Abstract: A secure control system includes a network of multiplexers that control end/field devices of an infrastructure system, such as an electric power grid. The multiplexers have a default secure lockdown state that prevents remote access to data on the multiplexers and prevents modification of software or firmware of the multiplexer. One or more of the multiplexers include a physical authentication device that confirms the physical proximity of a trusted individual when remote access is requested. A user accesses the network and one of the multiplexers remotely by way of login credentials. The trusted individual confirms the identity of the remote user and operates the physical authentication device connected with and in proximity to that multiplexer, thereby confirming that the remote user can be trusted to access data and reconfigure the multiplexers.

Abstract: Agentless method to automatically detect low latency groups in containerized infrastructures includes obtaining information about communication across workloads within a cluster of containers implemented by an operating environment. The information identifies multiple pairs of containers. Each pair includes a network source container and a corresponding network destination container. The information includes, for each pair of containers, a corresponding latency associated with a network call between the network source container and the corresponding network destination container. An undirected graph is generated using the obtained information. The undirected graph represents a node-wide latency within the cluster. Using the undirected graph, nodes within the cluster with a latency less than a threshold latency level are grouped. Grouped nodes with latencies less than the threshold latency level are provided.

Abstract: Disclosed is a method of a first wireless communication device configured for massive multi-user multiple-input multiple output (MU-MEMO) communication with two or more second wireless communication devices. The first wireless communication device comprises a plurality of antenna ports, each antenna port associated with at least one of a digital-to-analog converter (DAC) and an analog-to-digital converter (ADC). The method comprises acquiring an estimation of a communication channel between the first wireless communication device and the second wireless communication devices and acquiring an estimation of a quantization distortion caused by either DACs or ADCs. The method also comprises jointly determining (for the two or more second wireless communication devices) a transmission power and a transmission resource for each of the second wireless communication devices, wherein the joint determination is based on the estimation of the communication channel and on the estimation of the quantization distortion.

Abstract: Examples described relate to systems, methods, and apparatus for transmitting image data. The apparatus may comprise a memory buffer configured to store data elements of an image frame and generate a signal indicating that each of the data elements of the image frame have been written to the memory buffer, a processor configured to initiate a flush operation for reading out at least one data element of the image frame from the memory buffer and to output the at least one data element at a first rate, a rate adjustment unit configured to receive the at least one data element from the processor at the first rate and to output the at least one data element at a second rate, and a multiplexer configured to receive the at least one data element from the processor at the first rate and configured to receive the at least one data element from the rate adjustment unit at the second rate.

Abstract: A transmitting system, receiving system, and a method of processing broadcast signals are disclosed. The method for processing a broadcast signal in a broadcast receiver comprises receiving a DTV signal including a data group, the data group including mobile service data, segmented known data sequences, long known data sequences and transmission parameter data, compensating carrier frequency offset of the DTV signal and channel-equalizing the carrier frequency offset compensated DTV signal using at least one of the long known data sequences and segmented known data sequences in the data group of the DTV signal, wherein the channel-equalizing includes performing a Error Correction (FEC) decoding on data located between the segmented known data sequences, and estimating Channel Impulse Response (CIR) using the FEC decoded data as known data.

Abstract: A transmitting system, a receiving system, and a method of processing broadcast signals are disclosed. The method for processing a broadcast signal in a broadcast receiver comprises receiving a DTV signal including a data group, the data group including mobile service data, segmented known data sequences, long known data sequences and transmission parameter data, compensating carrier frequency offset of the DTV signal and channel-equalizing the carrier frequency offset compensated DTV signal using at least one of the long known data sequences and segmented known data sequences in the data group of the DTV signal, wherein the channel-equalizing includes performing a Error Correction (FEC) decoding on data located between the segmented known data sequences, and estimating Channel Impulse Response (CIR) using the FEC decoded data as known data.

Abstract: The disclosure relates to a method for serially transmitting a frame from a transmitter to at least one receiver by means of a bus line, as well as a subscriber station for a bus system. According to said method, stuff bits are inserted into the frame by the transmitter according to a predetermined rule in order to generate additional signal edges, and/or said stuff bits are removed again by the receiver when evaluating the frame, at least one item of information relating to a subsection of the frame additionally being added, and transmitted, outside of this subsection, and said subsection containing a predetermined sequence of bit values.

