Design Of Power Line Carrier Communication Equipment Based On Hierarchical Model Of Computer Network Communications

Power line carrier communication is a data transmitting technique over powerlines that is realized through carrier modulation, it outperforms other similartechniques in that it requires no redundant wire layout, which makes it cost-saving,easily realized and maintained.Currently, the technique is widely used in a greatnumber of power line systems. However, there is serious signal attenuation and noisein such system as a result of its awful communication environment, thus make it hardto achieve effective communication distance and communication reliability.Currently, researchers on carrier communication are dominantly focusing on how toprolonged communication distance and promote communication reliability of carriercommunication system and.In the paper, the system is divided into four layers in reference to TCP/IP modelthat is widely used in internet communication to solve the existed problems of lowsystem reliability and insufficient communication dis tance in power linecommunication system. From bottom to top, they are network interface layer,network layer, transmitting layer and application layer. The network interface layer,which is a integrated hardware system of sending and receiving circuit for ca rriersignals and drivers for modulation&demodulation chip, provides a hardware base forupper software.the network layer, as a integrated system of networking algorithm,routing policy and network reconstructing policy, allows the system to relay andtransmit signals among bases and thus help prolonged communication distance. TheTransmitting layer provides two transmitting algorithms of reliable transmittingalgorithm and half-reliable transmitting algorithm, the former one transmit signalsthrough ask-acknowledge mode, while the lateral one transmits through slidingwindow mechanics. Both of them allow automatic detection of package lost andtimely lost data call-back to ensure communication reliability. The application layeris responsible for devices initiation and defines how data should be processed in thesystem, threads that is responsible for data processing will call provided algorithmdefined in the network layer and transmitting layer to process data that is needed tobe processed.Test results shows that the designed system could send and receive data assupposed, and the auto-networking algorithm used in the networking layer could help build the network system rapidly and precisely, the selected routing policy allows thesystem to relay and transmit signals, which effectively prolonged communicationdistance. The proposed algorithm used in the transmitting layer could helpeffectively lower the probability of package lost in power line communication, andthus makes the communication system more reliable.