Abstract: An outdoor device of a timing system includes a receiver for receiving clock information from a satellite system, a processing system for running master functionality of a clock synchronization protocol to transfer the clock information to an indoor device of the timing system, and a transceiver for transferring data between the outdoor device and the indoor device. A memory device stores a fixed delay value estimating a time delay from a reception moment of a request message related to the clock synchronization protocol to a transmission moment of a reply message. There is no need to compute a difference between clock times corresponding to the reception moment and the transmission moment because the fixed delay value is used in lieu of the difference in the clock synchronization protocol. Thus, quality requirements related to an oscillator of the outdoor device can be mitigated.

Abstract: An outdoor device of a timing system includes a receiver for receiving clock information from a satellite system, a processing system for running master functionality of a clock synchronization protocol to transfer the clock information to an indoor device of the timing system, and a transceiver for transferring data between the outdoor device and the indoor device. A memory device stores a fixed delay value estimating a time delay from a reception moment of a request message related to the clock synchronization protocol to a transmission moment of a reply message. There is no need to compute a difference between clock times corresponding to the reception moment and the transmission moment because the fixed delay value is used in lieu of the difference in the clock synchronization protocol. Thus, quality requirements related to an oscillator of the outdoor device can be mitigated.

Abstract: A device for producing timing information comprises equipment (101) that extracts first preliminary timing information from a first circular polarized component of a radio signal and second preliminary timing information from a second circular polarized component of the radio signal. The second circular polarized component has an opposite handedness and a time-delay with respect to the first circular polarized component. The device comprises a processing system (102) that produces the timing information based on the first preliminary timing information and/or the second preliminary timing information, and uses stored correction data for reducing the effect of the time-delay on the timing information when using the second preliminary timing information for producing the timing information. Thus, the timing information corresponds to the first preliminary timing information also when the timing information is produced based on the second preliminary timing information.

Abstract: A network element is provided that includes a signal interface for receiving satellite signals transmitted by a satellite system and a processing system for producing the timing information based on the satellite signals and on assistance information received from a data transfer network. The network element transmits the timing information to the data transfer network in accordance with a timing transfer protocol. At a start-up, the network element requests a dynamic host configuration protocol server to send host configuration data containing a protocol address to be associated with the network element. The network element reads, from the host configuration data, information enabling the network element to get aware of the assistance information and obtains the assistance information in accordance with the read information. Thus, the dynamic host configuration protocol server enables the network element to operate as a network-assisted source of satellite-based timing.

Abstract: A device and a method for generating a secondary timing signal that is synchronous with a primary timing signal are presented. The method comprises deriving (401) an auxiliary timing signal from an auxiliary signal received at a first site and correcting (402, 403) the timing phase of the auxiliary timing signal so as to obtain the timing phase for the secondary timing signal. The timing phase is corrected with the aid of the following a) a constant phase shift between the auxiliary timing signal and another auxiliary timing signal derived in a second site where both the primary timing signal and the auxiliary signal are available and b) a dynamic phase shift between the other auxiliary timing signal and the primary timing signal at the second site.

Abstract: A network element for distributing timing information includes a signal interface for receiving satellite signals transmitted by a satellite system and a processing system for producing the timing information based on the satellite signals and on assistance information received from a data transfer network. The network element transmits the timing information to the data transfer network in accordance with a timing transfer protocol. At a start-up, the network element requests a dynamic host configuration protocol server to send host configuration data containing a protocol address to be associated with the network element. The network element reads, from the host configuration data, information enabling the network element to get aware of the assistance information and obtains the assistance information in accordance with the read information. Thus, the dynamic host configuration protocol server enables the network element to operate as a network-assisted source of satellite-based timing.

Abstract: A device for producing timing information comprises equipment (101) that extracts first preliminary timing information from a first circular polarized component of a radio signal and second preliminary timing information from a second circular polarized component of the radio signal. The second circular polarized component has an opposite handedness and a time-delay with respect to the first circular polarized component. The device comprises a processing system (102) that produces the timing information based on the first preliminary timing information and/or the second preliminary timing information, and uses stored correction data for reducing the effect of the time-delay on the timing information when using the second preliminary timing information for producing the timing information. Thus, the timing information corresponds to the first preliminary timing information also when the timing information is produced based on the second preliminary timing information.

