Abstract: A radio frequency communications system (100) includes wireless terminals (102) and base sites (104). The wireless terminals communicate with the base sites over a radio frequency channel (106). The base sites are interconnected to each other and other network elements via a packet network. The communication system has a radio frequency channel (400) with time slots (406, 408) for transmission of both delay-sensitive data, such as streaming audio and video, and non-delay-sensitive data. A method and apparatus are provided for determining whether a time slot in the radio frequency channel is to be allocated to delay-sensitive data or non-delay-sensitive data (704, 706, 708). Each packet of data transmitted over the wireless channel has a type of service field (900). The type of service field has a precedence or priority value (902) and a service type (904).

Abstract: A slot format and acknowledgment method for use in a communication network that contains one or more wireless links. The slot format provides for the segmenting and reassembly of packets for transport over a wireless link. It also provides support for multiple types of service for the data being carried over the wireless link as well as allocating of access to the wireless link among a plurality of communication units. The acknowledgment method provides for detection of errors over the wireless link, the selective acknowledgment of error-free transmissions and the selective resending of transmissions received in error.

Abstract: In a system having at least a first slot (104) and a first header (106), at least one field is provided in the first header (106). The first slot (104) is configured into at least a first segment and a second segment or into at least a signaling communications path comprising a plurality of messages, based on a value associated with at least a portion of the at last one field associated with the first header. The first segment/message is address to a first subscriber unit and the second segment/message is addressed to a second subscriber unit.

Abstract: An outbound message (200) identifies a slot type associated with each timeslot in a scheduling period. In one embodiment, the outbound message further identifies at least an address of a first subscriber group assigned to transmit in a first timeslot (206) if the slot type of the first timeslot is of a first type and an address of a second subscriber group assigned to transmit in a second timeslot (208) if the slot type of the second timeslot is of a second type, wherein the first type and the second type could be the same or different. In a second embodiment, the outbound message further identifies at least a group address associated with a plurality of subscriber units assigned to transmit in a first timeslot if the slot type of the first timeslot is of a first type.

Abstract: A subscriber (100) provides a cumulative adjustment value in memory. Upon transmission of the inbound signal to a base station (102), the subscriber receives a relative adjustment value. The base station calculates the relative adjustment value based on receipt of the inbound signal against a time window. The subscriber sums the adjustment value with the cumulative adjustment value to create a new cumulative adjustment value. The subscriber stores the new cumulative adjustment value in memory, and a subsequent inbound signal is transmitted using the new cumulative adjustment value. Alternatively, the subscriber obtains a priori information as to when a base station transmits a burst. Upon receipt of the burst, the subscriber calculates a time delay between when the burst was transmitted and when the burst was received. The subscriber stores the time delay, and advances the transmission timing by the time delay.

Abstract: An outbound message (200) identifies a slot type associated with each timeslot in a scheduling period. In one embodiment, the outbound message further identifies at least an address of a first subscriber group assigned to transmit in a first timeslot (206) if the slot type of the first timeslot is of a first type and an address of a second subscriber group assigned to transmit in a second timeslot (208) if the slot type of the second timeslot is of a second type, wherein the first type and the second type could be the same or different. In a second embodiment, the outbound message further identifies at least a group address associated with a plurality of subscriber units assigned to transmit in a first timeslot if the slot type of the first timeslot is of a first type.

Abstract: A scalable slot format defining positions of synchronization symbols, pilot symbols and data symbols for various numbers of sub-channels and various lengths of time in a multi-carrier communication system. An initial pattern (500) and one or more follow-on patterns (600, 700) are defined identifying positions of data symbols, synchronization symbols and pilot symbols for a first number of sub-channels corresponding to a first bandwidth. An extended pattern is constructed from the one or more follow-on patterns. The extension pattern is appended to the initial pattern to form a base pattern (810, 910, 1010). The base pattern (810, 910, 1010) is replicated zero or more times to form an expanded pattern (812, 910, 1015) identifying positions of data symbols, synchronization symbols and pilot symbols for an expanded number of sub-channels corresponding to a second bandwidth.

