摘要:
A wireless telecommunications systems (1) includes a central terminal (10) for transmitting and receiving radio frequency signals to and from a subscriber terminal (20). A downlink communication path is established from a transmitter (200) of the central terminal (10) to a receiver (202) of the subscriber terminal (20). A downlink signal (212) is transmitter from the transmitter (200) to the receiver (202) during setup and operation of the wireless telecommunications system (1). The receiver (202) of the subscriber terminal (20) compares a code and phase of a master code sequence in the downlink signal (212) to a code and phase of a slave code sequence of the receiver (202). The receiver (202) adjusts the phase of the slave code sequence until a match is obtained with the master code sequence. The downlink signal (212) includes an overhead channel (224) having a power control signal (236), a code synchronization signal (234), and a frame alignment signal (232). The power control signal (236) is capable of adjusting a transmitting power of a transmitter (204) in the subscriber terminal (20). The code synchronization signal (234) is capable of adjusting a phase of a transmitter (204) in the subscriber terminal (20). A receiver (206) in the central terminal (10) monitors an uplink signal (214) transmitted by the transmitter (204) in the subscriber terminal and provides changes to the code synchronization signal (234) such that the transmitter (204) is synchronized to the receiver (206). The receiver (202) monitors the downlink signal (212) to identify the frame alignment signal (232) and establishes the downlink communication path when two successive frame alignment signals (232) are identified. The wireless telecommunications system (1) operates in one of three operating modes. In an acquisition mode during establishment of the downlink communication path, the downlink signal (212) is transmitted at a high power level and a low transmit rate with the receiver (202) operating at the low transmit rate. In a standby mode after establishment of the downlink communication path, the downlink signal (212) is transmitted at a low power level and a low transmit rate with the receiver (202) operating at the low transmit rate. In a traffic mode upon a request for wireless communication transmission, the downlink signal (212) is transmitted at a high power level and a high transmit rate with the receiver (202) adjusting to operate at the high transmit rate. Upon completion of the wireless communication transmission, the wireless telecommunications system (1) returns to the standby mode and the receiver (202) adjusts to operate at the low transmit rate.
摘要:
A wireless telecommunications systems (1) includes a central terminal (10) for transmitting and receiving radio frequency signals to and from a subscriber terminal (20). A downlink communication path is established from a transmitter (200) of the central terminal (10) to a receiver (202) of the subscriber terminal (20). A downlink signal (212) is transmitted from the transmitter (200) to the receiver (202) during setup and operation of the wireless telecommunications system (1). The receiver (202) of the subscriber terminal (20) compares a code and phase of a master code sequence that includes an orthogonal code in the downlink signal (212) to a code and phase of a slave code sequence of the receiver (202). The receiver (202) adjusts the phase of the slave code sequence until a match is obtained with the master code sequence. The receiver (202) monitors the downlink signal (212) to identify the frame alignment signal (232) and establishes the downlink communication path when two successive frame alignment signals (232) are identified. A channel identifier signal within the downlink signal is identified and used to identify the orthogonal code included in the master code sequence. The channel identifier signal is matched to a reference identifier code to verify that the correct downlink signal is being read.
摘要:
Message packets for passing control information between a central telecommunications station and a controller for one or more telecommunications stations include: a packet header including a packet start pattern and a message size identifier for individually setting a message size for respective packets; a variable number of message records, each having a size relating to the message size selected for the packet; and a packet terminator including a unique packet end pattern invalid as an initial bit sequence for a message record. The tracking of transmissions is facilitated by the use of cyclical sequence numbers and an arrangement whereby up to a predetermined number of messages may be sent without an acknowledgment.
摘要:
The present invention provides an interference controller and method for limiting in one cell the effect of interference generated by other cells of a wireless telecommunications system, each cell of the wireless telecommunications system having a central terminal and a plurality of subscriber terminals, communication between a central terminal and a subscriber terminal being arranged to occur over a wireless link, and a plurality of code division multiplexed channels being provided within a single frequency channel to enable data items pertaining to a plurality of wireless links to be transmitted simultaneously within different code division multiplexed channels of said single frequency channel. The interference controller comprises an analyser for comparing with predetermined criteria parameters within the cell indicative of whether the code division multiplexed channels are subject to interference from signals generated by said other cells; and a channel controller, responsive to the analyser, to selectively prevent code division multiplexed channels from being used in order to reduce the effect of the interference from said other cells. In preferred embodiments, the interference controller is provided within a central terminal of at least one cell of the wireless telecommunications system.
摘要:
A wireless telecommunications systems (1) includes a central terminal (10) for transmitting and receiving radio frequency signals to and from a subscriber terminal (20). A downlink communication path is established from a transmitter (200) of the central terminal (10) to a receiver (202) of the subscriber terminal (20). A downlink signal (212) is transmitted from the transmitter (200) to the receiver (202) during setup and operation of the wireless telecommunications system (1). The downlink signal (212) includes an overhead channel (224) having a power control signal (236). The power control signal (236) is capable of adjusting a transmitting power of a transmitter (204) in the subscriber terminal (20). Adjustment of the transmitting power of the transmitter (204) facilitates establishment and maintenance of an uplink communication path between the transmitter (204) of the subscriber terminal and a receiver (206) of the central terminal (10).
摘要:
A communications protocol interface is arranged at a central station of a telecommunications network and is responsive to a control message received from a network controller in accordance with a first message protocol to transmit the control message in accordance with a second message protocol to subscriber stations and is responsive to a control message received in accordance with the second message protocol to transmit the control message to the network controller in accordance with the first message protocol. The first message protocol is a balanced protocol with the communications protocol converter or the network controller able to initiate an exchange of information. The second message protocol is a master-slave protocol with the communications protocol interface acting as master. The second control message protocol operates over central station bus for communicating with at least one network element in the central station.
摘要:
The present invention provides a system for handling telecommunications signals passed between a first and second element of a telecommunications network, the first element having an interface for transmitting and receiving signals in a first protocol, and the second element having an interface for transmitting and receiving signals in a second protocol. The system of the present invention comprises a first interface unit for receiving a first telecommunications signal transmitted in one of said first and second protocols between said first and second elements, the first interface unit being arranged to separate traffic bearing channels from non-traffic bearing channels within the first telecommunications signal. A traffic management element is then provided for performing a cross-connection function to map the traffic bearing channels to the appropriate format for the other of said protocols, whilst a protocol conversion element is provided for performing predetermined protocol conversion steps on the non-traffic bearing channels in order to regenerate those non-traffic bearing channels in the other of said protocols. Further, a second interface unit is provided for combining the channels as output by the traffic management element and the protocol conversion element in order to create a second telecommunications signal in the other of said protocols, the second interface unit being arranged to output the second telecommunications signal. Preferably, said first protocol has a concentrated format, and said second protocol has an unconcentrated format.