A multi-carrier communication system such as an OFDM or DMT system has nodes which are allowed to dynamically change their receive and transmit symbol rates, and the number of carriers within their signals. Changing of the symbol rate is done by changing the clocking frequency of the nodes' iFFT and FFT processors, as well as their serializers and deserializers. The nodes have several ways of dynamically changing the number of earners used. The selection of symbol rate and number of earners can be optimized for a given channel based on explicit channel measurements, a priori knowledge of the channel, or past experience. Provision is made for accommodating legacy nodes that may have constraints in symbol rate or the number of carriers they can support. The receiver can determine the correct symbol rate and number of earners through a priori knowledge, a first exchange of packets in a base mode that all nodes can understand, or an indication in the header of the data packet which is transmitted in a base mode of operation that all nodes can understand.

The disclosure is related to adaptive transcoding of video streams from a camera. A camera system includes a camera and a base station connected to each other in a first communication network, which can be a wireless network. When a user requests to view a video from the camera, the base station obtains a video stream from the camera, transcodes the video stream, based on one or more input parameters, to generate a transcoded video stream, and transmits the transcoded video stream to a user device. The base station can transcode the video stream locally, e.g., within the base station, or in a cloud network based on transcoding location factors. Further, the camera system can also determine whether to stream the video to the user directly from the base station or from the cloud network based on streaming location factors.

Techniques are directed to using communication metric data associated with multiple modulation schemes to achieve a link quality metric that is representative of the link as a whole, across the multiple modulation schemes that may be employed on the link. A calculation of a link quality metric may be triggered by a network layer transmission attempt, with communication metrics accumulated at the link layer of the link. A filter used to calculate the link quality metric may be updated based on network layer transmission attempts, based on successful and/or unsuccessful transmissions at a Media Access Control (MAC) layer of the link. More generally, a calculation of link quality may be triggered by a higher layer transmission attempt while being calculated based on transmission attempts at a lower layer of the link.

This application relates to the communications field, and provides a transmission mode determining method and an apparatus, to better select a transmission mode and/or a transmission parameter of data autonomously. The transmission mode determining method includes: A first device measures a first resource set based on first information, to obtain a first measurement value, where the first information includes at least one of the following information: a subcarrier spacing of the first resource set, a quality of service parameter of first data, and feedback information between the first device and a second device, and the first resource set is to be used to transmit the first data. The first device determines a transmission mode of the first data based on the first measurement value, and/or determines a transmission parameter of the first data based on the first measurement value.

A data packet for delivery to a user equipment can be inspected. Based on the inspecting, whether to use a robust downlink delivery can be determined. Based on the determining, a robust modulation coding scheme (MCS) for the data packet can be selected. The data packet can be transmitted utilizing the selected robust MCS. At least one of the inspecting, the determining, the selecting, and the transmitting is performed using at least one processor of at least one computing system. Related apparatus, systems, techniques, and articles are also described.

For a source stream of input data where FEC scheme(s) have been used to create a repair stream, transmitting by a network node packet(s) comprising data of the source stream or the repair stream packaged as at least part of PDU(s). An ARQ or HARQ process is applied to the PDU(s). The network node receives feedback information as part of the process corresponding to the PDU(s), including positive ACK/NACK response for the PDUs. The retransmissions of the negatively acknowledged PDU(s) are controlled when the FEC scheme is known not to be able to compensate for loss(e)s of packet(s) contained in the PDU(s) indicated as being negatively acknowledged. A UE receives packet(s), determines loss(es), and, in response to a determination the FEC scheme is known to be able to recover from the loss(es), sends at least one ACK for any lost packets that correspond to the one or more loss(es).

An encoding modulation method and transmitter are described. The method includes: oversampling and noise-shaping received multi-bit data to obtain N bits of data; using the N bits of data as a lookup table address to obtain a PWM puke modulation signal; multiplexing synthetic orthogonal (IQ) complex data of the PWM pulse modulation signal to be real number signal data; and converting the multiplexed real number signal data to an analog signal for power amplification and output, N being an integer representing a smaller number of bits than the received multi-bit data.

Embodiments of the present invention provide a transmission status determining method, where the method includes: receiving, by a receive end device in a first time period, a first symbol sequence sent by a transmit end device; determining a first modulation parameter set according to the first symbol sequence; and determining, according to preset first mapping relationship information, a first transmission status corresponding to the first modulation parameter set as a transmission status of the transmit end device in a second time period, where the first mapping relationship information is used to indicate a one-to-one mapping relationship between N transmission statuses and N modulation parameter sets, the first modulation parameter set belongs to the N modulation parameter sets, and the second time period is later than the first time period.

In one embodiment, a plurality of data rates available for communication is identified at a first device in a network. Slots of a channel hopping schedule are also identified and the data rates are assigned to the slots of the channel hopping schedule to generate a data rate hopping schedule. The generated data rate hopping schedule is further provided to a second device in the network.

A transmitter transmits payload data using Orthogonal Frequency Division Multiplexed (OFDM) symbols. The first OFDM symbol is a first type having a number of sub-carriers which is less than or equal to the number of sub-carriers of the one or more second OFDM symbols of a second type and a guard interval for the first OFDM symbol is selected in dependence upon the longest possible guard interval of the second OFDM symbol. Accordingly an OFDM communications system can be formed in which data is transmitted using a frame structure in which a guard interval is adapted to allow a mix of different types of OFDM symbols.