Abstract: An inbound message is received over a scalable adaptive modulation (“SAM”) interface (104). The inbound message comprises a SAM layer 2 (“L2”) header and data in which the SAM L2 header encapsulates. A hardware L2 address is identified for the first device from the encapsulated data and a SAM L2 address is identified for the second device from the SAM L2 header. Once both addresses are identified, an association between the hardware L2 address of the first device and the SAM L2 address of the second device is stored. Similarly, the association may be made between the hardware L2 address of the first device and the SAM L2 address of the first device, or between an Internet protocol (“IP”) address of the first device and a SAM L2 address of a second device or the first device.

Abstract: In a system having at least a first slot (104) and a first header (106), at least one field is provided in the first header (106). The first slot (104) is configured into at least a first segment and a second segment or into at least a signaling communications path comprising a plurality of messages, based on a value associated with at least a portion of the at last one field associated with the first header. The first segment/message is address to a first subscriber unit and the second segment/message is addressed to a second subscriber unit.

Abstract: In an outbound transmission (300), an address of a first subscriber unit assigned to transmit in a first inbound slot is identified. With one bit in the outbound transmission (300), an additional inbound slot the first subscriber unit is assigned to transmit is identified.

Abstract: Methods for sequencing datagram transmissions are disclosed, including, receiving an unqueued segment to be enqueued in a queue. The queue comprises at least one segment. Determining a priority level and a number of attempted transmissions for the unqueued segment (100). If the unqueued segment is enqueued in front of a segment belonging to a datagram in the queue, and at least one segment belonging to the datagram has been transmitted before all the segments belonging to the datagram have been transmitted, at least one of the following functions is performed: discarding any remaining segments belonging to the datagram in the queue, transmitting any remaining segments belonging to the datagram in the queue, and re-enqueuing segments belonging to the datagram at the same location in the queue as the partially transmitted datagram, but with a different identifier.

Abstract: Encryption synchronization (e-sync) is maintained between a transmitter (104) and one or more receivers (102) in a multi-modulation TDM system (100) where information is communicated in slots (402) comprising a slot header (404) and one or more data blocks (406), and wherein the data blocks are eligible to be encoded at different modulation rates thereby creating a likelihood of different numbers of blocks in different slots. The receiver and transmitter employ respective encryption elements (200, 300) comprising e-sync shifter elements (202, 302) and encryption algorithm blocks (204, 304). The e-sync shifter element provides an e-sync signal defining an encryption state vector to the encryption algorithm block and is operable to advance the encryption state vector (in the case of the receiver) according to a number of received bits plus a variable number of bits.

Abstract: A radio frequency communications system (100) includes wireless terminals (102) and base sites (104). The wireless terminals communicate with the base sites over a radio frequency channel (106). The base sites are interconnected to each other and other network elements via a packet network. The communication system has a radio frequency channel (400) with time slots (406, 408) for transmission of both delay-sensitive data, such as streaming audio and video, and non-delay-sensitive data. A method and apparatus are provided for determining whether a time slot in the radio frequency channel is to be allocated to delay-sensitive data or non-delay-sensitive data (704, 706, 708). Each packet of data transmitted over the wireless channel has a type of service field (900). The type of service field has a precedence or priority value (902) and a service type (904).

Abstract: A slot format and acknowledgment method for use in a communication network that contains one or more wireless links. The slot format provides for the segmenting and reassembly of packets for transport over a wireless link. It also provides support for multiple types of service for the data being carried over the wireless link as well as allocating of access to the wireless link among a plurality of communication units. The acknowledgment method provides for detection of errors over the wireless link, the selective acknowledgment of error-free transmissions and the selective resending of transmissions received in error.

