摘要:
A base site circuit (38) for operating in a communication system (10) having a plurality of base sites capable of allocating a communication channel for use by a communication unit (16) in response to a communication channel request from the communication unit. The base site circuit includes a receiver (34) that operates in a low sensitivity mode when there are no communication channel requests received, and that operates in a high sensitivity mode which is activated by a control signal. The base site further includes a transmitter (34) which is activated by the control signal and a control circuit (32) coupled to both the receiver and the transmitter, for controlling the receiver and the transmitter. The control circuit (32) provides the control signal to the transmitter and to the receiver, in response to a communication channel request.
摘要:
The present invention comprises a method and apparatus for selecting one of at least two antennas (202, 204) in a communication unit (200) for use in a wireless communication system (100). A signal is received by a radio frequency receiver during a receiving period from one of the at least two antennas (202,204) currently selected by an antenna switch (206), the signal having a plurality of bits. The receiver is capable of determining the quality of the receive signal by determining if the incoming bits transition periods fall within a predetermined time window. If it is determined by the receiver that the quality of the receive signal is below a predetermined threshold the currently selected antenna (202 or 204) is switched. The currently selected antenna remains selected when the currently selected antenna has been selected within a predetermined amount of time.
摘要:
A method for seamless transfer of a communication link from a first radio telephone base station to a second radio telephone base station comprises the following steps performed at the first base station: (100) receiving a communication link request from a calling portable radio unit; (102) synchronizing with the calling portable radio unit; (104) determining whether the calling radio has handoff authorization; (108) connecting received data to a second base to allow for synchronization to the calling radio; (112) measuring a first RSSI level at the first base station for the calling radio; (114) determining whether the first RSSI level for the calling radio is below a first handoff threshold; (116) determining a second RSSI level for the calling radio, as measured at the second base station, is above a second handoff threshold, if the first RSSI level for the calling portable radio unit is below the first handoff threshold, (118) determining whether the second RSSI level for the calling portable radio unit is above a second handoff threshold, and (120) alerting the second base station to pick up the communication link. The method further comprises the following step performed at a second base station: (122) commencing to transmit in the frame immediately following the last transmit frame of the first base.
摘要:
A base station allocates radio channels to radio telephone handsets in a second generation cordless telephone (CT2) communication systems by scanning each channel in a first band, and scanning each channel in a second band to measure an RSS level for each channel scanned. The base station scans the second band at a rate that is substantially faster than the rate at which it scans the first band. If a link request is received on a first channel within the first band, from a calling radio telephone, the base station determines whether the first channel has an RSS level above a predetermined threshold. If the RSS level of the first channel is above the threshold, and the calling radio telephone handset is capable of operating on the second band, the base station re-assigns a second channel, that is within the second band, to the calling radio telephone handset.
摘要:
A method for re-establishing a communication link that has been lost between a portable unit (406) and a fixed unit or base station (402) provides for a way of quickly re-establishing the lost communication link, on the previously used RF channel. The method is begun by transmitting a link re-establishment code word (900) using MUX 1 after determining that synchronization has been lost (502) for a predetermined period of time (504). This is followed by automatically switching the portable unit (406) from MUX 1 to MUX 3 communication protocol. Followed by re-establishing communication (re-establish synchronization) between the portable (406) and base station (402) in MUX 3 and switching the two communication devices (402 and 406) back to MUX 1 after the communication link has been re-established. The same steps can be followed by base site (402) if it had been the first to detect loss of the communication link.
摘要:
A method and apparatus for choosing the most optimum communication channel in a system (100) having a plurality of communication channels provides for reduced interference and increased system capacity. By establishing a set of threshold levels and comparing these threshold levels to receive signal strength level measurements for each of the communication channels, a communication device originating a call can be guaranteed of establishing communication using the communication channel with the least chance of being affected by interference or of affecting other channels already in use.
摘要:
A return loss meter (100) for base stations comprises a first transceiver (10) having a first transmitter (12), a first receiver (22 and 30), and a first antenna (20), a second transceiver (50) having a second transmitter (52), a second receiver (62 and 70), and a second antenna (60), wherein the first transceiver and the second transceiver are cross-coupled using at least one directional coupler (16) capable of being switched. The return loss meter includes a device for measuring reflected and transmitted power of the first antenna via a first directional coupler (16) capable of being switched and via a device (74) capable of measuring received signal strength at the second receiver and a device for measuring reflected and transmitted power of the second antenna via a second directional coupler (56) capable of being switched and via a device (34) capable of measuring received signal strength at the first receiver.
摘要:
The invention relates generally to a receiver unit in a digital broadcast system for receiving a broadcast signal comprising content segments and control data, and generating an output signal using the content segments and previously stored content segments. The previously stored content segments are retrieved from a local memory device using the control data and inserted among the received content segments.
摘要:
The invention relates generally to a digital broadcast system and receivers therein which are configured to allow the use of a reverse channel for transmitting responses to broadcast messages. The digital broadcast system is configured to receive requests for information from a mobile platform device (e.g., a GPS receiver) and broadcast information request messages. The receivers are configured to receive a broadcast information request message and communicate with a telematics-enabled device in a mobile platform such as a cellular telephone to initiate a transmission of a response message therefrom.
摘要:
The invention relates generally to a receiver unit in a digital broadcast system for receiving a broadcast signal comprising content segments and control data, and generating an output signal using the content segments and previously stored content segments. The previously stored content segments are retrieved from a local memory device using the control data and inserted among the received content segments.