387 results about "Robust Header Compression" patented technology

A demultiplexer 630 routes only one or more transport stream packets with a single packet identifier value to each physical layer pipe. A header compression unit 620 replaces the packet identifier of the transport stream packet with a short packet identifier of one bit length indicating at least whether the transport stream packet is a NULL packet.

The invention is a method of relocating of header compression/decompression functions between a plurality of network entities and mobile compressors and/or mobile decompressors. A method of communication in a packet network which transmits packets having compressed headers in accordance with the invention includes establishing a connection between a first network node and a second network node including storing context information used with compression and decompression of the headers of the packets at the first and second nodes; and changing the connection between the first network node and the second network node to a connection between the second network node and a third network node including transferring the context information representative of the context information stored by the first node to the third network node which is stored by the third node as the context information of the third node and using the stored context information at the second and third nodes for compression and decompression of the headers of the packets at the second and third nodes.

Compression of inner headers of IPSec tunnel packets is achieved by storing an inner IP header and an inner protocol header in a context sub-table associated with the security association database entry at a destination tunnel device. IPSec tunnel packets having compressed inner headers may be identified by the LSBs of the SPI number in the IPSec header. The SPI number may also identify whether the IPSec tunnel packet is a TCP packet. A portion of padding in the encapsulated portion may identify a particular context sub-table used for decompressing the inner headers. The context sub-table may be updated as portions of the inner headers change.

A compression context for a plurality of packets is established with a receiving device. Each of these packets is associated with one or more reliable multicast protocols, such as the Layered Coding Transform (LCT) protocol, the Asynchronous Layered Coding (ALC) protocol, the FLUTE protocol, the MUPPET protocol, and the NACK-Oriented Reliable Multicast (NORM) protocol. Upon establishment of the compression context, a compressed packet is generated for one of the plurality of packets and transmitted to the receiving device. The compressed packet has a reduced number of bits in its header. Upon receipt, the receiving device decompresses the compressed packet based on the compression context.

A UMTS (Universal Mobile Telecommunications System) core network supports a compression framework that provides for header compression of General Packet Radio Service Tunneling Protocol (GTP)-Encapsulated Packets. In particular; the GTP/UDP(User Datagram Protocol)/IP(Internet Protocol) header is compressed. In addition, the UMTS core network also supports RTP(Real Time Protocol)/UDP/IP header compression independent of the GTP/UDP/IP header compression.

Some embodiments relate to a network comprising two RBridges connected by a link where the two RBridges are not the ingress and egress RBridge for said frames, wherein said RBridges automatically exchange information as to their support of hop-by-hop reversible frame aggregation, reversible header compression, and reversible data compression, and wherein if both RBridges support any or all of these features in the same fashion, one or more of said features are automatically applied to appropriate frames at the transmitting RBridge and removed at the receiving RBridge, increasing the throughput of the link.

A method for communicating video data on a wireless channel in a packet-switched network includes the steps of operating at a wireless terminal a compression in packets on the video data during a video coding operation, detecting wireless channel conditions and adapting control parameters of the video coding operation to the detected wireless channel conditions. The compression operation is a robust header compression operation and the step of adapting control parameters of said video coding operation is performed in dependence of information about the wireless channel conditions detected on a feedback channel made available in a decompression step associated with the compression operation.

The invention concerns the bit error resilience of an IP protocol stack based on a secure link layer, in which packet flows are header compressed according to a suitable header compression standard. According to the invention, by analyzing each packet at the link layer it can be determined whether the packet is a full header packet, in which case the link layer checksum evaluation is used as normal for discarding faulty full header packets, or a header compressed packet in which case the link layer checksum evaluation is ignored and the packet is propagated upwards in the protocol stack. This solution not only opens up for more intelligent higher-level handling of faulty header compressed packets, but also solves the problem of properly protecting full header packets at the link layer. In order to compensate for ignoring the link layer checksum evaluation for header compressed packets, header protection is introduced at the header compression level of the link layer by using one or more local checksums. The invention is particularly applicable to delay-sensitive real-time data such as compressed voice or video.

A mobility header compression method and system for an IPv6-based LoWPAN is provided for supporting IPv6 mobility to the IPv6-based LoWPAN checks a packet carrying data and a first and a second headers containing transmission information about the data to determine whether the second header contains a compressed Internet Protocol version 6 (IPv6) information. When the second header contains a compressed IPv6 information, ands followed by a mobility header, a mobility support-indicative field of the first header is set to indicate that the second header is followed by the mobility header and the rest of the fields of the second header are compressed except for the mobility header-indicative field. A mobility information-indicative field of the mobility header is set to indicate inclusion of mobility information; and the rest of the fields of the mobility header are compressed except for the mobility information-indicative field.