Abstract: A packet-based, multimedia communication system is disclosed that extends IP host functionality to wireless terminals serviced by wireless links. A service controller of the communication system manages communications services such as voice calls, video calls, web browsing, video-conferencing and/or internet communications over a wireless packet network between source and destination host devices. A multimedia content server of the communication system provides access to one or more requested multimedia communication services. A bandwidth manager of the communication system determines an availability of bandwidth for the service requests and, if bandwidth is available, reserves bandwidth sufficient to support the service requests. Wireless link manager(s) of the communication system manage wireless communication resources required to support the service requests.

Abstract: A scalable slot format defining positions of synchronization symbols, pilot symbols and data symbols for various numbers of sub-channels and various lengths of time in a multi-carrier communication system. An initial pattern (500) and one or more follow-on patterns (600, 700) are defined identifying positions of data symbols, synchronization symbols and pilot symbols for a first number of sub-channels corresponding to a first bandwidth. An extended pattern is constructed from the one or more follow-on patterns. The extension pattern is appended to the initial pattern to from a base pattern (810, 910, 1010). The base pattern (810, 910, 1010) is replicated zero or more times to form an expanded pattern (812, 910, 1015) identifying positions of data symbols, synchronization symbols and pilot symbols for an expanded number of sub-channels corresponding to a second bandwidth.

Abstract: An APCO 25 radio communication system 200 includes a repeater 101 arranged to receive signals from an inbound repeater link 103, thereby forming received signals. The repeater 101 is arranged to forward the received signals to a subscriber 121 via an outbound radio frequency path 113. The received signals include two types of packets, namely, packets 105 with correctable errors 107, and "erasure packets"109 with detectable-but-uncorrectable errors 111. The inbound repeater link is equipped with error correcting means 110 for correcting the correctable errors 107. The inbound repeater link is also equipped with error mitigating means 130 for mitigating the detectable-but-uncorrectable errors 111. The error mitigation is performed in accordance with the improved multi-band excitation ("IMBE") process.

Abstract: In a modulator (300), a symbol weight determiner (301) determines a scaling factor (310) for at least one symbol (308). An integrator (303) and a complex symbol generator (305) operate to produce at least one complex symbol (314) based on the at least one symbol. The scaling factor (310) is used to scale the at least one complex symbol. In one embodiment, a scaler (307) comprises a gain-modifiable amplifier (609) and, in a second embodiment, the scaler comprises a gain-modifiable filter (809). When such a modulator is incorporated into an RF communication device (600, 800), the energy used to transmit any given symbol can be varied according to the relative importance of that symbol. Additionally, the overall received sensitivity of a communication, at a given signal strength, can be improved.

Abstract: A communication system (200) employs a method and apparatus for performing diversity voting in the communication system. A comparator (206) receives a signal frame (207-209) of code words from each of multiple signal sources (202-204). A prioritized code word of each signal frame occupies a corresponding frame position and has a respective signal quality metric associated therewith. The comparator determines whether each signal quality metric accurately represents the signal quality of its respective prioritized code word. When the signal quality metrics do not accurately represent the signal qualities of their respective prioritized code words, the comparator determines a supplemental signal quality metric for each prioritized code word. The comparator then selects one prioritized code word from all the corresponding prioritized code words based on a comparison of the supplemental signal quality metrics for input into the corresponding frame position of a voted signal frame (330).

Abstract: Delayed symbols (204), including a current symbol (205), are compared by a comparator (206) with at least one predetermined pattern when the current symbol is equivalent to one of a set of predetermined values. Alternatively, a sign of the current symbol is compared with signs of a previous and a subsequent symbol when the current symbol is equivalent to one of the set of predetermined values. When the current symbol is equivalent to one of the set of predetermined values and when either the delayed symbols are equivalent to one of the at least one predetermined pattern or the sign of the current symbol matches the signs of the previous and subsequent symbols, a symbol corrector (208) applies a predetermined function to the current symbol to produce a received symbol (210).