摘要:
A communication pathway (145) can be established between physically collocated narrowband (135) and broadband (105) devices. The narrowband device (135) can identify a communication channel. A transmission frequency used by the broadband device (105) can be spectrally-proximate to a reception frequency used by the narrowband device (135) in a frequency range associated with the communication channel, resulting in interference of the narrowband device's (135) reception when the broadband device (105) is transmitting and the narrowband device (135) is receiving concurrently. The narrowband device (135) can instruct the broadband device (105) to switch to a transmission spectrum block that is spectrally separated from the reception spectrum block of the communication channel to minimize interference between the devices when the narrowband device (135) handles a call assignment.
摘要:
A communication pathway (145) can be established between physically collocated narrowband (135) and broadband (105) devices. The narrowband device (135) can identify a communication channel. A transmission frequency used by the broadband device (105) can be spectrally-proximate to a reception frequency used by the narrowband device (135) in a frequency range associated with the communication channel, resulting in interference of the narrowband device's (135) reception when the broadband device (105) is transmitting and the narrowband device (135) is receiving concurrently. The narrowband device (135) can instruct the broadband device (105) to switch to a transmission spectrum block that is spectrally separated from the reception spectrum block of the communication channel to minimize interference between the devices when the narrowband device (135) handles a call assignment.
摘要:
A method (200, 300) for supporting telecommunications over a wide area network. The method can include receiving a first message from a first communications site (110), the first message communicated through a logical port (174) at the communications site and maintaining the logical port open for at least a minimum period. A second message can be received from a second communications site (112), the second message requesting an identifier associated with the first communications site. Further, a third message can be communicated to the first communications site through the logical port. The third message can identify the second communications site as a candidate for establishing a peer-to-peer communications link over which telecommunications content may be communicated to a first remote unit (104).
摘要:
A method, device, and system for establishing a group call among a plurality of communication devices. The method includes initiating a group call among at least some of the plurality of communication devices, wherein each communication device uses a unicast communication link to participate in the group call. The method further includes computing one or more broadcast or multicast parameters during the group call, identifying a subset of communication devices based on the broadcast or multicast parameters, and switching the identified subset of communications devices to a broadcast or multicast communication link during the group call.
摘要:
When a sequence of data bits is to be transmitted, the sequence is precoded into data symbols and organized as data frames. For each data frame, a number of phase reference points at predetermined intervals within the data frame are required to allow a receiving device to sufficiently estimate channel effects on the transmitted data frame. If a data frame has a field where inclusion of pilot symbols is undesirable, and if a phase reference point is required within that field, a set of pilot symbols associated with that phase reference point is generated and inserted into the data frame prior to the beginning of the field. The values for each of the pilot symbols in the set are chosen so as to force the phase reference point to a desired phase state.
摘要:
A method and apparatus for linking to a Peer-to-Peer (“P2P”) network for VOIP communications. An intermediary peer creates a map to link peers together in the P2P network. A series of messages are generated to open the ports of one peer to be accessible to other peers on the P2P network. Peers are then enabled to communicate directly with other peers. Steward peers can assume the functionality of the intermediary peer.
摘要:
When a sequence of data bits is to be transmitted, the sequence is precoded into data symbols and organized as data frames. For each data frame, a number of phase reference points at predetermined intervals within the data frame are required to allow a receiving device to sufficiently estimate channel effects on the transmitted data frame. If a data frame has a field where inclusion of pilot symbols is undesirable, and if a phase reference point is required within that field, a set of pilot symbols associated with that phase reference point is generated and inserted into the data frame prior to the beginning of the field. The values for each of the pilot symbols in the set are chosen so as to force the phase reference point to a desired phase state.
摘要:
Communication units are provided access to a communication system (100) in the following manner. A base station (202) receives, from a requesting communication unit, a request, via a shared inbound communication resource (209), for an available message path (207). When a dual-mode outbound communication resource is operating in a control mode (205), the message path (207), having a first inbound communication resource (204) and the dual-mode outbound communication resource operating in a partial control mode (206), is assigned to the requesting communication unit. Thus, the shared inbound communication resource is consistently available, providing access to the communication system.
摘要:
A method for measuring channel delay measures the delay for a message to propagate from a prime site (100, 400) to a remote site (200, 500) via the channel (300, 600). The prime site includes a clock for providing a first value, T1, based on the current time at the prime site. The remote site includes a clock for providing a second value, T2, based on the current time at the remote site. Both clocks are synchronized with a common timing source, such as a GPS satellite timing signal. Therefore, T2 equals T1. In one embodiment, the prime site determines T1, and simultaneously sends a message to the remote site via the channel, the message including T1. Upon receiving the message, the remote site simultaneously determines T2. The remote site decodes the message to determine T1, and then determines the delay based on the difference between T2 and T1.
摘要:
An adaptive digital equalization filter is provided to remedy the differential time delay problem in a digital simulcast system. The digital simulcast system includes an adaptive digital equalization filter with N coefficients, and a fixed analog anti-alias filter. According to the invention, the adaptive digital equalization filter first measures the amount of delay contributed to the output signal by the fixed anti-alias filter. This is accomplished by exciting the anti-alias filter with a unit impulse, and measuring the resulting impulse response. The adaptive filter next determines the characteristics needed to compensate for the amount of measured delay contributed to the output signal by the fixed filter. This is accomplished by computing a new set of N coefficients using the Levinson-Durbin algorithm. The adaptive filter next adjusts its coefficients based on these determined characteristics. Further, the adaptive filter periodically determines when it is time to update the N coefficients.