A method of relocating the header compression context in a packet network which transmits packets having compressed headers. A connection is established between a mobile terminal and a first network entity and context information used with compression and decompression of the headers of the packets is stored at the mobile terminal and the first network entity. The context information updating is stopped in the mobile terminal and in the first network entity and after that, a snapshot of the compression and decompression context information is taken and stored in the first network entity. The connection between the first network entity and the mobile terminal is changed to a connection between the mobile terminal and a second network entity. The context information snapshot stored by the first network entity is transferred to the second network entity to be stored therein as the context information of the second network entity. The stored context information at the mobile terminal and the second network entity is then used for compression and decompression of the headers of the packets.

A system and method for ATM header compression for DSL links is provided. One embodiment, among others, for compressing ATM headers for communication across an ATM network involves transmitting an initial full ATM header to a receiver in the ATM network. Thereafter, when data payloads are available for transmission, the ATM header that corresponds to the data payload is compressed by either a differential technique, dictionary technique, or a multi-cell technique. The compressed ATM header and the data payload are then communicated over the ATM network to the receiver, wherein the receiver is enabled to interpret the compressed ATM header accordingly. By compressing the ATM header, a greater number of ATM cells may be communicated in the ATM network than if the ATM header were communicated in an uncompressed format.

An improved aggregation scheme for wireless multi-hop mesh networks is disclosed. An aggregator at each node operates to merge VoIP packets at an ingress/source node with a forced delay, but at an intermediate node aggregated packets are either sent directly to their destination or to the next hop without deaggregation. A novel compression mechanism for compressing and decompressing the aggregated packets is also disclosed.

A method and system for communicating header compression layer control messages. Header compression control messages are generated by a header compression layer and are sent through at least one link layer data packet by a link transport communications protocol layer to a remote receiver. The link transport communications protocol layer monitors receipt of link layer data packet acknowledgements that are received from the link transport communications protocol layer of the remote receiver for the at least one link layer data packet. The link transport communications protocol layer determines successful transmission of the header compression control message and provides, to the header compression layer, an indication of successful header compression control message transmission.

The invention is related with network communication, in particular wireless networking. In order to improve bandwidth utilization, a header compression protocol is implemented in most wireless network systems, such as robust header compression ROHC for WLAN systems. When using multicast groups for data communication problems with ROHC are related with relative late initiation of stations that newly enter the multicast group. The invention proposes an improved state machine for the compressor in order to overcome this drawback. It is also proposed an improvement for the decompressors which omit sending positive acknowledgements in order to further improve compression efficiency. The invention also concerns an accordingly improved method for the exchange of data packets in a network of distributed stations.

A method is disclosed for transmitting and receiving packetized data having multiple protocol headers in a packet data communication system. An operating state of a network is determined, and a period for transmitting a full packet is decided according to a result of the determination. Full packets having uncompressed headers are transmitted during periodic transmission times according to the decided full-packet transmission period, and compressed packets are transmitted in other transmission times. If the operating state of the network is decided to be a congested state according to an average packet retransmission ratio produced in a period for measuring the operating state of the network, the full-packet transmission period is set to “1”. A value of the full-packet transmission period in an unloaded state is twice a value of the full-packet transmission period in a normal state. Thus, the number of packets to be discarded due to packet loss can be reduced, and the efficiency of transmission can be improved by header compression technologies.

A method of reducing the bandwidth required to send traffic comprising a payload and a header originating in a first communications network over another communications network. The traffic is characterized by having header information from which a path from its source to destination can be predetermined, the method comprising: determining redundant header information which is not used for forwarding the traffic in the other network; replacing at least part or all of the redundant header information with compression information having a smaller bandwidth than the replaced header information; appending header information to the traffic to enable forwarding along the path in the other network to an egress node; at the egress node, processing the traffic to remove the appended header information and restore the replaced header information by removing the compression information and using the compression information to perform a look-up operation which retrieves the replaced redundant header information from a data store, wherein the same compression information is used to replace the same redundant header information for all the traffic having the same predetermined path; compression information comprising a dummy header data structure which conforms to a communications protocol arranged to be identifiable by traffic type in a carrier frame.

33When an RRC procedure is combined with an SRNS Relocation procedure, a PDCP synchronization procedure is performed only if a next expected UL/DL Receive PDCP sequence number invalidity event is detected during the SRNS Relocation procedure. If no such invalidity event is detected, then no PDCP sequence number synchronization procedure is performed. If the RRC procedure is not executed in combination with the SRNS Relocation procedure, then the PDCP sequence number synchronization procedure is performed only if: (1) The RRC procedure causes the RLC entity that is used by the PDCP entity to be re-established; or, (2) The RRC procedure causes the header compression protocol used by the PDCP entity to be changed.

Provided is a content classifying section 203 for classifying and bundling to-be-transmitted contents on the basis of any piece of information of media kind, IP address, port number and session identifier. A packet header compressing section 204 carries out header compression on the transmission packet. Due to this, because contents can be packet-transferred with efficiency and excellent error resistance by the use of a communication and broadcast network, it is possible to realize, even on the Internet for broadcast in a broadcast form, a quality broadcast free of image or sound discontinuity as the terrestrial-wave TV broadcast.

The present invention relates to a method and an apparatus for relocating a header compression text, wherein the context updating properties of each individual header during the relocation process is disabled.