摘要:
An image coding method codes each block of a digital image divided into two-dimensional blocks, each block having a plurality of pixels. A coding mode for a target block is determined to output mode information of the target block. A codeword of the mode information of the target block is output, the codeword being determined based on a combination of the mode information of the target block and the mode information of previously coded blocks at a periphery of the target block, or a combination of the mode information of the target block and temporary mode information replacing the mode information of the blocks at the periphery of the target block when the blocks at the periphery are out of an image. Pixel data in the target block is coded according to the mode information of the target block.
摘要:
In a mobile network system composed of a mobile network with a mobile router and a terminal interconnected, and of a home agent, when the mobile router connects to an external network, the mobile router informs the home agent of path information to the mobile network including the mobile router. Receiving the path information, the home agent inquires the mobile router in the home network whether or not the mobile router connects to the mobile network informed. Then, the home agent advertises path information to this mobile network only when the mobile router connecting to the mobile network does not exist. Accordingly, the home agent can rapidly switch to an optimum path to the external network.
摘要:
In a mobile network system composed of plural mobile networks and a home agent, the home agent inquires mobile routers in a mobile network whether or not a terminal is connected, if detecting the absence of the terminal, when data addressed to the terminal arrives at a home network of the terminal in the mobile network. Responding to this inquiry, the mobile routers search whether or not the terminal is connected to the own mobile networks. If the terminal is connected, the mobile routers inform the home agent of the presence of the terminal. When receiving this notice, the home agent transfers data addressed to this terminal to a mobile router as a notice source. This process, even if a terminal moves to a mobile network having a same network prefix as that of the home network, allows transferring a packet accurately to the terminal.
摘要:
In a home agent device, a message reception unit receives a request of deleting a registration of a mobile router device which has become in a non-connection state, a binding cache registration deletion reception unit judges that it is for deleting a mobile router device which is not a transmission source, and if a mobile router device of the transmission source has the authority of deleting the registration of the target mobile router device, a proxy deletion reception judgment unit deletes the registration of the requested mobile router, therefore, it can be prevented that packets are transmitted to the mobile router device which has become in the non-connection state.
摘要:
When the routing function of router becomes disabled, a routing stop message is multicast to all terminals and another router in a LAN. If another router can provide the routing function, a routing start message is multicast to all terminals and the other router in the LAN. This method allows the terminals in the LAN to switch the default router at a predetermined timing according to both messages, thus minimizing the default router switching delay time and the packet loss.
摘要:
A router device includes a VRRP (Virtual Redundancy Router Protocol) realizing a virtual router device for operating a plurality of router devices virtually as one router device. The router device further includes a virtual router processing section for executing virtual router processing and a virtual router information processing section for extracting virtual router information upon reception of a virtual router information message and performing setting necessary for operation as a virtual router. When performing a new connection to a local area network, the virtual router information can be automatically set. Thus, it is possible to significantly reduce the load required for building a virtual router system by manual setting conventionally performed by a management operator.
摘要:
A mobile router device connects a mobile network containing several terminal devices and moving in a backbone network with the backbone network. The mobile router device includes: means for deciding whether to operate as a master router which is a router for actually connecting the mobile network with the backbone network; means for recording a virtual address, a care of address which is an address that the mobile router can use at the moving destination; and means for generating and transmitting a binding update message for correlating the virtual address to the care of address when the mobile router device operates as the master router.
摘要:
In the present invention, in updating a program stored in rewritable nonvolatile memory such as Flash ROM, a program portion in a block in the nonvolatile memory is expanded in RAM which includes a portion needing an update of the program stored, and only the portion needing the update is instructed from the outside and updated among the expanded program portion. Then, the block in the nonvolatile memory is erased, and the program portion updated in the RAM is recorded again in the erased block in the nonvolatile memory.
摘要:
An image decoding method is provided for decoding each block of a digital image divided into a plurality of blocks, from a coded image signal including codewords of the block and codewords of coding mode information of the block. The method comprises separating the codewords of a target block and the codeword of coding mode information of the target block from the coded image signal, and decoding the coding mode information of the target block from the separated codeword of the coding mode information using a codeword table. The codeword table is selected from a plurality of codeword tables by referring to a combination of coding mode information of previously decoded blocks at the periphery of the target block, the codeword tables each having codewords, each codeword being determined based on a combination of coding mode information of previously decoded blocks at the periphery of the target block. The method further comprises decoding pixel data of the target block from the separated codewords of the target block, based on the decoded coding mode information of the target block.
摘要:
An image coding method for coding each block of a frame of a digital image divided into a plurality of blocks is provided, where each block has a plurality of pixels, the method comprising determining a coding mode for a target block to output mode information of the target block, coding the mode information of the target block using the mode information of at least one previously coded block of the frame at the periphery of the target block, and coding the digital image in the target block according to the mode information of the target block.