Abstract: A transcoder which prevents tandem coding of speech in a mobile-to-mobile call within a mobile communication system uses a speech coding method for reducing transmission rate on the radio path. The transcoder includes a speech coder, which encodes the speech signal into speech parameters for transmission to a mobile station, and decodes the speech parameters received from the mobile station into a speech signal according to the speech coding method, as well as a PCM coder for transmitting an uplink speech signal to and for receiving a downlink speech signal from a PCM interface in the form of PCM speech samples. In addition to the normal operation, the transcoder transmits and receives speech parameters through a PCM interface in a subchannel formed by least significant bits of the PCM speech samples. Thus, it is possible to prevent tandem coding while maintaining the standard PCM interface, and the signaling and services associated thereto.

Abstract: A base station receiver and a reception method in a CDMA cellular radio system includes, in each cell, at least one base station communicating with a plurality of mobile stations situated within its area. The base stations measure the direction angle of a signal arriving from each mobile station with respect to the base station, and communicate with the mobile stations using antenna beams that change in time. The angles of the greatest gain of the beams are adjusted according to signal components arriving from the mobile station. In order to provide detection of good quality without a great deal of calculation, the detection of the desired signal utilizes simultaneously several signals received from different mobile stations taking into account the incoming direction of the signals when selecting the signals.

Abstract: A method of manipulating the header field in an ATM cell. In accordance with the method, the ATM cell is transferred via an interface where each byte of the cell appears in a parallel form on a plurality of parallel data conductors and where information on the start of cell (SOC) is also available. In order to be able to carry out header bit manipulation in a simple manner at such an interface, data conductors corresponding to the bits to be manipulated are led to a circuit carrying out the manipulation, and the other data conductors are led past the circuit. The bit to be manipulated is searched for by counting from start of cell up to the byte containing the bit to be manipulated, after which the bit is manipulated. An output conductor corresponding to the manipulated bit is led from the manipulation circuit to its own position among the data conductors that bypassed the circuit.

Abstract: A method for starting a short message transmission in a cellular communication system, a cellular communication system, and a cellular communication system subscriber location register includes the subscriber location register which stores information on the fact that at least one short message service center stores short messages to be transmitted to a subscriber to whom the messages cannot be transmitted for the time being, and the subscriber location register of the subscriber which transmits to at least one short message service center a short message transmission starting message when it is again possible to transmit short messages to the subscriber. In order that short messages can be transmitted to subscribers selectively, the subscriber location register maintains short message service center and subscriber-specific information on the conditions under on which the short message service center is to be transmitted short message transmission starting messages.

Abstract: A method, a mobile communication system and a mobile station for establishing a telecommunication connection on a direct mode channel and for improving radio coverage by way of using a simple and cheap repeater. An inexpensive and simple repeater is achieved by, instead of using two transceivers, using two receivers and just one transmitter. A mobile station, prepared for direct mode communication, is able to switch between channels answering to commands sent from the repeater.

Abstract: A method is provided for combining signals and a receiver implemented on the RAKE principle. The receiver includes a plurality of branches by which the receiver receives a signal, a precombining circuit which combines signals received via the branches of the receiver, a transmitter which transmits the precombined signals to a second receiver, and a combining circuit which combines the signals received via the receiver branches with the precombined signal.

Abstract: A method for call establishment in a cellular radio system including a mobile services switching center and a private branch exchange connected thereto, and a visitor location register for storing subscriber data on subscribers located within the service area of the mobile services switching center. To optimize call establishment, when the private branch exchange receives a connection establishment request from a subscriber located within its service area, the private branch exchange checks whether the private branch exchange is the home private branch exchange of the subscriber that sent the connection establishment request. If the private branch exchange is the home private branch exchange of the subscriber, the private branch exchange performs independently authentication, activation of ciphering procedures and assignment of a temporary subscriber identity and only thereafter sends a connection establishment request to the mobile services switching center.

Abstract: A method and a circuit arrangement for implementing timing between a microprocessor and its peripheral devices. An address bus and a data bus connect the microprocessor to the peripheral devices to transfer data from the microprocessor to a selected peripheral device, corresponding to writing to the peripheral device, and from a selected peripheral device to the microprocessor, corresponding to reading from the peripheral device. The method comprises generating to the peripheral devices (a) a signal controlling reading (Output Enable), which enables a peripheral device to apply data to the data bus, and (b) a signal controlling writing (Write Enable), which enables data to be written from the data bus to a peripheral device.

Abstract: For measuring the disturbance level of a base station that has at least one frequency hopping receiver and a way of measuring the signal level of signals received by the receiver, a free traffic channel is allocated. The allocated channel is caused to hop sequentially through all the frequency channels that the base station uses for reception, while signal levels of received signals are measured, and the results are transmitted to an operator. The base station also is provided with a site test and measurement unit, which is used for comparably measuring and reporting results in regard to frequency channels that the base station uses for transmission.

Abstract: A packet radio system encapsulates data packets of external data networks by a point-to-point protocol PPP (FIGS. 4A, 4B), and passes them through one or more sub-networks to a point which supports the protocol of the encapsulated data packet. In addition, a special radio link protocol of the packet radio network is required on the radio interface between a mobile data terminal equipment and a support node. PPP packets are encapsulated in data packets of said radio link protocol. The disadvantage of the arrangement is that the data packets of both the PPP protocol and the radio link protocol contain protocol-specific fields, which reduces the transmission capacity of user information. Therefore, a PPP packet is compressed (FIG. 4C) before the encapsulation (FIG. 4D) by removing therefrom the unnecessary control fields. After having been transferred over the radio interface, the PPP packet is decompresssed into its original format (FIGS. 4F, 4G).

