Abstract: A telecommunications system that recognizes “post-fix” codes after directory numbers are dialed. Such post-fix codes provide the calling party with the ability to invoke features or functions before the call is routed. By use of a post-fix code (for example, *X or *XX) the caller may, for example, control routing of a telephone call.

Abstract: A tamper detection method for digital images includes: providing a digitally watermarked image; digitally processing at least some watermarked parts of the image to obtain confidence values; and using the confidence values to provide an indication as to the likelihood that the image has been tampered with.

Abstract: A method to train a radio includes the steps of: in a radio (36), receiving a slot of information (2) containing at least an initial portion (4) containing training information (10), a second portion (5) containing training information (11), which second portion (5) is separated from the initial portion (4), and a concluding portion (6) containing training information (12), which concluding portion (6) is separated from the second portion (5). The method combining one of the initial portion (4) with the concluding portion (6a) of a previous slot of information (1) and the concluding portion (6) with an initial portion (4b) of a subsequent slot of information (3) to provide an at least one combined portion of training information. The method using the at least one combined portion of training information and the second portion of training information to train the radio.

Abstract: In a communications receiver (100) with a front stage (110) for receiving a transmitted RF input signal and a mixer stage (130) for mixing the RF input signal with an oscillator signal (OS) to provide an intermediate frequency (IF) signal, wherein the front stage (110) and the mixer stage (130) are coupled by an interconnecting section (130), intermodulation (IM) effects are reduced by (a) creating a forward (F) current through the section (120) by forward current means (R1, R3, R5, R4, C3, C1, C3, PD1, switch 140), (b) creating a reverse (R) current through the section (120) by reverse current means, (c) selectively coupling forward (F) and reverse (R) current means to the section (120) by selector means (140), to reduce the amplitude of the signal (RF OUT), which is applied to the mixer stage (130), and (d) operating the mixer stage in its linear operating range.

Abstract: A method and system for optimal radio channel management in a distributed connection and transport network. The method includes the steps of determining the quality of service required by a communication session, determining whether transport resources are available for immediate use by the communication session, and queuing the communication session for assignment to transport resources in accordance with the quality of service required and the availability of transport resources for immediate use.

Abstract: A communication device (200), such as a cellular mobile phone or a cordless phone, has a dial unit (208) for communication with a base station. An input device for dialing a phone number which forwards a coded dial signal (215) to the dial unit (208) is implemented as an optical character recognition (OCR) scanner (210) that reads phone numbers (202) from a printed or hand-written original (201). Optionally, especially for recognizing hand-writing, the scanner (210) sends graphical representations of input data to the base station that obtains the code dial signals by an external processor.

Abstract: A radio communication system (100) has talkgroups or working groups that intercommunicate with each other on broadcast calls. Multiple working groups are associated with an announcement group. A subscriber unit (112a-f) may monitor talkgroup communications or announcement group communications. When communications to a talkgroup are initiated, a grant message (300) is sent to subscriber units affiliated with the talkgroup. A new grant message (350) is generated for subscriber units affiliated with the announcement group. The new grant message relieves subscriber units from storing an association between talkgroups and announcement groups, thereby allowing the association of announcement groups and talkgroups to be assigned dynamically.

Abstract: A wireless communications system provides call transfer capability for an incoming call to a mobile subscriber unit. The mobile subscriber unit requests the call transfer to a serving MSC. The serving MSC relays the request to a home location register, and the home location register executes the request by initiating the call transfer in conjunction with an originating MSC. This arrangement obviates the need for supporting call transfer on the serving MSC and the need for inter-MSC facilities once the call transfer is completed. Moreover, the approach of the present invention enables call transfer to be ubiquitously supported within a wireless communications system.

Abstract: Detection of a locomotive or other vehicle is enhanced by transmitting an RF alert signal from the vehicle when the vehicle approaches a heightened alert area such as a railroad crossing. The RF alert signal is received by communication unit(s) carried by pedestrian(s) or residing in vehicle(s) approaching the heightened alert area, thereby providing an alert that supplements train whistles, gates, horns or other warning mechanisms known in the art. The RF alert signal may also be transmitted to infrastructure devices such as logging devices. In one embodiment, the RF alert signal is transmitted from a locomotive upon detecting operation of a train whistle associated with the locomotive and/or coincident to receiving an external alert signal or automatic vehicle location (AVL) information indicating that the locomotive is near a heightened alert area.

Abstract: Data for transmission may be convolutionally encoded and punctured prior to transmission. The invention relates to a method and apparatus for decoding such data. In accordance with the invention, a table of error metrics is prepared when a given group (Gt) of n bits is received at a particular time (t). The error metrics (Mti) are calculated for comparisons of the n bits received with each possible permutation (Pi) of n bits. These error metrics (Mti) are placed in the metric table. Next a look-up table (Tt) is consulted which lists each state change (Sj) which the encoder could have undergone at the particular time (t) together with the permutation (Pi) of bits which would have been produced by the encoder for that state change. The look-up table (Tt) is particular to the puncturing scheme which the encoder uses at the particular time (t). The metric table is then used to add to the look-up table (Tt) the error metric (Mti) appropriate to each state change (Si) in the table (Tt).

Abstract: A method of sending (321) a service utilization message in a communication system (100) includes the steps of forming (303 through 317) a service utilization message and sending (321) the service utilization message via a service port (109). The service utilization message includes a header, a service controller packet, and a service manager packet. The header includes a block source field (201), a block destination field (203), a block length field (205), and a block command type field (207). The service controller packet includes a block opcode field (209) and a controller packet (211). The service manager packet includes a manager packet (213) and a block sequence number field (215). The service utilization messages assist with call billing and call logging for communication systems (100). A service utilization linking message is similarly formed (503 through 517) and sent (521).

