How is 100Mbps achieved?

100Mbps performance is an enhancement to the 802.11g specification that enables higher throughput using a number of techniques. Similar to our previous 802.11b 22Mbps product offerings, 100Mbps performance is completely compatible with all 802.11g and 802.11b devices. Some of the 100Mbps performance throughput enhancements will be seen in a USRobotics to any vendor combination, whereas some are only seen in USRobotics to USRobotics connections.

100Mbps performance uses a procedure called packet aggregation, combining smaller data packets into larger ones. Traditional IEEE 802.11 implementations use a maximum packet length of approximately 1500 bytes, which is the standard for Ethernet LANs. The USRobotics physical layer is designed to use data packets that are up to 4000 bytes long. These longer packets help reduce protocol overhead and thereby increase effective throughput.

• Overall improvement from using this technique equates to up to 25-30 Mbps throughput versus 15-20 Mbps average in other 802.11g devices on the market.
• An access point using this technique will still talk to any 802.11b, 802.11b+ (22Mbps) or 802.11g products from USRobotics or any other vendor.
• If the wireless transmission rate goes below 11Mbps, this mechanism is disabled, since the larger packets, when sent at slower data rates, would actually reduce throughput due to the higher error rate and resultant retransmission of packets. The throughput improvement is only seen in connections between two USRobotics-based WLAN devices.