Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Panasonic Corporaton

Matsushita Electric Ind., Ltd.

Seiji Horii

Makoto Hagai

Yoshinori Matsui

Tatsuya Ohnishi

Hideaki Fukushima

Akihiro Miyazaki

Daisuke Murakami

Yuji Takai

Yoshiharu Watanabe

Mikio Shimazu

Akinori Tatsumi

Mitsuhiro Suzuki

Takako Hirose

Hiroaki Iwamoto

Tetsuji Kishi

Takuya Kobayashi

Takahide Baba

Takayuki Hamaki

Masahide Morozumi

Jun Yamaguchi

A data transmission apparatus including a receiving unit for receiving transmitted packets; a priority decision unit; a retransmission packet storage unit; a retransmission instruction receiving unit for receiving a retransmission request from a terminal at the receiving end; a retransmission decision unit; a transmission queue management unit; and a transmission unit.

Data transmission method and data transmission apparatus

An access request arbitration section, a data amount management section and a resource control section are provided between a plurality of masters and a shared resource. The data amount management section manages access data amounts passing between the plurality of masters and the resource. The access request arbitration section executes arbitrary arbitration of issuing access permission to a master determined according to the access data amount at any timing, in addition to periodic arbitration of issuing access permission to any of the masters at fixed-interval arbitration timing. If an access request of less than a defined data amount is granted in periodic arbitration, the remaining access chance can be used in arbitrary arbitration.

Resource management device

A data transmission apparatus for relaying data transmitted from the transmitting end in units of packets, each packet having additional information relating to its sequence number, priority and data reproduction time, comprises: a receiving unit for receiving packets transmitted from the transmitting end; a priority decision unit for deciding the priority of each of the received packets; a retransmission packet storage unit for storing packets the priorities of which are equal to or higher than a predetermined value, as retransmission packets, on the basis of the priority of each packet decided by the priority decision unit; a retransmission instruction receiving unit for receiving a retransmission request from a terminal at the receiving end; a retransmission decision unit for deciding whether retransmission of the packet for which the retransmission request has been made should be performed or not, on the basis of the retransmission request and the storage status of the retransmission packets in the retransmission packet storage unit a transmission queue management unit for setting the transmission order of the received packets and the packets which have been decided as packets to be retransmitted, on the basis of additional information which is given to each packet; and a transmission unit for transmitting the data of these packets in the transmission order set by the management unit. Therefore, the transmission quality in a radio section in real-time transmission is improved and, further, the number of retransmission times is reduced.

Retransmission packet structure having multiple sequence numbers

A resource management device of the present invention, used in a system where at least one bus master is connected to each of a plurality of buses, includes: a bus arbitration section for arbitrating an amount of access to be made from the buses to a shared resource; an arbitration information management section for managing, as bus arbitration information, a bus priority order and a highest access priority pattern for ensuring a predetermined access bandwidth to the shared resource for each bus for an arbitration operation by the bus arbitration section; and a resource control section for controlling, based on characteristics of the shared resource, an access to the shared resource from the bus whose access request has been granted by the bus arbitration section. Thus, it is possible to guarantee a minimum bandwidth for access to the shared resource for each of the plurality of bus masters.

Resource management device for managing access from bus masters to shared resources

In a data transmission method of the present invention, not only when relay of input packets is performed but also transmission of a retransmission packet or a correction packet is performed, changes in an output rate due to output rate control is suppressed, and data transmission is efficiently performed according to a capacity of an output channel. A data transmission device comprises a packet priority decision unitfor deciding priorities of input packets, a retransmission packet, and an FEC packet, an output delay calculation unitfor calculating a delay time until data of the respective packets is reproduced by a receiving terminal, and an FEC packet generation unitfor generating an FEC packet containing an error correcting code which corresponds to a packet designated on the basis of the priorities of the respective packets. When transmission of the retransmission packet and the FEC packet together with the input packets is performed, lower priority packets corresponding to a size of packets which are additionally transmitted are thinned out.

Data transmission method

Data transmission method, data transmission apparatus, data receiving apparatus, and packet data structure

In a radio communication system for performing digital radio communications by using time-division multiplexed time slots, a first personal station receives its user's speech through the microphone, converts it into audio data, and transmits them on time slots to a second personal station. On the other hand, the first personal station receives non-audio data from the data processor connected with the second personal station and stores. When the audio data amount inputted to the first personal station in a unit time period is lower than a threshold and the communications between the first personal station and the second personal station are put in a silence condition, the first personal station transmits non-audio data on times slots to the second personal station. When the communications return to a sound condition, audio data transmission is restored. Whether each time slot carries audio data or non-audio data is designated by an identifier which is written in a predetermined field of each time slot.

Digital radio communication system with efficient audio and non-audio

The caller personal station of the present invention includes the following units: a channel search unit for scanning the plurality of communication channels to search for an unoccupied channel and regarding the unoccupied channel as a multicast channel; and a simultaneous call unit for repeatedly transmitting a simultaneous call frame on the multicast channel for a first predetermined time period, the simultaneous call frame indicating a simultaneous call to the other personal stations; a multicast unit for transmitting multicast frames on the multicast channel when a second predetermined time period has passed, the multicast frames containing data to be multicast. On receiving the simultaneous call frame by sequentially sensing the plurality of communication channels, the other personal stations enter a receiving state of multicast frames on the multicast channel. The simultaneous call unit includes the following units: a simultaneous call frame generation unit for generating the simultaneous call frame; a transmission timer for counting the first predetermined time period and generating a time-out; and a simultaneous call frame transmission unit for repeatedly transmitting the simultaneous call frame on the multicast channel from a start of counting the predetermined time period until the time-out is generated.

Caller personal station equipped with simultaneous call function and

A cell station and a personal station at a sender's end in the cell station's radio zone which carry out digital radio communication and monitors whether wave condition is good or bad by calculating a generation rate of errors. When the wave condition is good, data links are established between the cell station and the personal station at the sender's end, and between the cell station and the personal station at the opposite end. Information signals are sent and received through the data links. When the wave condition is good, control delay by processing of layer 2 can be prevented. (Effect) The speed of the digital radio communication increases while the reliability of sending and receiving information signals is ensured.

Cell station and personal stations in a digital radio communication

Growing community of inventors

Kashiwara, Japan

Seiji Horii