Abstract:
A network processing node (e.g., MGW, MRFP) and method are described herein that can: (1) receive packets on a first heterogeneous link (e.g., wireless link); (2) manipulate the received packets based on known characteristics about a second heterogeneous link (e.g., "Internet" link); and (3) send the manipulated packets on the second heterogeneous link (e.g., "Internet" link). For example, the network processing node can manipulate the received packets by adding redundancy, removing redundancy, frame aggregating (re-packetizing), recovering lost packets and/or re-transmitting packets.
Abstract:
In packet communications that employ header compression/decompression, the computational complexity of checksum generation can be reduced by re-using static checksum information associated with header bits (S) that do not change from header to header. The static checksum information can be used together with information about header bits (T) that do change from header to header, in order to generate a desired checksum (CS). The checksum can then be used to verify a reconstructed header (17) produced from a compressed header by a header decompressor.
Abstract:
Techniques for discontinuous transmission (DTX) and fast in-band signaling of configuration changes and protocol messages in speech communications systems provide cost efficiency in terms of radio transmission capacity, in terms of fixed line transmission, and in terms of implementation effort. An exemplary method for performing discontinuous transmission (DTX) in a communications system in which source data is interleaved for transmission from a first component in the system to a second component in the system includes the steps of detecting periods of source data inactivity, and transmitting silence descriptor (SID) frames from the first to the second component during the periods of source data inactivity, certain of the transmitted SID frames being interleaved using a different interleaving algorithm as compared to that used for source data. For example, the source data can be block diagonally interleaved, and certain of the SID frames can be block interleaved. An exemplary method for effecting configuration changes in a communications system includes the step of transmitting an escape frame in place of a speech data frame, the escape frame including a gross bit pattern to distinguish the escape frame from speech data frames and conveying a configuration change indication. The escape frame can further include a data field to indicate a particular configuration change to be made. For example, where the communications system is an AMR system, an escape frame can be used to change an active codec mode set. Alternatively, an escape frame can be used to change a phase of codec information.
Abstract:
A command memory stores commands in memory words. Each command has a label field and an action field. The commands are consolidated to reduce the amount of information stored in the command memory. A control unit interprets the commands and restores the order that was removed by the consolidation. The control unit arranges the action fields as commands in a control word based on information in the label field. When the commands are compressed in the command memory, commands that are not performed in parallel can be stored in the same memory word. Commands that are performed in parallel can be stored in different memory words. The order of the commands in the control word is determined by information in the label field, such as whether the command is performed in parallel with a preceding command. Groups of commands that are decoded to form time-sensitive control words or control words that are the target of jump commands are aligned with a memory word boundary so that the commands forming the control word can be read during a single clock cycle. The group of commands can be aligned with a memory word boundary by inserting a special code or an illegal command in the previous memory word. Commands can be positioned within a group of commands so as to further reduce the size of the command memory. If a conditional command is the first command in a group of commands, the condition applies to all the commands in the group. If a conditional command is not the first command in a command sequence, the condition applies to only the immediately preceding command.