Telefonaktiebolaget Lm Ericsson (publ)

Lidforss, Thomas

Karim El Malki

Hesham Soliman

Georgios Karagiannis

Gianluca Verin

Geert Heijenk

In a system and method for handing off a mobile node in a seamless manner in a wireless access network, procedures are implemented for allowing the mobile node to synchronize the handoff with a base node (e.g., a home agent) and a correspondent node. In this way, a seamless handoff may be achieved, since few or no data packets sent between the base node or the correspondent node and the mobile node are lost. The procedures are supported by both Mobile IPv4 and Mobile IPv6 as well as Hierarchical Mobile IPv4 and Hierarchical Mobile IPv6.

Seamless handoff in mobile IP

An echo cancellation method and apparatus (20) determines whether a window W(m) of samples on an incoming communications path (30) contains silence, the window W(m) including the sample obtained at time t(m) and prior samples. If the window W(m) contains silence, coefficients of an adaptive filter (52) of the echo canceller (20) are set to silence detection values prior to receipt of a sample at time t(m+1). If the window W(m) does not contain silence and there is no double-talk, the sample obtained at time t(m) is used to update coefficients of the adaptive filter; the adaptive filter as updated generates an echo estimate after a sample is obtained at time t(m+1); and, the echo estimate is used to modify a signal on an outgoing communications path (32).

Silence-improved echo canceller

An echo cancellation apparatus (20) and method involves an operation AEPR for analyzing echo path response and thereafter an operation CR for configuring an adaptive FIR filter (52). The configuration of the adaptive filter (52) advantageously results in only a range of filter taps and coefficients between two specified tap endpoints being involved in filter multiplication, addition, and storage during the echo cancellation operation.

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Rome, Italy

Karim El Malki