Abstract: To provide a novel semiconductor device or display device. The semiconductor device includes a decoder circuit, an amplifier circuit, and an arithmetic circuit. The amplifier circuit includes a first amplifier and a second amplifier. One of the first amplifier and the second amplifier has a function of inspecting an output of the other of the first amplifier and the second amplifier. The arithmetic circuit has a function of calculating an error of a potential output from the first amplifier or the second amplifier, on the basis of a result of the inspection. The decoder circuit has a function of correcting a video signal input to the decoder circuit by subtracting the error of the potential from the video signal.

Abstract: A method transcodes a media program to produce a constant video quality transcoded version of the media program. The constant video quality transcoded version is transcoded by a transcoder operating in a first mode that targets video quality. A portion of the constant video quality transcoded version that fails to satisfy a constraint is determined. The method sets a transcoding parameter based on the portion failing to satisfy the constraint. A portion of the media program corresponding to the portion of the constant video quality transcoded version is transcoded according to the transcoding parameter to produce a constant bit rate version of the portion. The constant bit rate version is transcoded by the transcoder operating in a second mode that targets a bit rate. The method then substitutes the constant bit rate version for the portion of constant video quality transcoded version in generating a transcoded media program.

Abstract: A method includes obtaining a video based on images detected with cameras mounted on a vehicle and displaying a portion of the video corresponding to a time offset and a viewing angle.

Abstract: A driving device includes a phase detection unit, a signal reconstruction unit, and a plurality of transmission units. The signal reconstruction unit is coupled to the phase detection unit. The phase detection unit is configured to receive a plurality of synchronous signals corresponding to a plurality of data packets, and detect a phase difference between the synchronous signals to generate a detection result signal. The signal reconstruction unit is configured to generate a reconstructed synchronous signal according to the detection result signal. The plurality of transmission units is configured to receive the reconstructed synchronous signal, and synchronize a plurality of pixel data corresponding to the data packets according to the reconstructed synchronous signal for transmission to a plurality of display devices.

Abstract: Methods and apparatus are provided for embedded quantization parameter adjustment in video encoding and decoding. An apparatus includes an encoder for encoding picture data for at least a block in a picture. A quantization parameter, applied to one or more transform coefficients obtained by transforming a difference between an original version of the block and at least one reference block, is derived from reconstructed data corresponding to at least the block.

Abstract: The disclosure relates to a method for serially transmitting frames from a transmitter to at least one receiver via a bus line and to a participant station for a bus system. In the method, stuff bits are integrated into the frame by the transmitter dependent on the values of multiple previous bits in order to generate additional signals edges. The transmitter of the frame counts the stuff bits which are integrated depending on the value of multiple previous bits, and information on the number of counted stuff bits is transmitted in the transmitted frames.

Abstract: A method of enabling a communication channel between a first communication circuit and a second communication circuit is described. The method comprises establishing a communication link according to a communication protocol between the first communication circuit and the second communication circuit, wherein the communication protocol enables the transmission of data between the first communication circuit and the second communication circuit at a standardized data rate; determining a standardized data rate for which the communication link between the first communication circuit and the second communication circuit fails to meet a predetermined quality threshold; and establishing a communication link according to the communication protocol at a non-standardized data rate below the determined standardized data rate.

Abstract: Method and system for improving the security of storing digital data in a memory or its delivery as a message over the Internet from a sender to a receiver using one or more hops is disclosed. The message is split at the sender into multiple overlapping or non-overlapping slices according to a slicing scheme, and the slices are encapsulated in packets each destined to a different relay server as an intermediate node according to a delivery scheme. The relay servers relay the received slices to another other relay server or to the receiver. Upon receiving all the packets containing all the slices, the receiver combines the slices reversing the slicing scheme, whereby reconstructing the message sent.

Abstract: The present invention relates to methods and systems for streaming content and in particular, live content. The method includes the steps of: receiving a content stream; periodically encoding the received stream into a sequence of content files to thereby create a plurality of sequential content files; assigning a sequence identifier to each content file; storing the files on a host; delivering a data file to a media player responsive to a request for live content, said data file including information enabling the media player to sequentially and individually request each content file from the host and play the requested content file; and delivering requested content files responsive to each request.

