213 results about "Backward channel" patented technology

A method for controlling errors in a wireless link layer using a simultaneous multiple copy scheme and an adaptive forward error correction (FEC) scheme in a wideband wireless communication is provided. The method for controlling errors in a link layer in wideband wireless communication using an automatic repeat request (ARQ) scheme, in which a wideband wireless channel is used for communication between a first node and a second node, includes the steps of (a) estimating the error ratio of a forward (a direction in which a cell is transmitted from the first node to the second node) channel using the state of a backward (a direction in which a cell is transmitted from the second node to the first node) channel, and transmitting a cell, in which a forward error correction (FEC) code having an encoding ratio that varies depending on the estimated error ratio is included in a protocol data unit (PDU) of a wireless link layer, through the forward channel and (b) re-transmitting the copy of a cell transmitted in the step (a), when feedback information that indicates that an error exists in the cell transmitted in the step (a) is received through the backward channel. It is possible to reduce the number of times of re-transmission by improving the probability of correcting forward errors using more error controlling bits as the state of the channel is worse and to minimize the waste of resources using less error controlling bits as the state of the channel is better, to thus obtain the optimal performance and guarantee the minimum delay time.

Various embodiments are described to coordinate a wireless network over a power line network or other wired back channel.

In an overlay Wireless Location System, an Abis interface is monitored to obtain information used to locate GSM phones. Signaling links of the Abis interface are passively monitored to obtain certain information, such as control and traffic channel assignment, called number, and mobile identification, which is not available from the GSM air interface of the reverse channel. This approach also applies to IDEN and can include CDMA systems where the GSM architecture has been used and the system includes a separated BTS to BSC interface.

The present invention solves the above problems by attaching a cellular phone receiver to the set-top-box. This cellular phone receiver has a modem to transmit data between the subscriber's box and a cellular network. The cellular network may relay the data to the pay-television distributor. Other features and advantages of the present invention will become apparent from the following detailed description of the invention and the accompanying drawings.

A proxy mobile station for retransmitting reverse channel signals from a mobile station to a base station of a wireless network. The proxy mobile station comprises: 1) a controller for receiving reverse channel data to be transmitted to the base station and transmitting the reverse channel data using an assigned mobile station identifier associated with the mobile station; and 2) a radio frequency transceiver for up-converting the encoded reverse channel data for transmission to the base station. The assigned mobile station is modifiable and may be modified by an external control device.

A precoder and a precoding method in a multiuser multi-antenna system are provided. The precoder includes a channel checker for determining a DownLink (DL) channel condition of terminals in a service coverage area, a pre-compensator for pre-compensating, for channel distortion, signals to be sent to the terminals when a nonlinear algorithm is selected based on the channel condition of the terminals, and an interference remover for canceling interference in a channel by multiplying the pre-compensated signals by inverse channels of the terminals, and for canceling interference between the terminals. Accordingly, the pre-equalization can be carried out without global channel state information, and an increase of the transmit power can be prevented in the permutation.

An apparatus and method for transmitting Walsh information over a packet data control channel in a base station of a mobile communication system that transmits packet data and has the packet data control channel for transmitting control information related to transmission of packet data. Receivers decode reverse ACK channel (R-ACKCH) signals received from corresponding mobile stations, and count the number of NAKs from the decoded information. A Walsh mask broadcasting controller receives the number of NAKs from the receivers, and outputs a Walsh mask information broadcasting enable signal if the number of NAKs is larger than a predetermined threshold. A transmitter generates and broadcasts Walsh mask information of the base station upon receiving the Walsh mask information broadcasting enable signal.

The present embodiments provide methods and systems for use in controlling and / or optimizing resource usage of reverse channel (142) wireless communications. Some embodiments determine a starting time (1014) of an access channel slot (628) of a reverse channel. Prior to the starting time of the slot, resource usage is reduced (1024) for reverse channel resources by at least one of a plurality of communications over the reverse channel. Upon detecting an absence (1030) of an access channel communication the resource usage of at least one of the plurality of communications over the reverse channel are increased (1034). Some methods provide for the transmitting of non-access channel communications over a reverse channel and determine an offset threshold (1222) defined by a time duration (632, 648) prior to a starting time of an access channel slot. Upon detecting an occurrence of the offset threshold, transmission resource usage of the non-access channel communication is reduced (1228).

A communication infrastructure for a data processing apparatus, and a method of operation of such a communication infrastructure are provided. The communication infrastructure provides first and second switching circuits interconnected via a bidirectional link. Both of the switching circuits employ a multi-channel communication protocol, such that for each transaction a communication path is established from an initiating master interface to a target slave interface, with that communication path comprising m channels. The m channels comprise one or more forward channels from the initiating master interface to the target slave interface and one or more reverse channels from the target slave interface to the initiating master interface, and handshaking signals are associated with each of the m channels. The bidirectional link comprises n connection lines, where n is less than m, the bidirectional link supporting a first communication path from the first switching circuit to the second switching circuit and a second communication path in an opposite direction from the second switching circuit to the first switching circuit. Control circuitry is used to multiplex at least one forward channel of the first communication path and at least one reverse channel of the second communication path, with the multiplexing being performed in dependence on the handshaking signals associated with the channels to be multiplexed. This allows the 2m channels formed by the first and second communication paths to be provided by the n connection lines of the bidirectional link.