Abstract: A device and a method for generating a secondary timing signal that is synchronous with a primary timing signal are presented. The method comprises deriving (401) an auxiliary timing signal from an auxiliary signal received at a first site and correcting (402, 403) the timing phase of the auxiliary timing signal so as to obtain the timing phase for the secondary timing signal. The timing phase is corrected with the aid of the following a) a constant phase shift between the auxiliary timing signal and another auxiliary timing signal derived in a second site where both the primary timing signal and the auxiliary signal are available and b) a dynamic phase shift between the other auxiliary timing signal and the primary timing signal at the second site.

Abstract: A satellite receiver module (101) for telecommunication equipment includes circuitries (102, 103) configured to: receive timing information from one or more satellites, run at least a part of master-end functions of a synchronization protocol suitable for synchronizing master and slave clock-times over a data transfer network, and convert the timing information into timing messages that are accordant with the synchronization protocol. The satellite receiver module further includes a data interface (104) including a connector (105) for detachably attaching to a body device of the telecommunication equipment and for transferring a bit stream carrying the timing messages to the body device. Because the timing information received from the one or more satellites is converted into the timing messages that are accordant with the synchronization protocol, the timing information can be transferred among other possible digital data, e.g. location information, from the satellite receiver module to the body device.

Abstract: A phase synchronized optical master-slave loop comprises at the slave-end a processor (105) configured to include a first timing signal into a bit stream to be transmitted to the master-end, detect a second timing signal from a bit stream received from the master-end, and calculate a phase difference between a regenerated phase signal and a reference phase signal on the basis of a transmission moment of the first timing signal, a first time-stamp indicating a reception moment of the first timing signal at the master-end, a reception moment of the second timing signal, and a second time-stamp indicating a transmission moment of the second timing signal from the master-end. The processor is configured to read the time stamps from the received bit stream that corresponds to a received light signal according to a reception line-code. Thus, conversion of data format is not necessary for the phase synchronization.

Abstract: A device (104) for controlling a clock signal generator includes a processing system configured to form a control quantity at least partly on the basis of reception moments of data frames belonging to a given flow, the reception moments being time values based on a clock signal prevailing at a receiver. The processing system controls the clock signal generator with the control quantity so as to achieve synchronization between the clock signal and another clock signal in accordance of which the data frames have been transmitted. In order to identify data frames belonging to the relevant flow, the processing system checks whether pre-determined bits of a received data frame constitute a bit pattern that occurs when the data frame belongs to the relevant flow. Therefore, the reception moments of data frames belonging to the relevant flow are obtainable without deep inspection of the received data frames.

Abstract: The invention relates to transferring of a time of day value between network elements of a data transfer network. It has been surprisingly detected that the phase reference signals available to various network elements can be utilized in the synchronization of time of day values between these network elements. In the solution according to the invention, a first network element sends to a second network element a difference variable (401, 402, 403) that indicates how much the timing phase of the time of day value maintained in the first network element differs from the timing phase of the phase reference signal available to the first network element. In the second network element that receives the message, an estimate of the time of day value is formed (404, 405) based on the difference variable and the timing phase of the phase reference signal available to the second network element.

Abstract: The invention relates to a method and a system for transferring timing messages in a digital data transfer system. In a solution according to the invention a timing message is transferred (101, 102, 103) within control data carried in a protocol data unit. The timing message is dependent on a transmission moment of the protocol data unit from a network element of the digital data transfer system. The control data is a synchronization status message (Ethernet-SSM) carried in an Ethernet-frame. Therefore, the number of such protocol data units that are dedicated only for timing purposes can be reduced.

Abstract: A device for controlling frequency synchronization includes a processor for controlling a phase-controlled clock signal to achieve phase-locking with a reference clock signal, and for controlling a frequency-controlled clock signal so as to achieve frequency-locking with the reference clock signal. The processor is also configured to monitor a deviation between the frequency and phase-controlled clock signals, detect a change of circumstances such as temperature changes causing frequency drifting of the frequency-controlled clock signal, and replace or correct the frequency-controlled clock signal with, or on the basis of, the phase-controlled clock signal when both the monitored deviation and the detected change of circumstances show correlation confirming frequency drift of the frequency-controlled clock signal.