Abstract: A method by which a plurality of users share access to a resource such as a common communications channel. Each user is assigned a priority and is provided with a non-uniform probability distribution function corresponding to that priority, with the sum of the several non-uniform probability distribution functions being uniform. Whenever a user wishes to access the resource, the user selects a random number according to its non-uniform probability distribution function and computes an access time based on the selected random number.

Abstract: A portable or a mobile radio (2) can communicate with other such radios (4,6), and can place calls to telephone subscribers. A permanent memory (32) in the radio (2) serves as an address book. A user interface circuit (42,44) enables a user to send pre-stored messages to radios whose addresses are also pre-stored. Other regions of the permanent memory (32) store an access code which can be used to make a DTMF telephone call. The telephone calls can be ‘live dial’, but may be made automatically to pre-stored telephone numbers.

Abstract: A scalable pattern methodology defining positions of synchronization symbols, pilot symbols and data symbols for various numbers of sub-channels in a multi-carrier communication system. A base pattern (510) is defined identifying positions of data symbols, synchronization symbols and pilot symbols for a first number of sub-channels corresponding to a first bandwidth. The base pattern is replicated or scaled to form an expanded pattern (512, 514) identifying positions of data symbols, synchronization symbols and pilot symbols for an expanded number (M) of sub-channels corresponding to a second bandwidth. The pattern methodology may be implemented by a transmitter (100) having subdivided an original information signal into M bit streams and having encoded each of the M bit streams to 16QAM symbols to form M symbol streams, by inserting synchronization and pilot symbols into each of the M symbol streams at positions determined by the expanded pattern.

Abstract: In a speech processing system (10) characterized by a finite range of audio levels, the speech processing system (10) receiving an incoming audio signal, the speech processing system amplifying (12) the incoming audio signal by an audio gain factor, the speech processing system (10) representing the amplified audio signal by the finite range of audio levels, a method for adjusting the audio gain factor, including the steps of: decreasing the audio gain factor when detecting clipping of the amplified audio signal, maintaining the audio gain factor for a hold time period, and increasing the gain factor when detecting that the result of amplification of the incoming sound levels by the audio gain factor, is lower than the highest level of the finite range of audio levels.

Abstract: A method of registration in a communication system includes the steps of detecting (201) an elevated registration level of at least a part of a communication system, selecting (203) a group recovery time, determining (205) a first random registration time that is less than or equal to the group recovery time, registering (209) a first communication unit (111) from a first talkgroup at the first random registration time, and upon receiving (212) a group activity message for the first talkgroup, delaying (213) registration by at least a second communication unit (113) from the first talkgroup.

Abstract: A radio communication device (100) such as a mobile telephone comprises signal converters (110, 130, 140), a band-pass filter unit (120) and an oscillator (150). In the receiving mode (I) a first converter (110) converts an HF signal into an intermediate ZF signal (20) which, upon filtering by the band-pass filter unit (120), is converted into an NF signal by means of a second converter (130). In the transmission mode (II), the device (100) employs the first converter (110) and the filter (120) for compression of the dynamic range of a microphone signal (40). The first converter (110) converts the microphone signal (40) into a further intermediate ZF signal (50) which is subjected to amplitude limitation by means of a limiter circuit (121) in the filter unit (120) and filtered by means of a filter (122). The third converter (140) converts the filtered and limited signal (51, 52) again into a low-frequency signal (60).

Abstract: Encryption keys are transferred by obtaining a public and private key pair (42, 65) from a source device (21, 61). The public key is transmitted (42, 65) from the source device (43, 66) to a target device (23, 62). The target (23, 62) obtains a traffic key (44, 67) stored within the target device (23, 62). The traffic key is encrypted (45, 68) within the target device using the public key. The encrypted traffic key is transmitted to the source device (46, 69) where it is decrypted (47, 70) using the private key. The replacement encryption key(s) is(are) encrypted using the traffic key by the source device (48, 71) forming an encrypted replacement key message which contains a target slot identification for each of the replacement encryption keys. The encrypted replacement key message is transmitted to the target device (49, 72) where the replacement encryption key(s) is(are) recovered (50, 73). The replacement encryption key(s) is(are) then stored at the target device in an identified target slot (51).

Abstract: A method of handling an event by a plurality of consoles includes the steps of receiving an event (519) at a communication system and displaying the event at the consoles (101 and 117), wherein the event is displayed (525) using a first manner of display on each of the consoles (101 and 117). When the event is recognized (505) by a first console (101 and 117), the event is displayed (509) on the first console using a second manner of display in response to the recognition, and each of the consoles that is not the first console continues displaying (525) the event using the first manner of display. After the event is responded (511) to by a second console, the event is displayed (527) on the consoles using a third manner of display. After the event is responded to, the event is deleted (515) by a deleting console, and the event is displayed (533) on the consoles that is not the deleting console using a fourth manner of display and the displaying of the event is discontinued on the deleting console.

Abstract: A cellular radio communications system comprises: at least one base station for broadcasting radio signals to mobile stations within a cell; a mobile station addressable using IP addresses; and a first controller in the cell of the cellular radio communications system, the first controller being adapted: (i) to receive a request from the mobile station that the cellular radio communication system assign to the mobile station the static IP address previously assigned to the mobile station outside of the cell; (ii) in response to the request from the mobile station, to check with a second controller associated with the location where the mobile station was previously registered that the static IP address has not been assigned to another mobile station; and (iii) to assign the static IP address previously assigned to the mobile station, outside of the cell, to the mobile station for use in the cell, if the static IP address has not been assigned to another mobile station.