Abstract: Embodiments of systems and methods for the coexistence of wireless radios having differing protocols are generally described herein. Other embodiments may be described and claimed. In some embodiments systems and methods for synchronizing clocks between two radios, and using a signal to notify one of the radios to refrain from transmitting for a timeperiod are described.

Abstract: Embodiments of the present disclosure provide a transmitter, a receiver and methods of operating a transmitter and a receiver. In one embodiment, the transmitter for use in a base station of an OFDMA system and includes a primary module configured to provide a primary synchronization signal that furnishes a partial cell identity. Additionally, the transmitter also includes a secondary module configured to provide a secondary synchronization signal that furnishes a cell identity group and one or more cell-specific parameters based on using a two-segment secondary synchronization sequence. The transmitter further includes a transmit module configured to transmit the primary and secondary synchronization signals.

Abstract: A differential transmitter and an auto-adjustment method of data strobe thereof are provided. The differential transmitter includes a phase-detecting unit, a switching unit, a rising edge strobe unit, and a falling edge strobe unit. The phase-detecting unit detects a phase relation between a clock signal and a data signal to outputs a detection result. The rising edge strobe unit latches the data signal at a rising edge of the clock signal, and converts a latching result to a first differential output signal. The falling-edge-strobe unit latches the data signal at a falling edge of the clock signal, and converts a latching result to a second differential output signal. The switching unit determines whether to switch the clock signal and data signal to the rising edge strobe unit or to the falling edge strobe unit according to the detection result.

Abstract: A system includes a first cluster having multiple first wireless nodes. One first node is configured to act as a first cluster master, and other first nodes are configured to receive time synchronization information provided by the first cluster master. The system also includes a second cluster having one or more second wireless nodes. One second node is configured to act as a second cluster master, and any other second nodes configured to receive time synchronization information provided by the second cluster master. The system further includes a manager configured to merge the clusters into a combined cluster. One of the nodes is configured to act as a single cluster master for the combined cluster, and the other nodes are configured to receive time synchronization information provided by the single cluster master.

Abstract: The present invention increases the available spectrum in a wireless network by sharing existing allocated (and in-use) portions of the RF spectrum in a manner that will minimize the probability of interfering with existing legacy users. The invention provides interference temperature-adaptive waveforms, and a variety of physical and media access control protocols for generating waveforms based on measurement and characterization of the local spectrum. The invention measures the local spectrum at a receiving node, generates an optimal waveform profile specifying transmission parameters that will water-fill unused spectrum up to an interference limit without causing harmful interference to primary and legacy transmitters using the same frequency bands, and enables simultaneous transmit and receive modes at a multiplicity of transceivers in a wireless network.

Abstract: A device has a radio transmitter for a first radio link such as a Bluetooth link, having a coexistence controller arranged to communicate with a co-located other radio transmitter for another radio link, to enable both radio links to use potentially conflicting transmission frequencies. A link monitor monitors the first radio link, according to an output from the coexistence controller. By making the link monitor dependent on the coexistence controller, it can distinguish between transmission losses caused by the coexistence interface, and those caused by other effects, to reduce the risk of a data rate controller unnecessarily reducing a transmission rate if transmission losses caused by the coexistence control are misinterpreted as a drop in link quality.

Abstract: A wireless communication method capable of preventing communication interference and cut-off in one-to-multi wireless communication.

Abstract: A method of handling a variable of a Radio Link Control reset procedure during receiver-side-only re-establishment in a wireless communications system includes resetting a reset state variable, used for counting the number of times a RESET protocol data unit is scheduled to be transmitted, during receiver-side-only re-establishment.

Abstract: An RF transmitter that, during a transmission session, transmits multiple data slices, which are synchronized to each other by a transmit counter. Typically, the time between transmission of consecutive data slices is constant; however, to synchronize the transmission session with a base station, the time between transmission of consecutive data slices may be occasionally adjusted. By using the transmit counter to synchronize data transmissions, effects of uncompensated latencies or variances in latencies may be reduced or eliminated.

Abstract: A communication system for supporting communications with a target market area. The system includes one or more solar-powered aircraft maintained in, or successively passing through, flight stations or flight patterns around the market area. Each of the aircraft targets limited beamwidth communication antennas on a substantial portion of the target market area. The control system is configured to fly selective flight patterns depending on the aircraft characteristics and the flight conditions. The flight patterns may emphasize high-power-generation patterns such as flying away from the sun for aircraft with wing-mounted solar cells.

