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.

1 . Apparatus for mobile communication, comprising:
 a switch, having a plurality of ports for connection to a wired local area network (LAN);   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, and which are coupled by the 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; and   a manager node, which 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, and to send an instruction via the switch to the selected one of the access points to transmit a response to the mobile station.   
   
   
       2 . The apparatus according to  claim 1 , wherein the access points have respective service areas, and are arranged so that the service areas substantially overlap. 
   
   
       3 . The apparatus according to  claim 1 , wherein the access points are configured to communicate with the mobile station substantially in accordance with IEEE Standard 802.11. 
   
   
       4 . The apparatus according to  claim 1 , wherein the LAN is an Ethernet LAN. 
   
   
       5 . The apparatus according to  claim 1 , wherein the LAN is characterized by a data transmission rate of at least 1 Gbps. 
   
   
       6 . The apparatus according to  claim 1 , wherein the LAN is characterized by a data transmission rate that is substantially less than 1 Gbps. 
   
   
       7 . The apparatus according to  claim 1 , wherein the manager node has an address on the LAN, and wherein the access points are adapted to convey the messages over the LAN in the form of data frames directed to the address of the manager node. 
   
   
       8 . The apparatus according to  claim 7 , wherein the access points are configured to communicate over the LAN exclusively with the manager node. 
   
   
       9 . The apparatus according to  claim 7 , wherein the access points are adapted to receive an uplink data packet sent by the mobile station using the uplink signal, and to fragment the uplink data packet among a succession of the data frames for conveyance over the LAN via the switch to the manager node. 
   
   
       10 . The apparatus according to  claim 9 , wherein the access points are operative to fragment the uplink data packet so that the data frames have a length that is no more than 10% of a maximum frame length permitted on the LAN. 
   
   
       11 . The apparatus according to  claim 9 , wherein the access points are operative to fragment the uplink data packet so that the data frames have a length that is equal to a minimum frame length permitted on the LAN. 
   
   
       12 . The apparatus according to  claim 9 , wherein the uplink data packet comprises a destination address, and wherein the manager node is adapted to reassemble the uplink data packet from the succession of the data frames, and to convey the reassembled packet via the switch over the LAN to the destination address. 
   
   
       13 . The apparatus according to  claim 12 , wherein the manager node is connected to first and second ports among the plurality of the ports of the switch, and is configured to receive the data frames from the access points through the first port and to convey the reassembled packet to the LAN via the second port. 
   
   
       14 . The apparatus according to  claim 13 , wherein the manager node is further configured to receive a downlink data packet from the LAN via the second port, and to fragment the downlink data packet into a further succession of the data frames and to convey the further succession of the data frames via the first port to the selected one of the access points, which is operative to reassemble the downlink data packet for transmission over the WLAN to the mobile station. 
   
   
       15 . The apparatus according to  claim 9 , wherein the address of the manager node on the LAN comprises a Layer  3  address, and wherein each of the succession of the data frames among which the uplink data packet is fragmented comprises a Layer  3  encapsulating packet, having a destination address corresponding to the Layer  3  address of the manager node. 
   
   
       16 . The apparatus according to  claim 1 , wherein the messages conveyed by the access points responsively to the uplink signal comprise an indication of a strength of the uplink signal received respectively by each of the one or more of the access points, and wherein the manager node is adapted to select, responsively to the indication and prior to receiving the messages from all of the one or more of the access points, the one of the access points to respond to the uplink signal. 
   
   
       17 . The apparatus according to  claim 16 , wherein the access points are adapted to set, responsively to the strength of the uplink signal, a priority indicator in the messages to be conveyed over the LAN so as to cause the switch to deliver a first message indicating a strong uplink signal before delivering a second message indicating a weak uplink signal. 
   
   
       18 . The apparatus according to  claim 16 , wherein the access points are adapted, responsively to the strength of the uplink signal, to delay transmission of some of the messages over the LAN, so that a first message indicating a strong uplink signal is transmitted with a smaller delay than a second message indicating a weak uplink signal. 
   
   
       19 . Apparatus for mobile communication, comprising:
 a switch, having a plurality of ports for connection to a wired local area network (LAN);   a plurality of access points, which are arranged in a wireless local area network (WLAN) to communicate over the air with a mobile station, and which are coupled by the LAN to the switch so that upon receiving at one or more of the access points an uplink message transmitted over the WLAN by the mobile station, the one or more of the access points convey the uplink message over the LAN to the switch; and   a manager node, which is connected to first and second ports among the plurality of the ports of the switch, and is configured to receive the uplink message from the access points through the first port and to convey the uplink message via the second port over the LAN to a destination address of the message.   
   
   
       20 - 27 . (canceled) 
   
   
       28 . A method for mobile communication, comprising:
 arranging a plurality of access points in a wireless local area network (WLAN) to communicate over the air with a mobile station using a common basic service set identification (BSSID) for all the access points;   receiving at one or more of the access points an uplink signal transmitted over the WLAN by the mobile station using the common BSSID;   conveying messages responsively to the uplink signal from the one or more of the access points over a wired local area network (LAN) linking the access points to a manager node;   processing the messages at the manager node so as to select one of the access points to respond to the uplink signal, and conveying a response instruction from the manager node to the selected one of the access points; and   transmitting a response from the selected one of the access points to the mobile station responsively to the response instruction.   
   
   
       29 - 54 . (canceled)