Wireless LAN Control over a Wired Network

Abstract

Apparatus for mobile communication includes a switch and a plurality of access points, which are arranged in a wireless local area network (WLAN) to communicate over the air on a common frequency channel with a mobile station using a common basic service set identification (BSSID) for all the access points. The access points are coupled by a LAN to the switch so that upon receiving at one or more of the access points an uplink signal transmitted over the WLAN by the mobile station on the common frequency channel, the one or more of the access points convey messages responsively to the uplink signal over the LAN to the switch. A manager node is coupled to the switch so as to receive the messages and is adapted to process the messages so as to select one of the access points to respond to the uplink signal.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application is a continuation-in-part of U.S. patent application Ser. No. 10 / 664,631, filed Sep. 19, 2003, which is a continuation-in-part of U.S. patent application Ser. No. 10 / 214,271, filed Aug. 7, 2002. Both of these related applications are assigned to the assignee of the present patent application, and their disclosures are incorporated herein by reference.FIELD OF THE INVENTION[0002]The present invention relates generally to wireless communications, and specifically to methods and devices for improving the performance of wireless local area networks.BACKGROUND OF THE INVENTION[0003]Wireless local area networks (WLANs) are gaining in popularity, and new wireless applications are being developed. The original WLAN standards, such as “Bluetooth” and IEEE 802.11, were designed to enable communications at 1-2 Mbps in a band around 2.4 GHz. More recently, IEEE working groups have defined the 802.11a, 802.11b and 802.11g extensions to...

AI Technical Summary

Benefits of technology

"The present invention provides methods and devices for enhancing the coverage and speed of WLAN systems, particularly those built around a wired LAN infrastructure. The invention allows for the deployment of multiple access points in a service region, with overlapping coverage areas and collisions being resolved through a manager node that coordinates the access points. The access points communicate with mobile stations on a common frequency channel using a common BSSID, and the manager node assigns one access point to respond to each mobile station. The invention also provides techniques for low-latency communication between the access points and the mobile stations, and for efficient use of the LAN. The invention can be applied to different types of wireless LANs and communication protocols."

Problems solved by technology

The theoretical capability of new WLAN technologies to offer high communication bandwidth to mobile users is severely hampered by the practical limitations of wireless communications.

Therefore, even when wireless access points are carefully positioned throughout a building, some “black holes” generally remain—areas with little or no radio reception.

If a WLAN receiver receives signals simultaneously from two sources of similar strength on the same frequency channel, however, it is generally unable to decipher either signal.

In practice, this mechanism is of limited utility and can place a heavy burden on different BSSs operating on the same frequency channel.

As a result, in complex, indoor environments, it becomes practically impossible to distribute wireless access points closely enough to give strong signals throughout the environment without substantial overlap in the coverage areas of different access points operating on the same frequency channel.

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