Abstract: A hybrid DSMA-CR/CDMA methodology provides efficient access to one of a group of common packet channels in a cell of a spread spectrum wireless communication network. The base station broadcasts status information as to the availability and/or available data rates for each common packet channel (CPCH) or group of CPCH channels. Each mobile station uses the status information to select an available channel and/or a channel with sufficient data rate. The mobile station then starts transmission of a series of access preambles, each of which contains a signature corresponding to the selected channel. The mobile station transmits the preambles at increasing power levels. When the base station detects a preamble transmission, the base station responds with a corresponding acknowledgment. Upon receiving this acknowledgment, the mobile station preferably selects a collision detection (CD) signature and transmits a CD preamble containing that signature.

Abstract: A code-division-multiple-access (CDMA) system provides a collision avoidance mechanism for packet communications. When mobile stations attempt to establish links with a base station, the base station selects one mobile station to transmit data over an intended uplink channel. The base station transmits a predetermined sequence, during the first frame of the data transmission over the downlink control channel that corresponds to the intended uplink channel. If several mobile stations detect or mis-perceive successful access attempts, those stations begin data transmissions via respective desired uplink channels. At the same time, the mobile stations listen for the known sequence over the various corresponding downlink channels. Upon successful detection of the known sequence, one mobile station continues transmission of its data over the intended channel. However, any contending mobile station that does not detect the known sequence on the appropriate downlink channel immediately stops its data transmission.

Abstract: An improvement to a code-division-multiple-access (CDMA) system employing spread-spectrum modulation, with the CDMA system having a base station (BS) and a plurality of remote stations. The base station has a BS-spread-spectrum transmitter and a BS-spread-spectrum receiver. A remote station has an RS-spread-spectrum transmitter and an RS-spread-spectrum receiver. The BS transmitter transmits a broadcast common-synchronization channel, which includes a frame-timing signal. The broadcast common-synchronization channel has a common chip-sequence signal, which is common to the plurality of remote stations. In response to the RS-spread-spectrum receiver receiving the broadcast common-synchronization channel, and determining frame timing from the frame-timing signal, an RS-spread-spectrum transmitter transmits an access-burst signal. The BS-spread-spectrum transmitter, responsive to the BS-spread-spectrum receiver receiving the access-burst signal, transmits an acknowledgment signal.

Abstract: A system and method for encoding and transmitting data with a spread-spectrum packet-switched system. Data to be transmitted by a packet transmitter are encoded for privacy and to restrict intelligent receipt of the data to the intended recipient. The encoded data is demultiplexed into sub-data-sequence signals which are spread-spectrum processed and then combined as a multichannel spread-spectrum signal. The multichannel spread-spectrum signal is concatenated with a header to output a packet-spread-spectrum signal which is transmitted over radio waves to a packet receiver. The packet receiver obtains timing for the multichannel spread-spectrum signal from the header. The multichannel spread-spectrum signal is then despread and multiplexed as received-encoded data. The received-encoded data is decoded by the intended recipient and stored in a receiver memory for output.