Abstract: A phased array antenna that employs a switched least means squared architecture comprises plurality of receiving elements each having a respective weighting unit associated therewith, a summation unit, a processor, a plurality of sampling devise and a switching unit contains a switch arm having a contact at its free and, an ADC and a plurality of switch contacts corresponding to the ends of channels connected to the respective sampling devices. Each of a plurality of receiving elements is ampled by a respective sampling device prior to an incoming signal subjected to complex weighting by respective weighting units. Each of the signals sampled by the sampling device passes along respective channels to the switching unit. Thus, by switching between the contacts it is possible to vary which of the receiving elements is sampled.

Abstract: A digital communications system includes a transmitter and a receiver. The transmitter is capable of quadrature amplitude modulation (QAM) encoding each bit of at least one n-bit digital signal into at least one QAM signal and thereafter transmitting the QAM signals. And the receiver is capable of receiving the QAM signals and thereafter integrating the QAM signals. The receiver includes at least one tapped-delay line filter, which can then receive the integrated QAM signals and thereafter output a representation of each bit of the at least one n-bit digital signal.

Abstract: A communication system for transmitting encoded signals over a communication channel is disclosed. The system includes a transmitter, which has a source that is configured to output a plurality of input signals. The transmitter also includes an encoder that is configured to generate a plurality of output signals in response to the plurality of the input signals to output a code word according to the plurality of output signals, wherein the code word has a predetermined algebraic construction for space-frequency coding based upon the communication channel being characterized as a frequency selective block fading channel. Further, the transmitter includes a modulator that is configured to modulate the code word for transmission over the communication channel, and a plurality of transmit antennas that configured to transmit the modulated code word over the communication channel.

Abstract: In an automatic phase alignment circuit for a Cartesian feedback amplifier, the phase error is regularly monitored. In various implementations, this approach is used to provide true and continuous phase alignment. Based on a relationship between the up-converted and down-converted signals, another implementation of the invention provides phase-alignment for quadrature-phase components of a baseband signal by arithmetically combining the quadrature-phase components and the feedback components continuously and, in response, continuously phase-adjusting signals in the feed-forward signal path. Another aspect of the present invention is directed to an approach for calculating phase error for that is caused by DC-offset interference which, in turn, manifest at the outputs of many analog functional blocks.

Abstract: Embodiments of the invention provide for assigning bits to a discrete multi-tone modulation communications system. In an embodiment, one or more channels in the plurality of channels are assigned a number of bits based on a performance characteristic of that channel. One or more channels in the plurality of channels may also be assigned a gain value based on the performance characteristic of that channel.

Abstract: A method for data transmission includes forming a notched radio-frequency (RF) burst according to one or more data values, where a bandwidth of the notched RF burst is at least two percent of the center frequency of the notched RF burst. Forming a notched RF pulse includes altering, according to the data, at least one of the amplitude and phase of one or more selected components, where each of the selected components has a bandwidth within the bandwidth of the notched RF burst.

Abstract: Methods, apparatuses and systems are provided for identifying at least one multipath transmission delay within a reverse path data signal, determining at least one forward path pre-equalization parameter based on the transmission delay, and modifying a forward path data signal based on the forward path pre-equalization parameter. A reverse link transmission is used to help characterize the multipath delays that may exist between communicating devices. The reverse path data signal can include a training sequence or other like known/substantially-known data that can be analyzed to detect transmission delays, especially delays that extend beyond established guard intervals. Such pre-equalization techniques can be advantageously combined, for example, with antenna arrangements that support transmission diversity, spatial division transmission, and/or other like techniques.

Abstract: An RF transmitter provides both GSM and EDGE capability by implementing collector voltage control over the power transistor(s) in a power amplifier. During EDGE mode, linear base-biasing a power amplifier (PA) allows collector control to provide either saturated mode PA operation (during ramp up/ramp down) or linear mode PA operation (during data burst). Collector control can therefore be used to provide the accurate ramp up and ramp down profiles required for both GSM and EDGE burst output signals, and can also be used to set the level of the constant envelope data burst of a GSM burst output signal, while linear mode PA operation can provide the non-constant envelope EDGE data burst. A variable gain amplifier is used to adjust the input signal to the power amplifier such that the desired transmission level is achieved.