Abstract: A device for controlling a clock signal generator includes a processor (101) for forming at least two mutually different control quantities on the basis of reception moments of timing messages such as time stamps, where the reception moments are expressed as time values based on a first clock signal and the timing messages are transmitted in accordance with a second clock signal. The processor also calculates a weighted sum of the control quantities, and controls the clock signal generator with the weighted sum so as to synchronize the first clock signal and the second clock signal. The control quantities may represent, for example, a filtered value of observed phase-errors, a phase-error corresponding to a minimum observed transfer delay, and phase-errors corresponding to a given portion of the delay distribution. Using the weighted sum of the mutually different control quantities improves the utilization of the information content of the timing messages.

Abstract: A satellite receiver module (101) for telecommunication equipment includes circuitries (102, 103) configured to: receive timing information from one or more satellites, run at least a part of master-end functions of a synchronization protocol suitable for synchronizing master and slave clock-times over a data transfer network, and convert the timing information into timing messages that are accordant with the synchronization protocol. The satellite receiver module further includes a data interface (104) including a connector (105) for detachably attaching to a body device of the telecommunication equipment and for transferring a bit stream carrying the timing messages to the body device. Because the timing information received from the one or more satellites is converted into the timing messages that are accordant with the synchronization protocol, the timing information can be transferred among other possible digital data, e.g. location information, from the satellite receiver module to the body device.

Abstract: An arrangement for adjusting a clock signal in a network element of a communications network includes a processor device arranged to produce a control variable containing information about synchronization messages received from at least two other network elements. A situation in which the reception from a sending network element of synchronization messages of a good enough quality ceases will not significantly disturb the clock signal to be adjusted because only part of the control variable used for the adjustment depends on synchronization messages sent by an individual network element. In a preferred arrangement, the reference value of the control variable is changed in response to a situation where the reception from a sending network element of synchronization messages of a good enough quality ceases. Thus it is possible to reduce the change of the difference between the control variable and its reference value which further reduces disturbances caused in the clock signal to be adjusted.

Abstract: A device (104) for controlling a clock signal generator includes a processing system configured to form a control quantity at least partly on the basis of reception moments of data frames belonging to a given flow, the reception moments being time values based on a clock signal prevailing at a receiver. The processing system controls the clock signal generator with the control quantity so as to achieve synchronization between the clock signal and another clock signal in accordance of which the data frames have been transmitted. In order to identify data frames belonging to the relevant flow, the processing system checks whether pre-determined bits of a received data frame constitute a bit pattern that occurs when the data frame belongs to the relevant flow. Therefore, the reception moments of data frames belonging to the relevant flow are obtainable without deep inspection of the received data frames.

Abstract: A device for controlling frequency synchronization includes a processor for controlling a frequency-controlled clock signal on the basis of received timing messages so as to achieve frequency-locking between the frequency-controlled clock signal and a reference clock signal. For the purpose of finding such timing messages which have experienced similar transfer delays and thus are suitable for the frequency control, the processor is configured to control a phase-controlled clock signal on the basis of the timing messages so as to achieve phase-locking between the phase-controlled clock signal and the reference clock signal, and to select the timing messages to be used for the frequency control on the basis of phase-error indicators related to the phase control. Thus, the phase-controlled clock signal is an auxiliary clock signal that is utilized for performing the frequency control.

Abstract: A device for controlling frequency synchronization includes a processor for controlling a frequency-controlled clock signal on the basis of received timing messages so as to achieve frequency-locking between the frequency-controlled clock signal and a reference clock signal. For the purpose of finding such timing messages which have experienced similar transfer delays and thus are suitable for the frequency control, the processor is configured to control a phase-controlled clock signal on the basis of the timing messages so as to achieve phase-locking between the phase-controlled clock signal and the reference clock signal, and to select the timing messages to be used for the frequency control on the basis of phase-error indicators related to the phase control. Thus, the phase-controlled clock signal is an auxiliary clock signal that is utilized for performing the frequency control.