Abstract: An input bit stream including a clock signal and data bits is oversampled to obtain one or more sets of data samples. One or more sets of non-transitioning phases corresponding to data samples that do not switch between zero and one are then identified. Center phases corresponding to the one or more sets of non-transitioning phases are identified and then a final center phase that accurately represents the bits belonging to the input bit stream is selected. The data samples corresponding to the final center phase are extracted, thereby recovering the clock signal and data bits from the input bit stream.

Abstract: The invention relates to a method comprising the steps of: a first network device (DEVI) outputting content (CONT), the first network device (DEVI) retrieving an address (ADDR2) of a second network device (DEV2) from a third device (DEV3), and the first network device (DEVI) transmitting said content (CONT), which was output at the time of retrieving said address (ADDR2), to said second network device (DEV2). Furthermore, the invention relates to a network device (DEVI), comprising: means for outputting content (CONT), means for retrieving an address (ADDR2) of a second network device (DEV2) from a third device (DEV3), and means for transmitting said content (CONT), which was output at the time of retrieving said address (ADDR2), to said second network device (DEV2).

Abstract: The invention relates to method and device for detecting propagation paths in pulse transmission, wherein a received signal comprises pulses on each time symbol. After synchronizing a pulse-based reception, the inventive method consists (A) in determining the arrival times of pulses of the same current time symbol, (B) in generating a path hypotheses by assigning an initial score to each dated pulse, (C) in determining the arrival times of pulses of the time symbol following the current symbol, (D) in relatively comparing the arrival times of pulses of the following time symbol with the arrival times of the path hypotheses and (E) in updating scores according to the relative comparison results. Said path detecting method is suitable for pulse information transmission, in particular in UWB.

Abstract: In one embodiment, whether packet loss of link layer packets at a receiver has exceeded a lost threshold is detected. Feedback is sent to a transmitter indicating that a header compressor, for compressing higher layer packets at the transmitter, should send a less compressed header if the packet loss of the link layer packets has exceeded the lost threshold. The higher layer packets are at a higher layer than the link layer and are formed by the link layer packets.

Abstract: Synchronized UWB piconets for SOP (Simultaneously Operating Piconet) performance. A common backbone (either wired or wireless) is employed that provides a common CLK (clock signal) to all of the various PNCs (piconet coordinators) of various piconets that may operate within a sufficiently close region such that interference could undesirably occur. By providing a very reliable CLK signal from a common backbone to all of the PNCs of the various piconets operating within a substantially close proximity to one another, very precise synchronization may be ensured for all of the communications performed therein. The various piconets may then even operate using TDMA (Time Division Multiple Access)—whose performance would be substantially compromised without effective synchronization. In addition, combined TFC (time frequency code) and TDMA may also be employed to support the communications therein thereby providing even another degree of orthogonality that provided by TDMA alone.

Abstract: A network having multiple radios transmits a beacon signal from several radios substantially simultaneously. One embodiment includes a network having a communications backbone that connects several radio transceivers. Another embodiment includes a single station having multiple radio transceivers, which may or may not have directional antennas. Various methods for synchronizing the beacon signals may be used, including transmitting a heartbeat signal along the network so that the beacon signals are broadcast substantially simultaneously.

Abstract: A method and apparatus for synchronizing a system clock with a serving cell (102) associated with a first radio access technology and monitoring an adjacent cell (104) associated with a second radio access technology is provided. A communication device (100) includes a first synchronization device (205) capable of synchronization with the serving cell (102) and a second synchronization device (206) capable of independently synchronizing with the adjacent cell (104). The first synchronization device (205) and second synchronization device (206) include independent frequency correction modules (207,208). Thus, the second frequency synchronization device (206) may be corrected per the adjacent cell (104) while the first synchronization device (205) remains synchronized with the serving cell (102). Thus, the same corrected system clock may be used between two radio access technologies.

