Abstract: A method for interrupting voice transmissions within a multi site communication system includes operating a repeater to engage in an interruptible voice communication; to identify an open burst location based on a repeat delay when the interruptible voice communication is sourced directly via a wireless network, and to identify the open burst location as irrelevant when the interruptible voice communication is indirectly sourced via a wireless network; and repeat the interruptible voice communication including the open burst location.

Abstract: A method for interrupting active communications within a communication network, the method comprising in one embodiment: operating a communication device to terminate communication activity in response to receiving an interrupt request from an interrupting device; operating a repeater to wake up and initiate message communication activity in response to receiving a base station downlink activation message from the interrupting device; and operating the interrupting device to transmit one or more messages on a receive frequency of the repeater.

Abstract: Within a two way radio frequency communication system, a repeater transmits an identity of a rest channel when transmitting during an active communication call on a channel other than the rest channel. A subscriber unit communicating within the active communication, receives the identity of the rest channel, leaves the active communication; and initiates a new communication on the rest channel.

Abstract: A system for managing emergency alarm messages in a wireless communications system is disclosed. A first subscriber is assigned an emergency alarm responder role to send an acknowledgement message and present information from a received emergency alarm message to a user of the first subscriber, when the first subscriber receives the emergency alarm message. A second subscriber is assigned an emergency alarm monitor role to present information from the received emergency alarm message to a user of the second subscriber.

Abstract: A first device receives first data that includes a plurality of input vectors, which includes a primary input vector and a set of secondary input vectors and detects uncorrectable errors in the first data based on a quality metric indication. Based on detecting the uncorrectable errors in the first data, the first device substitutes a predetermined codeword for the primary input vector encoded using a non-perfect code, and substitutes a predetermined input vector for the primary input vector. The first device modulates a set of encoded secondary input vectors using the predetermined input vector to generate a modulated set of encoded secondary input vectors and transmits as second data the predetermined codeword and the modulated set of encoded secondary input vectors to a target device, wherein the substituting step creates a first number of errors that is detected by the target device as uncorrectable errors in the transmitted second data.

Abstract: A computer-readable storage element has code stored thereon that programs a processing device within a communication device to implement a method. The method includes: receiving a plurality of bursts and detecting a failure to receive a preceding header burst; extracting embedded data from the plurality of bursts; determining from the embedded data whether the plurality of bursts comprises valid voice bursts; and when the plurality of bursts comprises valid voice bursts, generating at least one header burst using the embedded data, and transmitting the at least one header burst and the voice bursts.

Abstract: A method and system include de-keying a base station in a conventional TDMA communications system and staffing a timer in the base station when the base station de-keys. The method and system further include receiving a transmission from a mobile station and re-keying and repeating the transmission, if the transmission is received with proper synchronization before expiration of the timer.

Abstract: To perform a channel inspection, a wireless communication device: monitors a common announcement channel (CACH) until detecting that a first set of identified parameters associated with a signal on a first channel matches a second set of known parameters for the first channel; performs an inspection on the first channel to determine whether the signal is of interest; and when the signal is not of interest, marks the first channel to prevent another inspection from being performed on the first channel until after the channel mark is removed. The communication device then leaves the first channel and continues to monitor the CACH for a change in the first set of identified parameters or an indication of an idle first channel, wherein the communication device removes the channel mark on the first channel.

Abstract: A wireless communication device accesses a scan list that includes a plurality of scan members sorted at least by receive frequency and attempts to detect whether a call of interest exists on a receive frequency by performing a group scan for a group of scan members that are marked scan undone and that have the same corresponding receive frequency, wherein the group includes a first scan member and at least one other scan member. The group scan includes inspecting the receive frequency to obtain inspection results; using the inspection results to determine that there is no signal on the receive frequency having signal attributes that match a set of attributes for the first scan member; and using the inspection results to evaluate at least one of the other scan members in the group to determine whether there is a corresponding signal of interest on the receive frequency.

Abstract: A transmitting device encrypts DMR voice superframes using encryption parameters and sends the encryption parameters in at least one of the voice superframes by: identifying a selected number of bits from a plurality of vocoder frames the voice superframe; replacing each of the identified bits with a corresponding bit of a first encryption parameter; placing at least one encryption parameter in an embedded signaling field of the voice superframe; and transmitting the voice superframe with the encryption parameters to a receiving device. The receiving device extracts the encryption parameters, which can be a key identifier, an algorithm identifier, and an initialization vector for use in decrypting messages from the transmitting device.

Abstract: To perform channel inspection, a wireless communication device conducts a full inspection on a first channel carrying a first signal that includes: determining a location of a first synchronization message; and determining whether the first signal is of interest. Upon determining that the first signal is not of interest, the first channel is marked, wherein the marking includes remembering the location of the first synchronization message. The device leaves the first channel and determines an expected location of a second synchronization message on the first channel based on the location of the first synchronization message. Upon returning to the first channel which carries a second signal, the communication device conduct a partial inspection that includes: detecting whether the second synchronization message is present at the expected location, wherein the presence of the second synchronization message indicates that the second signal is not of interest.

