77 results about "Frame check sequence" patented technology

A high speed communications interface divides data into a plurality of lanes, each lane encoded with clocking information, serialized, and sent to an interface. During cycles when there is no available data to send, IDLE_EVEN and IDLE_ODD cells are sent on alternating cycles. Data is transmitted by sending a header which spans all lanes and includes a START symbol. The final data transaction includes a Frame Check Sequence (FCS) which operates over the entire header and data. The packet is terminated by an END symbol, which is sent after the final data, and the remainder of the lanes are padded with IDLE_EVEN, IDLE_ODD, IDLE_EVEN_BUSY, or IDLE_ODD_BUSY cycles. The interface has a variable clock rate.

The present invention discloses a data transmission apparatus and method for transmitting data between physical layer side device and network layer device, which encapsulating a novel LAPS framing-de-framing into SPE / VC of a HDLC-like frame using a variable SAPI value. The LAPS encapsulation consists of the start Flag Sequence, address field (SAPI, Service Access Point Identifier), control field (0x03), Information field (Ipv4, Ipv6, or PPP protocol data unit), FCS (Frame check sequence) and the ending Flag Sequence, or consists of the start Flag, Address field, Control field, SAPI field (two octets), Information field, FCS field and the ending Flag Sequence. The Flag Sequence (0x7E) identifies the beginning / end of a LAPS frame. The present invention can be used to adapt Internet / Intranet to telecommunication infrastructure, and can be applied to network devices such as core and edge routers, switch devices, IP based network accessing equipment, line cards, and interfacing units used in high speed, e.g. Gigabit applications, for adapting IP directly to SDH / SONET or simplified SDH / SONET, or other physical layer devices.

This disclosure provides systems, devices, apparatus and methods, including computer programs encoded on storage media, for generating wake-up radio (WUR) frames formats and implementing WUR communications between transmitting and receiving wireless devices. A transmitting wireless device may identify one or more intended receiving wireless devices for which to send a WUR frame. The transmitting wireless device may generate the WUR frame, where the WUR frame has a first portion that includes a first field. The first field may indicate whether the WUR frame is a fixed length frame or a variable length frame. The transmitting wireless device may also determine a frame check sequence (FCS) type for use with a WUR frame for transmission. The FCS portion may be capable of being one of a plurality of FCS types. The transmitting wireless device may transmit the WUR frame to the one or more intended receiving wireless devices.

Initially the message frame comprising a header with length information, a data portion and a check sequence is expanded with gaps inserted to the data portion and the frame check sequence and the frame length information is updated, the frame is then scrambled and forward error correction data is generated and written into the gaps. An outer check sequence is generated and appended as part of the frame, after which the entire frame is transmitted. Error control decoding of the transmitted frame is achieved between reception and descrambling at a receiving device. The outer check sequence is optionally checked and removed, an error correction algorithm is applied to the frame in response to errors, after which the frame is descrambled, the forward error correction data and the inserted gaps are removed and the frame is restored to its original state and the length information is updated to its original value.

A medium access control (MAC) frame provision method establishes security in an IEEE 802.15.4 network. A MAC frame is generated, which includes a MAC header, a payload field, and a frame check sequence (FCS) field, the payload field including relevant main data according to a frame type defined in the MAC header. A disguised decoy data sequence number (DSN) is generated and inserted into the MAC header. A real DSN, which is a corresponding transmission sequence number of the MAC frame, is generated and inserted into the payload field. The MAC frame is transmitted, including the encrypted payload field, to a counterpart node. A MAC ACK frame acknowledges reception of the transmitted MAC frame; and a DSN is compared in the received MAC ACK frame with the real DSN. An authentication of the counterpart node is performed when the received MAC ACK frame is equal to the real DSN.

A method of transmitting a data frame is disclosed and may include transmitting a preamble, transmitting a physical layer convergence protocol (PLCP) header, and transmitting a plurality of MAC protocol data units (MPDUs). Each MPDU may be configured to reset a convolutional decoder state after each MPDU. The method may also include transmitting an MPDU aggregation header. The MPDU aggregation header may include a count of packed MPDUs, an array of offsets, an array of lengths, a frame check sequence (FCS) for the MPDU aggregation header, a group of tail bits, or a combination thereof. Further, an end of the MPDU aggregation header may be aligned to an interleaved symbol boundary.

A system providing sound to a user, having at least one audio signal source; a transmission unit with a digital transmitter which transmits audio signals via a wireless digital audio link as audio data packets, each packet having a start frame delimiter, audio data and a frame check sequence; at least one receiver unit having at least two digital receivers connected to a common processing unit and an antenna, and including a demodulator and a buffer, and a mechanism for stimulating the hearing of the user. Each receiver receives, verifies and buffers the audio data packets, and the processing unit reads an audio data packet from the buffer of one of the receivers. If the packet is correctly received by the receiver, the buffer of the other receivers is flushed, and if the packet has been incorrectly received, the audio data packet from the buffer of another receiver is read.

A system and method, associated with a receiver, for increasing the range or bandwidth of a wireless digital communication network and a receiver incorporating the system or the method. In one embodiment, the system includes: (1) a service class detector configured to determine a service class of a PDU received by the receiver from the wireless digital communication network and (2) a frame check sequence checker coupled to the service class detector and configured to disregard error-checking information in the PDU when the service class indicates that the PDU is a streaming media PDU.