Abstract: Aspects of a method and system for frame timing acquisition in evolved universal terrestrial radio access (EUTRA) may include determining a received secondary synchronization sequence (SSS) based on a selected cyclic prefix length and on synchronization of a primary synchronization sequence (PSS). A first portion of information associated with the received SSS may be processed separately from a second portion of information associated with the received SSS. A frame timing and/or base station identifier may be determined by comparing the processed first portion of information with the processed second portion of information. The cyclic prefix length may be selected from a finite set of possible cyclic prefix lengths. The cyclic prefix length may be, for example, 9 samples or 32 samples. The primary synchronization sequence synchronization may be determined via correlation.

Abstract: Apparatus, systems, and methods are provided for transmitting messages over a serial interface. A method comprises receiving a first signal at a first time and receiving a second signal at a second time, the second time being after the first time. If a difference between the second time and the first time is less than a threshold time period, the method comprises generating a first message that is representative of the first signal and the second signal and transmitting the first message over the serial interface. In accordance with one embodiment, the threshold time period is equal to one half of an interface acquisition delay time period associated with the serial interface.

Abstract: An embodiment of the present invention provides a method for discovering services provided in a wireless network, comprising enabling devices equipped with radio interfaces to advertise the services it provides and discover services offered by other nearby devices without establishing a network connection with the devices.

Abstract: An embodiment of the invention may include a method of receiving a transmission at a receiver. The method may include setting a receive window duration for receiving the transmission based on an elapsed time since last receiving a good transmission. The receive window duration may be a nonlinear function of the elapsed time. The method may further include opening a receive window to listen for the transmission for an amount of time equal to the set receive window duration.

Abstract: A communication system allocates a discrete line between a base station and each terminal device that allows discrete communication in a time span equivalent to several frames. The communication system includes a base station that has a processing function unit processing a physical layer using a given data format, and terminal devices each using an up-link line allocated by the base station. In the system, the base station and each terminal device communicates with each other by the orthogonal frequency division multiplexing method. The base station sends out a preamble signal cyclically, and has a means that sends out a vacant discrete connection identifier for identifying a vacant up-link line for a terminal device to send data to the base station when the base station receives an up-link line request from the terminal device.

Abstract: A multicarrier communication apparatus that is capable of suppressing interference of feedback information with other channels and alleviating a reduction in an uplink capacity. In PL signal reception section (260) of this apparatus, PL signal extraction section (261) extracts pilot signals and reception quality measuring section (262) measures reception quality such as an SIR. Here, since pilot signals are included in respective subcarriers, reception quality measuring section (262) measures reception quality of subcarriers. FBSC determining section (270) determines a feedback information subcarrier based on the reception quality of subcarriers. More specifically, FBSC determining section (270) determines a subcarrier having the highest reception quality as a feedback information subcarrier. FBSC determining section (270) outputs information about the feedback information subcarrier (FBSC information) to control CH transmission section (110) and FB information reception section (250).

Abstract: The present invention relates to an apparatus and method for estimating and compensating for a time offset and a carrier frequency offset in a Multiple Input Multiple Output (MIMO) communication system that supports Orthogonal Frequency Division Multiplexing (OFDM) or Orthogonal Frequency Division Multiplexing Access (OFDMA). According to the present invention, a phase difference of pilot signals of the same transmitting antenna, which are received through receiving antennas, is calculated. An arc tangent operation is then carried out on the phase difference of the pilot signals to calculate a time offset linear phase and/or a carrier frequency offset linear phase. Further, a time offset compensation value and/or a carrier frequency offset compensation value are found by employing the time offset linear phase and/or the carrier frequency offset linear phase.

Abstract: An apparatus for a base station of a wireless communication network includes a detector to detect an access code received from a mobile station in each of a plurality of time durations and to detect a timing offset of the access code detected in each of the plurality of time durations, an estimator to estimate a carrier-to-interference noise ratio (CINR) during each of the plurality of time durations, and a determining unit to determine a timing offset correction value to be applied to subsequent signals from the mobile station using the CINR, the timing offset, and the access code detected in each of the plurality of time durations.

Abstract: A base station is configured to reduce interference with other base stations and/or devices in a multi-cell wireless network. The base station includes a wireless interface, detector and controller. To reduce interference, the wireless interface may provide services to a first wireless communication device (WCD) using a pilot signal emitted from the base station at a reduced power level. In the reduced pilot signal mode, when the detector detects a second WCD within the base station's service area, the controller increases the pilot signal's power level above the reduced power level in order to establish communications with the second WCD. Upon successfully connecting to the first and second WCDs, the base station may again reduce the pilot signal's power level to reduce interference with other base stations or wireless devices.