Abstract: A method for offering a set of services is disclosed. The method may comprise storing, by a cloud infrastructure system, subscription order information identifying a service from a set of services provided by the cloud infrastructure system, the cloud infrastructure system comprising one or more computing devices. A computing device from the one or more computing devices may determine a service declaration for the service, the service declaration comprising information indicative of procedures for provisioning resources for enabling the service. A computing device from the one or more computing devices may cause the service to be provisioned based on the service declaration.

Abstract: In one example, a method may include assigning a time requirement for a transmission of data from a first data storage node to a second data storage node, assigning a maximum channel transmission rate for each of a maximum number of available transmission channels based on predetermined parameters of a transmission channel, and transmitting the data in accordance with the time requirement and the maximum number of available transmission channels.

Abstract: The present invention provides a high-speed 100 G optical transceiver for InfiniBand and Ethernet with associated mapping to frame InfiniBand and Ethernet into GFP-T. The optical transceiver utilizes an architecture which relies on standards-compliant (i.e., multi-sourced) physical client interfaces. These client interfaces are back-ended with flexible, programmable Field Programmable Gate Array (FPGA) modules to accomplish either InfiniBand or Ethernet protocol control, processing, re-framing, and the like. Next, signals are encoded with Forward Error Correction (FEC) and can include additional Optical Transport Unit (OTU) compliant framing structures. The resulting data is processed appropriately for the subsequent optical re-transmission, such as, for example, with differential encoding, Gray encoding, I/Q Quadrature encoding, and the like. The data is sent to an optical transmitter block and modulated onto an optical carrier. Also, the same process proceeds in reverse on the receive side.

Abstract: A method of transferring data in a wireless communication system is disclosed. A method of transferring data in a transmitting side of a wireless communication system includes checking whether at least one priority change condition is satisfied, changing a previously set priority of a plurality of upper layer channels if the at least one priority change condition is satisfied, and allocating radio resources of a lower layer channel to data of each of the plurality of upper layer channels in accordance with the changed priority.

Abstract: A method that includes determining a multi-flow configuration for a multi-flow communication of a user equipment (UE), wherein the multi-flow configuration identifies whether a multi-frequency configuration is utilized and whether multiple-input multiple-output (MIMO) communication is configured for at least one cell in the multi-flow communication, determining one or more cell groups based on the multi-flow configuration, and determining at least one of a channel quality indicator (CQI) repetition rule or a hybrid automatic repeat request acknowledgment (HARQ-ACK) repetition rule for the multi-flow communication based on one or more of the multi-flow configuration or the one or more cell groups.

Abstract: Embodiments of the present invention disclose a method for the generic mapping procedure GMP mapping, a method for GMP demapping, and an apparatus. The method for mapping includes: carrying, in an overhead GMP OH of the ith GMP block container, information about a TS that needs to be occupied by the (i+n)th GMP block container; adjusting the (i+n)th GMP block container according to the information about the TS that needs to be occupied by the (i+n)th GMP block container; performing, according to the adjusted (i+n)th GMP block container, the GMP mapping on customer service data to be sent, so that a receive end is capable of adopting a corresponding demapping manner according to a change of the block container, which implements lossless mapping and demapping processing by adopting a GMP for a variable block container.

Abstract: A communication device utilizing an interrupting alignment pattern is disclosed. The communication device may comprise a plurality of inputs, a pattern generator, a multiplexer, a control circuit, an interrupt circuit, and an output. The pattern generator may be configured to generate an alignment pattern. The control circuit may be configured to control the multiplexer to multiplex a plurality of incoming data streams into a serialized output data stream. The interrupt circuit may be configured to interrupt the serialized output data stream with the alignment pattern. The output may be configured to output the alignment pattern in place of the serialized output data stream, when the serialized output data stream is interrupted by the alignment pattern.

Abstract: An apparatus and method for generating a multiplex of media streams, the method includes the steps of: (i) receiving a set of media streams that comprises first type media stream components and second type media stream components; (ii) applying a modification process that is not adapted to modify second type media stream components, such as to provide at least one modified first type media stream component; and (iii) multiplexing at least the second type media stream components and the modified first type media stream components.

Abstract: A method for receiving packet data at a communication channel and transmitting the packet data over serial links of the communication channel. The packet data is sliced into n-bit data portions which are concatenated with a header prior to transmitting an n-bit portion across one of the serial links of the communication channel. The header may include an invert bit to alter the majority sign of an n-bit portion. Other aspects of the present invention are also described herein.

