Abstract:
Embodiments of a power line communication (PLC) transmitter device for overlapping priority contention windows are presented. A processor is configured to perform a physical channel sense operation to detect an idle channel on a PLC network. A transmitter transmits a normal priority data packet on the channel during a high priority contention window. In another embodiment, a Normal Priority Contention Window (NPCW) is allowed to overlap with a High Priority Contention Window (HPCW). The minimum contention window for the normal priority frames (i.e., NPCW) is equal to or longer than the contention window for high priority frames (i.e., HPCW). By making the NPCW longer than the HPCW, the high priority frames will have a better chance than normal priority frames to get access to the channel on transmission reattempts.
Abstract:
In a method for communicating with a plurality of devices using different communication protocols, a signal is received at a transceiver device from a neighbor device via a physical layer of a communication media. At a first time the signal contains a header frame from a first device conforming to a first communication protocol and at another time the signal contains a header frame from a second device conforming to a second communication protocol. The transceiver determines which of the different communication protocols is being used by each of the plurality of devices. The transceiver may then process inbound payload data using the indentified protocol type. Data frames are transmitted to the first device using the first communication protocol and data frames are transmitted to the second device using the second communication protocol.
Abstract:
Systems and methods for setting a Network Allocation Vector (NAV) in a PLC node are disclosed. In a PLC standard, coexistence is achieved by having the nodes detect a common preamble and backing off by a Coexistence InterFrame Space (cEIFS) time period to help the node to avoid interfering with the other technologies. In one embodiment, a PHY primitive is sent from the PHY to the MAC know that there has been a preamble detection. A two-level indication may be used—one indication after receiving the preamble and other indication after decoding the entire frame. The MAC sets NAV to EIFS if a native preamble is detected. The MAC sets NAV to cEIFS if only a coexistence preamble is detected or if a non-native preamble is detected.
Abstract:
Embodiments of methods and systems are presented for generating PHY frames with multiple Reed-Solomon encoded blocks in PLC networks. In one embodiment, a MAC layer divides a data frame from a higher level into data blocks. The MAC layer may add a MAC header and/or an error-detection code to each data block. The MAC layer then passes the data blocks to a PHY layer to be individually Reed-Solomon encoded and combined into a single PHY frame for transmission on a PLC network. In other embodiments, the MAC layer passes a single data frame to the PHY layer, which divides the MAC data frame into segments to be individually Reed-Solomon encoded. The individual Reed-Solomon encoded segments are combined into a single PHY frame for transmission on a PLC network.
Abstract:
Systems and methods for routing protocols for power line communications (PLC) are described. In some embodiments, a method performed by a PLC device, such as a PLC meter, may include selecting one or more transmit sub-bands on which to transmit frames, where the transmit sub-bands comprise groups of six carrier frequencies. The PLC device then generates a frame comprising a tone map that indicates which transmit sub-bands are used to carry data for the frame. The tone map using two bits per transmit sub-band to indicate a status of each transmit sub-band. The PLC device then transmits the frame on the selected transmit sub-bands using OFDM. A resolution bit and a mode bit may be used to provide additional information about the transmit sub-bands, such as an amount of power adjustment that has been applied to carrier frequencies and whether dummy bits are transmitted on unused carrier frequencies.
Abstract:
A wireless network with network-level channel hopping. A wireless network includes a wireless device. The wireless device includes a receiver, a data channel selector, and a transmitter. The receiver is configured to receive a beacon signal comprising a beacon sequence value. The data channel selector is configured to select, as a pseudorandom function of the beacon sequence value, a data channel on which to transmit in an interval following reception of the beacon signal. The transmitter is configured to transmit on the data channel selected by the channel selector.
Abstract:
Embodiments of methods and systems for supporting coexistence of multiple technologies in a Power Line Communication (PLC) network are disclosed. A long coexistence preamble sequence may be transmitted by a device that has been forced to back off the PLC channel multiple times. The long coexistence sequence provides a way for the device to request channel access from devices on the channel using other technology. The device may transmit a data packet after transmitting the long coexistence preamble sequence. A network duty cycle time may also be defined as a maximum allowed duration for nodes of the same network to access the channel. When the network duty cycle time occurs, all nodes will back off the channel for a duty cycle extended inter frame space before transmitting again. The long coexistence preamble sequence and the network duty cycle time may be used together.
Abstract:
A radio communications device includes a RTC configured to run even during sleep for receiving from a coordinator node (CN) in an asynchronous channel hopping WPAN an asynchronous hopping sequence (AHS) frame that includes the CN's hopping sequence. A processor implements a stored sleepy device operation in asynchronous channel hopping networks algorithm. The algorithm is for determining a time stamp for the AHS frame and the CN's initial timing position within the hopping sequence, storing the time stamp, going to sleep and upon waking up changing a frequency band of its receive (Rx) channel to an updated fixed channel. A data request command frame is transmitted by the device on the CN's listening channel that is calculated from the CN's hopping sequence, time stamp, CN's initial timing position and current time, and the device receives an ACK frame transmitted by the CN at the updated fixed channel of Rx operation.
Abstract:
Authentication of a networked device with limited computational resources for secure communications over a network. Authentication of the device begins with the supplicant node transmitting a signed digital certificate with its authentication credentials to a proxy node. Upon verifying the certificate, the proxy node then authenticates the supplicant's credentials with an authentication server accessible over the network, acting as a proxy for the supplicant node. Typically, this verification includes decryption according to a public/private key scheme. Upon successful authentication, the authentication server creates a session key for the supplicant node and communicates it to the proxy node. The proxy node encrypts the session key with a symmetric key, and transmits the encrypted session key to the supplicant node which, after decryption, uses the session key for secure communications. In some embodiments, the authentication server encrypts the session key with the symmetric key.
Abstract:
Systems and methods for setting a carrier-sensing mechanism in a PLC node are disclosed. In a PLC standard, coexistence is achieved by having the nodes detect a common preamble and backing off by a Coexistence InterFrame Space (cEIFS) time period to help the node to avoid interfering with the other technologies. In one embodiment, a PHY primitive is sent from the PHY to the MAC know that there has been a preamble detection. A two-level indication may be used—one indication after receiving the preamble and other indication after decoding the entire frame. The MAC sets the carrier-sensing mechanism based on the preamble detection.