Abstract: A device detects a first signal on a channel that is one of a plurality of channels arranged in a first order on a list, with each channel being associated with a different site in a multi-site communication system. Upon detecting the first signal, the device attempts to measure and record signal strength of a signal at each channel on the list based on the first order beginning with the detected first signal, and selects as a home site the site associated with the channel having the signal with the highest recorded signal strength. The device rearranges the channels on the list into a second order based on the recorded signal strengths with the home site channel at the top. If necessary, the radio attempts to awaken its repeaters one after another based on the second order until a repeater is found to transmit a signal.

Abstract: A repeater receives and repeats, on a multi-site channel, a sequence of control and media transmissions included in a session, wherein the session has a plurality of participants. While repeating these transmissions, the repeater further detects, from at least one of the transmissions, a start of the session and a type of the session. Based on the type of the session, the repeater determines whether to perform an arbitration during the session to control access to the multi-site channel, and restricts each performed arbitration to only transmissions received from the participants to the session. In addition, after repeating at least one of the control transmissions, the repeater sets a hang time having a duration that is determined based on a type of the transmission preceding the setting of the hang time.

Abstract: The present invention discloses, in a two-way radio frequency (RF) communications system having at least one repeater, a plurality of channels, and a plurality of subscriber units, a repeater receives a message that identifies a channel that is selected to serve as a rest channel for the system. The channel that is currently serving as the rest channel for the system is monitored by subscriber units that are idle in the system. If the repeater determines that the channel selected to serve as the rest channel is hosted by the repeater, the repeater periodically transmits an identity of the channel as the channel currently serving as the rest channel on at least the channel.

Abstract: A subscriber unit monitors a first channel currently serving as a rest channel for the system, wherein the channel currently serving as the rest channel for the system is monitored by subscribers that are idle in the system. The subscriber unit determines that a first call is being initiated on the first channel. If the first call is not of interest, the subscriber unit ceases to monitor the first channel, and monitors a second channel that will serve as the rest channel for the system when the first call starts on the first channel. If the first call is of interest, the subscriber unit participates in the first call on the first channel, and before or after the first call ends, participates in a second call on a third channel or monitors a channel currently serving as the rest channel for the system when the subscriber unit becomes idle.

Abstract: In a two-way radio frequency (RF) communications system having at least one repeater, a plurality of channels, and a plurality of subscriber units, a repeater hosts a first channel that is currently serving as a rest channel. The channel that is currently serving as the rest channel is monitored by subscriber units that are idle in the system. When the repeater determines to select a second channel to serve as the rest channel, it determines whether there is at least one eligible channel to serve as the rest channel. If there is at least one eligible channel in the system, the repeater may select the second channel to serve as the rest channel from one of the eligible channels.

Abstract: A repeater receives an indication that a subscriber unit is initiating a call session on a channel, and indicates that the channel is busy. The repeater repeats a transmission from the subscriber unit and sets a timer for a first time upon determination that the transmission has ended. The timer is set for a second time if a new transmission is not received from a subscriber unit that is allowed to transmit on the channel prior to the expiration of the first time; otherwise, the repeater accepts a new transmission from a subscriber unit that is allowed to transmit on the channel if the new transmission is received prior to an expiration of the second time. Upon receipt of each new transmission received prior to the expiration of the second time, the repeater clears the timer, repeats the transmission on the channel, and resets the timer for the first time upon determination that the transmission has ended.

Abstract: The time required for the receiving device to synchronize to a desired timeslot is reduced. In operation, a transmitting device selects a synchronization pattern associated with the desired timeslot that is at least mutually exclusive from synchronization patterns associated with other timeslots on the same frequency in the system. Once selected, the transmitting device transmits a burst embedding the synchronization pattern that was selected, where appropriate. If the receiving device detects the synchronization pattern, it immediately synchronizes with the timeslot with confidence that it is synchronizing to the desired timeslot.

Abstract: A system and method for interrupting a transmitting device during a call. In the system, calls are transmitted from a first device on a communication channel as a series of channel frames. At predetermined times during the transmission, the transmitting device is configured to drop channel frames, resulting in open channel frame periods where the transmitting device is not transmitting on the communication channel. During these open channel frame periods, the transmitting device is also configured to switch to a receiving mode. Other devices in the system are capable of switching into a transmitting mode during the open channel frame periods and, when applicable, sending an interrupt request on the communication channel to the transmitting device in order to request access to the channel.

Abstract: A method and device dynamically changes preamble duration of a message. A message is transmitted over a forward channel to a target device, wherein the message includes a preamble of a predetermined time duration. A reverse channel is monitored for a confirmation message from the target device. The transmission of the preamble is stopped before expiration of the predetermined time duration upon receiving the confirmation message over the reverse channel.