Multi-communications-media network device

Abstract

A network device may include a processor executing higher layer processes including layers of a protocol stack higher than a media access layer, a first physical interface (PHY) and a second PHY coupled respectively to first and second communications media. A media access controller (MAC) may execute the media access layer of the protocol stack. An association table may list a plurality of known destination MAC addresses, an association between each known destination MAC address and one of the first and second PHYs, and at least one association between pairs of known MAC addresses that are collocated, each pair of known MAC addresses including a MAC address associated with the first PHY and a MAC address associated with the second PHY. Media selection logic may select one of the first and second PHYs for communication with a device designated by a target MAC address provided by the higher layer processes.

1 . A network device, comprising:
 a processor executing higher layer processes including layers of a protocol stack higher than a media access layer;   a first physical interface (PHY) coupled to a first communications medium;   a second PHY coupled to a second communications medium; and   a media access controller (MAC) to execute the media access layer of the protocol stack, the MAC coupled to the higher layer processes, the first PHY, and the second PHY, the MAC comprising:
 an association table listing a plurality of known destination MAC addresses and an association between each of the known destination MAC addresses and one of the first PHY and the second PHY, and 
 media selection logic to select one of the first PHY and the second PHY for communication with a target device designated by a target MAC address provided by the higher layer processes, 
 wherein the association table lists at least one association between pairs of known destination MAC addresses that are collocated, one of each pair of known destination MAC addresses associated with the first PHY and the other of each pair of known destination MAC address associated with the second PHY. 
   
     
     
         2 . The network device of  claim 1 , wherein the second communications medium is different from the first communications medium. 
     
     
         3 . The network device of  claim 1 , wherein the MAC has a first MAC addresses associated with the first PHY and the first communications medium, and a second MAC address associated with the second PHY and the second communications medium. 
     
     
         4 . The network device of  claim 1 , wherein
 when the association table lists an association between the target MAC address associated with one of the first and second PHYs and a collocated alternative MAC address associated with the other of the first and second PHYs, the media selection logic selects one of the first PHY and the second PHY for communicating with the target device.   
     
     
         5 . The network device of  claim 4 , wherein the media selection logic selects one of the first PHY and the second PHY based on conditions of the respectively associated communications media. 
     
     
         6 . The network device of  claim 4 , wherein the media selection logic selects one of the first PHY and the second PHY to minimize the power required to communicate with the target device. 
     
     
         7 . The network device of  claim 4 , further comprising:
 a first queue to hold frames awaiting transmission via the first PHY; and   a second queue to hold frames awaiting transmission via the second PHY.   
     
     
         8 . The network device of  claim 7 , wherein
 the media selection logic selects the first PHY when the first queue has a shorter wait time than the second queue, and selects the second PHY when the second queue has a shorter wait time than the first queue.   
     
     
         9 . The network device of  claim 1 , wherein
 the media selection logic is configured to determine, upon receipt of a target MAC address from the higher layer processes, whether or not the target MAC address is a known destination MAC address listed in the association table.   
     
     
         10 . The network device of  claim 1 , wherein
 the MAC is logically opaque, such that the higher layers of the protocol stack are unaware of the presence of two PHYs.   
     
     
         11 . The network device of  claim 1 , wherein
 a common security protocol is employed when communicating via the first PHY and the second PHY.   
     
     
         12 . The network device of  claim 1 , wherein
 the network device is configured to bridge frames between the first communications medium and the second communications medium via the first PHY, the MAC, and the second PHY.   
     
     
         13 . The network device of  claim 1 , wherein
 the first PHY is configured to communicate wirelessly in accordance with a protocol defined in Institute of Electrical and Electronic Engineers (IEEE) Std 802.11, and   the second PHY is configured to communicate via power line communications.   
     
     
         14 . The network device of  claim 13 , wherein
 the higher layers of the protocol stack and the interface between the MAC and the higher layers of the protocol stack are in accordance with a protocol defined in IEEE Std 802.11.   
     
     
         15 . A network device, comprising:
 a processor executing higher layer processes including layers of a protocol stack higher than a media access layer;   a first physical interface (PHY) coupled to a first communications medium;   a second PHY coupled to a second communications medium;   a media access controller (MAC) to execute the media access layer of the protocol stack, the MAC coupled to the higher layer processes, the first PHY, and the second PHY; and   media selection logic to select one of the first PHY and the second PHY for communication with a target device designated by a target MAC address provided by the higher layer processes,   wherein the MAC is logically opaque, such that the higher layers of the protocol stack are unaware of the presence of two PHYs.   
     
     
         16 . The network device of  claim 15 , wherein the second communications medium is different from the first communications medium. 
     
     
         17 . The network device of  claim 15 , wherein the MAC has a first MAC addresses associated with the first PHY and the first communications medium, and a second MAC address associated with the second PHY and the second communications medium. 
     
     
         18 . The network device of  claim 15 , wherein
 the first PHY is configured to communicate wirelessly in accordance with a protocol defined in Institute of Electrical and Electronic Engineers (IEEE) Std 802.11, and   the second PHY is configured to communicate via power line communications.   
     
     
         19 . The network device of  claim 18 , wherein
 the higher layers of the protocol stack and the interface between the MAC and the higher layers of the protocol stack are in accordance with a protocol defined in IEEE Std 802.11.