Abstract: A method of synchronizing a telecommunications connection in a mobile communications system having at least one base station, and having a first and at least a second mobile station communicating on a direct mode channel, the first mobile station operating on the direct mode channel transmits a registration message to the base station of the mobile communications system on a system channel of the mobile communications system, the registration message indicating a wish of the first mobile station to operate in dual watch mode on the control channel of the mobile communications system. In response to the registration message, a specific control channel of the base station and the timing information related to the control channel are communicated to the first mobile station, the first mobile station switches to dual watch mode in order to communicate either on the direct mode channel or on the allocated control channel during the time indicated by the timing information.

Abstract: The invention relates to a transmission method and a cellular radio system comprising base stations and at least one vocoder, the base stations and the vocoder transmitting a signal to each other, the base stations transmitting a signal to the vocoder substantially simultaneously, the vocoder receiving the substantially simultaneously transmitted signals at different moments of reception, in which cellular radio system after the vocoder has received the first signal, the vocoder is arranged to transmit signals to the base stations the signals of which arrive at the vocoder at least partly during a predetermined time window.

Abstract: The invention relates to a transmission method and a cellular radio system comprising base stations and at least one vocoder. The base stations and the vocoder transmit a signal to each other. The base stations transmit a signal to the vocoder substantially simultaneously, the vocoder receiving the simultaneously transmitted signals at different moments of reception. The cellular radio system comprises comparing means for comparing the moments of reception of the signals to a predetermined time window, measuring means for measuring and comparing the quality of the received signals, and selection means for selecting a signal on the basis of the aforementioned signal measurement and comparison.

Abstract: A radio telephone system is installed in an underground railway system. The telephone system has base stations A, B at respective railway stations 1, 2 and the base stations serve leaky cables serving the railway stations and further cables extending along the tunnel bores interconnecting the railway stations. To improve the availability of channels available as station calls to users of mobile radios within the areas of the railway stations, switches 20 are incorporated to prevent any channel occupied as a station call being directed into the cable serving the tunnel. This enables channels allocated as train call channels at one base station to be re-used as station call channels at an adjacent base station.

Abstract: A subscriber multiplexer includes a receiver for receiving signals transmitted from subscriber interfaces a feeder and for feeding those signals further to a telephone exchange via a respective PCM connection, and a feeder for feeding signals transmitted from the telephone exchange via the respective PCM connection further to the subscriber interfaces. For detecting the condition of the subscriber interfaces, the subscriber multiplexer includes measuring devices for checking the condition of the subscriber interface of the subscriber multiplexer, and a controller for activating the measuring devices in response to a measurement request signal transmitted by the telephone exchange via the respective PCM connection to achieve a measurement result, and for transmitting a message describing the measurement result to the telephone exchange to a telephone system and a method for communicating the condition of a subscriber interface of a subscriber multiplexer.

Abstract: A method for maintaining a group call in a mobile radio system, and a mobile station in a mobile radio system, wherein the geographical area covered by the system is divided into radio cells. Each radio cell includes a base station. A group call is established between the mobile stations belonging to a group call group and residing within the areas of the radio cells forming a limited group call area. In order that the mobile station, upon changing radio cells, is able to select the base station within the area of which the group call is in progress, the respective base stations send one or a plurality of group call maintenance messages to the mobile stations involved in the group call. The group call maintenance message contains information concerning the base stations located within the areas of the radio cells forming the group call area, and the group call group identity.

Abstract: A method and a subscriber unit and a subscriber network element, in a radio system provided with a wireless local loop, for handling a collision of an outgoing call from the subscriber unit and a terminating call at the subscriber unit. When the collision is detected, the switching of the outgoing call is interrupted, a release frame is transmitted to the subscriber unit, a busy tone is transmitted from the subscriber unit to a subscriber in response to the release frame, a calling is transmitted to the subscriber unit, and the terminating call is switched to the subscriber unit after responding to the calling.

Abstract: The present invention relates to a protocol-independent routing of data packets between a mobile station of a packet radio network and a party(Host) connected to an external network. In the invention, a data packet of an extraneous protocol(IPX) is transferred through a packet radio network using a second protocol as encapsulated in a data packet according to the second protocol. The transferring packet radio network does not thus need to understand the protocol of the transferred extraneous data packet or to be able to interpret the content of the data packet. A data packet network is connected to other packet radio networks, data networks or the backbone network between packet data networks via a gateway node(GPRS GSN), which uses the network-internal protocol towards the dedicated packet network and the protocol of each network towards other networks.

Abstract: A method and a system for congestion management in a frame relay network, which includes a) buffering of data at the input boundary of a subscriber node to virtual-channel-specific buffers, b) transmitting congestion notifications in a backward direction from the network nodes to the subscriber node of the moment, and c) controlling the amount of traffic supplied towards the network from the subscriber node buffer.

Abstract: In a mobile communication system, two or more parallel traffic channels are allocated for high-speed data transmission over the radio path. Different channel numbers are assigned to these parallel traffic channels for the duration of the connection. The data of a high-speed data signal is inserted at the distribution point of the transmission end into frames each of which is provided with a channel number indicating the parallel traffic channel used for the transmission. The frames transmitted in a traffic channel always contain the same channel number during the whole call. The frames are divided into parallel traffic channel in the sequential order according to the channel numbering. At the reception end the data contained in the frames is reassembled into a high-speed data signal in the sequential order according to the channel numbers in the frames. Frame numbering may be used within each of the traffic channels so that at least two successive frames always have a different frame number.