Patent ID: 8488583

Claim:
A method of relocating a header compression context of data packets from a source communication network node to a target communication network node during a mobility event in a communication network system, in which said data packets comprising said header compression context are transmitted initially between a compression endpoint in a user equipment and a compression endpoint in said source communication network node, and after said mobility event, between a compression endpoint in said user equipment and a compression endpoint in said target communication network node over a radio interface, said method comprising: disabling context updating properties of each individual header during the relocation process; relocating compressor context information from said source communication network node to said target communication network node, whereby said compressor context information comprises at least one of an information validity mask and two constructed headers per context, wherein each constructed header contains values for each field of a format of protocol headers that said context is compressing; wherein a first one of the constructed headers represents a collection of minimum values from a history of previous headers, one minimum value from each dynamically changing field, and a second one of the constructed headers represents a collection of maximum values from a history of previous headers, one maximum value from each dynamically changing field; marking said compressor context information corresponding to each non-dynamic field as valid if said field has been constant for a number of repetitions used to ensure robustness; and otherwise, marking said compressor context information as invalid.