Meru Networks introduced a new access point yesterday that it says supports both 802.11g and 802.11b clients at their maximum speeds: Typically, in a mixed environment, an 802.11b client will cause an 802.11g client to slow down considerably.
The Meru AP virtually separates 802.11g and 802.11b traffic on a per packet basis. Because the packets don't see each other, the 802.11g traffic doesn't switch to a backward compatibility mode, which would require it to communicate with the AP in a way that creates overhead that typically slows down traffic in a mixed environment, said Sarah Kim, senior marketing manager for Meru. Because it is waiting for a patent, Meru is reluctant to disclose more about how the AP works, she said.
Unstrung reports some more details on how the APs work. The APs don't give priority to 802.11g or 802.11b clients but they use what Meru calls "fairness algorithms" that deal with channel allocation in a mixed environment, preventing 802.11g and 802.11b clients from transmitting at the same time.
Chipmaker Engim avoids the problems that typically occur in mixed environments by separating the traffic onto different channels. But Meru is using a single channel, Kim said.
Update: Jim Thompson speculates on possible underlying technologies for Meru's approach and the potential difficulties with those alternatives.