Abstract: A medium access protocol which adjusts number of contention slots in a variable length frame and superimposes a variable window structure over the frame structure. The number of contention slots (24) in a frame (28, 30) is changed on a frame by frame basis by determining if a collision occurred in any contention slot (44). If not the contention slot is removed (48) and if so, the number of slots is increased (52). In high traffic situations, if the average load is greater than a threshold (107, 120) the number of frames in a window is increased (130). If the load drops below the threshold (120), the number of frames per window is decreased (124).

Abstract: Enhanced detection of an FM signal is provided through the use of a coded pattern signal which is processed at a receiver (120) non-linearly to facilitate pattern detection. The received signal is conditioned to limit signal amplitudes according to a particular noise threshold (530, 540, 550). The conditioned signal is then processed to determine the presence of the coded pattern (560). In this manner, the probability of detecting signals in weak signal conditions can be enhanced, while maintaining a particular detection falsing rate.

Abstract: A radio communication system (100) includes a repeater (111) that operates with a transceiver (132) on a channel hopping sequence. The repeater receives a request for repeater service transmitted by the transceiver (410), and responds by obtaining a communication slot on the channel hopping sequence (420). The repeater then executes a call setup procedure with the transceiver and with other participants of a communicating group (430). Preferably, the call setup procedure provides the repeater with information on the suitability of the communication slot (440). The repeater then retransmits information received on an inbound channel on a corresponding outbound channel using the communication slot, as the slot transitions across the channel hopping sequence (460, 470).

Abstract: A signaling protocol for an infrastructureless short range communication system uses slow frequency hopping compatible with the industrial/scientific/medical (ISM) frequency spectrum. The signaling protocol utilizes a multi-tiered structure having an acknowledgment request frame (200), ping frame (300), connect frame (400) and voice frame (500). These frames are used to determine an appropriate allocation of frequency spectrum from an initiating station (11') to at least one other non-initiating station (11). The signaling protocol allows an initiating station (11') to rapidly identify other stations (11) within a talk group (13) and resolve actual and/or potential collisions to establish clear and reliable infrastructureless communication.

Abstract: A radio communication system (10) has multiple transceivers (12, 14) attempting to initiate communications on a shared communication channel substantially simultaneously. A method for detecting and handling potential channel use collisions is provided for an initiating transceiver (12, 14). The transceiver (12, 14) transmits on the communication channel, a message including an identifying code word. The transceiver (12, 14) then receives data in a predetermined slot of the communication channel, and compares this data with the code word transmitted. A channel use collision is detected when the data received is not equal to the code word transmitted.

Abstract: A communication system (100) operates on a system acquistion channel, and a set of communication channels organized into a sequence (200) which includes a set of reservation channels (202, 204) selected from the sequence (200). The system (100) includes a communication unit (113) which initiates communications by selecting one of the reservation channels (610), and by executing a collision detection protocol on that reservation channel (620). When no collision is detected, the initiating communication unit transmits, on the system acquisition channel, call information, including information for another reservation channel selected from the reservation channels (530).

Abstract: A method is provided for autonomous radio talk group configuration among radio transceivers. The radio transceivers are placed in a group configuration mode that operates on a communication channel (310, 320). A configuration master transceiver is selected and the other transceivers designated as configuration slave transceivers (330). The configuration master transceiver transmits radio talk group identification information on the communication channel, and the configuration slave transceivers receive and store this radio talk group identification information for use in radio talk group communications (340).

Abstract: A method and apparatus is provided for a operating a radio system (100) on shared communication channels. The system (100) has a sequence of communication channels (205), including a reservation channel, and a channel hopping protocol for operating on the sequence (205). A hop period is defined for the channel hopping protocol. The reservation channel is monitored for at least the channel hop period to find an open communication slot indicated by the absence of a reservation signal (320, 325, 330). Communications is then established within the open slot, and channel hopping occurs through the sequence of communication channels in the open slot (345, 350). The slot is preserved by transmitting a reservation signal on the reservation channel, when operating on the reservation channel (355, 360).

Abstract: A radio communication system (10) operates over a sequence of communication channels using a synchronized channel hopping protocol. A first communication device (16) is provided which is capable of communicating over the sequence of communication channels using channel hopping, and which has an operating communication channel. A second communication device (13) is provided, which is capable of determining the operating communication channel and channel hopping parameters of the first communication device (16). The second communication device (13) can communicate over the sequence of communication channels using channel hopping synchronized with the channel hopping of the first communication device (16), while selecting an operating communication channel different from the operating communication channel of the first communication device (16) when both communication devices (13, 16) operate simultaneously.

Abstract: A code division multiple access (CDMA) communication system (10) for reuse of available spreading codes includes a first communication device (100) and a second communication device (106). The first and second communication devices (100, 106) are capable of identifying spreading codes and operating frequencies that are optimum for their respective radios. The identity of the optimum spreading code and the frequency of the optimum frequency is communicated from one communication device (100) to another (106), hence allowing the two devices to communicate with each other using their respective optimum codes and frequencies. These codes and frequencies may be periodically updated to provide reusability of codes. By dynamically updating codes and frequencies without the use of a central station, the efficiency and reusability of codes in the CDMA system (10) is significantly enhanced.