Abstract: It is becoming increasingly important to improve data throughput in wireless networks. By transmitting data simultaneously at different modulation amplitudes and/or using different code strengths, terminals having different carrier to noise ratios are able to decode the different amplitude levels with varying degrees of success. This allows distant terminals to receive low data rate transmissions at high modulation levels or code rates while nearer terminals can use additional capacity in the transmission by receiving lower level modulation signals or code rates. In this way, distant terminals do not degrade overall network performance. By arranging for terminals to acknowledge receipt of data, retransmission at different modulation levels or code rates may be carried out by the base station in order to improve performance in the presence of noise without a priori knowledge of the carrier to noise ratio for a particular terminal.

Abstract: The present invention is a method and apparatus to remove the adverse effects due to the imbalance between in-phase (I) and quadrature (Q) channels for I-Q demodulators and modulators in multi-carrier systems. A first balancer generates a first balancing signal from a first signal of a first index corresponding to a first frequency. A first combiner combines the first balancing signal and a second signal of a second index corresponding to a second frequency. The second frequency is symmetrical to the first frequency with respect to a center frequency in a multi-carrier composite signal. The first combiner generates a first balanced signal corresponding to the second frequency.

Abstract: A method and apparatus for monitoring and adjusting an analog signal of an operating circuit. The apparatus includes a control circuit, an analog-to-digital converter, and a comparator. The control circuit has an analog generator for generating the analog signal and an adjusting circuit for adjusting the strength of the analog signal. The analog-to-digital converter receives the analog signal and converts the analog signal to a digital signal. The comparator then compares the value of the digital signal to a predetermined value and generates a comparator signal. The adjusting circuit then receives the comparator signal and adjusts the strength of the analog signal based upon the value of the comparator signal. The method includes generating the analog signal, converting the analog signal to a digital signal, comparing the value of the digital signal to a predetermined value and adjusting the strength of the analog signal.

Abstract: A method is described for correcting sampling frequency offset (SFO) of a data packet in a communications system where carrier frequency (fc) and sampling frequency (fs) are driven by a common clock source. The method comprises, for each lth symbol in the data packet, estimating carrier frequency offset (CFO) in a received data packet. From the CFO estimate, an SFO estimate is derived, wherein the SFO is approximately equal to fs multiplied by said CFO estimate, and divided by fc. An SFO phase correction is generated according to the SFO estimate for each kth tone in a data stream. The SFO phase correction is then applied to each received data stream.

Abstract: A method and apparatus for processing a signal is presented. An accumulator receives an input signal and generates an accumulated value. A hysteresis controller sets an adjustable upper and lower limit. The upper and lower limits are compared with the accumulated value in a comparator. The comparator outputs a result, which is fed back into the hysteresis controller through a feedback loop. Once the input signal stays within the upper and lower limits, a test signal is considered within specification. When the input signal is outside of the boundary limits, a corrupt test signal is detected.

Abstract: A receiver determines a symbol synch time for recovering data from a symbol of signal samples generated in accordance with Orthogonal Frequency Division Multiplexing. Each symbol includes a guard period which carries data repeated from a data bearing part of the symbol and pilot signal samples. The receiver compromises a pilot assisted tracker, a guard adapted filter processor and a filter controller. The controller is operable to excite the filter with the symbol signal samples to generate an output signal which provides a further representation of the channel impulse response. A symbol time adjustment estimator is operable to adjust the symbol synch time in accordance with the adjustment provided by at least one the pilot assisted tracker and the guard adapted filter processor. The pilot assisted tracker estimates the symbol synch time from a channel impulse response estimate generated from pilot signal samples.

Abstract: An avoidance method for co-channel interference in a wireless network. The first step of the method is to evaluate an interference measure on each subcarrier. Based on the interference measure of each subcarrier, a peak-to-average measure ratio of interference within the received symbol is then obtained. If the peak-to-average measure ratio of interference is greater than a predetermined threshold, a most interfered subcarrier at which the maximal interference measure occurs is detected. Accordingly, a downgrading factor is set for the most interfered subcarrier.

Abstract: Error contributions in a DMT system where a received DMT-signal is effected by intersymbol interference, intercarrier interference and additive noise are minimized. Intersymbol interference average power, intercarrier interference average power, and additive noise average power are calculated. A cost function is determined by adding the intersymbol interference average power, the intercarrier interference average power, and the additive noise average power. A constraint is introduced which avoids a trivial solution where a time domain equalizer (TEQ) vector is equal to zero. The cost function is minimized by optimizing the TEQ vector.

