Abstract:
An element for an in home power line network is housed within the power supply of laptop computer. The element communicates with the power line and carries out network operations over that line. The device also includes logic therein which automatically detects the format of the network being communicated with so that a number of different network types can be automatically connected.

Description:
The present invention teaches an adapter for a home power line network that determines the kind of Power line network being communicated with and automatically enables transmission. 
     BACKGROUND 
     One existing home network operation operates over the power lines. The network operates by modulating information onto the existing power lines at a different frequency than the AC power. An add-in card for desktop PC&#39;s can be used, or a component within a motherboard or a PCMCIA solution for a notebook computer. This device can have a connector that is connected to the power line. 
     It is desirable to simplify the connection and the hardware as much as possible. 
     SUMMARY 
     The present specification teaches a power line network system, that has a stand alone power supply for a personal computer. The stand alone power supply has a housing that holds a power supply and a device which communicates network information onto a AC power line. The power supply also has a connector. A computer is connected to the connector to receive power and network information signals from the stand alone power supply. 
     Another aspect incorporates an element into the external power supply that automatically determines which of a number of different predetermined networks are existing on the power supply line. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other aspects will now be described in detail with reference to the accompanying drawings, wherein: 
     FIG. 1 shows a basic block diagram of the system using a laptop computer and an external power supply; and 
     FIG. 2 shows a flowchart of operation of this system. 
    
    
     DETAILED DESCRIPTION 
     The basic system is shown in FIG. 1 which shows a personal computer  100 , here a laptop, powered by a power supply  120  that is connected to the AC Power line  140  via connector plug  130 . The laptop is within its own housing  101 . According to this system, the PC operates a software layer  102  which runs certain application programs. The power supply  120  is held within a housing  111 , and within that housing includes multiple parts. A power supply portion  124  can transform the power from the AC power line  140  into a different voltage or current that is output as power  122  to the laptop. 
     Power supply  120  also includes a power supply modulator/demodulator  132  which is connected in parallel to the power supply line, and which receives additional modulated information from the power supply line. Different ways of modulating information on and receiving modulated information from the power supply line are known. One such power supply modulator  132  is the model AN1000 chipset from Adaptive Networks, Cambridge, Mass. Any other such device can alternately be used. These power supply modulator devices modulate information onto the power supply line at a different frequency than the frequency of the actual power line. The output of power supply modulator  132  is shown as a dual line output  134 . The power output  122  and power supply information output  134  are combined on to a single, multi pin connector  136 . 
     Connector  136  connects to the corresponding receptacle for receiving power and data in the PC  108 . The power on line  122  is used to power the components in the PC. The logic signal  134  is connected to line  110 , that in turn connects to logic module  104 . Logic module  104  can include an optical isolator, a line receiver, or more sophisticated structure. The operation of logic module  104  is controlled by software  102  which includes the application layer software. This application layer software runs according to the flowchart of FIG.  2 . 
     Operation in many different formats of network communication is well known. This system can operate in any of these different communication protocols as controlled by the operating software. 
     The software sends polls in different formats, to determine if it receives answers to those polls. Step  200  shows the initial step of sending a poll in power line Ethernet format. Step  202  waits for a response for a specified time out period. If a response is received, then an Ethernet power line mode is established at step  204 , and the appropriate flag is set. Thereafter, all communications with the network are carried out in Ethernet power line mode. 
     Step  206  is carried out if there is no response to step  202 . At step  206 , a power line network-at-home poll is carried out, and the response is monitored at step  208 . If received, then power line network at home mode is sent at step  210 . Any other known or custom format can be polled for using this system. The system operates by polling for each network protocol, and establishing a response based on the responses. 
     Step  212  generically shows polling for other requests, and checking for responses at step  214 . 
     If no responses are received at step  220 , then the system eventually determines that no network is installed. This would happen, for example when the user is in an airport or at some other location where no network is installed. 
     FIG. 2 shows polling for each network format separately and detecting whether a response has been received. However it should be understood that the FIG. 2 flowchart could be modified to send all polls quickly and then wait for any and all responses. This could operate faster and also enable determining if multiple different networks were installed on the same power line. 
     The system shown in FIG. 2 establishes a hierarchy indicating which network should be accepted based on the order of polling. The first network to answer and establish a network connection becomes the operating network. Operation is thereafter carried out with that found network. The flag set at step  204 ,  210 ,  216  is then used to indicate that further operations should be carried in that specified format, and that specified format is programmed into the logic module  104 . 
     The logic module  104  can include, for example, a multifunction network communication device, including a number of different chipsets which operate in a number of different formats. Alternately, the logic  104  can be a reconfigurable application specific integrated circuit (“ASIC”) or field programmable gate array (“FPGA”), or a digital signal processor which is reconfigured to emulate any desired network mode. 
     Other embodiments are within the disclosed embodiment. For example while the specification describes operating in software, it should be understood that dedicated hardware within the computer could be used for this operation. For example, hardware defined by hardware definition language could be used for this purpose. All such modifications are intended to be encompassed within the claims, in which: