Time retention at wireless device and time-as-a-service of wireless network

Abstract

Disclosed is a wireless device comprising a processor and an internal clock, the processor configured to: run a timer using the internal clock, where the timer is started when a first clock time is retrieved from an external source; and requesting a second clock time from a second external source when the timer expires.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of U.S. Patent Application No. 18 / 058,133, filed on November 22, 2022, and entitled "TIME KEEPING AT A WIRELESS DEVICE AND TIME AS A SERVICE BY WIRELESS NETWORKS", which is hereby incorporated by reference in its entirety. Technical Field

[0003] This disclosure generally relates to wireless devices that request or send time information. Background Art

[0004] In wireless devices, time information is needed to display it to the user and to properly send and receive timestamped data. Such wireless devices use an internal clock to track time. However, if a wireless device relies only on its internal clock, the tracked time starts to drift from the actual current time. For example, in a smartwatch (as a wireless device), the time is typically obtained only from a paired smartphone. If the smartwatch is turned off and / or not paired with the smartphone for several weeks, for some smartwatches, the time can be off by several hours from the actual time. Such time errors are a problem. This problem can exist in many different types of wireless devices. Summary of the Invention

[0005] An example of a wireless device includes a processor and an internal clock, the processor being configured to: run a timer using the internal clock, where the timer starts when a first clock time is obtained from an external source; and when the timer expires, request a second clock time from a second external source.

[0006] Specific implementations of such wireless devices include one or more of the following features. The wireless device also includes a display configured to display a message to the user if a second clock time cannot be obtained via a wireless connection or if a wireless connection cannot be established. The wireless device also includes a battery, and the processor is configured to run a timer only when the remaining power of the battery is higher than a threshold. The processor is configured to set the length of the timer based on the uncertainty of the first clock time and / or the uncertainty of an external source. The internal clock is a low-power clock; or the wireless device includes different clocks with different accuracies depending on the remaining power; or the clock can operate in different energy modes. The processor is configured to use a connection to a smart phone, a cellular network, satellite positioning, an Internet connection, or other wireless network to request a second clock time. The processor is configured to select a connection based on the environment of the wireless device. The wireless device is a smart watch. The external source and the second external source are the same external source. The external source and the second external source are different external sources. The processor is further configured to request a second clock time from a third external source different from the second external source when the second clock time cannot be obtained from the second external source.

[0007] An example of a method for keeping time includes: running a timer using an internal clock, where the timer starts when a first clock time is obtained from an external source; and when the timer expires, requesting a second clock time from a second external source.

[0008] Specific implementations of this method may include one or more of the following features. The method also includes: displaying a message to the user if a second clock time cannot be obtained via a wireless connection or if a wireless connection cannot be established. The method also includes setting the length of the timer based on the uncertainty of the first clock time or the uncertainty of an external source. The method also includes setting the clock to an energy mode based on the energy level. The method also includes: requesting a second clock time from a third external source different from the second external source when the second clock time cannot be obtained from the second external source.

[0009] An example of a computer program product includes instructions that, when executed by a computer, cause the computer to perform the above method.

[0010] An example of a device for keeping time includes: means for running a timer, where the timer starts when a first clock time is obtained from an external source; and means for requesting a second clock time from a second external source when the timer expires.

[0011] An example of a wireless unit is configured to: receive a request for time information from a wireless device; and in response to the request for time information, send a signal to the wireless device, the signal including time information.

[0012] The specific implementation of such a wireless unit may include one or more of the following features. The wireless unit may also be configured to send a signal including time information without considering the user subscription and / or authentication of the wireless device from which the request is received. The request is received via a wireless connection between the wireless unit and the wireless device, and the signal is sent via a wireless connection between the wireless unit and the wireless device. Both the wireless unit and the wireless device are wireless access points (APs). The wireless device is also configured to calculate the time delay of the request or the signal. The wireless unit is a cellular network AP, and the request is received via a random access channel, and the signal is sent via a random access channel.

[0013] An example of a method for sending time information includes: receiving, by a wireless unit, a request for time information from a wireless device; and sending, by the wireless unit in response to the request for time information, a signal to the wireless device, the signal including time information.

[0014] The specific implementation of this method may include one or more of the following features. Sending the signal including time information is performed without considering the user subscription or authentication of the wireless device from which the request is received. The request is received via a wireless connection between the wireless unit and the wireless device, and the signal is sent via a wireless connection between the wireless unit and the wireless device. The method further includes calculating, by the wireless device, the time delay of the request and / or the signal.

[0015] An example of a computer program product includes instructions that, when executed by a computer, cause the computer to perform the above method.

[0016] An example of a device for sending time information includes: means for receiving a request for time information; and means for sending, in response to the request for time information, a signal including time information.

[0017] The methods and devices according to the present disclosure support wireless devices to correct and check their internal clocks or at least warn users of the wireless devices of the high risk of incorrect time.

[0018] This has outlined the features and technical advantages of the present disclosure in a relatively broad manner so that the following detailed description can be better understood. Additional features and advantages of the present disclosure will be described below. Those skilled in the art should understand that the present disclosure can be easily used as a basis for modifying or designing other structures for implementing the same purpose as the present disclosure. Those skilled in the art should also recognize that such equivalent structures do not depart from the teachings of the present disclosure set forth in the appended claims. The novel features considered to be characteristics of the present disclosure, both in terms of its organization and method of operation, together with further objectives and advantages, will be better understood when the following description is considered in conjunction with the accompanying drawings. However, it should be clearly understood that each of the accompanying drawings is provided for illustrative and descriptive purposes only and is not intended as a definition of the limitation of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] To understand the present disclosure more completely, reference is now made to the following description taken in conjunction with the accompanying drawings.

[0020] Figure 1 A block diagram of a wireless device with an external source is shown.

[0021] Figure 2 A block diagram of an exemplary wireless device is shown.

[0022] Figure 3 An intelligent watch with an external source is shown.

[0023] Figure 4 A process flow diagram of a method for keeping time is shown.

[0024] Figure 5 Shows Figure 4 A process flow diagram of an exemplary step of one step of

[0025] Figure 6 Shows Figure 4 A process flow diagram of an example of a specific implementation of the method of

[0026] Figure 7 A message flow diagram of an example message between a wireless device and an external source is shown. DETAILED DESCRIPTION

[0027] The following detailed description presented in conjunction with the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the described concepts can be practiced. To provide a thorough understanding of the various concepts, the detailed description includes specific details. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form to avoid obscuring such concepts.

[0028] Based on the teachings, those skilled in the art should recognize that the scope of the present disclosure is intended to cover any aspect of the present disclosure, whether that aspect is implemented independently of any other aspect of the present disclosure or in combination with any other aspect. For example, a device may be implemented or a method may be practiced using any number of the aspects set forth. In addition, the scope of the present disclosure is intended to cover such devices or methods practiced using other structures, functionalities, or a combination of structures and functionalities that supplement or are different from the various aspects of the present disclosure as set forth. It should be understood that any aspect of the present disclosure disclosed may be embodied by one or more elements of a claim.

[0029] As described, the use of the term "and / or" is intended to mean "inclusive or", and the use of the term "or" is intended to mean "exclusive or". The word "exemplary" is used to mean "serving as an example, instance, or illustration". Any aspect described as "exemplary" need not be construed as superior or better than other aspects.

[0030] Although specific aspects have been described, numerous variations and permutations of these aspects fall within the scope of the present disclosure. While some benefits and advantages of the preferred aspects have been mentioned, the scope of protection of the present disclosure is not intended to be limited by specific benefits, uses, or objects. Instead, the aspects of the present disclosure are intended to be applicable broadly to different technologies, system configurations, networks, and protocols, some of which are illustrated by way of example in the figures and the following description of the preferred aspects. The detailed description and the figures are merely illustrative of the present disclosure and not limiting, and the scope of the present disclosure is defined by the appended claims and their equivalents.

[0031] Figure 1 An example system is shown that includes a wireless device 110 having an external source 120 (which is also a first external source) and a second external source 130. The wireless device 110 includes a clock 112, a processor 114, and a wireless connection unit 116. The (first) external source 120 includes a clock 122, a processor 124, and a wireless connection unit 126. The second external source 130 includes a clock 132, a processor 134, and a wireless connection unit 136. Additional units may be present in one or more of the wireless device 110 and the first external source 120 and the second external source 130. A wireless connection 140 may exist between the wireless connection unit 116 of the wireless device 110 and one or both of the wireless connection units 126 of the first external source 120 and 136 of the second external source 130 shown by the dashed lines in Figure 1 There may be a wireless connection 140 between the wireless connection unit 116 of the wireless device 110 and one or both of the wireless connection units 126 of the first external source 120 and 136 of the second external source 130 shown by the dashed lines.

[0032] The wireless device 110 may correspond to a smart watch, cellular phone, smartphone, laptop computer, tablet computer, PDA, tracking device, or some other portable or mobile device. Generally, although not necessarily, the wireless device may support wireless communications such as using GSM, WCDMA, LTE, CDMA, HRPD, WiFi, BT, WiMAX, etc. The wireless device may be a single entity or may include multiple entities, such as in a personal area network, where the user may employ audio, video, and / or data input / output (I / O) devices and / or body sensors and a separate wired or wireless modem. The wireless device 110 may be a user equipment or user device capable of sending and receiving wireless signals. The wireless device 110 may not need to constantly receive power from an external power source. Also described below with respect to Figure 2 an exemplary wireless device.

[0033] The first external source 120 and the second external source 130 (either or both) may exemplarily be one of a mobile device (such as a smartphone), a wireless ( / WIFI) router, an access point (AP) for a mobile (data) connection, a network access point, a Bluetooth beacon, a satellite (for example, for a satellite positioning system (SPS)), a computer, a personal computer, a smart watch, or another wireless transceiver.

[0034] The wireless connection 140 (either or both) may be a Bluetooth connection, a WIFI connection, a cellular network connection, a near field communication (NFC) connection, or another wireless connection. The wireless connection 140 (either or both) may be a continuous connection that lasts for a long time, or it may be established, for example, actively by the wireless device 110.

[0035] The wireless communication technologies described herein can be combined with various wireless communication networks, such as wireless wide area networks (“WWANs”), wireless local area networks (“WLANs”), wireless personal area networks (WPANs), etc. The terms “network” and “system” can be used interchangeably herein. A WWAN can be a code division multiple access (“CDMA”) network, a time division multiple access (“TDMA”) network, a frequency division multiple access (“FDMA”) network, an orthogonal frequency division multiple access (“OFDMA”) network, a single-carrier frequency division multiple access (“SC-FDMA”) network, or any combination of the above networks, etc. A CDMA network can implement one or more radio access technologies (“RATs”), such as cdma2000 or wideband CDMA (“W-CDMA”). Here, cdma2000 can include technologies implemented according to the IS-95, IS-2000, and IS-856 standards. A TDMA network can implement the global system for mobile communications (“GSM”), the digital advanced mobile phone system (“D-AMPS”), or some other RAT. GSM and W-CDMA are described in the literature from an organization named “Third Generation Partnership Project” (“3GPP”). Cdma2000 is described in the literature from an organization named “Third Generation Partnership Project 2” (“3GPP2”). 3GPP and 3GPP2 documents are publicly available. In one aspect, 4G long term evolution (“LTE”) communication networks and / or 5G communication networks can also be implemented in accordance with the claimed subject matter. For example, a WLAN can include an IEEE 802.11x network, and a WPAN can include a Bluetooth network, IEEE 802.15x. The wireless communication implementations described herein can also be used in conjunction with any combination of WWANs, WLANs, or WPANs.

[0036] The clock 112 (of the wireless device 110) is a unit that maintains or at least helps maintain an internal time. The internal time should preferably be the same as the current time. In the context of the present disclosure, the current time (sometimes also referred to as the "actual current time") is the time presented by a watch or clock when the watch or clock is correct. In this way, the current time is connected to Coordinated Universal Time or UTC (but may vary according to time zones and potential daylight saving times). The current time may include the time of day (e.g., in hours, minutes, seconds, and smaller units) as well as the date (day of the month and month) and year. The clock 112 may provide the internal time in the same form as the current time that can be presented. Alternatively, the clock 112 may provide a clock signal that can maintain the internal time. In an embodiment, the clock 112 may be a low-power clock, the wireless device 110 includes more than one clock, or the wireless device 110 includes the clock 112 that can operate in different energy modes. In an embodiment with more than one clock, each clock may have different power consumption and different accuracy. Depending on the remaining energy of the battery of the wireless device 110, a clock with higher accuracy and power consumption (when more energy remains in the battery) or lower accuracy and power consumption (when little energy remains in the battery) may be used. There may be a threshold of the remaining energy in the battery for selecting the clock to be used. In an embodiment of a single clock 112 with different energy modes, the clock 112 has an energy mode that consumes more energy and has higher accuracy and a different mode that consumes less energy and has lower accuracy. These different energy modes may be used according to the remaining energy in the battery (higher energy consumption when more energy remains, and lower energy consumption when less energy remains). The energy level may be selected based on an energy threshold in the battery. Alternatively, the selection from power modes or from more than one clock may depend on whether the wireless device is on, off, or in standby.

[0037] In the present disclosure, the term accuracy is used for both: accuracy and precision. When discussing high accuracy or low accuracy, this may mean that both accuracy and precision are high / low, or that one of accuracy and precision is high / low. The time of a clock with low accuracy (and / or precision) will deviate from the actual current time more quickly.

[0038] The processor 114 (of the wireless device 110) may be the main operating part in the wireless device 110. It may implement the methods disclosed herein. It may be connected to other parts of the wireless device 110 via a bus system.

[0039] As Figure 2As shown, the wireless connection unit 116 (of the wireless device 110) may include one or more antennas 202. The wireless connection unit 116 may transmit and receive wireless signals via one or more wireless connections 140. The wireless connection unit 116 may be capable of receiving and transmitting at least one of the possible signals mentioned for the above-mentioned wireless connection 140. The wireless connection unit 116 may be capable of maintaining one wireless connection or more than one wireless connection at a time. Some embodiments may include multiple wireless connection units and wireless antennas to enable the transmission and / or reception of signals according to corresponding multiple wireless communication standards, such as, for example, versions of IEEE Std.802.11, CDMA, WCDMA, LTE, UMTS, GSM, AMPS, Zigbee, and Bluetooth.

[0040] The clock 122, the processor 124, and the wireless connection unit 126 of the first external source 120, and the clock 132, the processor 134, and the wireless connection unit 136 of the second external source 130 may exhibit substantially the same properties and characteristics as those described above for the corresponding parts of the wireless device 110. Those skilled in the art will understand how the first external source 120 and the second external source 130 need to be adapted.

[0041] Figure 2 An exemplary wireless device 110 is shown, which may also be Figure 1 the wireless device 110 shown in. The wireless device 110 may further include a display 204, a battery 206, a memory 208, and one or more input / output (I / O) ports 210. In addition, the wireless connection unit 116 may include one or more antennas 202.

[0042] The display 204 may display the time to the user. The display may also display messages and warnings to the user. The display 204 may be several displays. The display 204 may be integrated into the wireless device 110 and / or may be coupled to the wireless device 110. Examples of the display 204 include a liquid crystal display (LCD) screen, a light-emitting display (LED) screen, an organic light-emitting display (OLED) screen, a plasma screen, a cathode ray tube (CRT) screen, etc. In some specific implementations, the wireless device 110 may be a smart phone or a smart watch with an integrated display. In another example, the wireless device 110 may be linked to one or more remote displays 204 and / or include one or more remote devices including one or more displays 204.

[0043] The battery 206 may store energy so that the wireless device 110 can operate without being connected to an external energy source. The battery 206 may be a battery that only powers the clock 112 (in which case, there may be another battery that powers the entire wireless device 110), or the battery 206 may be a battery that powers the entire wireless device 110.

[0044] The memory 208 can be a computer-readable storage medium (CRM). The processor 114 can execute processor-executable code stored by the CRM. The CRM can include any suitable type of data storage medium, such as volatile memory (e.g., random access memory (RAM)), non-volatile memory (e.g., flash memory), optical media, magnetic media (e.g., magnetic disks), and so on. In the context of the present disclosure, the CRM is implemented to store instructions, data, and other information of the wireless device 110.

[0045] The I / O port 210 enables data exchange or interaction with other devices, networks, or users. The I / O port 210 can include serial ports (e.g., universal serial bus (USB) ports), parallel ports, audio ports, infrared (IR) ports, user interface ports such as touchscreens, and so on.

[0046] The wireless device 110 may also include a digital signal processor (DSP) (not shown) connected to the bus through a bus interface (as much as possible for all parts of the wireless device 110), a general-purpose processor 114 connected to the bus through a bus interface, and a memory 208. The bus interface can be integrated with the DSP, the general-purpose processor 114, and the memory 208. In various embodiments, functions can be executed in response to the execution of one or more machine-readable instructions stored in the memory 208, such as stored on a computer-readable storage medium such as RAM, ROM, FLASH, or a disk drive. The one or more instructions may be executable by the general-purpose processor 114, a dedicated processor, or the DSP. The memory 208 can include non-transitory processor-readable memory and / or computer-readable memory storing software code (programming code, instructions, etc.), the software code being executable by the processor 225 and / or the DSP and / or other processors to perform the functions described herein.

[0047] The wireless device 110 may also include a user interface, which may include any one of a number of devices, such as, for example, a speaker, a microphone, a display device (including the display 204), a vibration device, a keyboard, and / or a touch screen. In a particular embodiment, the user interface may enable a user to interact with one or more applications hosted on the mobile device. For example, the devices of the user interface may store analog or digital signals on the memory 208 for further processing by the DSP or the general-purpose processor 114 in response to user actions. Similarly, applications hosted on the wireless device 110 may store analog or digital signals on the memory 208 to present output signals to the user. In another embodiment, the wireless device 110 may optionally include dedicated audio input / output (I / O) devices, including, for example, dedicated speakers, microphones, digital-to-analog circuits, analog-to-digital circuits, amplifiers, and / or gain controls. However, this is merely an example of how audio I / O may be implemented in a wireless device, and the claimed subject matter is not limited thereto. The wireless device 110 may include touch sensors responsive to touches or pressure on a keyboard or touch screen device.

[0048] The wireless device 110 may also include a dedicated camera device for capturing still or moving images. The camera device may include, for example, an imaging sensor (e.g., a charge-coupled device or a CMOS imager), a lens, analog-to-digital circuits, and a frame buffer. Additional processing, conditioning, encoding, or compression of the signals representing the captured images may be performed at the general-purpose / application processor 114 or the DSP. A dedicated video processor may perform conditioning, encoding, compression, or manipulation of the signals representing the captured images. The video processor may decode / decompress stored image data for presentation on a display device on the wireless device 110.

[0049] The wireless device 110 may also include sensors coupled to the bus, which may include, for example, inertial sensors and environmental sensors that enable the wireless device 110 to determine relative changes in position and / or current speed and heading. The inertial sensors among the sensors may include, for example, accelerometers (e.g., jointly responsive to the acceleration of the wireless device 110 in three dimensions), one or more gyroscopes, or one or more magnetometers (e.g., to support one or more compass applications). The environmental sensors of the wireless device 110 may include, for example, a temperature sensor, a barometric pressure sensor, an ambient light sensor, a camera imager, or a microphone. The sensors may generate analog or digital signals, which may be stored in the memory 208 and processed by the DPS or the general-purpose application processor to support one or more applications (such as, by way of example, applications related to positioning or navigation operations).

[0050] Figure 3 illustrates Figure 1 an example of a Figure 3In this case, the wireless device 110 is a smartwatch 310, the external source 120 is a smartphone 320, and the second external source 130 is a wireless AP 330. In addition, the wireless connection 340 (equivalent to the wireless connection 140) is depicted as an arrow. The display (204) of the smartwatch shows the time (3:23 am).

[0051] If the smartwatch 310 does not receive time information (such as the current time) for a period of time, the time displayed on the display may deviate from the actual current time, as described above. This also applies to other wireless devices 110. To prevent this, the method 400 illustrated in Figure 4 can be implemented.

[0052] The method 400 includes steps 402 and 404. The method 400 can be implemented by the wireless device 110 (or the processor 114 of the wireless device 110). In step 402, a timer is run using the internal clock 112, where the timer starts when the first clock time is obtained from the external source 120.

[0053] When the wireless device 110 obtains the first clock time from the external source 120, the wireless device 110 can correct the internal clock with the first clock time or replace the internal time with the first clock time (or at least compare these two times). The clock time is time information including the current time or at least the internal time from the external source 120, which has high accuracy (possibly deviating from the current time by less than 5 seconds, or less than one second, or a few milliseconds). If not stated otherwise, the terms clock time and time information are used to represent the same meaning. From then on, with the help of the clock 112, the wireless device 110 keeps the time up-to-date (or as up-to-date as possible). During the time when no new time information is received, the wireless device 110 can rely only on the internal clock 112 to keep time. Due to the insufficient accuracy of the clock 112, the internal time of the wireless device 110 may deviate from the actual current time. Generally, this deviation increases over time. In this way, the length of the timer represents a duration during which the deviation generally does not increase to a serious level.

[0054] The timer can be a duration that counts down like a stopwatch. When the timer counts down to zero (0), the timer expires. The timer can also be similar to the alarm clock 112. When the timer starts (runs), the end time of the timer is set. When the internal clock reaches this end time, the timer expires. The duration of the timer is usually on the order of hours or days. The duration can be exemplarily 6 hours, 12 hours, 1 day (24 hours), 2 days, 7 days, or a different duration. This time can count down with the time (or clock signal) of the internal clock 112.

[0055] In step 404, when the timer expires, a request for a second clock time is made to a second external source 130.

[0056] When the timer expires, the wireless device 110 attempts to obtain time information from an external source (the second external source 130). The second external source 130 can be a source as described above, the same source as the first external source 120, or, for example, user input via a touch screen. The request for the second clock time can include one or more of requesting or establishing a connection to the second external source 130, sending a request for time information, displaying a message that the internal time may be significantly off from the actual current time, and requesting user input of time information.

[0057] When the remaining energy in the battery 206 exceeds an energy threshold, the wireless device 110 can implement only the time and implement method 400 therewith.

[0058] Figure 5 Exemplary specific implementation method 500 of step 404 is illustrated. Steps 502 through 510 require the wireless device 110 to have the ability to establish different types of wireless connections. If the wireless device 110 implementing this method 550 cannot connect in this way, each of these steps 502 through 510 can be omitted, or each step can be modified to other wireless connection types that the wireless device 110 may have. Method 500 can be implemented by the wireless device 110.

[0059] In step 502, an attempt is made to connect to a smart phone (if not already connected) and request clock time from the smart phone. If this is not possible, the method proceeds to the next step.

[0060] When the timer expires, the wireless device 110 can check whether the connection to the smart phone is still active. If the connection is not active, the wireless device 110 can attempt to establish a connection to the smart phone. If the connection to the smart phone is maintained (either because it was already maintained or because it was successfully established), the wireless device 110 can request clock time from the smart phone. If this is successful, method step 404 ( Figure 5 the method shown in) can stop here. The wireless device 110 can reset the timer. In this way, method 400 can repeat itself to prevent the internal time from deviating too much. If the wireless device does not successfully obtain the (second) clock time from the smart phone, it can proceed to the next step 504.

[0061] In step 504, an attempt is made to turn on cellular reception and connect to a phone / data network (if not already connected), and request clock time from the network. If this is not possible, the method proceeds to the next step.

[0062] If the wireless device 110 is not already turned on, then turn on its ability to receive and send mobile data. The wireless device 110 can check if the connection to the mobile data AP is still active (if not already connected). If the connection is not active, then the wireless device 110 can attempt to establish a connection to the mobile data AP. If the connection to the mobile data AP persists (because it remained or because it was successfully established), then the wireless device 110 can request the clock time from the mobile data AP. If this is successful, then method step 404 ( Figure 5 the method shown therein) can stop here. The wireless device 110 can reset the timer. In this way, method 400 can repeat itself to prevent the internal time from deviating too much. If the wireless device does not successfully obtain the (second) clock time from the mobile data AP, then it can proceed to the next step 506. If the wireless device 110 is in airplane mode, then user permission can be obtained. This user permission can be obtained using a message on the display 204.

[0063] In step 506, attempt to connect to the satellite positioning system (if not already connected), and request the clock time from the satellite positioning system. If this is not possible, then the method proceeds to the next step.

[0064] Instead of attempting to connect to the satellite positioning system, it is possible to attempt to connect to a satellite; or instead of connecting to the satellite positioning system, it is possible to connect to a satellite. The wireless device 110 turns on its ability to receive and send with the satellite positioning system (if not already turned on). The wireless device 110 can check if the connection to the satellite positioning system is still active (if not already connected). If the connection is not active, then the wireless device 110 can attempt to establish a connection to the satellite positioning system. If the connection to the satellite positioning system persists (because it remained or because it was successfully established), then the wireless device 110 can request the clock time from the satellite positioning system. If this is successful, then method step 404 ( Figure 5 the method shown therein) can stop here. The wireless device 110 can reset the timer. In this way, method 400 can repeat itself to prevent the internal time from deviating too much. If the wireless device does not successfully obtain the (second) clock time from the satellite positioning system, then it can proceed to the next step 508. The wireless device 110 does not need to obtain location information from the satellite positioning system. It is sufficient to receive time information from the satellite positioning system. Thus, the wireless device 110 can have a wireless connection to only one satellite. If the remaining energy in the battery 206 exceeds a higher threshold (e.g., higher than the threshold for implementing method 400), then the wireless device 110 can establish a connection to only the satellite. This saves energy because the power consumption for connecting to the satellite is high.

[0065] In step 508, attempt to connect to another wireless network (if not already connected), and request the clock time from that other wireless network. If this is not possible, the method proceeds to the next step.

[0066] Wireless device 110 activates its ability to receive and transmit with one or more other wireless networks (if not already activated). Wireless device 110 may check whether the connection to one or more other wireless networks is still active (if not already connected). If the connection is not active, wireless device 110 may attempt to establish a connection to one or more other wireless networks. If the connection to one or more other wireless networks persists (either because it was already maintained or because it was successfully established), wireless device 110 may request the clock time from one or more other wireless networks. If this is successful, method step 404 ( Figure 5 the method shown therein) may stop here. Wireless device 110 may reset the timer. In this way, method 400 may repeat itself to prevent the internal time from deviating too much. If wireless device 110 does not successfully obtain the (second) clock time from one or more other wireless networks, it may proceed to the next step 510.

[0067] In step 510, attempt to connect to the Internet (if not already connected), and request the clock time from the Internet. If this is not possible, the method proceeds to the next step.

[0068] Wireless device 110 activates its ability to receive and transmit with the Internet (if not already activated). Wireless device 110 may check whether the connection to the Internet is still active (if not already connected). If the connection is not active, wireless device 110 may attempt to establish a connection to the Internet. If the connection to the Internet persists (either because it was already maintained or because it was successfully established), wireless device 110 may request the clock time from the Internet. If this is successful, method step 404 ( Figure 5 the method shown therein) may stop here. Wireless device 110 may reset the timer. In this way, method 400 may repeat itself to prevent the internal time from deviating too much. If wireless device 110 does not successfully obtain the (second) clock time from the Internet, it may proceed to the next step 510.

[0069] In step 512, display a warning to the user, and optionally provide a manual option to set the clock time if an accurate clock time cannot be obtained.

[0070] If the wireless device 110 does not successfully acquire the second clock time in an automatic manner through any (potential) wireless connection, it may display a warning ( / message) on its display 204. The warning provides the user with information that the risk of the internal time of the wireless device 110 seriously deviating from the actual current time is increased. Additionally or alternatively, the wireless device 110 may request the user to manually input time information, and thereby the wireless device 110 may acquire the (second) clock time. Such time information acquired from the user is generally not as accurate as the time information from the electronic source (e.g., acquired through one of steps 502 to 510). Therefore, when the time from the user is acquired, the wireless device 110 may set a new timer, wherein the new timer lasts shorter than the timer of step 402. The wireless device 110 may also or alternatively display a list in the warning. The list may include possible wireless connections through which the second clock time can be acquired. The list may include the option of acquiring the time from a satellite, especially when such a connection does not exist and / or is not established in step 506. In addition, the wireless device 110 may prompt the user to allow and / or enable one or more of the wireless connections on the list (including satellite connections, especially when not attempted in step 506). This may be done, for example, by the user allowing and / or enabling the Bluetooth function (and / or other functions like mobile data, WIFI, GNSS, etc.) on the wireless device 110.

[0071] Figure 6 An aspect of the method 400 is illustrated. In this aspect, when the wireless device 110 receives the time information, the timer is reset.

[0072] In step 602, the wireless device 110 obtains the clock time from an external source, and in step 604, the wireless device 110 runs a timer using the internal clock 112. These steps 602 and 604 largely correspond to step 402. Those skilled in the art will be able to compare these steps in both figures.

[0073] In step 610, when the timer expires, the wireless device 110 requests a (second) clock time from a second external source. This step 610 corresponds in large part to step 404. A person skilled in the art will be able to compare these steps.

[0074] In step 606, the wireless device 110 receives a third clock time from a third (or other) external source without request. This may occur when the wireless device 110 receives time information without requesting the time information (before a timer expires). For example, Figure 3 The smart phone 320 can send time information to the smart watch 310, and the smart watch 310 does not need to request the time information.

[0075] The wireless device 110 can directly use the received time information to correct the internal time and reset the timer, and return to step 604. Alternatively, the wireless device 110 can proceed to step 608.

[0076] In step 608, if the uncertainty of the third clock time from a third (or other) external source is less than a threshold, the internal clock 112 is set and the timer is reset.

[0077] In this step, the wireless device 110 checks how accurate the unsolicited time information is. Information about the accuracy (as opposed to uncertainty) of the time information can be part of the time information, it can be received separately from the time information from the same external sources 120, 130, it can be received from an external source different from the time information, and / or it can (previously) be known to the wireless device 110. In the last alternative, the wireless device 110 can have a register or table that matches accuracy values (or ranges of accuracy values) to each external source and / or each type of external source (e.g., types such as smart phones, WiFi, satellites, etc.). For example, the time information from a satellite may be very accurate, while the information from a user's manual input may be less accurate, and the time information from WiFi may be accurate.

[0078] The wireless device 110 can compare this accuracy with a threshold. The threshold can be a constant and predefined threshold, or it can be a variable threshold. If the threshold is variable, it can be based on the (previously obtained) time information on which the current internal time is based (starting from the last time the internal clock was corrected / comparison; short: previously used time information). It can be based in such a way that the accuracy of the previously used time information, the length of time the timer has counted down, the accuracy of the internal clock (signal) (e.g., caused by the drift of the internal clock), and / or other values are used to calculate the variable threshold.

