancer is carried out directly from the Network Properties with two operating modes available - Ad Hoc for peer-to-peer networks and an Infrastructure mode for users connecting to the LAN via a wireless base station. Encryption isn't supported, so only a WLAN (wireless LAN) identifier can be used to restrict access, as it's essentially a secret workgroup name. You can have other wireless networks adjacent to each other by using different channel numbers but DSSS only allows three of the 14 available channels to be used simultaneously without overlapping. We also tested the ISA-2 card in a Pentium II/266 system running Windows 98. The card wasn't identified at startup but the Windows hardware detection routine picked it up and installed it as a PCIC-compatible PC Card adaptor where it worked first time.

Elsa offers two types of wireless base station. The L-2 provides basic LAN access while the IL-2 adds an integrated basic rate ISDN router to the equation. At £380 and £453 respectively, both offer excellent value, although the IL-2 is particularly tempting as Elsa ISDN routers are well featured. Using Elsa's LANconfig utility, you can view and configure all base stations on the local network or over a wireless link. Access can be password-protected and blocked after a number of login failures, while station and protocol filters can be applied to restrict access between the local network and WLAN.

So far, the AirLancer products look good, but performance was disappointing. Using the Infrastructure mode, a 90Mb collection of files copied from a Toshiba PortÚgÚ laptop to a system on the local network took 15 minutes, 30 seconds, for an average of only 0.77Mbits/sec. We saw a top speed of 1.08Mbits/sec when copying the same files from a local workstation across to the laptop. You can modify the data packet sizes, but after adjusting this from the default 1,550 bytes to 1,000 bytes the speed dropped further to only 0.44Mbits/sec over an Ad Hoc link. Changing this value is more appropriate when interference is affecting transfers as it improves reliability, but the ratio of management overheads to data are much higher and clearly affect performance.

In comparison with Farallon's SkyLine, Elsa's AirLancer package offers better value as both the PC Cards and base station cost less. Although installation is far simpler, performance is a concern, but Elsa has advised us that testing with the new 11Mbits/sec wireless standard is nearly completed and existing cards can be upgraded to support the higher speeds.

Author: Dave Mitchell