Abstract:
A coding system is disclosed wherein the receive side includes a decoder capable of producing, in addition to the hard information decoded output, either or both symbol and/or bit soft information values. For a certain information bit position, a value proportional to the joint probability that a received symbol and the set of all hypothesized transmitted codewords led to the estimated or detected hard information output is calculated. The calculated probabilities with respect to plural codewords having a zero in that certain information bit position are compared to the calculated probabilities with respect to the plural codewords having a one in that certain information bit position. The result of the comparison provides an indication of whether the hard information output in that same information bit position is more likely a one or a zero. The output soft information values are further processed in comparison to a preset threshold, with instances exceeding the threshold triggering block rejections and/or retransmissions.
Abstract:
A mobile subscriber enters a service code followed by a called party number (210). An application module (200) associated with a mobile station (40) stores (240) the received called party number at an attached Subscriber Identity Module (SIM) card (50). After determining (250) that the mobile station has traveled into the designated home zone (110), the application module retrieves the stored called party number and automatically originates an outgoing call (80) towards the called party number. By waiting until the mobile station has entered the home zone, the resulting call connection avoids additional air time charges.
Abstract:
Whenever a roaming mobile subscriber's preferred long distance carrier is not ascertainable by a visited Public Land Mobile Network (PLMN) (306), instead of utilizing a default long distance carrier selected by the visited PLMN, the serving mobile switching center (MSC) (106) analyzes the received International Mobile Subscriber Identity (IMSI) number to determine the home network provider or PLMN (10a) associated with the roaming mobile subscriber. Using the determined home network provider (130) data, the serving MSC retrieves the correlated home (PLMN) preferred long distance carrier data (140) from its associated register. A long distance carrier specified by the retrieved data is then utilized by the serving MSC to serve all long distance calls originated from and forwarded by the roaming mobile station (40).
Abstract:
A short-range wireless radio communications system is provided that can carry data, voice, or data and voice traffic simultaneously. The band is divided into a plurality of channels or hops, and a burst composed of either voice information, data information, or a combination of data and voice information is transmitted during one of the hops. The system operates preferably in a simplex mode, but full duplex operation can also be employed. The present system can also be operated in a cellular, TDMA system. A multiple time slot method is employed whereby one time slot can carry data and another time slot can carry voice information.
Abstract:
A cover (12) for a housing (14) is maintained in a fixed position with respect to the housing by a latch arrangement (10) that has at least one edge surface (38, 40) disposed along one edge of a flange (32) which engages a mating surface on the housing when the cover is assembled with the housing. The other side of the flange is integrally formed with an elongated beam (22) that is attached to the cover structure. The elongated beam is torsionally loaded upon assembly of the cover with the housing, and provides a bias force on the edge surface of the flange to maintain the forcible engagement of the edge surface with a mating surface (42) of the housing. The latch arrangement combines the cost effectiveness and space efficiency characteristics of plastic latch designs with the durability, dependability and tactile qualities of mechanical spring arrangements.
Abstract:
A dual band transceiver for operating in a first lower frequency band such as the band allocated to cellular systems, and in a second higher frequency band such as the band allocated to personal communication services (PCS) systems (as shown in Figs. 2-4). In a representative embodiment, the dual band transceiver (108 and 118) comprises a main voltage controlled oscillator (VCO) (134) for generating a local oscillator (LO) signal; an offset VCO (136) for generating an offset frequency (OF) signal; a first mixer (132) for combining the LO signal with the OF signal to produce a first transmit signal; a modulator (130) for modulating the first transmit signal with a data signal to produce a first data modulated transmit signal; and a second mixer (154) for combining the first data modulated transmit signal with the LO signal to produce a second data modulated signal. The main VCO (134) and the offset VCO (136) can be programmed such that the first data modulated transmit signal is in the first band and the second data modulated transmit signal is in the second band.
Abstract:
Whenever a subscriber associated with a plurality of subscriber features receives or originates a call, an application module associated with the serving local exchange links into the established call. The application module thereinafter intercepts all incoming calls towards that subscriber and transmits control data over the existing call connection to the subscriber terminal informing it of the new incoming call. The control data are transmitted over the existing call connection using out-of-band voice frequencies or during silent portions of the speech connection. Over the same existing call connection, the application module receives an instruction from the subscriber terminal for providing a particular terminating call treatment for this incoming call. The application module then provides the instructed terminating call treatment as instructed by the subscriber. Such a treatment may include call forwarding to a third subscriber, the enablement of call waiting, forwarding of the call to a voice mail, and similar subscriber services.
Abstract:
A method and apparatus for decoding digitally encoded communication signals transmitted over a fading channel. According to the disclosed embodiments, a sequence of test bits are transmitted in each TDMA slots, and a mathematical distance (e.g., a Hamming or Euclidean distance) is calculated and used to determine reliability information indicative of the reliability of the bits or symbols in a received time slot. Alternatively, a concatenated coding scheme can be used to transmit digital communication signals. Reliability information can be generated using the innner code and the output of the inner decoder.
Abstract:
A routing address representing an alternative terminal is assigned to a particular service area. Such a service area comprises a Local Access and Transport Area (LATA), Mobile Switching Center (MSC) area, Location Area, and Cell Area. Whenever an incoming call is received towards a mobile station currently located within the particular service area, instead of transmitting a routing address representing the mobile station, the serving Mobile Switching Center (MSC) transmits a signal containing the routing address representing the alternative terminal. Instead of routing the call to the intended mobile station, the Gateway Mobile Switching Center (GMSC) utilizes the received routing address and reroutes the incoming call to the alternative terminal. By rerouting all incoming calls towards the alternative terminal in case of an emergency, all available access channels are reserved for making outgoing calls by the mobile subscribers located within the emergency service area.
Abstract:
A method and apparatus for initializing a radio transmission apparatus comprising a voltage control oscillator, a phase lock loop, and a power amplifier is disclosed so as to avoid generating unwanted interference in neighboring radio channels. First, the voltage control oscillator is enabled and the phase locked loop is switched from a narrow band mode to a wide bandwidth mode to give faster settling time and reduced overshoot. The power amplifier is then smoothly ramped up to a final power level. Finally, the phase locked loop is switched from the wide bandwidth mode to the narrow bandwidth mode after the power amplifier has substantially reached the final power level.