[0079] In one example, the variable threshold is lower when the previously used time information has low accuracy, and / or when the time is closer to expiration, and / or when the internal clock has low accuracy. In this example, the variable threshold is higher when the previously used time information has high accuracy, and / or when the time has only counted down a small fraction of its duration, and / or when the internal clock has high accuracy. A low variable threshold means that the accuracy of the new time information can be relatively low and will be used to correct / compare the internal time. A high variable threshold means that new time information with low or average accuracy will be discarded and the internal clock will not be changed. All of these can prevent the internal time from being deteriorated by new time information.

[0080] The (new) timer duration can also be adapted based on the accuracy of the new time information (if the internal clock is corrected). If the new time information has low accuracy, the new timer has a smaller duration. If the new time information has high accuracy, the new timer has a longer duration. This can improve the accuracy of future internal clock times.

[0081] The decision of whether to correct / compare the internal time with the new time information can also be based on a target error tolerance. If the accuracy of the internal time is greater than the target error tolerance and / or if the accuracy of the new time information is less than the target error tolerance, the internal time can be corrected / compared only. For everyday use, the target error tolerance can be on the order of a few seconds. A warning / message to the user may include the error range of the accuracy of the internal time.

[0082] The wireless device 110 can also consider this operation when it is powered off. The wireless device 110 can keep the low-power clock on when the wireless device 110 is turned off. To this end, the accuracy of the internal time can be adjusted. This can help account for the potentially higher time drift of the low-power clock. If the clock 112 is powered off and the operation of the (low-power) clock 112 can no longer be maintained, or if the timer expires when the wireless device 110 is turned off (when no wireless connection can be established to obtain time information), a status flag can be written to non-volatile memory. When the wireless device 110 is turned on again, this can cause the wireless device 110 to implement step 404 and / or method 500 and / or method 600. When the wireless device 110 is not turned off, the timer in the power-off mode can be changed to a timer.

[0083] The wireless device 110 can also include situational awareness and act accordingly. When the wireless device 110 is in airplane mode, it can avoid using WiFi and cellular (and other connections) to obtain time information and instead directly display a warning / message to the user (or rely on possible connections such as Bluetooth and NFC). Even if the wireless device 110 is not in airplane mode, it can detect that it is in flight. This can be detected by, for example, flags of consecutive search failures, cabin pressure measurements, etc. (and / or by using environmental sensors). When the wireless device 110 detects that it is in flight, it can display a (corresponding) warning / message to the user. Not attempting to establish a wireless connection can save power. Therefore, a wireless connection can be attempted in flight / airplane mode only when there is enough energy remaining in the battery 206.

[0084] Figure 7A message flow diagram showing example messages between a wireless device 110 and external sources 120, 130 (where the second external source 130 may be the same as the wireless unit 730). The message in step 702 includes a first clock time and is sent from the first external source 120 to the wireless device 110. This can also be part of method step 402. When the wireless device 110 receives the first clock time, it runs a timer shown in block 704. When the timer expires, the wireless device 110 proceeds to step 706. In step 706, the wireless device 110 requests time information (which may be the same as a second clock time) from the wireless unit 730 (which may be the same as the second external source 130). Step 706 may be included in step 404. In response, the wireless unit 730 sends a signal to the wireless device 110 that includes the time information. This is shown in step 708.

[0085] From the perspective of the wireless unit 730, this looks as follows: In step 706, the wireless unit 730 receives a request for time information from the wireless device 110. In response to the request for time information, the wireless unit 730 sends a signal to the wireless device 110, where the signal includes the time information (step 708). This concept will be referred to as "time as a service".

[0086] In time as a service, the wireless device 110 can obtain time information from the wireless unit on demand. In this way, whenever the wireless device 110 sees it fit itself (e.g., when the timer expires or when the wireless device 110 resets), the wireless device 110 can correct (or at least check) its internal clock time. The wireless device 110 can initiate the time as a service process, and the wireless unit 730 can respond. If time as a service is implemented as a standard for a particular device, time as a service can work particularly efficiently. Then, when the wireless device 110 is in different locations, the wireless device 110 can request time from many different wireless units 730.

[0087] The wireless unit 730 can be, by way of example, one of a mobile device, a wireless ( / WIFI) router, an access point (AP) for mobile (data) connections, a network access point, a Bluetooth beacon, a satellite (e.g., for a satellite positioning system), a computer, a personal computer, or another wireless transceiver.

[0088] The request for time information in step 706 and / or the sending of the time information in step 708 can be direct. This means that the wireless unit 730 does not forward the packet to another node or server. This provides a local solution that can be simpler.

[0089] Time as a Service may not require the wireless device 110 to have a (user) subscription and / or authentication with the wireless unit 730 or the services provided through the wireless unit 730. In one example, when the wireless unit 730 is a WIFI router (AP or another type) and the wireless device 110 is able to connect to the WIFI router, the wireless device 110 will not need to register in the wireless network of the WIFI router. The wireless device 110 does not have to connect to the Internet via the WIFI router. However, the wireless device 110 can still send a request for time information to the WIFI router, and in response, the WIFI router will send a signal with the time information. In one example, in the case where the wireless unit 730 is an IEEE 802.11 device (such as a router or a beacon), the time information can be added as an optional field. In another example, the request-response procedure for Time as a Service (as shown in steps 706 and 708 above) may be added to Bluetooth or other wireless local area networks.

[0090] In another example, the wireless unit 730 can be a router (or AP or other type) of another technology (such as Bluetooth or another wireless network, including a wireless local area network). Thus, the wireless connection is also of this technology. In one example of using a cellular network, the time information can be sent in the system information broadcast, for example, in SIB9 (System Information Block) in 5G. An example of how to construct such SIB9 is shown in the following table:

[0091] SIB9 timeInfo timeInfoUTC INTEGER (0……549755813887) dayLightSavingTime BIT STRING (SIZE(2)) leapSeconds INTEGER (-127……128) localTimeOffset INTEGER (-73……74)

[0092] In one example, Time as a Service is implemented for a cellular network, where no (user) subscription is required to provide time information on demand. The wireless device 110 can request time information in a random access message (RACH). This can be achieved by adding a new field to msg3 in the regular 4-step RACH in Release 15 NR or the 2-step RACH in Release 17 NR. The network (wireless unit 730) can reply to this request in a random access response. This response can contain the same information as SIB9 shown above. Without a (user) subscription, RRC (Radio Resource Control) is not required. This is feasible because all data exchanges occur during the RACH procedure.