Network endpoints using TCP / IP operate to determine the maximum transmission unit (MTU) of the path between them. This determination is done so as to avoid the expensive IP fragmentation that will occur when transitting links with a smaller MTU size. The standard method of determining the path MTU (PMTU) has several known deficiencies, including: inefficient use of bandwidth as proper operation will likely result in the loss of one or more packets and difficulty of implementation as the reverse channel communication mechanism, reception of ICMP messages indicating the discarding of unfragmentable packets, is frequently blocked by firewalls and other security apparatus. A method of determining the PMTU between intermediate proxies is disclosed that does not require reception of ICMP messages or the inefficient use of bandwidth due to the presumed dropping of packets with valid data.

A method of efficiently assigning a plurality of reverse HARQ channels to an MS in a BS in a mobile communication system supporting HARQ is provided. To transmit reverse data to the BS, the MS transmits a reverse data rate request message to the BS, receives from the BS one grant message containing a reverse data rate, and transmits to the BS different packet data at predetermined intervals at the reverse data rate on a packet data channel.

A system and method for remote device registration, to monitor and meter the injection of keying or other confidential information onto a device, is provided. A producer who utilizes one or more separate manufacturers, operates a remote module that communicates over forward and backward channels with a local module at the manufacturer. Encrypted data transmissions are sent by producer to the manufacturer and are decrypted to obtain sensitive data used in the devices. As data transmissions are decrypted, credits from a credit pool are depleted and can be replenished by the producer through credit instructions. As distribution images are decrypted, usage records are created and eventually concatenated, and sent as usage reports back to the producer, to enable the producer to monitor and meter production at the manufacturer.

A method of performing lawful interception of a multimedia call between two or more terminals. The method comprises detecting the initiation of said call at monitoring equipment located in the call path, and forwarding from the monitoring equipment to a gateway, parameters defining at least one of the forward and reverse channels of said call. At least one multimedia call is set up from said gateway to a monitoring terminal in dependence upon the received parameters. Following the setting up of the first mentioned multimedia call, forward and / or reverse channel data is intercepted at said monitoring equipment, the intercepted data routed to said gateway, and the data transmitted to the monitoring terminal over the forward channel of the or each second mentioned multimedia call.

Techniques are disclosed for passing Extended Display Identification Data (EDID) or Enhanced-EDID (E-EDID) in an uncompressed multimedia communication system including a video sink side communicatively coupled to a video source side. An EDID AVAILABLE packet is communicated via a serial backward channel from the video sink side. A REQUEST is communicated to the video sink side via a serial forward channel to indicate the video sink side can send the EDID data. The EDID data is then communicated to the video sink side via the serial backward channel.

A serial transmission protocol and architecture are provided that can be used to transmit uncompressed multimedia (e.g., video / audio / control data) over a high speed serial forward communication channel. A backward channel is also provided, for communicating control data. The protocol is implemented with a flexible packet format that supports all different modes of video data, and also supports 24 bit and 30 bit video data (or higher). An example application where the architecture and protocol can be used is a home entertainment multimedia system. A mechanism to implement EDID pass-through and protocols such as HDCP is also provided.

A serial transmission protocol and architecture are provided that can be used to transmit uncompressed multimedia (e.g., video / audio / control data) over a high speed serial forward communication channel. A backward channel is also provided, for communicating control data. The protocol is implemented with a flexible packet format that supports all different modes of video data, and also supports 24 bit and 30 bit video data (or higher). An example application where the architecture and protocol can be used is a home entertainment multimedia system. A mechanism to implement EDID pass-through and protocols such as HDCP is also provided.

Disclosed is a method for reporting channel state information between a mobile station and a base station to the base station by the mobile station in a mobile communication system. The method includes the steps of mapping the channel state information to a value stored in a channel state information table. The mapping is determined by a range of traffic-to-pilot ratio (TPR) values. The TPR values are determined according to an encoder packet site packet data rate relation. The mapping is then transmitted to the base station.

A disclosed radio relay apparatus receives signals from a transmitter via multiple receive antennas and transmits relay signals derived from the received signals to a receiver via multiple transmit antennas. The apparatus includes a channel estimation unit configured to estimate a forward channel matrix H1 representing radio channel characteristics between the transmitter and the radio relay apparatus and a loop channel matrix G representing interference occurring in the relay signals due to concurrently transmitting and receiving signals at the radio relay apparatus, a weight optimization unit configured to derive a canceling matrix C through iterative operations using the forward channel matrix H1, the loop channel matrix G and a backward channel matrix H2 representing radio channel characteristics between the radio relay apparatus and the receiver, and a feedback compensation unit configured to subtract a signal weighted in accordance with the canceling matrix C in a feedback path from a relay signal in a main signal path to adjust the relay signal.