Abstract: A method for providing a personalized bidirectional channel in broadcasting systems. In cellular broadcasting system the method contains the steps of: allocating a first group of subcarriers to broadcast transmission and a second group of subcarriers to personalized channels; reducing interference in the broadcast transmission by using equalizer; and reducing interference in the personalized channels by using controlled allocation of subcarriers in the second group to each subscriber. In OFDM broadcasting system the method contains the steps of: transmitting OFDM transmission from the base-station to the subscriber units; transmitting from the subscriber units to the base-station signals that are orthogonal to signals transmitted from the base-station; and receiving the orthogonal signals at the base-station.

Abstract: The MS detects a difference in timing or frequency between a reference signal being any one of the received signals from a plurality of BSs and each of the other received signals, notifies the results of detection to BSs other than the source BS of the reference signal, and the BSs other than the source BS of the reference signal control the timing or frequency of transmission of the signal to be received by other MSs other than the MS on the basis of the results of the detection.

Abstract: A multi-cell communication system comprises at least a first base station and first terminal and a second base station and second terminal. When the first and second base stations need to perform interference control, the first terminal may relay a message related to the interference control between the first base station and the second base station. That is, the first terminal may transfer a message related to the interference control from the first base station to the second base station, and a message related to the interference control from the second base station to the first base station. As such, the first base station and the second base station can transmit/receive messages that are for performing interference control via the first terminal.

Abstract: Techniques and apparatus are described for detecting a position of a target. A position detection device associated with a wireless communication system includes an accumulator to sample and accumulate a pulse signal included in an input signal. A double-sliding window is connected to the accumulator to detect a starting point of the input signal. Also, a synchronization controller is connected to the accumulator to generate a synchronization signal to enable the accumulator to sample and accumulate the pulse signal. In addition, a time shift calculator is connected to the accumulator to correct the detected starting point of the input signal based on the accumulated pulse signal. Further, a position calculator is connected to the time shift calculator to calculate a position of a target based on the corrected starting point.

Abstract: A method and system for GPS (Geographical Positioning System) synchronization of a femtocell, as defined in the application, in a wireless telecommunications network, the system including a Base Transceiver Station (a “sync-BTS”) for transmitting synchronization signals, a module for GPS synchronization coupled to the sync-BTS, at least one femtocell, and a processor in each femtocell for performing time and frequency synchronization on the sync-BTS over an air interface.

Abstract: Aspects of a method and system for compensating for using a transmitter to calibrate a receiver for channel equalization are provided. Various embodiments of the invention may be applicable wireless devices in TDM systems, Bluetooth, and/or WLAN applications, for example. Transmit tones may be generated by a transmitter PLL and the baseband response may be measured for each of the injected tones. The tones may be swept over a frequency range and a corresponding oscillator signal may be mixed with the received signal to determine the response of, for example, the receiver filters. Adjusting any of a plurality of receiver and/or transmitter parameters based on baseband measurements may provide appropriate channel compensation or calibration. Accordingly, the baseband circuitry may generate equalization signals, which may be utilized to adjust receiver and/or transmitter circuitry. This approach may be provide I/Q balancing and transmit filtering calibration after receiver calibration is completed.

Abstract: A communication method includes establishing a first communication session over a first connection between a wireless terminal and a base station (BS) of a long-range wireless data network, which operates in accordance with a first protocol that defines a sequence of time frames. Based on the time frames defined by the BS, time slots are allocated for establishing a second communication session over a second connection between the wireless terminal and a peripheral wireless device, which operates in accordance with a second, short-range time-slotted communication protocol different from the first protocol. Time intervals are allocated within the time frames for communication between the BS and the wireless terminal over the first connection, such that the allocated time intervals are interleaved with and do not overlap the allocated time slots. The first and second communication sessions are concurrently conducted in the allocated time intervals and the assigned time slots, respectively.

Abstract: In one embodiment, the present invention provide a method for detecting signal quality metrics of a constant modulo (CM) signal received in two different signal paths, and combining the signal from the two signal paths based at least in part on the detected first and second signal quality metrics. Such method may be implemented in a radio receiver such as an automobile receiver.

