Patent ID: 6690719
Filing Date: 2004-02-10
Classification: H04L

Abstract:
A modem controller apparatus for use in a modem having a transmitter and a receiver, said modem coupled between a communications channel and a host, comprising:means for receiving transmit data and control data from said host wherein said transmit data is transmitted over said communications channel by said transmitter and said control data is used to configure and control the operation of said modem; means for receiving data transmitted over said communications channel from said receiver and for forwarding said receive data to said host; means for waiting an optional wait period before attempting transmission of a packet onto said channel; means for transmitting an optional preamble comprising at least one quiet period and the transmission of at least one predetermined symbol: back-off means for detecting the reception of a packet during one or more quiet periods of said preamble and aborting transmission if reception of a packet is detected; means for conveying first information comprising an indication of reception success or failure of the last packet received by said modem in a packet being transmitted; and means for declaring partial synchronization, including notification of said host that a synchronization event has occurred, upon detection of a fewer number of valid symbols than that required to achieve full synchronization, and wherein full synchronization is either reaffirmed or de-affirmed one or more additional symbol times in the future.