A system and a method for channel equalization are provided. A linear equalizer using a continuous-time linear equalization and a decision feedback equalizer using a discrete-time decision feedback equalization are integrated together from a hybrid receiver equalizer. The continuous-time linear equalization scheme and the discrete-time decision feedback equalization scheme are blended using a joint adaptation algorithm to form an equalization scheme for inter-symbol interference cancellation in the hybrid receiver equalizer. The hybrid receiver equalizer controls crosstalk while maintaining signal bandwidth and linearity of a signal by the high-order high frequency roll-off of the linear equalizer used. Using this configuration, the hybrid receiver equalizer eliminates the need for adaptive bandwidth controller used in conventional low-pass receiver equalization schemes. The hybrid receiver equalizer can be used in receivers for dual-speed simultaneous transmission on the same physical link. The hybrid receiver equalizer can also be used in receivers for simultaneous forward and back-channel transmission using differential-signaling in multi-Gbps transceivers.

A repeater for re-transmitting signals between first and second wireless devices. The repeater comprises a first antenna array for receiving a forward channel signal transmitted from the first wireless device and a second antenna array for receiving a reverse channel signal transmitted from the second wireless device. The repeater also comprises a first transceiver chain for down-converting the received forward channel signal, processing the down-converted forward channel signal, and up-converting the processed forward channel signal to thereby produce an outgoing forward channel signal. The repeater also comprises a second transceiver chain for down-converting the received reverse channel signal, processing the down-converted reverse channel signal, and up-converting the processed reverse channel signal to thereby produce an outgoing reverse channel signal. The first antenna array comprises a first antenna element and the second antenna array comprises a second antenna element that is cross-polarized with respect to the first antenna element.

Infrared control signals are repeated and communicated in a system including a source device and a sink device that are communicatively coupled by a serial communication link that includes a forward channel and a backward channel. Modulated infrared remote control data is detected by an infrared detector without de-modulation, and sampled in modulated form. Sampled data corresponding to the modulated remote control signal is transmitted from the sink device to the source device over the serial communication link, which in one example is a single optical fiber. The source device receives the sampled data and regenerates the infrared control data, which is then used to control the operation of the source device.

Disclosed is a ring type wavelength division multiplexing (WDM) passive optical network (PON) system using the same wavelength for forward and backward channels while inexpensively implementing a redundancy function, and a switching media converter usable in the ring type WDM PON system. The WDM PON system provided a redundancy function to each node, so that the central office of the system can have a simplified architecture. Accordingly, there is an advantage in that the construction costs of the central office can be reduced. And, the network construction costs can be minimized because it is possible to provide a desired redundancy to a part of the nodes, taking into consideration the significance of each node.

Data such as high definition (HD) video may be sent from a transmitter such as a laptop computer to a receiver such as a video projector using a 60 GHz (and, hence, inherently directional, short range, and thus secure) forward channel wireless link. Encryption information such as encryption keys are also exchanged over the forward channel link. The encryption information is used to encrypt control signals that can be exchanged over a reverse channel link that may operate at a frequency of 2.4 GHz.

The invention discloses a interference detecting method, resource distributing method and device in frequency division multiple access system. The interference detecting method in the invention includes following steps: said system includes several geography areas, useful frequency band of reversed channel in the area are divided into at least two sub-bands; detecting the interference of said sub-bands; Sending the interference detecting result information of said sub band. With the invention, AT can obtain more accurate reversed channel interference information. So, AT decides the emitting power based on every sub band, the character of frequency selecting can be used to improve performance; considering the resource interfered little is distributed to AT, the sub band with big interference is avoided to improve the performance of AT, and the interference between the sector / area is decreased.

In accordance with the present invention, a radio frequency identification (RFID) tag for use with an RFID system which includes one or more RFID tag readers, includes a tag communication device adapted to communicate with each of the one or more tag readers, a one-way hash function stored on the RFID tag, and a memory having stored therein a metaID. The tags may be locked and unlocked. The system includes a reader and a database. The system communicates with the tags via a forward channel and a backward channel. The present invention can singulate one tag from several responding tags and acquire the ID for the singulated tag.

A system and method for pausing communications from a transmitting radio for a certain period of time in order to allow transmission of other messages. When a first radio determines that a message needs to be transmitted either to a second radio or the transmitting radio, the first radio determines whether there are any available forward channels to transmit the call. If no forward channel is available, the first radio determines a period of time required to transmit the message and sends, on a reverse channel, a “request to pause” signal to the transmitting radio identifying that period of time. Upon receiving the “request to pause” signal, the transmitting radio ceases transmission on the forward channel for the specified period of time, during which time the first radio transmits the message.

Disclosed is a wireless communication system for providing a service in a time division duplexing (TDD) mode and a frequency division duplexing (FDD) mode according to a duplexing mode determination factor of a mobile station in a base station communicating with the mobile station. During call setup, the mobile station transmits the duplexing mode determination factor to the base station, sets a TDD mode or an FDD mode as a reverse mode set by the base station, and sets up a channel for the set reverse mode and a forward channel to perform communication. During call setup, the base station receives the duplexing mode determination factor from the mobile station, sets a reverse mode to the TDD mode or the FDD mode using the received duplexing mode determination factor, and sets up a reverse channel for the set mode and a TDD mode for forward transmission to communicate with the mobile station.