Abstract: A communication apparatus for communicating data conveyed by a plurality of transport channels, the data of the transport channels being multiplexed into at least one multiplexing frame, includes a processing unit. The processing unit transforms an input data block of an initial size into an output data block of a final size in accordance with a rate matching ratio of the final size to the initial size, transmits information on a maximum payload of the at least one multiplexing frame the communication apparatus can send, receives a first parameter relative to the rate matching ratio, and calculates the final size, according to the initial size of the input data block, the first parameter, a second parameter and the maximum payload of the at least one multiplexing frame. The second parameter is representative of a maximum puncture rate and is a predefined parameter for calculating the final size.

Abstract: A system and method is disclosed for adding a low data rate data channel to a 100Base-T Ethernet link without significantly impacting an IEEE defined 100Base-T protocol for the Ethernet link. A dual data channel transmitter encodes a high data rate data stream in an MLT-3 encoder and encodes a low data rate data stream using bit representations that are not valid bit representations in the MLT-3 encoder. The dual data channel transmitter transmits both of the encoded bit streams in a dual data stream. A dual data channel receiver receives the dual data stream and separates and decodes the two bit streams. A low data rate data channel is provided in conjunction with a high data rate data channel without significantly impacting the operation of the high data rate data channel.

Abstract: Digital signals having respective pieces of frequency information different from each other are bundled, and transmitted at high speed. On receiving side, digital signals retaining the respective pieces of frequency information are recovered and separated. Transmitter apparatus divides pieces of transmission data that have the different pieces of frequency information and correspond to respective input channels into data blocks having a fixed length, as valid data, and subsequently multiplexes the data blocks corresponding to the respective input channels and outputs the multiplexed data to a transmission path. A receiver apparatus divides data string received into data flows and subsequently restores the transmission data, from the data blocks consecutive in each data flow and stores the restored data, and outputs transmission data corresponding to the respective data flows in synchronization with clocks generated for these data flows.

Abstract: Method and apparatus for transporting client signals in an OTN are illustrated. In one embodiment, the method includes: receiving a client signal; determining a quantity of n-bit data units of the client signal based on a clock of the client signal and a local clock; mapping the quantity of n-bit data units of the client signal to an overhead of a first Optical Channel Data Tributary Unit (ODTU) frame; mapping the n-bit data units of the client signal to a payload area of a second ODTU frame next to the first ODTU frame according to the quantity of n-bit data units mapped in the overhead of the first ODTU frame; mapping each n-bit data unit of the second ODTU frame to an Optical Channel Payload Unit-k Tributary Slot (OPUk TS) in an OPUk frame; and forming an Optical Channel Transport Unit-k (OTUk) frame including the OPUk frame for transmission.

Abstract: A spread spectrum generator module is configured to provide data for spreading frequency spectra of at least first and second lower bandwidth asynchronously clocked communication links. A packet scheduling module aggregates the two (or more) lower bandwidth links into a higher bandwidth link or interface. The frequency spectra of the lower bandwidth links are spread in accordance with the data for spreading the frequency spectra. A downstream disaggregation element filters high frequency noise resulting from the spreading of the spectra.

Abstract: A microwave radio terminal capable of multiple gigabits/sec bit rate is provided. The radio terminal may use QAM modulation, including the two lowest modulation formats of BPSK and QPSK. The serial bit stream, including forward error correction (FEC) and all other overhead, is prepared in a digital circuit, such as a filed programmable gate array (FPGA) and is output serially, using SERDES devices inside the FPGA, as two separate channels known as “I-channel” and “Q-channel”.

Abstract: An output control unit outputs data of bit rate A to a first header-attaching unit and data of bit rate B to a second header-attaching unit. An instructing unit instructs the first or the second header-attaching unit to attach a header of bit rate being the least bit rate to the data of bit rate A or B. The first header-attaching unit creates a header of bit rate A, including an ID of a destination ONU of the data of bit rate A and information concerning the data length, and attaches the header of bit rate A to the data of bit rate A. The second header-attaching unit creates a header of bit rate A, including an ID of the destination ONU of the data of bit rate B and information concerning the data length, and attaches the header of bit rate A to the data of bit rate B.