Abstract: Providing a frequency reference to a mobile telecommunications base station is disclosed. A radio frequency signal that includes a periodic component having a known frequency is received. A frequency reference is derived from the received radio signal, based at least in part on the periodic component. The frequency reference is used to transmit from the base station at an assigned frequency.

Abstract: A method of spectrum access for wireless communications by a secondary unlicensed unit in a CRN environment comprising one or more secondary unlicensed mobile units and one or more primary licensed units includes receiving information indicative of a location and movement of one or more secondary unlicensed units and a channel usage pattern and spatial distribution of one or more primary licensed units is accessed and a guard distance to shield the one or more primary licensed units from interference is calculated. The channel availability to the one or more secondary unlicensed units is then calculated according to a two-state Markov model including the guard distance as a constraint and based on the information indicative of the location and movement of the one or more secondary unlicensed units and the channel usage pattern and spatial distribution of the one or more primary licensed units.

Abstract: A method for verifying alignment between first and second integrated devices coupled together using a reference and a coupling capacitor, including: transmitting a reference signal on a transmission electrode of the reference capacitor; receiving a coupling signal on a reception electrode of the reference capacitor; amplifying the coupling signal, generating a reception reference signal; generating a reception control signal as a function of the reception reference signal; transmitting a communication signal on an electrode of the coupling capacitor; receiving a reception signal on an electrode of the coupling capacitor; amplifying the reception signal, generating a first compensated signal; controlling a level of amplification of amplifying the coupling signal and the reception signal as a function of the reception control signal; and detecting a possible misalignment between the first and second devices based on an amplitude of the communication signal and an amplitude of the compensated signal.

Abstract: A base station apparatus is disclosed for use in a mobile communication system including multiple cells having multiple sectors. The base station apparatus includes a synchronization channel generation unit configured to generate a synchronization channel for use in cell search by a user apparatus and a transmitting unit configured to wirelessly transmit a signal including the synchronization channel. The synchronization channel includes a primary synchronization channel and a secondary synchronization channel. The primary synchronization channel includes multiple types of sequences, and the secondary synchronization channel transmitted in a sector of a cell includes a code derived from a predefined generation polynomial equation corresponding to the primary synchronization channel.

Abstract: In 3GPP Release (Rel) 8, a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) may be transmitted in six resource blocks, occupying, for example, the center 62 tones (i.e., subcarriers) of an LTE-A system, wherein the center tone may be skipped. In synchronous networks, cells may transmit their respective PSS and SSS on the same frequency at the same time, wherein strong cells may overshadow the weak ones. However, strong cells may not be the serving cell for a user equipment (UE), particularly in a heterogeneous network. Traditionally, interference cancelation, an enhanced receiver technique, has been used, wherein the UE may first find the strong cells and cancel them out to find the serving cell. However, due to propagation delay and synchronization uncertainty, a timing offset may exist among cells, even in synchronous networks.

Abstract: A system includes a transmitting device, an intermediate communications device, and a receiving device. The system establishes a first synchronous wireless link between a transmitting device and the intermediate device, and a second synchronous wireless link between the intermediate device and the receiving device. The transmitting device may include a wireless audio transmitter, a sampling unit configured to convert an incoming audio signal to a stream of digitized audio samples, an encoder unit configured to code the stream of digitized audio samples according to an audio codec based on a sample oriented audio compression algorithm to provide a stream of coded digitized audio samples, and a signal transmitting unit transmitting the stream of coded digitized audio samples over the first synchronous wireless link to the intermediate device. The intermediate device transmits the stream of coded digitized audio samples to the receiving device through the second synchronous wireless link.

Abstract: A method of determining a residual frequency offset between a transmitter and a receiver in a transmission of data via a communication channel, is described, wherein the message is transmitted from the transmitter to the receiver via the communication channel and the message comprises at least one short preamble (201), at least one long preamble (202) and user data (203). The at least one long preamble (202) comprises residual frequency offset determination information based on which the residual frequency offset is determined.

Abstract: A method and apparatus for generating and use of a position location reference signal that allows a receiver to receive position location signals from relatively weak signal generators when in the presence of a strong signal source. The position location reference signals from multiple sources can be synchronized to occur within a scheduled time slot of a time division multiplexed communication system. During the scheduled time slot, each signal source can configure a transmission that includes a media access control address that corresponds to a value reserved for position location signals. Each signal source also configures the transmission to include a position location reference signal that corresponds to the signal source. The position location signals from each of the signal sources is positioned to occur at a time within the data portion of the scheduled time slot that no neighboring signal source transmits its corresponding position location signal.

