Engim hired independent tester the Tolly Group to demonstrate how dramatically the performance of Wi-Fi networks decreases when a low performing device is within range: The study included eight different scenarios, each involving a different mix of client devices. In most cases, the average throughput of any user dropped to the lowest common denominator. So for example, nearby 802.11g clients would only connect as high as 3 Mbps but more often closer to 1 Mbps when an 802.11b client was set to connect to the access point at 1 Mbps.
While it's no secret that this happens in Wi-Fi networks, Engim found that few enterprises were aware of it. "If you're sharing a network among b and g users, they associate at different rates so that the 54 Mbps guy gets incredibly penalized," said Scott Lindsay, vice president of marketing for Engim. "This is something IT managers didn't know about."
Engim says its chips can help solve the problem. Its chips can support multiple channels simultaneously. This Network World story offers a good overview of how the Engim chips work. Products with the chips can deliver three times as much capacity, but they can also allow users to separate traffic. For example, an OEM could write software that instructs the chip to place all voice calls onto one specific channel. The access point would know that a device associating with it is a voice over IP phone by its MAC address. Or, an OEM could write software that enables the access point to note the rate at which a client is connecting and if it's slow, relegate that user to a channel that is reserved for slow traffic.