摘要:
Systems and methods for designing, using, and/or implementing non-beacon network communications using frequency subbands are described. In various implementations, these systems and methods may be applicable to Power Line Communications (PLC). For example, a method may include transmitting a beacon request message over a given one of a plurality of frequency subbands, receiving a plurality of beacons in response to having transmitted the beacon request message, each of the plurality of beacons received over a respective one of the plurality of frequency subbands, and calculating a downlink quality report based, at least in part, upon the received beacons. The method may also include transmitting the downlink quality report over each of the plurality of frequency subbands and receiving a subband allocation command in response to having transmitted the downlink quality report, the subband allocation command indicating a downlink subband assignment and an uplink subband assignment.
摘要:
Systems and methods for designing, using, and/or implementing media access control (MAC) protocols with subbanding are described. In some embodiments, a method may include receiving a beacon packet during one of a plurality of beacon slots of a superframe, each beacon slot corresponding to one of a plurality of different downlink subbands. The method may also include identifying, based on the received beacon packet, contention access periods following the beacon slots, each of the contention access periods corresponding to one of a plurality of different uplink subbands. The method may further include transmitting an information packet over each of the plurality of uplink subbands during the contention access periods. Then, the method may include receiving, during a guaranteed time slot following the contention access periods, an indication of a selected one of the plurality of uplink subbands to be used in a subsequent communications.
摘要:
Systems and methods for designing, using, and/or implementing slotted channel access techniques in network communications are described. In some embodiments, a method may include selecting one of a plurality of time slots within a contention access period (CAP), each of the plurality of time slots having a predetermined duration, and transmitting a packet during the selected time slot. For example, the time slot may be selected randomly or based on a round-robin algorithm. In some implementations, the duration of each of the plurality of time slots may correspond and/or be equal to: (a) a duration of a data packet of maximum size, (b) a sum of durations of a request-to-send packet, an interframe space, and a clear-to-send packet, and/or (c) a duration of a guaranteed time slot (GTS) or contention free period (CFP) request packet, as prescribed by a given communication protocol or standard.
摘要:
Systems and methods for implementing power line communications (PLC) across different voltage domains using multiple frequency subbands are described. From an end node's perspective (e.g., a PLC device), a method may include scanning a plurality of downlink subbands usable by a base node (e.g., a PLC router, etc.) to communicate with one or more PLC devices (e.g., other end nodes) from a medium voltage (MV) to a low voltage (LV) power line, and transmitting association request(s) to the base node that select and/or allow the base node to select one or more downlink subbands for use in subsequent communications. From the base node's perspective, the method may include selecting one or more of a plurality of uplink subbands for use in subsequent communications based on the received association request(s). In various implementations, the selection of downlink and/or uplink subbands may be based on signal-to-noise ratio (SNR) values and/or congestion indicators.
摘要:
Communication devices, such as base nodes and modems, that comply with two or more different standards operate on a shared communication channel. To avoid mutual interference, a base node operating under a first standard reserves time using a contention free period designation. The base node allows devices operating under a second standard to communicate during the reserved time by not assigning the contention free period to another device operating under the first standard. Alternatively, a device using the first standard may avoid interference from transmissions generated under the second standard by modifying data packets prior to transmission. A prefix corresponding to a preamble in the second standard is added to the beginning of the data packet created under the first standard. Devices operating under the second standard observe the prefix and recognize that the channel is active. The second-standard devices backoff from transmission thereby minimizing interference.
摘要:
Systems and methods for power line transmission are disclosed in which transmitters and receivers are connected to one or more phases of the power line. At least one symbol stream to be transmitted on the power line network is generated. The at least one symbol stream is scaled using a weight vector to generate a plurality of scaled symbol streams. The weight vector comprises a plurality of weights, each corresponding to a phase of the power line network. Each of the scaled symbol streams are transmitted on a corresponding phase of the power line network. A zero crossing detector identifies phase information for a receiver. A concentrator adapts signals to be sent to the receiver based upon the phase associated with the receiver.
摘要:
The present invention provides a method of operating a base station transmitter. The method includes providing a cellular downlink synchronization signal having primary and secondary portions, wherein the primary portion employs a corresponding one of a plurality of different primary signals allocated to adjoining transmission cells. The method also includes further providing cell-specific information in the secondary portion and transmitting the cellular downlink synchronization signal. In one embodiment, the primary portion explicitly indicates a partial cell identification information and the remaining cell identification information is carried in the secondary portion. In another embodiment, the plurality of different primary signals are simply used to avoid the channel mismatch effect. The present invention also provides a method of operating user equipment. The method includes receiving a cellular downlink synchronization signal having primary and secondary portions wherein the timing acquisition is performed in conjunction with the primary synchronization sequence index detection via the primary portion. In addition, the secondary portion provides cell-specific parameters and identifying and extracting the secondary portion.
摘要:
Systems and methods for designing, using, and/or implementing beacon-enabled communications for variable payload transfers are described. In various embodiments, these systems and methods may be applicable to power line communications (PLC). For example, a method may include implementing a superframe having a plurality of beacon slots, a plurality of intermediate slots following the beacon slots, and a poll-based Contention Free Period (CFP) slot following the intermediate slots. Each of the beacon slots and each of the intermediate slots may correspond to a respective one of a plurality of frequency subbands, and the poll-based CFP slot may correspond to a combination of the plurality of frequency subbands. The method may also include receiving a poll request over a first of the plurality of frequency subbands during the poll-based CFP slot, and then transmitting a data packet over a second of the plurality of frequency subbands during the poll-based CFP slot.
摘要:
Systems and methods for application profiles and device classes in power line communications (PLCs) are described. In some embodiments, a PLC device may include a processor and a memory coupled to the processor. The memory may be configured to store program instructions, which may be executable by the processor to cause the PLC device to communicate with a higher-level PLC apparatus over a power line using a frequency band. The frequency band may be selected based upon an application profile and/or a device class associated with the PLC device. In some implementations, the higher-level PLC apparatus may include a PLC gateway or a data concentrator, and the PLC device may include a PLC modem or the like. Examples of application profiles include access communications, in-premises connectivity, AC charging, and/or DC charging. Device classes may represent a minimum communication data rate and/or an operating frequency band restriction of the PLC device.
摘要:
Systems and methods for implementing symbol-level repetition coding in power line communications (PLC) are described. In some embodiments, these systems and methods may provide reliable communication in severe channel environments of PLC networks, at least in part, by changing the forward error correction (FEC) used by various devices operating within current PLC systems. For example, a method may include receiving a PLC signal and applying convolutional encoding to the received signal, the convolutional encoding producing an encoded signal. The method may also include performing a subcarrier modulation operation upon the encoded signal, the subcarrier modulation operation producing a modulated signal. The method may further include applying symbol-level repetition coding to the modulated signal, the symbol-level repetition coding producing a repetitious signal. In some cases, one or more distinct repetition patterns may be applied to different symbols or portions thereof. The repetitious signal may then be transmitted over a power line.