Abstract: The embodiments relate to a wireless communication system that counts UEs using an MBMS. The wireless communication system is connected with a UE through a radio link, and includes a Node B and a controlling radio network controller (CRNC). The Node B receives sequence setting information on a sequence included in a preamble transmitted from the UE network manager. The CRNC controls the Node B, detects a sequence according to whether to use an MBMS based on the sequence setting information, and performs a counting process for counting UEs based on whether the UE uses the MBMS. According to the embodiments, counting of UEs using an MBMS can be performed by using a predetermined sequence. Particularly, the counting process can be simplified by reducing complexity in access probability management of a network manager, thereby increasing efficiency in data transmission by reducing signaling for random access probability and omitting a random access probability calculation process.

Abstract: Clock synchronization for a wireless communication system is described. The communication system utilizes a server with a radio coupled to receive a radio frequency (RF) signal and a clock interface to receive a reference clock signal. The server includes a network interface configured to receive, from a base station, a time that the RF signal was received at the base station. The server further includes a processing device configured to determine when the RF signal was transmitted and a location of the base station, and configured to calculate clock offset value representative of a time to delay a local clock signal at the base station to synchronize the local clock signal at the base station with the reference clock signal.

Abstract: A method and system is disclosed for a device to quickly determine if data is being sent to it. If no data is being sent to the device, the device may return to a sleep mode so as to conserve energy. The present invention includes organizing and transmitting, one at a time, all device destination identifiers. If a message listing search indicates that no message is being sent for a device, the device can continue with any other activity that needs servicing, or if no other activity is pending, it may shut down to conserve power until the next wake up period arrives. If the search returns a positive indication, the count value when the identifier is found can be used to determine the location of the pointer to the message.

Abstract: A radio base-station apparatus with improved frame transmission efficiency by avoiding interference of preambles and frame control information between sectors of a cell or between cells with a frequency reuse factor. In the apparatus OFDMA multiple-access processing is performed for each of a plurality of sectors of a cell, and frames made of logical subchannel numbers and OFDMA symbol numbers are configured in synchronization respectively for the plurality of sectors, and offsets are added to the beginnings of given frames such that the preambles and frame control information arranged sequentially from the beginnings of the frames do not overlap on the OFDMA symbol numbers.

Abstract: Data is synchronized between a mobile device and a computing device over a wireless link. Synchronization operations are scheduled according to a synchronization schedule that is based on a current time of day. In one embodiment, the day can be divided into different time periods by the user. The user can also specify the frequency with which synchronization operations are to be performed during each specified period. Further, the user can specify an override schedule which overrides the ordinary synchronization schedule established by the user when override criteria are present. For instance, if the mobile device is roaming, the synchronization schedule will be dictated by the override schedule, which may sync much less often, or not until a specific user synchronization request has been received. The present invention can be embodied both as a method and as a apparatus.

Abstract: A data relay apparatus according to one embodiment described herein can include a phase detection unit that can detect a phase difference between a clock output from a transmitter and a clock output from a receiver, and generate a plurality of phase detection signals, a data relay control unit that can distinguish a difference in clock timing between the clocks of the transmitter and the receiver in response to the plurality of phase detection signals, and output a relay data selection signal and a relay control clock, and a data relay unit that can transmit data output from the receiver to the transmitter in response to the relay data selection signal and the relay control clock.

Abstract: A mobile ad hoc network, a mobile ad hoc network node and a method for establishing a system time within a mobile ad hoc network are provided. The network nodes may include a global positioning system (GPS) receiver for receiving GPS signals and for providing a GPS time derived from the GPS signals. The GPS time may be employed by the network node as the system time. Even though the network nodes of a mobile ad hoc network independently determine the GPS time and, in turn, the system time, the system time will be common for each of the network nodes. Mobile ad hoc network nodes may therefore join and leave the mobile ad hoc network with each network node being able to determine the system time prior to its joinder based upon the GPS time provided by the respective GPS receiver.

Abstract: A method of communicating using evolutionary synthesis for band-limited voice and data channels.