Abstract: Double data rate (DDR) synchronous dynamic random access memory (SDRAM) data is sampled into a synchronization circuit on both rising and falling edges of a data strobe (DQS) signal, into separate latches. A delay calculation and timing synchronization unit determines the location of the data strobe signal relative to rising/falling edges of an internal clock, then decides which sample to transfer into the internal data path and whether to use the rising or falling internal clock edge. Every DDR-SDRAM read transaction is thus automatically synchronized without the need for predetermined delay(s), allowing a wide range of operating frequencies and frequency variations to be accommodated.

Abstract: A substantially passive implementation of a clock recovery circuit may be employed to reduce or eliminate the amount of jitter added to the recovered clock by the recovery circuitry. NRZ data may be received in differential form (i.e., a separate NRZ signal and an inverted NRZ signal are received). The inverted NRZ data may be delayed by one-half of a unit interval with respect to the NRZ data by a delay element. The NRZ data and the delayed NRZ data may be combined by a broadband combiner (e.g., a resistive adder). The combined signal may be split into two signals. The two split signals may be rectified by suitable components. One of the limited split signals may be subtracted from the other limited split signal to generate an output signal. The generated output signal then possesses a spectral component at a clock frequency of the NRZ data.

Abstract: A noise-resistive, burst-mode receiving apparatus including a voltage control signal generator for multiplying a frequency of a system clock signal and generating a voltage control signal having a level that corresponds to the multiplied frequency; a reset signal generator for delaying an irregular input signal in the unit of a packet, in response to the voltage control signal, performing an exclusive OR operation on the delayed and input signals, and outputting the result as a reset signal; a clock signal generator for generating a signal having a level that is changed at the middle point of each bit included in the packet as a recovered clock signal in response to the reset signal and the voltage control signal and outputting the recovered clock signal; and an output buffer for buffering the input signal and outputting the buffered signal as recovered data in response to the recovered clock signal.

Abstract: A fully integrated single-loop frequency synthesizer, which can serve as a local oscillator for a broadband tuner, is disclosed, thus allowing the creation of a single-chip solution for broadband applications. The tank circuits are integrated into the tuner chip through the combination of a phase-locked loop and multiple on-chip VCOs comprising narrow-tuning range varactors. Drift in the VCOs caused by heat is overcome by designing the VCOs to overlap each other. Initial tolerance problems associated with the VCOs are overcome by the use of a calibration method. The calibration of the VCOs is accomplished by utilizing the lock detect output of the phase-locked loop and a binary search algorithm. The edges of each VCO are determined with this calibration method, thereby enabling VCO selection based on the desired channel. A sufficient number of VCOs are provided such that whatever the initial tolerance shift, the full broadband spectrum can still be covered after calibration.

Abstract: A system and method for monitoring rod moving coils in nuclear power system. The system ensures that these coils are each functioning properly, and thus prevent movement of the other coils when a dysfunctional coil is detected. The method for accomplishing this monitoring is to provide constant power to all of the coils and to measure the negatively induced EMF from this induction. This level of EMF is then compared to a standard EMF. When the EMF level is below a threshold limit, which may be either preset or calculated from a variety of other variables, a signal is sent to an alarm.

Abstract: A basket has a lattice-like section for accommodating individual used nuclear fuel in predetermined positions in a cask. The basket is made from aluminum composite material having good neutron absorption ability, excellent mechanical property and workability. The aluminum composite material is made by having, in an Al or Al alloy base phase, B or B compound with a neutron absorption ability and an additive element, e.g. Zr or Ti, for giving a high strength property, and subjecting to a sintering under pressure.

Abstract: The invention relates to a shift register cell for safely providing a configuration bit having a master latch which can be connected to a serial data input on the shift register cell for the purpose of buffer storing a data bit; a first slave latch which can be connected to the master latch for the purpose of buffer storing the data bit; at least one second slave latch which can be connected to the master latch for the purpose of buffer storing the data bit, and having an evaluation logic unit which outputs the configuration bit on the basis of the data bits which are buffer stored in the master latch and in the slave latches. In addition, the invention provides a shift register for safely providing configuration bits which has a plurality of inventive shift register cells which are connected in series to form a shift register chain.