Abstract: A method for adapting the rates of a certain number of asynchronous HDLC channels (15) to a single clock domain suited for interfacing with an HDLC processor (13) through a synchronous pseudo-TDM interface (14) in which the HDLC channels are multiplexed in time and vice versa in the opposite direction. In one direction the algorithm is based on the writing of the HDLC channels in a dedicated buffer (17) and in reading these buffers with a common synchronous clock just above the expected maximum HDLC rate. The under-run condition is avoided by inserting neutral information between the end byte and the start byte of the HDLC packets when this is suggested by the buffer fill monitoring function. A simple function to locate the first and last bytes of each HDLC packet read by the buffer is hence used in combination with the buffer fill monitoring function.

Abstract: A digital microwave link and system are provided that has an adaptive data rate.

Abstract: In a DOCSIS-based communications system, different upstream channel descriptors (UCDs) all identify a single logical upsteam channel identifier (UCID) regardless of the type of cable modem (CM) to which the UCDs are sent. Different CMs having different capabilities (e.g., CMs configured according to the different DOCSIS standards 1.x, 2.0, and 3.0) receive their respective UCDs from an upstream headend. All the UCDs, however, refer to the same logical upstream channel. The different CMs therefore share this single logical upstream channel.

Abstract: A multiplexer/demultiplexer (MUX/DEMUX) system for multiplexing and demultiplexing information from a plurality of traffic channels is configured according to a Plesiochronous Digital Hierarchy (PDH) standard into a composite signal transferred to and from a telecommunciations interface. A PDH traffic interface receives PDH channel signals from a plurality of PDH channels and a bit-pipe interface receives bit-pipe traffic transported as a packet data stream. A composite signal generation module and interface then creates, outputs and receives a single composite serial data stream including, in a single composite format, information from the received PDH channel signals as well as the packet data stream. The rate of the bit-pipe traffic may be adaptively modulated as a function of the composite rate.

Abstract: A distributed antenna system and related methods are provided to reduce interference among wireless mobile devices in a distributed antenna system. A combiner is provided that is configured to be coupled to a plurality of remote transceiver stations deployed in a coverage area and which wirelessly transmit downlink signals to and receive uplink signals from wireless mobile devices. A plurality of input streams that carry uplink signals transmitted by wireless mobile devices are received on individually assigned signal paths from each of the remote transceiver stations. At least one parameter of an input stream received from the one or more of the remote transceiver stations is monitored. A mapping function is determined based on the monitoring. The plurality of input streams are combined based on the mapping function to produce the two or more output streams and the two or more output streams are sent to corresponding receivers in a base station.

Abstract: Systems, methods, and computer-readable media are for selectively establishing radio access bearers configured to support simultaneous voice and data communications in a mobile telecommunications network. An exemplary method includes receiving a request to initiate a data session at a mobile device that is currently engaged in a voice session and, in response to receiving the request, determining if the mobile device is capable of supporting a radio access bearer configured to simultaneously support the data session and the voice session. The method further includes allowing or denying establishment of the radio access bearer based upon the determination.

Abstract: A DTV transmitting system includes two pre-processors. The first pre-processor codes high-priority enhanced data for forward error correction (FEC) and expands the FEC-coded data. The second pre-processor codes low-priority enhanced data for FEC and expands the FEC-coded low-priority enhanced data. The DTV transmitting system further includes a data formatter generating enhanced data packets including the pre-processed data, a multiplexer multiplexing the enhanced data packets with main data packets, an RS encoder RS-coding the multiplexed data packets, a data interleaves interleaving the RS-coded data packets, and a block processor which codes each block of enhanced data in the interleaved enhanced data packets and bypasses the interleaved main data packets.

Abstract: Systems and methods for de-combining a single combined data stream into a plurality of original data streams, where each original data stream has its own timing information, and passing respective original data steams to, e.g., one or more DVB-T modulators for broadcast into, e.g., a single frequency network. The original data streams and the single combined data stream may be, e.g., MPEG-compliant data streams.

Abstract: A powerline communications device comprises a powerline communications interface and at least one other communications interface configured to communicate over a computing network. The powerline communications interface is further configured to receive electrical power. The computing network may comprise mediums including powerlines, telephone lines, and/or coaxial cables. In some embodiments, the powerline communications interface may communicate with a network apparatus, such as a personal computer, via an Ethernet interface. The powerline interface, the telephone line interface, and/or the coaxial cable interface may all be associated with the same media access control (MAC) address. The powerline communications device may receive a message via a first medium and repeat the message via a second medium based on a quality of service (QoS) metric. In some embodiments, the powerline communications device may communicate using multiple frequency bands.