[0093] In another example, the wireless device 110, being a smartwatch, may request time information from another smartphone that is a wireless unit 730 to which it is not fully connected (in the sense of not being fully paired or subscribed; an "other" smartphone, such as another smartphone relative to the smartphone fully linked to the smartwatch). When the other smartphone supports time as a service, the smartwatch and the other smartphone can still see (meaning be able to connect to each other) each other, and the other smartphone can send time information to the smartwatch. The request and the sending of the time information can be sent, for example, via a 5G side link, WiFi Direct, regular WiFi, or other wireless connections.

[0094] In one example, there may be further conditions for the wireless unit 730 to send time information in response to a request for time information from the wireless device 110. Such a condition can be that the wireless device 110 is able to fully enter the network of the wireless unit 730. For example, this can be that the wireless device 110 includes a SIM card that allows access to the (cellular) network of the wireless unit 730. An alternative can be that the cellular network operator (or the wireless unit 730) can handle requests for time information in a manner similar to that of emergency services, where all such inquiries / requests will be answered regardless of the user subscription (this alternative can be suitable for any type of wireless connection). Either way, the wireless device 110 may not have to be fully connected to the network of the wireless unit 730. When a request for time information is received, the condition can be checked by the wireless unit 730. The provider of the network of the wireless unit 730 may not charge for this time as a service. Idle time as a service may only be provided to wireless devices 110 that have a general service (user) subscription (e.g., a SIM card that allows access to the provider's cellular network or the provider's possible business partners). This can give potential providers of time as a service an economic incentive to implement time as a service.

[0095] Another condition can be that only a specific number of requests for time information (per unit time) are being served. This can be implemented, for example, in a WiFi network / WiFi AP. This can prevent the wireless unit 730 from being flooded or attacked. One implementation is that the user does not need any association with the WiFi access point. For example, its request for time information will be answered without the need for a password (or other type of user subscription or authentication) to access the AP.

[0096] If the wireless unit 730 is a user device, the consent of the user of the wireless unit 730 may be required as a condition. This is mutually beneficial for the user.

[0097] The system can also follow security procedures implemented, for example, in IEEE 1609.2-based CV2X security procedures. This can be implemented for cellular, WiFi, and / or other solutions. This can improve security.

[0098] The techniques described herein may be used with a satellite positioning system ("SPS") that includes any one and / or combination of a number of global navigation satellite systems ("GNSS"), such as the Global Positioning System ("GPS"), the Russian GLONASS system, the European Union's Galileo system, and China's Beidou and Beidou-2 systems. Additionally, such techniques may be used with a positioning system that utilizes ground transmitters acting as "pseudolites" or a combination of SVs and such ground transmitters. For example, the ground transmitter may include a ground-based transmitter that broadcasts a PN code or other ranging code (e.g., similar to a GPS or CDMA cellular signal). Such transmitters may be assigned unique PN codes to permit identification by remote receivers. For example, in scenarios where SPS signals from orbiting SVs may not be available (such as in tunnels, mines, buildings, urban canyons, or other enclosed areas), the ground transmitter may be useful to, for example, augment the SPS. Another specific implementation of a pseudolite is referred to as a radiobeacon. As used herein, the term "SV" is intended to include ground transmitters acting as pseudolites, equivalents of pseudolites, and possibly other items. As used herein, the terms "SPS signal" and / or "SV signal" are intended to include SPS-like signals from ground transmitters, including ground transmitters acting as pseudolites or equivalents of pseudolites.

[0099] Example embodiments may include one or more of the following clauses.

[0100] 1. A wireless device comprising a processor and an internal clock, the processor being configured to:

[0101] Run a timer using the internal clock, where the timer starts when a first clock time is obtained from an external source; and

[0102] When the timer expires, request a second clock time from a second external source.

[0103] 2. The wireless device according to clause 1, wherein the wireless device further includes a display configured to display a message to a user if the second clock time cannot be obtained via a wireless connection or if a wireless connection cannot be established.

[0104] 3. The wireless device according to any of the preceding clauses, wherein the wireless device further includes a battery, and the processor is configured to run the timer only when the remaining power of the battery is higher than a threshold.

[0105] 4. The wireless device according to any one of the above clauses, wherein the processor is configured to set the length of the timer according to the uncertainty of the first clock time or the uncertainty of the external source.

[0106] 5. The wireless device according to any one of the above clauses, wherein the internal clock is a low-power clock; or

[0107] wherein the wireless device includes different clocks with different accuracies according to the remaining power usage; or

[0108] wherein the clock can operate in different energy modes.

[0109] 6. The wireless device according to any one of the above clauses, wherein the processor is configured to request the second clock time using a connection to a smart phone, a cellular network, satellite positioning, an Internet connection, or other wireless network.

[0110] 7. The wireless device according to clause 6, wherein the processor is configured to select the connection according to the environment of the wireless device.

[0111] 8. The wireless device according to any one of the above clauses, wherein the wireless device is a smart watch.

[0112] 9. The wireless device according to any one of the above clauses, wherein the external source and the second external source are the same external source.

[0113] 10. The wireless device according to any one of the above clauses, wherein the external source and the second external source are different external sources.

[0114] 11. The wireless device according to any one of the above clauses, wherein the processor is further configured to: when the second clock time cannot be obtained from the second external source, request the second clock time from a third external source different from the second external source.

[0115] 12. A method for keeping time, the method comprising:

[0116] running a timer using an internal clock, wherein the timer starts when a first clock time is obtained from an external source; and

[0117] when the timer expires, requesting a second clock time from a second external source.

[0118] 13. The method according to clause 12, the method further comprising: if the second clock time cannot be obtained via a wireless connection or if a wireless connection cannot be established, displaying a message to the user.

[0119] 14. The method according to any one of clauses 12 and 13, the method further comprising setting a length of the timer according to an uncertainty of the first clock time or an uncertainty of the external source.

[0120] 15. The method according to any one of clauses 12 to 14, the method further comprising setting the clock to an energy mode according to an energy level.

[0121] 16. The method according to any one of clauses 12 to 15, the method further comprising: when the second clock time cannot be obtained from the second external source, requesting the second clock time from a third external source different from the second external source.

[0122] 17. A computer program product, the computer program product comprising instructions that, when executed by a computer, cause the computer to perform the method according to any one of clauses 12 to 16.

[0123] 18. A device for maintaining time, the device comprising:

[0124] a component for running a timer, wherein the timer starts when a first clock time is obtained from an external source; and

[0125] a component for requesting a second clock time from a second external source when the timer expires.