Abstract: A method for collecting computed tomography (CT) image data includes determining a number of intervals N into which a respiratory cycle is to be divided, determining a number of respiratory cycles M to be covered in one gantry rotation, and rotating a gantry to collect at least M×N sets of CT image data of at least a portion of a patient, wherein each set of the CT image data corresponds to a phase of a respiratory cycle.

Abstract: The present invention is directed to scintillator module for a CT detector as well as an apparatus and method of manufacturing the same. The scintillator module is comprised of a scintillator array having a plurality of scintillators aligned in parallel with respect to one another. A collimator assembly includes a comb having a number of teeth and a plurality of collimator plates positioned proximate to the scintillator array. The scintillator array includes at least one indexing pin extending therefrom. The indexing pin engages the comb and is constructed to improve alignment of the scintillator array relative to the collimator plates.

Abstract: The present invention provides a computed tomography system that only requires rotational scans for image pickup, the system enabling images of a plurality of testing objects to be simultaneously picked up without increasing the volume of noise or the scale of the system, thus enabling high-quality tomographic images to be efficiently picked up. In the computed tomography system, a plurality of turn tables 11a to 11d are provided in a region of irradiation with X-ray beams emitted by an X-ray irradiation system. Testing objects Ma to Md are placed on the respective turn tables. Images of the plurality of testing objects can be simultaneously picked up by irradiation with X-ray beams. This enables precise image pickup to be efficiently achieved without increasing the size of the scale.

Abstract: An apparatus for imaging objects with x rays using an x-ray tube, refractive x-ray lens and area detector. Cross sectional images of individual planes within an object are achieved through tomographic and laminographic exposure and image processing. The use of refractive x-ray lenses to achieve high resolution eliminates the need for vanishingly small microspot x-ray sources to achieve high resolution that current x-ray tomographic and laminographic systems suffer.

Abstract: Method and device for digital x-ray tomosynthesis. Tomographic and/or three-dimensional images of an object are obtained with an x-ray source and a digital x-ray image sensor. The source, object and sensor are positioned relative to each other and attenuation data is obtained for a large number of rays of x-radiation through the object. A special algorithm is provided to convert the data into images. To calculate the images the algorithm uses iterative processes with a least squares type technique but with generalized (as opposed to specific) functions. The algorithm solves for the functions which are the images.

Abstract: An imaging inspection apparatus which utilizes a plurality of individual imaging inspection devices (e.g., X-ray Computer Tomography scanning devices) positioned on a frame for directing beams onto articles having objects therein to detect the objects based on established criteria. The apparatus utilizes a conveyor which is not physically coupled to the frame having the imaging inspection devices to pass the articles along a path of travel to an inspection location within the apparatus, whereupon the inspection devices direct beams onto the article and the beams are detected and output signals provided to a processing and analysis assembly which analyzes the signals and identifies certain objects which meet the criteria.

Abstract: An x-ray tube emits X-rays in response to a current control signal. An X-ray detector detects the emitted X-rays and provides a detected X-ray signal indicative thereof to a control system, which provides the current control signal. The X-ray detector provides feedback stabilization of the X-ray output from a source of X-rays, such as, for example an X-ray tube. The detector produces an electrical signal proportional to the X-ray output of the X-ray tube, and that signal is used to control the electron beam current in the tube in order to stabilize the X-ray output of the tube at a predetermined value.

Abstract: An X-ray imaging apparatus includes a body unit including a bed unit where an object is put, an X-ray irradiation unit configured to irradiate an X-ray to the object and an X-ray detector configured to detect the X-ray passing through the object, an input unit configured to input control information to control at least part of operation of the body unit, a selection unit configured to select ON or OFF of a lock mode and a controller configured to determine at least part of the control information is locked when the lock mode is ON and the at least part of the control information is released when the lock mode is OFF.

Abstract: The connection architecture is configured to digitally monitor filters therein, directly connecting a test table to the intermediate distribution frame without requiring wiring to the DSLAM. Filter cards of the dominant operators and of second operators, at least one smart card containing the relays that are activated from the test table, for which a digital bus is used, allowing measurement of the subscriber loop for filters of second operators and the DSLAM signal as well for the dominant operator, are further provided with an additional card in charge of receiving and distributing the signal that arrives from the DSLAM, between the filters, and connectors to which are connected the filter cards so that when they are extracted, the input (voice) is connected to the output (voice +data) so that the voice signal is not disconnected.

