Abstract: A network device implements a repetition scheme to generate a repetition-encoded forward error correction (FEC) codeword for a FEC codeword. The repetition-encoded FEC codeword includes a set of N offset-shifted bit sequences. In some embodiments, each bit sequence is formed by M replicas of the FEC codeword and an offset is applied to shift the bit sequence where the offset is different for each bit sequence. The set of N offset-shifted bit sequences are allocated into N orthogonal frequency-division multiplexing (OFDM) symbols, wherein each offset-shifted bit sequence is allocated over a corresponding OFDM symbol.

Abstract: A network device implements a repetition scheme to generate a repetition-encoded forward error correction (FEC) codeword for a FEC codeword. The repetition-encoded FEC codeword includes a set of N offset-shifted bit sequences. In some embodiments, each bit sequence is formed by M replicas of the FEC codeword and an offset is applied to shift the bit sequence where the offset is different for each bit sequence. The set of N offset-shifted bit sequences are allocated into N orthogonal frequency-division multiplexing (OFDM) symbols, wherein each offset-shifted bit sequence is allocated over a corresponding OFDM symbol.

Abstract: A network device implements a repetition scheme to generate a repetition-encoded FEC codeword for a FEC codeword. The repetition-encoded FEC codeword includes a set of bit sequences concatenated together. The set of bit sequences corresponds to a set of OFDM symbols. In some embodiments, each bit sequence is formed by M replicas of the FEC codeword and an offset is applied to shift the bit sequence where the offset is different for each bit sequence. In one embodiment, a right cyclic shift is used to offset the bits in each symbol. Each shifted bit sequence is allocated into subcarriers of an OFDM symbol over a frequency range indicative of an operating frequency band of a domain to form the respective OFDM symbol. The set of OFDM symbols is transformed into a time domain signal for transmission.

Abstract: A network device implements a repetition scheme to generate a repetition-encoded FEC codeword for a FEC codeword. The repetition-encoded FEC codeword includes a set of bit sequences concatenated together. The set of bit sequences corresponds to a set of OFDM symbols. In some embodiments, each bit sequence is formed by M replicas of the FEC codeword and an offset is applied to shift the bit sequence where the offset is different for each bit sequence. In one embodiment, a right cyclic shift is used to offset the bits in each symbol. Each shifted bit sequence is allocated into subcarriers of an OFDM symbol over a frequency range indicative of an operating frequency band of a domain to form the respective OFDM symbol. The set of OFDM symbols is transformed into a time domain signal for transmission.

Abstract: A method for communication includes transmitting a first uplink message from a first remote node (200, 300, 400) to a central node (100) in a wireless communication system according to a first frequency hopping scheme, and transmitting a second uplink message from a second remote node to the central node in the wireless communication system according to a second frequency hopping scheme, different from the first scheme. Both the first and the second uplink messages are received and processed at the central node.

Abstract: A method for communication includes transmitting a first uplink message from a first remote node (200, 300, 400) to a central node (100) in a wireless communication system according to a first frequency hopping scheme, and transmitting a second uplink message from a second remote node to the central node in the wireless communication system according to a second frequency hopping scheme, different from the first scheme. Both the first and the second uplink messages are received and processed at the central node.

Abstract: A method for communication includes transmitting a first uplink message from a first remote node (200, 300, 400) to a central node (100) in a wireless communication system according to a first frequency hopping scheme, and transmitting a second uplink message from a second remote node to the central node in the wireless communication system according to a second frequency hopping scheme, different from the first scheme. Both the first and the second uplink messages are received and processed at the central node.

Abstract: A method for communication includes transmitting a first uplink message from a first remote node (200, 300, 400) to a central node (100) in a wireless communication system according to a first frequency hopping scheme, and transmitting a second uplink message from a second remote node to the central node in the wireless communication system according to a second frequency hopping scheme, different from the first scheme. Both the first and the second uplink messages are received and processed at the central node.

Abstract: A method for communication includes transmitting a first uplink message from a first remote node (200, 300, 400) to a central node (100) in a wireless communication system according to a first frequency hopping scheme, and transmitting a second uplink message from a second remote node to the central node in the wireless communication system according to a second frequency hopping scheme, different from the first scheme. Both the first and the second uplink messages are received and processed at the central node.

Abstract: A method for communication includes transmitting a first uplink message from a first remote node (200, 300, 400) to a central node (100) in a wireless communication system according to a first frequency hopping scheme, and transmitting a second uplink message from a second remote node to the central node in the wireless communication system according to a second frequency hopping scheme, different from the first scheme. Both the first and the second uplink messages are received and processed at the central node.