Abstract: A transmitting system, a receiving system, and a method of processing broadcast signals are disclosed.

Abstract: Provided are: a multiplexing apparatus for comparing priorities, selecting multiplexed data in an arbitrary output rate, and outputting the multiplexed data; and a receiving apparatus for combining data outputted from the multiplexing apparatus in a time sequential order, and thereafter outputting the data.

Abstract: A network terminal includes an operating system on which a plurality of user environments can run in parallel, a plurality of calling units corresponding to the plurality of user environments respectively, and a plurality of cooperative units corresponding to the plurality of user environments respectively. Priorities different from one another is assigned to the plurality of user environments respectively. Each calling unit is configured to convert a first telephone signal received from an interface and a second telephone signal received from an IP telephone terminal so that an IP telephone communication is performed between the interface device and the IP telephone terminal. Each cooperative unit is configured to communicate the interface with the corresponding calling unit in response to a calling request received from the IP telephone terminal.

Abstract: An encoding device capable of realizing a scalable CODEC of a high performance. In this encoding device, an LPC analyzing unit (551) analyzes an input voice (301) efficiently with a synthesized LPC parameter obtained from a core decoder (305), to acquire an encoded LPC coefficient. An adaptive code note (552) is stored with its sound source codes, as acquired from the core decoder (305). The adaptive code note (552) and a stochastic code note (553) send sound source samples to a gain adjusting unit (554). This gain adjusting unit (554) multiplies the individual sound source samples by an amplification based on the gain parameters acquired from the core decoder (305), and then adds the products to acquire sound source vectors. These vectors are sent to an LPC synthesizing unit (555). This LPC synthesizing unit (555) filters the sound source vectors acquired at the gain adjusting unit (554), with the LPC parameter, to acquire a synthetic signal.

Abstract: MPEG video encoders and MPEG audio encoders encode video signals and audio signals, respectively. An SI/EPG data generator generates program information. A transport stream multiplexer multiplexes the program information with video data and audio data. A system controller controls the data output rates of the encoding operations and the multiplexing ratio.

Abstract: A digital broadcast transmitting/receiving system and a method for processing data are disclosed. The method for processing data may enhance the receiving performance of the receiving system by performing additional coding and multiplexing processes on the traffic information data and transmitting the processed data. Thus, robustness is provided to the traffic information data, thereby enabling the data to respond strongly against the channel environment which is always under constant and vast change.

Abstract: A plurality of programs are statistically multiplexed using a statistical multiplexing (stat mux) system. Rchannel, a constant total bit rate for the plurality of programs, is determined. Cl,Ff,picTYpe, a complexity for each picture in the plurality of programs, is determined. Tl,Ff,picType, a bit allocation for each picture in the plurality of programs, is determined based on Cl,Ff,picTYpe and Rchannel. The plurality of programs are encoded using a plurality of encoders, a combined encoder buffer, and Tl,Ff,picType to form a plurality of variable bit rate (VBR) compressed bit streams. The plurality of VBR compressed bit streams are multiplexed to form a single constant bit rate (CBR) bit stream.

Abstract: A first header-attaching unit attaches to data of a low speed bit rate A, a header of the bit rate A. A second header-attaching unit attaches the header of the bit rate A to data of a high speed bit rate B. A combining unit combines outputs of the first and the second header-attaching units. A low speed scrambling unit performs a scrambling process on combined data by using a clock corresponding to the bit rate A. A high speed scrambling unit performs a scrambling process on the data of the bit rate B by using a clock corresponding to the bit rate B. During a timing corresponding to the bit rate A in the frame, a selector selects an output of the low speed scrambling unit. During a timing corresponding to the bit rate B in the frame, the selector selects an output of the high speed scrambling unit.

Abstract: The invention relates to a communications node (10) for routing an optical signal 5 comprising at least one data packet, the node (10) having an input optic fiber (12) and an output optic fiber (14) in communication with each other, the input optic fiber (12) in communication with an optical splitter (20) which is arranged to split an incoming optical signal into at least two substantially identical optical signals, the optical splitter (20) further arranged to pass one of the optical signals to an optical correlator (22) and the other of the optical signals to an input optical switch (24), the optical correlator (22) being arranged to compare an address of the packet with a reference address (40) and to generate a trigger if the reference address (40) matches the address of the packet, the input optical switch (24) being arranged to route the data packet to an optical to electrical converter (28) in response to the trigger.