Abstract: A telecommunications system central office includes a piece of central office equipment and a cross-connect frame that is configured to provide a connection point to the piece of central office electronic equipment. An electronic looping system is connected between the piece of central office equipment and the cross-connect frame. The electronic looping system includes electronically controlled switches that are operable to loop selected transmission paths between the piece of central office equipment and the electronic looping system, to open selected transmission paths between the piece of central office electronic equipment and the electronic looping system, to loop selected transmission paths between the electronic looping system and the cross-connect frame, to open selected transmission paths between the electronic looping system and the cross-connect frame and/or to pass-through selected transmission paths between the piece of electronic equipment and the cross-connect frame.

Abstract: An apparatus for the management and the remote and/or automatic control of electric characteristics and signal transmissivity of the metallic line pairs connected to a telephone exchange, including measurement means and means able to connect said measurement means to the single line pairs connected to the telephone exchange and to all of the lines of a distribution whether they are active or redundant.

Abstract: The present invention is related to the delivery of requests for emergency service initially handled by an emergency service call center to a public safety answering point. The invention additionally allows for enhancement information to be provided to a public safety answering point operator visually in connection with calls routed to that public safety answering point. This information may include caller identification, and additional information, such as information regarding the location of the caller and the nature of the emergency. Furthermore, the routing of requests for emergency service to an appropriate public safety answering point can be accomplished for requests received over a wide geographic area. In particular, requests can be appropriately routed even though they may originate from locations encompassed by different E9-1-1 tandems.

Abstract: The invention includes a communication network that comprises a conforming emergency system coupled to an emergency services network by a media channel. The emergency services network includes a resource coupled to a plurality of emergency services. When in operation, the conforming emergency system transmits an emergency event message to the resource over the media channel. The emergency event message includes a retrieval key. Responsive to receiving the emergency event message and the retrieval key, the resource initiates an emergency event session corresponding with the retrieval key. During the emergency event session, the resource transmits multiple responses to the conforming emergency system. Also during the emergency event session, the resource receives information corresponding with the retrieval key from at least one of the emergency services, and transmits the multiple responses containing the information.

Abstract: In order that emergency service vehicles can be dispatched to the correct destination promptly, accurate information about the location of the caller is needed. Another problem concerns routing emergency calls to the correct destination. For emergency calls a universal code is used such as 911 in North America and 112 in Europe. This universal code cannot be used to identify the destination of the call. These problems are particularly acute for nomadic communications systems such as voice over internet protocol communications networks. That is because user terminals change network location. These problems are solved by enabling the geographical location of the emergency caller to be determined by entities within a packet-based network without the need for modification of existing emergency services network infrastructure.

Abstract: A system and method that provides a map image as part of, or along with, ALI information by dispatching a map query to a central map server after receipt of the ALI information, which includes an address, geo-coordinates or both. A map image corresponding to the requested location is returned. The ALI database may request the map image after retrieving or determining the location of the caller. Data to generate map images is stored in a central server or group of servers. In this manner, the data only has to be updated once for all users to have the updates. Further, the map server may be connected to wireline telephone facilities, wireless telephone facilities, or both, in a manner that is complimentary to the topography of the telephone network.

Abstract: A system to enable TTY communication between a legacy TTY phone and an IP phone over a packet network using a TTY relay protocol established between the IP phone and a media gateway at a central office of the PSTN. The system may also use a voice over Internet Protocol gateway to connect a personal computer to the packet network instead of an IP phone to accomplish TTY communication between software on the computer and a legacy TTY phone.

Abstract: Embodiments of the invention are directed to automated reception systems that may receive voice information indicating action to be taken by the system. The automated reception system may receive a call and transmit a speech message to the caller identifying actions that the caller may ask the system to take. The caller may verbally select an action for the system to execute. Possible actions may depend upon the system context and information about possible actions may be provided to the caller through dynamically generated messages. The caller may also access voicemail or electronic mail messages using embodiments of the invention. Furthermore, in some embodiments, a caller may be able to control a separate communication session using voice or other commands input during a telephone session.

