Venture capital funds lead to wireless LAN gold rush

Almost every month, it seems a new wireless LAN technology surfaces, promising to change networking forever. A number of technologies, many just now emerging in early product releases, hold great promise for deploying wireless LANs.

The still-evolving chip, radio and antenna technologies have drawn lots of venture funding, with the investors and a host of new companies searching for the next big thing in wireless LANs. The intellectual ferment and the product churn pose some special issues for network executives trying to plan wireless LAN investments.

According to Growthink Research, 135 privately held wireless companies raised nearly $1.4 billion in venture capital in the first half of 2002. The firm estimates that one in every 10 venture capital dollars spent through June went into the wireless market.

At the Fall Comdex show this week in Las Vegas, some of these product trends are on display. Among them:

• The first demonstrations of 802.11g wireless LANs, which use the same 2.4-GHz frequency as the widely used 802.11b  nets, but boost the data rate from 11M to 54M bit/sec.
• A new product from MeshNetworks that expands wireless LAN ranges by letting client adapter cards hop through a series of other client adapters to reach a wireless access point .
• A number of dual-band wireless LAN client cards and access points, which use silicon that can connect to 802.11b (or in future 802.11g) nets or to 802.11a nets, in the 5-GHz band, at 54M bit/sec.

Longer range

Radio physics means that for a given power output, performance drops as the distance between access points and adapter cards increase. The Federal Communications Commission restricts the power output of wireless LAN products. That means that under ideal conditions, 802.11b has a range of roughly 300 feet, 802.11b about one-third of that. Actual throughput for 802.11b can drop from 5M to 7M bit/sec to one-half, one-third or less, depending on distance and the materials between the client and the access point. A similar drop happens with 802.11a.

New antenna designs and silicon-based antennas are creating range boosts. Another technology is MeshNetworks' software and routing algorithms that turn any 802.11 radio into a repeater-router. That means that a PDA with a wireless LAN card can hop to a laptop with a wireless LAN card, and to other clients to reach an access point that connects to a corporate LAN or a provider back-haul network.

Faster

Users today can choose from 11M bit/sec 802.11b wireless LANs or the 54M bit/sec 802.11a wireless LANs. But sooner than most observers expected, 802.11g will arrive. The standard has been a controversial attempt to boost data rates in the 2.4-GHz band through competing modulation schemes. In the end, the IEEE 802.11g task group has opted to use the same modulation scheme for 802.11g as used for 802.11a, but is allowing another, championed by Texas Instruments, as an option.