Abstract: A method for communication includes transmitting a first uplink message from a first remote node (200, 300, 400) to a central node (100) in a wireless communication system according to a first frequency hopping scheme, and transmitting a second uplink message from a second remote node to the central node in the wireless communication system according to a second frequency hopping scheme, different from the first scheme. Both the first and the second uplink messages are received and processed at the central node.

Abstract: A method for communication includes transmitting a first uplink message from a first remote node (200, 300, 400) to a central node (100) in a wireless communication system according to a first frequency hopping scheme, and transmitting a second uplink message from a second remote node to the central node in the wireless communication system according to a second frequency hopping scheme, different from the first scheme. Both the first and the second uplink messages are received and processed at the central node.

Abstract: A hypothesis-based frame synchronization mechanism for use in a digital communications system, such as a powerline based communications network. The receiver detects the start of a preamble and achieves symbol synchronization. To achieve frame synchronization, the receiver generates a plurality of candidate hypotheses, each hypothesis corresponding to a potential starting point for the header section of the packet. The receiver evaluates each candidate hypothesis and selects the hypothesis having the highest likelihood of being valid. Frame synchronization is based on the selected hypothesis and detection and decoding of the data portion of the packet proceeds in accordance with the selected hypothesis.

Abstract: A method for communication includes transmitting a first uplink message from a first remote node (200, 300, 400) to a central node (100) in a wireless communication system according to a first frequency hopping scheme, and transmitting a second uplink message from a second remote node to the central node in the wireless communication system according to a second frequency hopping scheme, different from the first scheme. Both the first and the second uplink messages are received and processed at the central node.

Abstract: A novel and useful media access control (MAC) protocol that is intended for use over noisy shared media channels. The MAC protocol provides layer 2 functionality over a network using a shared medium including a backoff mechanism for CSMA/CA channel access, link addressing that reduces the overhead of long MAC addresses, a flooding scheme having controlled exposure for broadcast transmissions, multicast transmissions using selective ACKs, implementation of traffic prioritization using an adaptive backoff scheme, a second layer repeater establishment process and multi-packet transport for short packets and fragmentation for long packet transport.

Abstract: A wireless local area network (WLAN) access point (AP) system comprises a first plurality of distributed remote antenna units operative to transmit and receive RF signals and a central WLAN beam-forming unit connected to each distributed remote antenna unit and operative to provide communication between the antenna units and a second plurality of wireless clients. The WLAN AP system can be used for simultaneous communications with the wireless clients over the same radio frequency (RF) channel while avoiding mutual interferences.

Abstract: A novel and useful mechanism for detecting intrusion and jamming attempts by an imposter node. A time window defined as an emergency window is reserved after the end of a packet and before an acknowledgement window. Nodes that detect the presence of an intruder transmit an emergency packet during the emergency time window to inform the receive node that the packet it received was sent from an imposter node. Attempts to jam the transmission of the emergency packet from the victim node to the receive node are detected by listening during the emergency window time period for carrier signal that indicates that an emergency packet is trying to be sent. An emergency packet request message is sent by the receive node in response which causes the victim node to resend the emergency packet.

Abstract: A novel and useful distributed synchronization mechanism. The synchronization loop of each station on the shared media based network considers only synchronization signals received having a time phase earlier than the time phase of its internal clock. From among the plurality of synchronization signals received by a given station having a time phase earlier than that of its internal clock, only the earliest of the received synchronization signals is considered. This allows the use of a second order synchronization tracking loop wherein both the phase and rate of the internal clock are tracked and adjusted. The station with the fastest internal clock effectively functions as an ad-hoc synchronization master for all stations in a given maximum connected group.

Abstract: A novel media access control (MAC) mechanism utilizing synchronization signaling that enables nodes from different networks having different technologies and protocols to coexistence using the same shared media. The present invention is suitable for use with a wide range of different types of network and technologies and is particularly useful in providing coexistence capabilities to powerline based data communication systems. Specific time slots are assigned for the transmission of a frame occupation signal to indicate to all nodes that the channel is occupied. A synchronization signal is randomly transmitted during a preassigned time slot within the frame to provide accurate timing for the frame occupation signal. During times that a node does not transmit the synchronization signal, it listens to the channel. A timing signal is derived from the synchronization signals received from other nodes during this quiet period wherein the node is in a listening mode.

Abstract: A method of dynamic modification of a communication link is provided. The method includes assigning a new carrier frequency to a first communication link. The method further includes adjusting the carrier frequency of the first communication link until the new carrier frequency is reached without substantially interrupting the first communication link. Further, the first communication link uses a single link during the modification.