Asynchronous transfer mode local area network having a ring structure with wireless terminals

Abstract

The invention relates to a local area network operating in the asynchronous transfer mode (ATM) for transmitting cells, comprising a plurality of network interfaces ( 1 to 8 ) coupled to a ring by ring connections ( 29 to 32 ), each network interface including a switch ( 24 ). For providing a more flexible local area network, at least one network interface ( 1 to 8 ) includes a radio device ( 33 ) for exchanging data with at least one terminal ( 9 to 21 ) located in the radio coverage area of the network interface ( 1 to 8 ). For controlling the cell transport within a network interface, a switch ( 24 ) is provided.

1 . A local area network operating in the asynchronous transfer mode (ATM) for transmitting cells, which includes a plurality of network interfaces ( 1  to  8 ) coupled to a ring via ring connections ( 29  to  32 ), the network interfaces including each a switch ( 24 ), characterized in that at least one network interface ( 1  to  8 ) comprises a radio device ( 33 ) for exchanging data with at least one terminal ( 9  to  21 ) located in the radio coverage area of the network interface ( 1  to  8 ), and in that the switch ( 24 ) is provided for transporting the cells at least between ring connections ( 29  to  32 ) and the radio device ( 33 ).  
     
     
         2 . A local area network as claimed in  claim 1 , characterized in that the switch ( 24 ) includes a receive circuit ( 47 ) assigned to a receive connection ( 39 ), in that each receive circuit ( 47 ) is used for evaluating the header field of a received cell and in that on the basis of the information derived from the header field at least one receive circuit ( 47 ) is used for extracting a switch mode from the assigned path memory ( 44 ).  
     
     
         3 . A local area network as claimed in  claim 2 , characterized in that the path memory ( 44 ) which is coupled to the receive connection ( 47 ) coming from the radio device ( 33 ), stores 
 a first switch mode for a connection at least between two local terminals ( 9  to  21 ), in which mode the switch ( 24 ) couples the receive and transmit connections ( 38 ,  39 ) connected to the radio device ( 33 ),    a second switch mode for a connection at least between a local and a remote terminal ( 9  to  21 ), in which mode the switch ( 24 ) couples the receive connection ( 39 ) connected to the radio device ( 33 ) and one transmit connection ( 30 ,  32 ) connected to a ring,    a third switch mode for providing a connection between at least two local and at least one remote terminal ( 9  to  21 ), in which mode the switch ( 24 ) couples the receive connection ( 39 ) connected to the radio device ( 33 ) to the transmit connection ( 38 ) connected to the radio device ( 33 ) and to a transmit connection ( 30 ,  32 ) connected to a ring,    a fourth switch mode for a connection between a local terminal ( 9  to  21 ) and the local controller ( 40 ), in which mode the switch ( 24 ) couples the receive connection ( 39 ) connected to the radio device ( 33 ) to the local controller ( 40 ),    a fifth switch mode for a connection between a local terminal ( 9  to  21 ) and the local and at least one remote controller ( 40 ), in which mode the switch ( 24 ) couples the receive connection ( 39 ) connected to the radio device ( 33 ) to the local controller ( 40 ) and a transmit connection ( 30 ,  32 ) connected to a ring, and    a sixth switch mode for deleting cells which contain non-existing connections.    
     
     
         4 . A local area network as claimed in  claim 3 , characterized in that for a connection set-up the controller ( 40 ) stores the switch mode for a virtual link in at least one path memory ( 42  to  44 ).  
     
     
         5 . A local area network as claimed in  claim 4 , characterized in that the VCI (Virtual Channel Identifier) and VPI (Virtual Path Identifier) contained in the header field of a cell together feature a virtual link and in that the path memory ( 42  to  44 ) for storing the type of connection, the type of cell and the switch mode is included in this identifier.  
     
     
         6 . A local area network as claimed in one of the  claims 1  to  5 , characterized in that a terminal ( 9  to  21 ) has, as has a network interface ( 1  to  8 ), a radio device ( 33 ,  49 ) including a high-frequency circuit ( 51 ), a modem ( 52 ) and a protocol device ( 53 ), in that the radio device ( 49 ) of a terminal exchanges data with the radio device ( 33 ) of the assigned network interface, in that a terminal ( 9 ,  21 ) exchanges identification data by a registration channel, MAC signaling data (MAC=Medium Access Control) by a MAC signalization channel and payload information by at least one transport channel, and in that the payload information contains at least part of a cell.  
     
     
         7 . A local area network as claimed in one of the  claims 1  to  6 , characterized in that a network interface ( 1 ) controls the connection set-up and disconnection.  
     
     
         8 . A network interface ( 1  to  8 ) for an asynchronous transfer mode (ATM) local area network for transmitting cells, which is coupled to a plurality of network interfaces ( 1  to  8 ) xx Rich include each a switch ( 24 ) combined to a ring and coupled via ring connections ( 29  to  32 ), characterized in that the network interface ( 1  to  8 ) includes a radio device ( 33 ) for exchanging data with at least one terminal ( 9  to  21 ) located in the radio coverage area of the network interface ( 1  to  8 ) and in that the switch ( 24 ) transports cells at least between ring connections ( 29  to  32 ) and the radio device ( 33 ).