Abstract: The event driven multi-media communication management system comprises a controller that interfaces with a plurality of communication space stations and with one or more communication medium service providers. The communication space station is a modular device that includes a platform, a voice system for providing an audio user interface, and a docking bay for coupling with a subscriber device. The controller accesses a subscriber contact directory that is associated with the subscriber device, communicates content messages representing at least a portion of the subscriber contact directory to the subscriber station, receives control messages representing subscriber selection of a contact, and establishes a communication channel in accordance with the selected subscriber communication information.

Abstract: Methods and apparatus are described for creating, scheduling and delivering messages. A message having a first audio component is generated in response to input from a user. The input includes words entered by the user. The first audio component is operable to facilitate audible playback of the words. Delivery of the message at a future time to a communication device is scheduled in response to specification of the future time by the user. A connection to the communication device is established at the future time via a communications network. The message is transmitted over the connection such that the words associated with the first audio component of the message are audible via the communication device.

Abstract: In a CTI system an incoming call is alerted to the called user's list of users who have expressed a primary level of interest in that called user's incoming calls, and the call is routed by the PBX to a Voicemail system if, for example the call is not answered within a predetermined time. The Voicemail system plays an announcement inviting the caller to key “one” to have the call re-presented, and if that digit is keyed by the caller, the Voicemail system makes a call to a predetermined extension of the PBX. The PBX recognizes, e.g. by using call ID or DNIS, that the call received on that extension is a re-presented call, and alerts the called user's list of users who have expressed a secondary level of interest, with or without alerting the “primary” list users. A tertiary list of users who have expressed a tertiary level of interest in that called user's incoming calls may be used in the event that the call is routed to the Voicemail system for a second time and the caller again keys “one”.

Abstract: A system for providing voicemail services includes a network device that receives voicemail messages intended for subscribers. The subscribers may be associated with a number of different local telephone service providers. The network device also stores the voicemail messages for later retrieval by the subscribers.

Abstract: A mechanism is disclosed for displaying, on a telephone display, actions that are appropriate for a particular context when accessing a voice mail system (VMS). These actions may vary depending on the context of a user's access to the VMS. The actions are identified by text adjacent to buttons (softkeys) on the user's telephone, and are initiated when the user pushes the softkey associated with a particular action. The softkey text corresponding to a particular state of the user's access to the VMS is identified herein as a VMS softkey template. When the VMS and a telephone switch are first initialized, template information is downloaded from the VMS to the switch, and thereafter, when the VMS is accessed by a user via a telephone, runtime instructions passed between the VMS and the switch will direct the switch to display softkey templates corresponding to a particular context within the VMS.

Abstract: Devices, softwares and methods selectively limit a duration of an individual modem-on hold session. A network device receives and holds data for an individualized on-hold timeout time limit for each user, such as an ISP subscriber.

Abstract: Calling plan information is provided whenever a user makes a call that fits within the plan. The user may be assigned an account related to the calling plan with information associated with the account. The information may include a time function such as the time remaining until expiration of the calling plan or the time used in the calling plan. A call made from an originating number that is associated with the calling plan triggers the provision of information. After the information is provided, the call may be routed to a terminating number as dialed by the user. After the call, the information associated with the calling plan may be updated.

Abstract: A residential phone system allows for local control of call features from any phone extension. The phone system may include a microcontroller that communicates along the phone lines at a non-utilized frequency to several extension phones in a residence. The microcontroller permits each phone to control call features such as call waiting, conference calling, paging, or other features. A control box may be included at any or all of the extension phones to provide a convenient user interface to access the call features.

Abstract: A system for implementing telephone services on one or more telephone installations, themselves having several telephone terminals managed by one or more private automatic branch exchanges. To this end, the system has a piece of server type computer equipment, accessible by a computer network, and one or more interfaces capable of sending signaling control signals corresponding to the service or services requested to drive one or more automatic branch exchanges, these interfaces being connected for this purpose to telephone lines of the automatic branch exchanges.

Abstract: The multi-media communication management system comprises a controller that interfaces with a plurality of communication space stations and with one or more communication medium service providers. The controller provides for multicasting or real time voice communications to selected recipients. To provide such multicasting, the controller receives a recipient list of subscribers to include in the multicast session. The controller identifies a communication space station serving a subscriber device associated with each recipient and invites such communication space station to the multicast session. If a recipient's subscriber device is not served by a communication space station, the multicast message is packaged as an audio file and sent to the recipient by e-mail.