[0126] 19. A wireless unit, the wireless unit being configured to:

[0127] receive a request for time information from a wireless device; and

[0128] send a signal to the wireless device in response to the request for the time information, the signal including the time information.

[0129] 20. The wireless unit according to clause 19, the wireless unit further being configured to send the signal including the time information without considering a user subscription or authentication of the wireless device from which the request is received.

[0130] 21. The wireless unit according to any one of clauses 19 and 20, wherein the request is received via a wireless connection between the wireless unit and the wireless device, and the signal is sent via the wireless connection between the wireless unit and the wireless device.

[0131] 22. The wireless unit according to clause 21, wherein both the wireless unit and the wireless device are wireless access points AP.

[0132] 23. The wireless unit according to any one of clauses 21 and 22, wherein the wireless device is further configured to calculate the time delay of the request or the signal.

[0133] 24. The wireless unit according to clause 19, wherein the wireless unit is a cellular network AP, the request is received via a random access channel, and the signal is sent via a random access channel.

[0134] 25. A method for sending time information, the method comprising:

[0135] receiving, by a wireless unit, a request for the time information from a wireless device; and

[0136] sending, by the wireless unit, a signal including the time information to the wireless device in response to the request for the time information.

[0137] 26. The method according to clause 25, wherein sending the signal including the time information is performed without considering the user subscription or authentication of the wireless device from which the request is received.

[0138] 27. The method according to any one of clauses 25 and 26, wherein the request is received via a wireless connection between the wireless unit and the wireless device, and the signal is sent via a wireless connection between the wireless unit and the wireless device.

[0139] 28. The method according to clause 27, the method further comprising calculating, by the wireless device, the time delay of the request or the signal.

[0140] 29. A computer program product, the computer program product comprising instructions that, when executed by a computer, cause the computer to perform the method according to any one of clauses 25 to 28.

[0141] 30. A device for sending time information, the device comprising:

[0142] means for receiving a request for time information; and

[0143] means for sending a signal including the time information in response to the request for the time information.

Claims

1. A wireless device, the wireless device comprising a processor and an internal clock, the processor being configured to: Run a timer using the internal clock, wherein the timer starts when a first clock time is obtained from an external source; and When the timer expires, request a second clock time from a second external source.

2. The wireless device according to claim 1, wherein the wireless device further comprises a display, the display being configured to: display a message to a user if the second clock time cannot be obtained via a wireless connection or if a wireless connection cannot be established.

3. The wireless device according to claim 1, wherein the wireless device further comprises a battery, and the processor is configured to run the timer only when the remaining power of the battery is higher than a threshold.

4. The wireless device according to claim 1, wherein the processor is configured to set the length of the timer according to the uncertainty of the first clock time or the uncertainty of the external source.

5. The wireless device according to claim 1, wherein the internal clock is a low-power clock; or Wherein the wireless device comprises different clocks with different accuracies according to the remaining power; or Wherein the internal clock can operate in different energy modes.

6. The wireless device according to claim 1, wherein the processor is configured to use a connection to a smart phone, a cellular network, satellite positioning, an Internet connection or other wireless networks to request the second clock time.

7. The wireless device according to claim 6, wherein the processor is configured to select the connection according to the environment of the wireless device.

8. The wireless device according to claim 1, wherein the wireless device is a smart watch.

9. The wireless device according to claim 1, wherein the external source and the second external source are the same external source.

10. The wireless device according to claim 1, wherein the external source and the second external source are different external sources.

11. The wireless device according to claim 1, wherein the processor is further configured to: when the second clock time cannot be obtained from the second external source, request the second clock time from a third external source different from the second external source.

12. A method for maintaining time, the method Comprises: Running a timer using an internal clock, wherein the timer starts when a first clock time is obtained from an external source; And When the timer expires, request a second clock time from a second external source.

13. The method according to claim 12, the method further Comprises: If the second clock time cannot be obtained via a wireless connection or if a wireless connection cannot be established, display a message to a user.

14. The method according to claim 12, the method further comprises setting the length of the timer according to the uncertainty of the first clock time or the uncertainty of the external source.

15. The method according to claim 12, the method further comprises setting the clock to an energy mode according to the energy level.

16. The method according to claim 12, the method further Comprises: When the second clock time cannot be obtained from the second external source, request the second clock time from a third external source different from the second external source.

17. A computer program product, the computer program product comprising instructions that, when executed by a computer, cause the computer to perform the method according to claim 12.

18. An apparatus for maintaining time, the apparatus comprising: means for running a timer, wherein the timer starts when a first clock time is obtained from an external source; and means for requesting a second clock time from a second external source when the timer expires.

19. A wireless unit, the wireless unit being configured to: receive a request for time information from a wireless device; and send a signal to the wireless device in response to the request for the time information, the signal including the time information.

20. The wireless unit according to claim 19, the wireless unit further being configured to send the signal including the time information without considering a user subscription or authentication of the wireless device from which the request is received.

21. The wireless unit according to claim 19, wherein the request is received via a wireless connection between the wireless unit and the wireless device, and the signal is sent via the wireless connection between the wireless unit and the wireless device.

22. The wireless unit according to claim 19, wherein both the wireless unit and the wireless device are wireless access points AP.

23. The wireless unit according to claim 19, wherein the wireless device is further configured to calculate a time delay of the request or the signal.

24. The wireless unit according to claim 19, wherein the wireless unit is a cellular network AP, and the request is received via a random access channel, and the signal is sent via the random access channel.

25. A method for sending time information, the method comprising: receiving, by a wireless unit, a request for the time information from a wireless device; and sending, by the wireless unit, a signal to the wireless device in response to the request for the time information, the signal including the time information.

26. The method according to claim 25, wherein sending the signal including the time information is performed without considering a user subscription or authentication of the wireless device from which the request is received.

27. The method according to claim 25, wherein the request is received via a wireless connection between the wireless unit and the wireless device, and the signal is sent via the wireless connection between the wireless unit and the wireless device.

28. The method according to claim 27, the method further comprising calculating, by the wireless device, a time delay of the request or the signal.

29. A computer program product, the computer program product comprising instructions that, when executed by a computer, cause the computer to perform the method according to claim 25.

30. An apparatus for sending time information, the apparatus comprising: A component for receiving a request for time information; and A component for sending a signal including the time information in response to the request for the time information.

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