Abstract: A radio controller monitors a radio channel for a first period of time and determines a first indication of signals received without detecting synchronization or with detecting synchronization but failing error correction during that time. Responsive to determining that the first indication is above a predetermined threshold indicative of an interference condition, causing an instruction to be broadcast identifying a subset of subscriber devices allowed transmitting random access requests on the radio channel. The radio controller monitors the radio channel for a second period of time and determines a second indication during that time. If the second indication is an improvement over the first indication, the radio controller determines that the interference condition is caused by the mass random access event.

Abstract: A radio controller monitors a radio channel for a first period of time and determines a first indication of signals received without detecting synchronization or with detecting synchronization but failing error correction during that time. Responsive to determining that the first indication is above a predetermined threshold indicative of an interference condition, causing an instruction to be broadcast identifying a subset of subscriber devices allowed transmitting random access requests on the radio channel. The radio controller monitors the radio channel for a second period of time and determines a second indication during that time. If the second indication is an improvement over the first indication, the radio controller determines that the interference condition is caused by the mass random access event.

Abstract: A process for consolidating location-dependent information in a two-way radio system includes determining a geographic location of each subscriber unit in a group of subscriber units active within a radio frequency (RF) coverage area of a base station (BS), determining a single representative geographic location for the group of subscriber units based on their geographic locations, requesting location-dependent information from a content provider using the representative geographic location, and causing the location-dependent information to be broadcast within the RF coverage area.

Abstract: A process for consolidating location-dependent information in a two-way radio system includes determining a geographic location of each subscriber unit in a group of subscriber units active within a radio frequency (RF) coverage area of a base station (BS), determining a single representative geographic location for the group of subscriber units based on their geographic locations, requesting location-dependent information from a content provider using the representative geographic location, and causing the location-dependent information to be broadcast within the RF coverage area.

Abstract: A method and apparatus for enabling a radio to track channel timing and support channel scanning A non-leading radio operating on a communications channel, determines a diffusion period during which channel timing is to be propagated from a leading radio to non-leading radios operating on the communications channel. The non-leading radio implements a first scanning pattern during the diffusion period to scan a CT designated channel for a control timing message with a timing signal sent from the leading radio. The first scanning pattern involves scanning the CT designated channel during every other scan interval and scanning non-priority channels and priority channels during scan intervals not used on the CT designated channel.

Abstract: A method for diffusing channel timing among a plurality of subscriber units operating in TDMA Direct Mode, wherein the method includes: receiving, from a second one of the subscriber units operating in the TDMA Direct Mode, a first message; determining first channel timing from the received message; determining whether the received first channel timing is correct, wherein the determining is based at least on comparing a generation of the first subscriber unit with a generation of the second subscriber unit; when the received first channel timing is correct, starting a random delay; upon expiration of the random delay, transmitting a first forced propagation message to propagate the first channel timing to at least a third one of the subscriber units operating in the TDMA Direct Mode and having a higher generation than the generations of the first and the second subscriber units.

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: A method and apparatus for enabling a radio to track channel timing and support channel scanning A non-leading radio operating on a communications channel, determines a diffusion period during which channel timing is to be propagated from a leading radio to non-leading radios operating on the communications channel. The non-leading radio implements a first scanning pattern during the diffusion period to scan a CT designated channel for a control timing message with a timing signal sent from the leading radio. The first scanning pattern involves scanning the CT designated channel during every other scan interval and scanning non-priority channels and priority channels during scan intervals not used on the CT designated channel.

Abstract: A method for diffusing channel timing among a plurality of subscriber units operating in TDMA Direct Mode, wherein the method includes: receiving, from a second one of the subscriber units operating in the TDMA Direct Mode, a first message; determining first channel timing from the received message; determining whether the received first channel timing is correct, wherein the determining is based at least on comparing a generation of the first subscriber unit with a generation of the second subscriber unit; when the received first channel timing is correct, starting a random delay; upon expiration of the random delay, transmitting a first forced propagation message to propagate the first channel timing to at least a third one of the subscriber units operating in the TDMA Direct Mode and having a higher generation than the generations of the first and the second subscriber units.

Abstract: A system and method for pausing communications from a transmitting radio for a certain period of time in order to allow transmission of other messages. When a first radio determines that a message needs to be transmitted either to a second radio or the transmitting radio, the first radio determines whether there are any available forward channels to transmit the call. If no forward channel is available, the first radio determines a period of time required to transmit the message and sends, on a reverse channel, a “request to pause” signal to the transmitting radio identifying that period of time. Upon receiving the “request to pause” signal, the transmitting radio ceases transmission on the forward channel for the specified period of time, during which time the first radio transmits the message.

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: 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 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: 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 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 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 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: 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 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 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.